WO2018141256A1 - 一种发送随机接入前导的方法及其装置 - Google Patents

一种发送随机接入前导的方法及其装置 Download PDF

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Publication number
WO2018141256A1
WO2018141256A1 PCT/CN2018/074983 CN2018074983W WO2018141256A1 WO 2018141256 A1 WO2018141256 A1 WO 2018141256A1 CN 2018074983 W CN2018074983 W CN 2018074983W WO 2018141256 A1 WO2018141256 A1 WO 2018141256A1
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WIPO (PCT)
Prior art keywords
random access
access preamble
preamble
user equipment
network device
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PCT/CN2018/074983
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English (en)
French (fr)
Inventor
颜矛
陈磊
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Huawei Technologies Co Ltd
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Huawei Technologies Co Ltd
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Publication date
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Priority to EP18747197.4A priority Critical patent/EP3562252B1/en
Priority to BR112019016025-6A priority patent/BR112019016025A2/pt
Publication of WO2018141256A1 publication Critical patent/WO2018141256A1/zh
Priority to US16/530,649 priority patent/US11026267B2/en
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L41/00—Arrangements for maintenance, administration or management of data switching networks, e.g. of packet switching networks
    • H04L41/06—Management of faults, events, alarms or notifications
    • H04L41/0654—Management of faults, events, alarms or notifications using network fault recovery
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W72/00—Local resource management
    • H04W72/50—Allocation or scheduling criteria for wireless resources
    • H04W72/56—Allocation or scheduling criteria for wireless resources based on priority criteria
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W74/00—Wireless channel access
    • H04W74/08—Non-scheduled access, e.g. ALOHA
    • H04W74/0833—Random access procedures, e.g. with 4-step access
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W74/00—Wireless channel access
    • H04W74/002—Transmission of channel access control information
    • H04W74/006—Transmission of channel access control information in the downlink, i.e. towards the terminal

Definitions

  • the present invention relates to the field of communications technologies, and in particular, to a method and apparatus for transmitting a random access preamble.
  • the contention-based random access procedure can be seen in the flowchart shown in FIG. 1 , including: User Equipment (UE) sends a random access preamble to the base station (message 1)
  • the base station sends a random access response (message 2) to the UE when detecting the random access preamble sent by the UE, and the message 2 includes the index number of the detected random access preamble, the adjustment information for the uplink time synchronization, Sending the uplink resource allocated by the message 3 to the UE; when receiving the message 2, the UE decodes the message 2, obtains the uplink time synchronization and the uplink resource, and sends the message 3 to the base station, where the message 3 carries the UE identifier; the base station detects When the message 3 is sent, the UE sends a conflict resolution message (message 4), and the message 4 carries the UE identifier.
  • UE User Equipment
  • the UE determines whether the UE identifier carried by the message 4 matches the UE identifier carried in the message 3 to determine whether the message is successful.
  • the access base station determines that the UE successfully accesses the base station if it matches, and determines that the UE fails to access the base station if it does not match.
  • the UE may experience an access failure during the random access process.
  • the reasons for the failure of LTE random access are as follows: (1) the random access preamble sent by the UE to the base station does not reach the base station, so that the base station does not detect the random access preamble; (2) the base station detects the random access preamble and sends the random access preamble to the UE. The random access response, but the UE failed to successfully detect the random access response; (3) the UE successfully detected the random access response, and sent the message 3 to the base station, but the base station did not detect the message 3, or the message 3 detected an error.
  • the base station successfully detects the message 3, and sends the message 4 to the UE, but the UE does not detect the message 4; or the UE detects the message 4, but the message 4
  • the carried UE identifier does not match the UE identifier carried by the message 3 sent by the UE.
  • the UE may also experience access failure during the random access process.
  • the solution to the random access failure in the LTE system may not be applicable to the future wireless communication network, and has not been proposed yet.
  • the embodiment of the invention provides a method for transmitting a random access preamble and a device thereof, which solves the problem of random access failure caused by a random access preamble not arriving at a network device in a future wireless communication network, and can improve a random access preamble The probability of reaching a network device, thereby increasing the success rate of random access.
  • an embodiment of the present invention provides a method for sending a random access preamble, including:
  • the user equipment sends a first random access preamble to the network device, where the first random access preamble is used by the user equipment to access the network device;
  • the user equipment If the user equipment fails to access the network device by using the first random access preamble, the user equipment sends at least one second random access preamble to the network device, where the at least one second The access feature information of each second random access preamble in the random access preamble is different from the access feature information of the first random access preamble, where the access feature information includes a time length, a transmit beam, and a random At least one of the access resources, the at least one second random access preamble is used by the user equipment to access the network device.
  • the user equipment selects at least one second random access preamble different from the access feature information of the first random access preamble to access, if the first random access preamble access network device fails, The problem of random access failure caused by the random access preamble not reaching the network device in the future wireless communication network is solved, and the probability of the random access preamble reaching the network device is improved, thereby improving the success rate of the random access.
  • the access feature information of any two of the at least one second random access preamble is different, so as to improve the success rate of the random access.
  • each of the second random access preamble if the length of time of each second random access preamble is different from the length of time of the first random access preamble, then each of the second random access preambles The length of time is longer than the length of time of the first random access preamble, such that the energy of each of the second random access preambles is higher than the energy of the first random access preamble to improve the second each The probability that the random access preamble arrives at the network device.
  • each of the second random access preamble if the transmit beam of each second random access preamble is different from the transmit beam of the first random access preamble, then each of the second random access preambles
  • the random access resource is the same as or different from the random access resource of the first random access preamble, that is, if the transmit beams are different, the same or no random access resources as the first random access preamble may be used.
  • the same random access resource performs the transmission of the second random access preamble, and attempts to obtain the best matched transmit beam-random access resource, thereby improving the success rate of the random access.
  • each of the second random access preamble random access resources is different from the first random access preamble random access resource
  • each of the second random The transmit beam of the access preamble is the same as or different from the transmit beam of the first random access preamble, that is, if the random access resources are different, the transmit beam of the first random access preamble may be selected to be the same or not.
  • the same transmit beam performs the second random access preamble transmission, and attempts to obtain the best matched transmit beam-random access resource, thereby improving the success rate of the random access.
  • the random access resource corresponds to a receive beam of the network device, or a location in time, or a location on a frequency.
  • the transmit power of each second random access preamble is the same as or different from the transmit power of the first random access preamble, and the at least one second random access preamble is in the middle
  • the transmit power of any two second random access preambles is the same or different.
  • the transmit power of each of the second random access preambles may be greater than the transmit power of the first random access preamble to improve the success rate of the random access.
  • the transmit power of each of the second random access preambles may also be smaller than the transmit power of the first random access preamble.
  • the user equipment sends the at least one second to the network device according to the length of time, the sending power, the sending beam, and a priority level of the random access resource.
  • Random access preamble to improve the success rate of random access.
  • the priority order of the four elements is from high to low, the transmit beam, the random access resource, the transmit power, and the length of time.
  • the first random access preamble access fails, the first random access is selected.
  • the second random access preamble A (the other three elements may be the same as the first random access preamble) with different transmit beams of the preamble is transmitted, and in the case that the second random access preamble A access fails, the selection and the A random access preamble or a second random access preamble B with different random access resources of the second random access preamble A is sent, and so on, until the access is successful or the number of transmissions reaches the maximum number of times.
  • the user equipment may change at least two elements to select a random access preamble to transmit, if the second random access preamble access fails by changing an element, to improve The success rate of random access.
  • the number of the at least one second random access preamble is indicated by the downlink random access channel information sent by the network device, and the number of the at least one second random access preamble is avoided. More conflicts.
  • an embodiment of the present invention provides a method for receiving a random access preamble, including:
  • the at least one second random access preamble Receiving, by the network device, at least one second random access preamble sent by the user equipment, where the first random access preamble request fails to access the network device, the at least one second random access
  • the access feature information of each second random access preamble in the preamble is different from the access feature information of the first random access preamble, where the access feature information includes a time length, a transmit beam, and a random access resource.
  • At least one of the at least one second random access preamble is configured to request access to the network device.
  • the network device receives at least one second random access preamble that is different from the access feature information of the first random access preamble. Improve the success rate of random access of user equipment.
  • the access feature information of any two of the at least one second random access preamble is different, so as to improve the success rate of the random access.
  • each of the second random access preamble if the length of time of each second random access preamble is different from the length of time of the first random access preamble, then each of the second random access preambles The length of time is longer than the length of the first random access preamble, such that the energy of each of the second random access preambles is higher than the energy of the first random access preamble, so that the network device can receive .
  • each of the second random access preamble if the transmit beam of each second random access preamble is different from the transmit beam of the first random access preamble, then each of the second random access preambles
  • the random access resource is the same as or different from the random access resource of the first random access preamble, that is, if the transmit beams are different, the same as the random access resource of the first random access preamble may be the same or not
  • the same random access resource performs the reception of the second random access preamble, thereby improving the success rate of the random access.
  • each of the second random access preamble random access resources is different from the first random access preamble random access resource
  • each of the second random The transmit beam of the access preamble is the same as or different from the transmit beam of the first random access preamble, that is, if the random access resources are different, the same as the transmit beam of the first random access preamble may be the same or not
  • the same transmit beam performs the reception of the second random access preamble, thereby improving the success rate of the random access.
  • the random access resource corresponds to a receive beam of the network device, or a location in time, or a location on a frequency.
  • the transmit power of each second random access preamble is the same as or different from the transmit power of the first random access preamble, and the at least one second random access preamble is in the middle
  • the transmit power of any two second random access preambles is the same or different.
  • the transmit power of each of the second random access preambles may be greater than the transmit power of the first random access preamble, so that the network device can receive, thereby improving the success rate of the random access.
  • the transmit power of each of the second random access preambles may also be smaller than the transmit power of the first random access preamble.
  • the network device sends a downlink random access channel information indication to the user equipment, indicating the number of the at least one second random access preamble, and avoiding the at least one second random connection. Too many of the predecessors caused conflicts.
  • an embodiment of the present invention provides a user equipment, including a processor and a transceiver.
  • the transceiver is configured to send a first random access preamble to the network device, where the first random access preamble is used by the user equipment to access the network device;
  • the transceiver is further configured to: when the user equipment fails to access the network device by using the first random access preamble, send at least one second random access preamble to the network device, where The access feature information of each of the at least one second random access preamble is different from the access feature information of the first random access preamble, where the access feature information includes a time length, At least one of a transmit beam and a random access resource, where the at least one second random access preamble is used by the user equipment to access the network device.
  • the user equipment provided by the third aspect is used to perform the method for transmitting a random access preamble provided by the first aspect.
  • an embodiment of the present invention provides a network device, including a processor and a transceiver.
  • the transceiver unit is configured to receive a first random access preamble sent by the user equipment, where the first random access preamble is used to request access to the network device;
  • the receiving unit is further configured to receive, when the first random access preamble request fails to access the network device, at least one second random access preamble sent by the user equipment, where the at least one The access feature information of each second random access preamble in the second random access preamble is different from the access feature information of the first random access preamble, where the access feature information includes a time length, a transmit beam, At least one of the random access resources, the at least one second random access preamble is used to request access to the network device.
  • the network device provided by the fourth aspect is configured to perform the method for receiving a random access preamble provided by the second aspect.
  • an embodiment of the present invention provides a computer storage medium for storing computer software instructions for use by the user equipment, including a program designed to perform the above aspects.
  • an embodiment of the present invention provides a computer storage medium for storing computer software instructions used by the network device, including a program designed to perform the above aspects.
  • the user equipment when the first random access preamble access network device fails, the user equipment sends the access feature information to the network device and the access feature information of the first random access preamble is not
  • the same at least one second random access preamble is used to solve the problem of random access failure caused by the random access preamble not reaching the network device in the future wireless communication network, and the probability of the random access preamble reaching the network device is improved, thereby improving The success rate of random access.
  • 1 is a schematic flowchart of a contention-based random access procedure in an LTE system
  • FIG. 2 is a schematic diagram of a network architecture to which an embodiment of the present invention is applied;
  • 3a is a schematic diagram of random access time in an LTE system
  • FIG. 3b is a schematic diagram of random access time in an embodiment of the present invention.
  • FIG. 4 is a schematic diagram of communication of a random access method according to an embodiment of the present invention.
  • FIG. 5 is a schematic diagram of an example of a random access method 1 according to an embodiment of the present disclosure
  • FIG. 5b is a schematic diagram of an example of a random access mode 2 according to an embodiment of the present disclosure.
  • FIG. 5 is a schematic diagram of an example of a random access mode 3 according to an embodiment of the present disclosure.
  • FIG. 5 is a schematic diagram of an example of a random access method 4 according to an embodiment of the present disclosure.
  • FIG. 5 e is a schematic diagram of an example of a random access method 5 according to an embodiment of the present disclosure.
  • FIG. 6 is a schematic diagram of a beam according to an embodiment of the present invention.
  • FIG. 7 is a schematic diagram of an example of a random access manner for different receiving beams according to an embodiment of the present invention.
  • FIG. 7 is a schematic diagram of an example of a random access manner for different transmit beams according to an embodiment of the present invention.
  • FIG. 7c is a schematic diagram of another example of a random access manner for different receiving beams according to an embodiment of the present disclosure.
  • FIG. 7 is a schematic diagram of another example of a random access manner for different transmit beams according to an embodiment of the present disclosure.
  • FIG. 8 is a schematic structural diagram of a user equipment according to an embodiment of the present disclosure.
  • FIG. 9 is a schematic structural diagram of a network device according to an embodiment of the present invention.
  • GSM Global System of Mobile Communication
  • CDMA Code Division Multiple Access
  • WCDMA Wideband Code Division Multiple Access
  • LTE Long Term Evolution
  • FDD Frequency Division Duplex
  • TDD Time Division Duplex
  • UMTS Universal Mobile Telecommunication System
  • Future wireless communication systems may include fifth generation mobile communication (5th-Generation, 5G) systems.
  • a user equipment may also refer to an access terminal, subscriber unit, subscriber station, mobile station, mobile station, remote station, remote terminal, mobile device, user terminal, terminal, wireless communication device, user agent, or user device.
  • the access terminal may be a cellular phone, a cordless phone, a Session Initiation Protocol (SIP) phone, a Wireless Local Loop (WLL) station, a Personal Digital Assistant (PDA), with wireless communication.
  • the present invention describes various embodiments in connection with a network device.
  • the network device may be a device for communicating with the user equipment, for example, may be a base station (Base Transceiver Station, BTS) in the GSM system or CDMA, or a base station (NodeB, NB) in the WCDMA system, or may be An evolved base station (Evolutional Node B, eNB or eNodeB) in the LTE system, or the network device may be a relay station, an access point, an in-vehicle device, a wearable device, and a network device in a future wireless communication network.
  • BTS Base Transceiver Station
  • NodeB NodeB
  • NB base station
  • eNodeB evolved base station
  • the network device may be a relay station, an access point, an in-vehicle device, a wearable device, and a network device in a future wireless communication network.
  • FIG. 2 is a schematic diagram of a network architecture to which an embodiment of the present invention is applied.
  • the figure is a network architecture diagram of a cell, including a network device and a user equipment. It should be noted that the network device and the user equipment shown in FIG. The number and form do not constitute a limitation on the embodiments of the present invention.
  • the network device broadcasts a downlink random access channel (RACH) information to the user equipment in the cell, and the downlink RACH information may be sent through system information (SI) in a future wireless communication network.
  • the downlink RACH information may also be sent by using other information.
  • the user equipment selects a random access preamble according to the downlink RACH information, and sends a random access preamble to the network device; the network device detects the random access. At the time of the preamble, a random access response can be sent to the user equipment.
  • the user equipment in the embodiment of the present invention may select a random access preamble, a transmit beam, and a random access preamble according to downlink RACH information and transmission information of the user equipment (eg, retransmission times, downlink path loss estimation values, and the like). Transmit power, etc.
  • the user equipment may further select a receiving beam of the network device according to the downlink RACH information and the sending information of the user equipment.
  • the network device in the embodiment of the present invention may receive a random access preamble of different time lengths sent by the user equipment, a random access preamble of different preamble formats, a random access preamble of different transmission powers, and random access sent by different transmit beams. Preamble, random access preamble sent through different random access resources
  • the random access time in the embodiment of the present invention refers to the time when the user equipment has the opportunity to initiate random access.
  • the default user equipment has obtained the downlink RACH information when initiating the random access.
  • the name of the random access time is used to indicate the time when the user equipment has the opportunity to initiate random access.
  • the name does not constitute a limitation on the embodiment of the present invention. Other names may be used to indicate that the user equipment has the opportunity to initiate random access. Access time.
  • the random access resource in the embodiment of the present invention refers to a specific resource used by the user equipment to send a random access preamble to the network device, and the random access resource and the transmission beam of the synchronization signal have a certain correspondence relationship, and the user equipment can pass The synchronization signal is detected to determine the random access resources it uses.
  • a random access resource can be understood as a receiving beam of a network device, or a position in time, or a position in frequency.
  • FIG. 3a is a schematic diagram of random access time in an LTE system.
  • the preamble is a random access preamble, and its time domain structure includes a Cyclic Prefix (CP) and a preamble sequence.
  • CP Cyclic Prefix
  • the preamble sequence is used to distinguish user equipments during the random access procedure, and the time delay amount is estimated.
  • the five preamble formats are defined in the LTE system, the CP parameters and the length of time in the various preamble formats are different.
  • the network equipment in the LTE system uses the downlink RACH information to designate user equipments in the same cell to adopt the same preamble format.
  • the preamble is sent.
  • FIG. 3b is a schematic diagram of random access time in an embodiment of the present invention, which may be a schematic diagram of random access time in a wireless communication system in the future.
  • a random access time includes K optional preambles.
  • the preamble m transmitted at the first random access time may be the same as or different from the preamble format of the preamble n transmitted at the second random access time; the sequence of the preamble m and the preamble n may be the same or different;
  • the frequency domain resources occupied by the preamble m and the preamble n may be the same or different; the time domain positions corresponding to the preamble m and the preamble n may be the same or different.
  • the same time domain position corresponding to the preamble n and the preamble n refers to the same receive beam of the preamble m and the preamble n for the network device.
  • the receive beam 1 of the network device can receive 4 orthogonal frequency division multiplexing (Orthogonal Frequency Division Multiplexing, OFDM) symbol
  • the preamble m can carry two OFDM symbols
  • the preamble n can carry two OFDM symbols
  • the user equipment sends the preamble m to the receiving beam 1, in the case that the access through the preamble m fails and the network device detects the preamble m
  • the receiving beam 1 can also receive two OFDM symbols, and the user equipment can continue to transmit the preamble n to the receiving beam 1, that is, the preamble m and the preamble n are both for the receiving beam 1, and the preamble m has the same time domain position corresponding to the preamble n.
  • FIG. 4 is a schematic diagram of communication of a random access method according to an embodiment of the present invention. It should be noted that the embodiment shown in FIG. 4 is described by a network device and a user equipment in a cell. The method shown in this embodiment includes but is not limited to the following steps:
  • Step S101 The user equipment sends a first random access preamble to the network device.
  • the user equipment receives the downlink RACH message sent by the network device, and the downlink RACH message is used to notify the user equipment that random access may be initiated before sending the random access preamble to the network device.
  • the downlink RACH message includes configuration information of random access, and the configuration information may include Preamble Initial Received Target Power, power offset based on a preamble format (Delta_Preamble), and power ramp factor (Power). Ramping Step) and other information.
  • the Preamble Initial Received Target Power indicates the initial power of the random access preamble that the network device expects to receive, and the user equipment uses the value to calculate the transmission power of the random access preamble to initiate a random access procedure.
  • the Delta_Preamble is associated with the preamble format, and its value can be indicated by the downlink PACH message or by looking up the table.
  • the Power Ramping Step indicates the increased transmit power of the next access after each access failure.
  • the Preamble Initial Received Target Power, the Delta_Preamble, and the Power Ramping Step may be used by the user equipment to calculate a preamble reception target power (PREAMBLE_RECEIVED_TARGET_POWER) that the network device expects to receive.
  • the downlink RACH message is further used to indicate that the number of preambles corresponding to the random access time is one or more, and a preamble format of each preamble, a sequence of each preamble bearer, and the like.
  • the user equipment sends a first random access preamble to the network device at a first time, where the first random access preamble is used by the user equipment to access the network. device.
  • the time is used to indicate the time when the user equipment can initiate random access, which may be referred to as a random access time, or may be referred to as another name.
  • the specific value of the random access time is set by the network device. set.
  • the first time may be understood as the time when the user equipment may initiate random access after receiving the downlink RACH message, and may also be understood as the first time after the random access failure of the user equipment.
  • the time when one or a certain random access can be initiated can also be understood as the time when any random access can be initiated.
  • the first random access preamble is one of the K optional preambles corresponding to the random access time, and specifically, which is selected by the user equipment.
  • the user equipment may select one of the multiple preambles corresponding to the first time as the first random access according to the downlink RACH message and the path loss of the user equipment to the network device. Leading.
  • the user equipment sends a first random access preamble to the network device for the first time, where the first random access preamble is used by the user equipment to access the user equipment.
  • the first random access preamble sent by the user equipment to the network device may or may not be received by the network device. And if the network device detects the first random access preamble, the network device sends a random access response for the first random access preamble to the user equipment, where the random access response includes An index number of the first random access preamble, adjustment information used for uplink time synchronization, an uplink resource allocated to the user equipment, and the like. If the network device does not detect the first random access preamble, the user equipment does not receive the random access response sent by the network device for the first random access preamble. The first random access preamble may not be sent to the network device, and the user equipment fails to access the network device by using the first random access preamble.
  • Step S102 If the user equipment fails to access the network device by using the first random access preamble, the user equipment sends at least one second random access preamble to the network device, where the at least The access feature information of each second random access preamble in the second random access preamble is different from the access feature information of the first random access preamble, and the access feature information includes a time length and a sending At least one of a beam and a random access resource;
  • the user equipment may determine, by using the following procedure, whether the first random access preamble successfully accesses the network device:
  • the user equipment determines, in a first preset time period, whether a random access response of the network device for the first random access preamble is received, and if the random access response is not received, Determining the access failure, wherein the first preset time period is a random access response window (Random Access Response window);
  • the user equipment sends a message 3 to the network device, where the message 3 carries the identifier of the user equipment;
  • the user equipment determines, in the second preset time period, whether the message 4 sent by the network device for the message 3 is received, and if the message 4 is not received, determining that the access fails, wherein the second The preset time period is a time period corresponding to a medium access control-macrier resolution timer (mac-Contention Resolution Timer);
  • the user equipment determines whether the identifier of the user equipment carried in the message 4 matches the information reported to the network device in the message 3. If the user equipment matches, the user equipment It is considered that the random access conflict is won and the access is determined to be successful; if not, the random access failure is determined.
  • the processes (1) and (2) are also applicable to the non-contention based random access procedure.
  • the user equipment fails to access the network device by using the first random access preamble according to the following conditions:
  • the first random access preamble sent by the user equipment to the network device does not reach the network device, and the network device does not detect the first random access preamble
  • the network device detects the first random access preamble, and sends a random access response to the user equipment, but the user equipment does not successfully detect the random access response;
  • the network device successfully detects the message 3, and sends the message 4 to the user equipment, but the user equipment does not detect the message 4; or the user equipment detects the message 4, but the user carried by the message 4
  • the device identification does not match the identity of the user equipment in message 3.
  • the user equipment needs to send the random access preamble again. And in a case that the user equipment fails to access the network device by using the first random access preamble, the user equipment sends at least one second random access preamble to the network device.
  • the at least one second random access preamble is used by the user equipment to re-access the network device.
  • the access feature information of each of the at least one second random access preamble is different from the access feature information of the first random access preamble, and the access feature information includes time At least one of a length, a transmit beam, and a random access resource. As long as one of the three elements of the second random access preamble is different from the first random access preamble, the access feature information of the second random access preamble and the first random access preamble may be determined.
  • the access feature information is different.
  • the user equipment sends a second random access preamble A to the network device at a second time.
  • the access feature information of the second random access preamble A is different from the access feature information of the first random access preamble, for example, the time length of the second random access preamble A is greater than the
  • the first random access preamble has a long time length.
  • the second time is the same as the time length of the first time, and the second time is a time after the user equipment fails to access the user equipment by using the first random access preamble. It is not necessarily the next time immediately following the first time.
  • the user equipment sends another second random to the network device at a third time.
  • the access feature information of the second random access preamble B is different from the access feature information of the first random access preamble, and the access feature information of the second random access preamble A is not
  • the length of the second random access preamble A is longer than the length of the first random access preamble, and the second random access preamble B has a longer time length than the second random access.
  • the length of the leading A is long. This is repeated until the user equipment successfully accesses the network device, or the number of transmissions exceeds the maximum allowed number of transmissions.
  • the maximum allowed number of transmissions is indicated by the downlink RACH information.
  • the third time is a time after the user equipment fails to access the user equipment by using the second random access preamble, and is not necessarily the next time immediately after the second time. .
  • the user equipment sends at least a first second random access preamble to the network device. Specifically, the user equipment sends a second random access preamble B at a third time, and sends a second random access preamble C... at a fourth time until the user equipment successfully accesses the network device, or sends The number of times exceeds the maximum allowed number of transmissions.
  • the maximum allowed number of transmissions is indicated by the downlink RACH information.
  • the possible implementation manner may be applied to the scenario where the user equipment is at a cell edge or the signal strength of the user equipment is weak. This kind of possible implementation can effectively reduce the access delay and improve the success rate of random access.
  • the user equipment when the user equipment fails to determine that the user equipment fails to access the network device by using the second random access preamble, the user equipment sends the foregoing to the network device at a third time.
  • the second access preamble B at this time, the third time is the next time immediately following the second time.
  • the random access channel time is 10 ms
  • the second time is 11-20 ms
  • the third time is 21-30 ms.
  • the user equipment sends the network device to the network device.
  • the third random access preamble is described.
  • the possible implementation manner is configured by the downlink RACH information, that is, the network device configures the capability for the user equipment, or the user equipment has the capability, and the downlink RACH information indicates the user The device activates this capability.
  • the user equipment sends a second random access preamble A to the network device for a second time.
  • the access feature information of the second random access preamble A is different from the access feature information of the first random access preamble, for example, the time length of the second random access preamble A is greater than the The first random access preamble has a long time length.
  • the user equipment In a case that the user equipment fails to access the network device by using the second random access preamble A, the user equipment sends another second random access preamble B to the network device for a third time.
  • the access feature information of the second random access preamble B is different from the access feature information of the first random access preamble, and the access feature information of the second random access preamble A is not
  • the length of the second random access preamble A is longer than the length of the first random access preamble
  • the second random access preamble B has a longer time length than the second random access.
  • the length of the leading A is long. This is repeated until the user equipment successfully accesses the network device, or the number of transmissions exceeds the maximum allowed number of transmissions.
  • the maximum allowed number of transmissions is indicated by the downlink RACH information.
  • the user equipment sends at least one second random access preamble to the network device for a second time, and each second random access in the at least one second random access preamble The access feature information of the preamble and the access feature information of the first random access preamble.
  • the number of the at least one second random access preamble may be indicated by the downlink RACH information, and avoiding the collision of the number of the at least one second random access preamble is too large.
  • the time length of each of the second random access preambles is smaller than the first random number
  • the length of time to access the preamble is long.
  • the length of the first random access preamble is 1 ms
  • the length of the second random access preamble A is 2 ms.
  • the user equipment selects a preamble whose time length is longer than the length of the first random access preamble, and uses the first random access preamble A as the second random access preamble A, specifically the first random access.
  • the difference in time length between the preamble and the second random access preamble is not limited.
  • the user equipment superimposes or lengthens the time length of the first random access preamble to obtain the second random access preamble A, and the superimposed multiple and the extended length are not used herein.
  • the first random access preamble has a time length of 1 ms, and is superimposed by 1 time to obtain a preamble with a time length of 2 ms, and the preamble is determined as the second random access preamble A.
  • the length of the random access preamble allowed in the random access process is limited, that is, the time length threshold exists. Once the time length reaches the time length threshold, the time length is not increased.
  • the specific value of the time length threshold may be set by the network device, and the user equipment may be notified by downlink system information or RACH information.
  • the transmit beam of each of the second random access preambles is different from the transmit beam of the first random access preamble, the random access resources of each second random access preamble and the first The random access resources of the random access preamble are the same or different.
  • the transmit beams of any two of the at least one second random access preamble are the same or different.
  • the transmit beam of each second random access preamble and the The transmit beams of the first random access preamble are the same or different.
  • the random access resources of any two of the at least one second random access preamble are the same or different.
  • the transmission power of each of the second random access preambles is the same as or different from the transmission power of the first random access preamble, and any two of the at least one second random access preamble are randomly selected.
  • the transmit power of the preamble is the same or different.
  • the sequence of the first random access preamble and the second random access preamble bearer are different.
  • the first random access preamble is the same as or different from the frequency domain resource occupied by the second random access preamble.
  • the same means that the number of occupied subcarriers is the same and the positions of the occupied subcarriers are the same.
  • the user equipment sends the at least one second random access preamble to the network device according to a time length, a transmit power, a transmit beam, and a priority level of the random access resource.
  • the four elements of the time length, the transmission power, the transmission beam, and the random access resource are prioritized, and after the failure of the random access preamble access by changing one element, the priority is selected.
  • the random access preamble of another element is sent, for example, the priority order of the four elements is from high to low, the transmit beam, the random access resource, the transmit power, and the length of time, and the first random access preamble access fails.
  • the transmit beam is different from the first random access preamble, and the second random access preamble is used.
  • the second random access preamble B different from the random access resource of the first random access preamble or the second random access preamble A is selected for transmission, and so on, until the access is successful or The maximum number of times sent.
  • the transmit beam of the second random access preamble B is the same as or different from the transmit beam of the second random access preamble A.
  • selecting to change the random access preamble of at least two of the four elements for transmission after changing the random access preamble access of one element, selecting to change the random access preamble of at least two of the four elements for transmission.
  • the embodiment shown in FIG. 4 solves the problem that the random access preamble does not reach the network device in the future wireless communication network by sending the random access preamble with the access feature information different from the access feature information of the last random access preamble.
  • the problem of random access failure can improve the probability that the random access preamble arrives at the network device, thereby improving the success rate of random access.
  • FIG. 5 is a schematic diagram of an example of five random access modes according to an embodiment of the present invention.
  • FIG. 5a to FIG. 5 e show horizontal access preambles sent by user equipments, and cross-stripes indicate network equipment reception. Random access preamble to. The following five methods are respectively introduced, where the number of transmissions is three, and it is assumed that the network device can detect the random access preamble sent by the user equipment.
  • the user equipment performs the first transmission, and sends the first random access preamble to the network device.
  • the second transmission is performed, and the second random is sent to the network device.
  • the length of the third random access preamble is longer than the second random access preamble, and the length of the second random access preamble is longer than the first random access preamble, and the transmission power of the third transmission is the same, assuming the transmit power Is P.
  • the calculation method of P is not limited herein.
  • the calculation formula of the transmission power P is:
  • the unit of P is dBm;
  • P CMAX (i) represents the maximum allowed transmission power of the user equipment in the i-th subframe, and the unit is dBm;
  • PL represents the path loss (PathLoss) of the user equipment to the network equipment estimated by the user equipment, The unit is dB;
  • PREAMBLE_RECEIVED_TARGET_POWER is the preamble receiving target power that the network device expects to receive, and is designated as Preamble Initial Received Target Power by the Media Access Control (MAC) layer, and the downlink RACH message sent by the network device by the Preamble Initial Received Target Power. Specified.
  • Figure 5b differs from the first method in that the transmission power of the random access preamble is different in the second mode, and the second time is smaller than the first time, and the third time is smaller than the second time.
  • the transmit power P1 of the first random access preamble is calculated by the user equipment according to the path loss and the downlink RACH message, and the difference between the transmit power of the second random access preamble and the first random access preamble is calculated by the downlink RACH message.
  • the specific calculation method is not limited herein.
  • the length of time of the k random access preamble for the k-th transmission T k, its transmission power P k may be calculated according to the formula:
  • P k min ⁇ P CMAX (i), PREAMBLE_RECEIVED_TARGET_POWER+PL ⁇ ,
  • P CMAX (i) represents the maximum allowed transmission power of the user equipment in the i-th subframe, and the unit is dBm
  • PL represents the path loss of the user equipment to the network equipment estimated by the user equipment, and the unit is dB
  • PREAMBLE_RECEIVED_TARGET_POWER is the preamble receiving target power that the network device expects to receive, which is specified by the MAC layer as: Preamble Initial Received Target Power–10log10(T k /T 1 )+(k–1)*Power Ramping Step.
  • the PREAMBLE_TRANSMISSION_COUNTER is the number of retransmissions.
  • the Power Ramping Step indicates the transmission power boosted by the next access after each access failure, which is specified by the downlink RACH message.
  • Preamble Initial Received Target Power is specified by the downstream RACH message.
  • the third method can be seen in Figure 5c.
  • the difference from the first method is that the transmission power of the random access preamble is different every time in the third mode, and the second time is larger than the first time, and the third time is larger than the second time. .
  • Increasing the transmission power can solve the access failure caused by the distance between the user equipment and the network equipment.
  • the length of the second random access preamble sent by the second time is the same as the length of the first random access preamble sent by the first time, and the sending power of the second random access preamble is higher than The transmission power of the first random access preamble;
  • the transmission power of the third random access preamble transmitted in the third time is the same as the transmission power of the first random access preamble sent in the first time, and the length of the third random access preamble Greater than the transmit power of the first random access preamble.
  • Mode 4 first increases the transmission power for access. If the transmission power access fails, the random access preamble with a longer duration is selected for access to improve the access success rate.
  • Method 5 is different from the first method in that the total length of the random access preamble sent in the third manner in the fifth manner is longer, and the sending time is discontinuous.
  • the scenario implemented by the foregoing five access modes is to perform multiple random access preamble transmissions based on the same transmit beam and the same random access resource. If the random access preamble access network device fails to be sent through the third access mode, the fourth random access preamble transmission is performed and repeated according to this, until the number of successful access or transmission exceeds the maximum. The number of times allowed to send.
  • the length of the random access preamble sent in the fourth time may be longer than the random access preamble sent in the third time, and the sending power is larger than the random preamble sent in the third time; or the random access preamble sent in the fourth time.
  • the length of time is the same as that of the random access preamble sent for the third time, and the transmission power is larger than that of the random preamble transmitted for the third time; or the time length of the random access preamble transmitted for the fourth time is more random than the random transmission of the third transmission.
  • the length of the incoming preamble is the same as the random preamble of the third transmission; or the total length of the random access preamble sent for the fourth time is longer than the total length of the random access preamble sent for the third time, and the transmission power is It is the same as the random preamble sent for the third time or larger than the random preamble sent for the third time.
  • Beamforming techniques are used to limit the energy of a transmitted signal to a certain beam direction, thereby increasing the efficiency of signal transmission and reception. Beamforming technology can effectively expand the transmission range of wireless signals and reduce signal interference, thereby achieving higher communication efficiency and higher network capacity.
  • FIG. 6 is a schematic diagram of a beam according to an embodiment of the present invention.
  • the user equipment can transmit through three transmit beams, and the network device can receive through three receive beams.
  • the number of the beams shown in FIG. 6 does not limit the embodiment of the present invention, and the specific number depends on the specific situation.
  • the transmit beam (Beam) and the receive beam need to be matched first, so that the gain from the sender to the receiver is maximized, otherwise a relatively high communication efficiency cannot be obtained.
  • the base station beam is required to be scanned. Therefore, when the user equipment and the base station respectively establish an uplink connection and a downlink connection, beam scanning is required to obtain an optimal transmit-receive beam pair.
  • the transmit beam of the user equipment does not match the receive beam of the base station, which may cause random access failure.
  • FIG. 6 it is assumed that the transmit beam 2 of the user equipment and the receive beam 2' of the network device are the best transmit-receive beam pairs, but the user equipment sends the transmit beam 2 to the receive beam 2', which may cause random connection. Failure failed.
  • the random access retransmission method in the LTE system does not support multi-beam scanning and cannot meet the requirements of future wireless communication systems.
  • the random access preamble in the embodiment of the present invention may be sent through different transmit beams or through the same transmit beam; the random access preamble may be for different receive beams or for the same receive beam. It is possible to achieve a match between the transmit beam and the receive beam, thereby increasing the random access success rate.
  • the five access modes shown in FIG. 5a to FIG. 5e can be performed under the condition that the transmit beam and the receive beam are matched. If the start transmit beam does not match the receive beam, the user equipment needs beam scanning, and the handover is performed.
  • Beams and/or receive beams are used to attempt random access to determine matching transmit and receive beams.
  • the receiving beam of the network device corresponds to a random access resource, or a position in time (for example, in FIG. 7c, two receiving beams B2 and B3 are adjacent in time, and are recorded as t1 to t4.
  • the network device does not have the definition of "beam", then the different receiving beams are distinguished by the position in time, in other words, the receiving beam B2 occupies t1 ⁇ t2, the receiving beam B3 occupies t3 ⁇ t4), or the position on the frequency.
  • FIG. 7 is a schematic diagram of an example of a random access manner for different receiving beams according to an embodiment of the present invention.
  • the user equipment performing a first transmission, the transmission power P 1 for transmitting a first random access preamble received beams B1 network device.
  • the transmission power P 1 for a time reception beam B1 than the first network device transmits a random access preamble of the long length of the second random access preamble.
  • the third transmission is performed, and the transmission power P 2 is sent to the receiving beam B2 of the network device to send a third random access preamble that is longer than the second random access preamble for the network device. .
  • P 1 and P 2 and a downlink path loss calculated RACH message by a user equipment both may be the same or different.
  • the user equipment can switch the receiving beam to transmit and send a random access preamble that is longer than the previous time.
  • the path loss in the transmit power P 1 is obtained according to the first receive beam B1 sent by the network device to the user equipment, and the path loss in the transmit power P 2 is sent to the user equipment according to the network device.
  • Receive beam B2 is obtained.
  • the user equipment may send a random access preamble that is higher than the transmit power.
  • the user equipment may send a random access preamble that is longer than the previous time and has a higher transmit power.
  • FIG. 7a shows two kinds of receiving beams (B1 and B2, respectively corresponding to cross and diagonal stripes) and one type of transmitting beam (horizontal stripes), that is, for different receiving beams, based on the same transmitting beam.
  • the user equipment may determine whether to switch the receiving beam according to the spatial positional relationship between the receiving beams, for example, the receiving beam 2 is spatially adjacent to the receiving beam 1, and then the random access preamble access for the receiving beam 1 After the failure, a random access preamble for receive beam 2 is transmitted.
  • the user equipment may determine whether to switch the receiving beam according to the receiving quality of the receiving beam. For example, the user equipment determines that the receiving beam 2 may obtain better receiving quality than the receiving beam 1, and then performs random access for the receiving beam 1. After the preamble access fails, a random access preamble for the receive beam 2 is transmitted.
  • FIG. 7 is a schematic diagram of an example of a random access manner for different transmit beams according to an embodiment of the present invention.
  • the user equipment performs a first transmission based on the transmit beam b1 to transmit power P 1 .
  • a second transmission based on the transmission beams b1, transmitted at transmission power P 1 is longer than the first random access preamble time length of the second random access preamble.
  • the third transmission based on the transmission beams b2, P 2 transmits the transmission power of the transmission time is longer than the length of the second random access preamble of the random access preamble to a third network device.
  • P 1 and P 2 and a downlink path loss calculated RACH message by a user equipment both may be the same or different.
  • the user equipment can switch the transmit beam to transmit and send a random access preamble that is longer than the previous time.
  • the user equipment may send a random access preamble that is higher than the transmit power.
  • the user equipment may send a random access preamble that is longer than the previous time and has a higher transmit power.
  • FIG. 7b shows two kinds of transmission beams (b1 and b2 corresponding to horizontal stripes and vertical stripes, respectively) and one reception beam (cross-strip), that is, for different transmission beams, based on the same reception beam.
  • the user equipment can simultaneously switch the transmit beam and the receive beam when the random access preamble access with a longer duration is used.
  • the user equipment may select whether to switch the transmit beam according to the spatial location relationship between the transmit beams. For example, if the transmit beam 2 is spatially adjacent to the transmit beam 1, then the random access preamble access based on the transmit beam 1 is used. After the failure, a random access preamble based on the transmit beam 2 is transmitted.
  • the user equipment may determine whether to switch the transmit beam according to the transmission quality of the transmit beam. For example, the user equipment determines that the transmit beam 2 may obtain better transmission quality than the transmit beam 1, and then performs random access based on the transmit beam 1. After the preamble access fails, a random access preamble based on the transmit beam 2 is transmitted.
  • FIG. 7c is a schematic diagram showing another example of a random access manner for different receiving beams according to an embodiment of the present invention.
  • the difference from FIG. 7a is that the random access preamble transmitted here for the third time is performed in two receiving beams of the network device, and the total time is longer than the second transmission time, and the two transmission times are not Continuously, the time interval of the specific interval of the two transmission times, the user equipment can learn from the PACH information.
  • the random access preamble transmitted for the third time is not limited to being performed in two receiving beams of the network device, and may be performed in more receiving beams.
  • FIG. 7 is a schematic diagram of another example of a random access manner for different transmit beams according to an embodiment of the present invention.
  • the random access preamble transmitted here is performed by two transmission beams of the user equipment, and the total time is longer than the second transmission time, and the two transmission times are discontinuous.
  • the random access preamble transmitted for the third time is not limited to being performed by two transmission beams of the user equipment, and may be performed by using more transmission beams.
  • the four random access modes shown in FIG. 7a to FIG. 7d are based on FIG. 5a, that is, the transmission power is unchanged, and the random access preamble with a longer time length is selected for random access. It should be noted that the five random access modes shown in FIG. 5a to FIG. 5e can be arbitrarily combined with the four random access modes shown in FIG. 7a to FIG. 7d, for example, as shown in FIG. 7a.
  • the random access mode is combined with the random access mode shown in FIG. 5c, that is, the receiving beam is changed, the transmission power is increased, and the random access preamble with a longer time length is selected for random access.
  • FIG. 8 is a schematic structural diagram of a user equipment according to an embodiment of the present invention.
  • the user equipment 90 may include a transceiver 913.
  • the transceiver 913 is configured to send a first random access preamble to the network device, where the first random access preamble is used by the user equipment to access the network device;
  • the transceiver 913 is further configured to: when the user equipment fails to access the network device by using the first random access preamble, send at least one second random access preamble to the network device, where The access feature information of each second random access preamble in the at least one second random access preamble is different from the access feature information of the first random access preamble, and the access feature information includes a time length. At least one of a transmit beam and a random access resource, where the at least one second random access preamble is used by the user equipment to access the network device.
  • the access feature information of any two of the at least one second random access preamble is different.
  • the length of time of each second random access preamble is different from the length of time of the first random access preamble, the length of time of each second random access preamble is greater than The first random access preamble has a long time length.
  • the random access resource of each second random access preamble is The random access resources of the first random access preamble are the same or different.
  • each second random access preamble is different from the random access resource of the first random access preamble
  • the sending of each second random access preamble is performed.
  • the beam is the same or different from the transmit beam of the first random access preamble.
  • the transmit power of each second random access preamble is the same as or different from the transmit power of the first random access preamble, and any two of the at least one second random access preamble The transmission power of the two random access preambles is the same or different.
  • the transceiver 913 is configured to send the at least one second random access preamble to the network device according to the time length, the transmit power, the transmit beam, and the priority level of the random access resource. .
  • transceiver 913 is configured to perform step S101 and step S102 in the embodiment shown in FIG. 4, and is also used to implement communication or data transmission between the user equipment 90 and a network device such as a satellite.
  • the transceiver 913 can also be a transceiver circuit or a communication module or the like.
  • User device 90 also includes a processor 914, a power source 911, a user interface 912, a display system 915, a sensing system 916, and an audio system 917.
  • the user equipment 90 may represent the user equipment described in FIG. 4, and the structure of the user equipment shown in FIG. 8 does not constitute a limitation on the embodiment of the present invention.
  • the processor 914 can be a central processing unit (CPU), a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), and a field programmable gate. Field Programmable Gate Array (FPGA) or other programmable logic device, transistor logic device, hardware component, or any combination thereof. It is possible to implement or carry out the various illustrative logical blocks, modules and circuits described in connection with the present disclosure.
  • the processor may also be a combination of computing functions, for example, including one or more microprocessor combinations, a combination of a DSP and a microprocessor, and the like.
  • the power supply 911 provides power protection for the implementation of various functions of the user equipment 90.
  • the user interface 912 is used by the user device 90 to connect with other devices or devices to enable communication or data transfer of other devices or devices with the user device 90.
  • Display system 915 is used for output display of information and for receiving user input operations.
  • Sensing system 916 includes various sensors such as temperature sensors, distance sensors, and the like.
  • Audio system 917 is used for the output of audio signals.
  • FIG. 9 is a schematic structural diagram of a network device according to an embodiment of the present invention.
  • the network device 100 may include a transceiver 1012.
  • the transceiver 1012 is configured to send a first random access preamble to the network device, where the first random access preamble is used by the user equipment to access the network device;
  • the transceiver 1012 is further configured to: when the user equipment fails to access the network device by using the first random access preamble, send at least one second random access preamble to the network device, where The access feature information of each second random access preamble in the at least one second random access preamble is different from the access feature information of the first random access preamble, and the access feature information includes a time length. At least one of a transmit beam and a random access resource, where the at least one second random access preamble is used by the user equipment to access the network device.
  • the transceiver 1012 is further configured to send downlink RACH information to the user equipment.
  • the transceiver 1012 performs the foregoing process.
  • the network device 100 may receive the first random access preamble, may not receive the first random access preamble, may receive the second random access preamble, and may not receive the second random access preamble.
  • the network device 100 may receive random access preambles of different time lengths sent by the user equipment, random access preambles of different preamble formats, and random access preambles of different transmission powers.
  • Network device 100 also includes a processor 1011 and an antenna. It should be noted that, in actual application, the transceiver 1012 is not limited to two, and the antenna is not limited to two. The structure of the network device 100 does not constitute a limitation on the embodiment of the present invention.
  • the processor 1011 mainly includes four components: a cell controller, a voice channel controller, a signaling channel controller, and a multiplexer interface for expansion.
  • the processor 1011 is responsible for all mobile communication interface management, primarily the allocation, release and management of wireless channels.
  • the transceiver 1012 includes a receiver and a transmitter. For the user equipment, uplink data can be transmitted through the transmitter, and downlink data can be received through the receiver.
  • the embodiment of the invention further provides a computer storage medium for storing computer software instructions for the user equipment, which comprises a program designed to execute the above aspects.
  • the embodiment of the invention further provides a computer storage medium for storing computer software instructions used by the network device, which comprises a program designed to execute the above aspects.
  • Computer readable media includes both computer storage media and communication media including any medium that facilitates transfer of a computer program from one location to another.
  • a storage medium may be any available media that can be accessed by a computer.
  • the computer readable medium may include a random access memory (RAM), a read-only memory (ROM), and an electrically erasable programmable read-only memory (Electrically Erasable Programmable).
  • EEPROM Electrically Error Read-Only Memory
  • CD-ROM Compact Disc Read-Only Memory
  • Any connection may suitably be a computer readable medium.
  • the software is transmitted from a website, server, or other remote source using coaxial cable, fiber optic cable, twisted pair, Digital Subscriber Line (DSL), or wireless technologies such as infrared, radio, and microwave, Then coaxial cable, fiber optic cable, twisted pair, DSL or wireless technologies such as infrared, wireless and microwave are included in the fixing of the associated medium.
  • DSL Digital Subscriber Line
  • a disk and a disc include a compact disc (CD), a laser disc, a compact disc, a digital versatile disc (DVD), a floppy disk, and a Blu-ray disc, wherein the disc is usually magnetically copied, and the disc is The laser is used to optically replicate the data. Combinations of the above should also be included within the scope of the computer readable media.

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Abstract

本发明实施例公开了一种随机接入前导发送的方法及其装置，其中方法包括：用户设备向网络设备发送第一随机接入前导，第一随机接入前导用于用户设备接入网络设备；在用户设备通过第一随机接入前导接入网络设备失败的情况下，向网络设备发送至少一个第二随机接入前导，每个第二随机接入前导的接入特征信息与第一随机接入前导的接入特征信息不相同，接入特征信息包括时间长度、发送波束、随机接入资源中的至少一种，至少一个第二随机接入前导用于用户设备接入网络设备。本发明实施例解决了未来无线通信网络中由于随机接入前导未到达网络设备而导致的随机接入失败的问题，能够提高随机接入前导到达网络设备的概率，从而提高随机接入的成功率。

Description

一种发送随机接入前导的方法及其装置 技术领域
本发明涉及通信技术领域，尤其涉及一种发送随机接入前导的方法及其装置。
背景技术
在长期演进(Long Term Evolution，LTE)系统中，基于竞争的随机接入过程可参见图1所示的流程示意图，包括：用户设备(User Equipment，UE)向基站发送随机接入前导(消息1)；基站在检测到UE发送的随机接入前导时，向UE发送随机接入响应(消息2)，消息2包括检测到的随机接入前导的索引号、用于上行时间同步的调整信息、为UE发送消息3分配的上行资源；UE在接收到消息2时，对消息2进行译码，获得上行的时间同步和上行资源，并向基站发送消息3，消息3携带UE标识；基站在检测到消息3时，向UE发送冲突解决消息(消息4)，消息4携带UE标识；UE在接收到消息4时，根据消息4携带的UE标识与消息3携带的UE标识是否相符来确定是否成功接入基站，若相符则确定UE成功接入基站，若不相符则确定UE接入基站失败。
基于图1所示的流程示意图，UE在随机接入过程中，可能会出现接入失败的情况。LTE的随机接入失败原因主要有：(1)UE向基站发送的随机接入前导未到达基站，导致基站没有检测到随机接入前导；(2)基站检测到随机接入前导，向UE发送了随机接入响应，但是UE未能成功检测到随机接入响应；(3)UE成功检测到随机接入响应，向基站发送了消息3，但是基站没有检测到消息3，或消息3检测出错，或消息3连续出错的次数超过最大重传失败次数；(4)基站成功检测到消息3，向UE发送了消息4，但是UE未检测到消息4；或UE检测到消息4，但是消息4携带的UE标识与UE发送的消息3携带的UE标识不相符。
在未来无线通信网络中，UE在随机接入过程中，也可能会出现接入失败的情况，LTE系统中针对随机接入失败的解决方法可能不适用于未来无线通信网络中，目前也未提出针对未来无线通信网络中随机接入失败的解决方法。
发明内容
本发明实施例提供一种发送随机接入前导的方法及其装置，解决了未来无线通信网络中由于随机接入前导未到达网络设备而导致的随机接入失败的问题，能够提高随机接入前导到达网络设备的概率，从而提高随机接入的成功率。
第一方面，本发明实施例提供了一种发送随机接入前导的方法，包括：
用户设备向网络设备发送第一随机接入前导，所述第一随机接入前导用于所述用户设备接入所述网络设备；
在所述用户设备通过所述第一随机接入前导接入所述网络设备失败的情况下，所述用户设备向所述网络设备发送至少一个第二随机接入前导，所述至少一个第二随机接入前导中的每个第二随机接入前导的接入特征信息与所述第一随机接入前导的接入特征信息不相同，所述接入特征信息包括时间长度、发送波束、随机接入资源中的至少一种，所述至少一个第二随机接入前导用于所述用户设备接入所述网络设备。
第一方面，用户设备在通过第一随机接入前导接入网络设备失败的情况下，选择与第一随机接入前导的接入特征信息不同的至少一个第二随机接入前导进行接入，来解决未来无线通信网络中由于随机接入前导未到达网络设备而导致的随机接入失败的问题，提高随机接入前导到达网络设备的概率，从而提高随机接入的成功率。
在一种可能实现的方式中，所述至少一个第二随机接入前导中的任意两个第二随机接入前导的接入特征信息不相同，以提高随机接入的成功率。
在一种可能实现的方式中，若所述每个第二随机接入前导的时间长度与所述第一随机接入前导的时间长度不相同，则所述每个第二随机接入前导的时间长度比所述第一随机接入前导的时间长度长，使得所述每个第二随机接入前导的能量高于所述第一随机接入前导的能量，以提高所述每个第二随机接入前导到达所述网络设备的概率。
在一种可能实现的方式中，若所述每个第二随机接入前导的发送波束与所述第一随机接入前导的发送波束不相同，则所述每个第二随机接入前导的随机接入资源与所述第一随机接入前导的随机接入资源相同或不相同，即在发送波束不相同的情况下，可使用与第一随机接入前导的随机接入资源相同或不相同的随机接入资源进行第二随机接入前导的发送，尝试获取最佳匹配的发送波束-随机接入资源，进而提高随机接入的成功率。
在一种可能实现的方式中，若所述每个第二随机接入前导的随机接入资源与所述第一随机接入前导的随机接入资源不相同，则所述每个第二随机接入前导的发送波束与所述第一随机接入前导的发送波束相同或不相同，即在随机接入资源不相同的情况下，可选择与第一随机接入前导的发送波束相同或不相同的发送波束进行第二随机接入前导的发送，尝试获取最佳匹配的发送波束-随机接入资源，进而提高随机接入的成功率。
在一种可能实现的方式中，所述随机接入资源对应所述网络设备的接收波束，或时间上的位置，或频率上的位置。
在一种可能实现的方式中，所述每个第二随机接入前导的发送功率与所述第一随机接入前导的发送功率相同或不相同，所述至少一个第二随机接入前导中的任意两个第二随机接入前导的发送功率相同或不相同。所述每个第二随机接入前导的发送功率可以比所述第一随机接入前导的发送功率大，以提高随机接入的成功率。所述每个第二随机接入前导的发送功率也可以比所述第一随机接入前导的发送功率小。
在一种可能实现的方式中，所述用户设备根据所述时间长度、所述发送功率、所述发送波束、所述随机接入资源的优先等级向所述网络设备发送所述至少一个第二随机接入前导，以提高随机接入的成功率。例如，这四个元素的优先等级顺序从高到低为发送波束、随机接入资源、发送功率、时间长度，在第一随机接入前导接入失败的情况下，选择与第一随机接入前导的发送波束不同的第二随机接入前导A(其它三种元素可与第一随机接入前导的相同)进行发送，在第二随机接入前导A接入失败的情况下，选择与第一随机接入前导或第二随机接入前导A的随机接入资源不同的第二随机接入前导B进行发送，以此类推，直到接入成功或发送次数达到最大次数。
在一种可能实现的方式中，所述用户设备在通过改变一种元素的第二随机接入前导接入失败的情况下，可改变至少两种元素来选择随机接入前导进行发送，以提高随机接入的成功率。
在一种可能实现的方式中，所述至少一个第二随机接入前导的数量由所述网络设备发送的下行随机接入信道信息指示，避免所述至少一个第二随机接入前导的数量太多造成冲突。
第二方面，本发明实施例提供了一种接收随机接入前导的方法，包括：
网络设备接收用户设备发送的第一随机接入前导，所述第一随机接入前导用于请求接入所述网络设备；
在所述第一随机接入前导请求接入所述网络设备失败的情况下，所述网络设备接收所述用户设备发送的至少一个第二随机接入前导，所述至少一个第二随机接入前导中的每个第二随机接入前导的接入特征信息与所述第一随机接入前导的接入特征信息不相同，所述接入特征信息包括时间长度、发送波束、随机接入资源中的至少一种，所述至少一个第二随机接入前导用于请求接入所述网络设备。
第二方面，在第一随机接入前导请求接入网络设备失败的情况下，网络设备通过接收与第一随机接入前导的接入特征信息不相同的至少一个第二随机接入前导，来提高用户设备随机接入的成功率。
在一种可能实现的方式中，所述至少一个第二随机接入前导中的任意两个第二随机接入前导的接入特征信息不相同，以提高随机接入的成功率。
在一种可能实现的方式中，若所述每个第二随机接入前导的时间长度与所述第一随机接入前导的时间长度不相同，则所述每个第二随机接入前导的时间长度比所述第一随机接入前导的时间长度长，使得所述每个第二随机接入前导的能量高于所述第一随机接入前导的能量，以便所述网络设备能够接收到。
在一种可能实现的方式中，若所述每个第二随机接入前导的发送波束与所述第一随机接入前导的发送波束不相同，则所述每个第二随机接入前导的随机接入资源与所述第一随机接入前导的随机接入资源相同或不相同，即在发送波束不相同的情况下，可通过与第一随机接入前导的随机接入资源相同或不相同的随机接入资源进行第二随机接入前导的接收，进而提高随机接入的成功率。
在一种可能实现的方式中，若所述每个第二随机接入前导的随机接入资源与所述第一随机接入前导的随机接入资源不相同，则所述每个第二随机接入前导的发送波束与所述第一随机接入前导的发送波束相同或不相同，即在随机接入资源不相同的情况下，可通过与第一随机接入前导的发送波束相同或不相同的发送波束进行第二随机接入前导的接收，进而提高随机接入的成功率。
在一种可能实现的方式中，所述随机接入资源对应所述网络设备的接收波束，或时间上的位置，或频率上的位置。
在一种可能实现的方式中，所述每个第二随机接入前导的发送功率与所述第一随机接入前导的发送功率相同或不相同，所述至少一个第二随机接入前导中的任意两个第二随机接入前导的发送功率相同或不相同。所述每个第二随机接入前导的发送功率可以比所述第一随机接入前导的发送功率大，以便所述网络设备能够接收到，从而提高随机接入的成功率。所述每个第二随机接入前导的发送功率也可以比所述第一随机接入前导的发送功率小。
在一种可能实现的方式中，所述网络设备向所述用户设备发送下行随机接入信道信息 指示，指示所述至少一个第二随机接入前导的数量，避免所述至少一个第二随机接入前导的数量太多造成冲突。
第三方面，本发明实施例提供了一种用户设备，包括处理器和收发器，
所述收发器，用于向网络设备发送第一随机接入前导，所述第一随机接入前导用于用户设备接入所述网络设备；
所述收发器，还用于在所述用户设备通过所述第一随机接入前导接入所述网络设备失败的情况下，向所述网络设备发送至少一个第二随机接入前导，所述至少一个第二随机接入前导中的每个第二随机接入前导的接入特征信息与所述第一随机接入前导的接入特征信息不相同，所述接入特征信息包括时间长度、发送波束、随机接入资源中的至少一种，所述至少一个第二随机接入前导用于所述用户设备接入所述网络设备。
第三方面提供的用户设备用于执行第一方面所提供的发送随机接入前导的方法。
第四方面，本发明实施例提供了一种网络设备，包括处理器和收发器，
所述收发器单元，用于接收用户设备发送的第一随机接入前导，所述第一随机接入前导用于请求接入所述网络设备；
所述接收单元，还用于在所述第一随机接入前导请求接入所述网络设备失败的情况下，接收所述用户设备发送的至少一个第二随机接入前导，所述至少一个第二随机接入前导中的每个第二随机接入前导的接入特征信息与所述第一随机接入前导的接入特征信息不相同，所述接入特征信息包括时间长度、发送波束、随机接入资源中的至少一种，所述至少一个第二随机接入前导用于请求接入所述网络设备。
第四方面提供的网络设备用于执行第二方面所提供的接收随机接入前导的方法。
第五方面，本发明实施例提供了一种计算机存储介质，用于储存为上述用户设备所用的计算机软件指令，其包含用于执行上述方面所设计的程序。
第六方面，本发明实施例提供了一种计算机存储介质，用于储存为上述网络设备所用的计算机软件指令，其包含用于执行上述方面所设计的程序。
在本发明实施例中，用户设备在通过发送的第一随机接入前导接入网络设备失败的情况下，通过向网络设备发送接入特征信息与第一随机接入前导的接入特征信息不相同的至少一个第二随机接入前导，来解决未来无线通信网络中由于随机接入前导未到达网络设备而导致的随机接入失败的问题，提高随机接入前导到达网络设备的概率，从而提高随机接入的成功率。
附图说明
为了更清楚地说明本发明实施例或背景技术中的技术方案，下面将对本发明实施例或背景技术中所需要使用的附图进行说明。
图1是LTE系统中基于竞争的随机接入过程的流程示意图；
图2是一种应用本发明实施例的网络架构的示意图；
图3a是LTE系统中的随机接入时间的示意图；
图3b是本发明实施例中的随机接入时间的示意图；
图4是本发明实施例提供的一种随机接入方法的通信示意图；
图5a是本发明实施例提供的随机接入方式一的举例示意图；
图5b是本发明实施例提供的随机接入方式二的举例示意图；
图5c是本发明实施例提供的随机接入方式三的举例示意图；
图5d是本发明实施例提供的随机接入方式四的举例示意图；
图5e是本发明实施例提供的随机接入方式五的举例示意图；
图6是本发明实施例提供的一种波束示意图；
图7a是本发明实施例提供的一种针对不同接收波束的随机接入方式的举例示意图；
图7b是本发明实施例提供的一种针对不同发送波束的随机接入方式的举例示意图；
图7c是本发明实施例提供的另一种针对不同接收波束的随机接入方式的举例示意图；
图7d是本发明实施例提供的另一种针对不同发送波束的随机接入方式的举例示意图；
图8是本发明实施例提供的一种用户设备的结构示意图；
图9是本发明实施例提供的一种网络设备的结构示意图。
具体实施方式
应理解，本发明实施例的技术方案可以应用于各种通信系统，例如：全球移动通讯(Global System of Mobile Communication，GSM)系统、码分多址(Code Division Multiple Access，CDMA)系统、宽带码分多址(Wideband Code Division Multiple Access，WCDMA)系统、长期演进(Long Term Evolution，LTE)系统、LTE频分双工(Frequency Division Duplex，FDD)系统、LTE时分双工(Time Division Duplex，TDD)、通用移动通信系统(Universal Mobile Telecommunication System，UMTS)、以及未来无线通信系统等。未来无线通信系统可以包括第五代移动通信(5th-Generation，5G)系统。
本发明结合用户设备描述了各个实施例。用户设备也可以指接入终端、用户单元、用户站、移动站、移动台、远方站、远程终端、移动设备、用户终端、终端、无线通信设备、用户代理或用户装置。接入终端可以是蜂窝电话、无绳电话、会话启动协议(Session Initiation Protocol，SIP)电话、无线本地环路(Wireless Local Loop，WLL)站、个人数字处理(Personal Digital Assistant，PDA)、具有无线通信功能的手持设备、计算设备或连接到无线调制解调器的其它处理设备、车载设备、可穿戴设备，未来无线通信网络中的用户设备等。
本发明结合网络设备描述了各个实施例。网络设备可以是用于与用户设备进行通信的设备，例如，可以是GSM系统或CDMA中的基站(Base Transceiver Station，BTS)，也可以是WCDMA系统中的基站(NodeB，NB)，还可以是LTE系统中的演进型基站(Evolutional Node B，eNB或eNodeB)，或者该网络设备可以为中继站、接入点、车载设备、可穿戴设备以及未来无线通信网络中的网络设备等。
请参见图2，是一种应用本发明实施例的网络架构的示意图，该图是一个小区的网络架构示意图，包括网络设备和用户设备，需要说明的是，图2所示网络设备和用户设备的数量和形态并不构成对本发明实施例的限定。
在图2中，网络设备向该小区内的用户设备广播下行随机接入信道(Random Access Channel，RACH)信息，下行RACH信息可以通过系统信息(System Information，SI)发送，在未来无线通信网络中下行RACH信息还可以通过其它信息发送；用户设备在接收到该下行RACH信息时，根据该下行RACH信息选择随机接入前导，并向网络设备发送随机接入前导；网络设备在检测到随机接入前导时，可向用户设备发送随机接入响应。
本发明实施例中的用户设备可根据下行RACH信息和用户设备的发送信息(例如，重传次数、下行路径损耗估计值等)来选择随机接入前导、发送波束、以及确定随机接入前导的发送功率等。可选地，用户设备还可根据下行RACH信息和用户设备的发送信息来选择网络设备的接收波束。
本发明实施例中的网络设备可接收用户设备发送的不同时间长度的随机接入前导，不同前导格式的随机接入前导，不同发送功率的随机接入前导，通过不同发送波束发送的随机接入前导，通过不同随机接入资源发送的随机接入前导
本发明实施例中的随机接入时间是指用户设备有机会发起随机接入的时间，默认用户设备在发起随机接入时已经获得了下行RACH信息。需要说明的是，随机接入时间这个名称用于表示用户设备有机会发起随机接入的时间，但是该名称并不够构成对本发明实施例的限定，可以采用其它名称来表示用户设备有机会发起随机接入的时间。
本发明实施例中的随机接入资源是指用户设备向网络设备发送随机接入前导所使用的特定资源，随机接入资源与同步信号的发送波束之间具有确定的对应关系，用户设备可通过检测同步信号来确定它所使用的随机接入资源。随机接入资源可以理解为网络设备的接收波束，或者时间上的位置，或者频率上的位置。
请参见图3a，是LTE系统中的随机接入时间的示意图。如图3a所示，在时间轴上存在多个随机接入时间，任意两个相邻的随机接入时间可以是连续的，也可以是非连续的。一个随机接入时间内，只有一个可选的前导(Preamble)，该前导对应一种前导格式。前导也即随机接入前导，其时域结构包括循环前缀(Cyclic Prefix，CP)和前导序列，前导序列在随机接入过程中用于区分用户设备，估计时间延时量。虽然LTE系统中定义了五种前导格式，各种前导格式下的CP参数和时间长度有所差别，但是LTE系统中的网络设备通过下行RACH信息来指定同一小区中的用户设备采用同一前导格式的前导进行发送。
请参见图3b，是本发明实施例中的随机接入时间的示意图，可以为未来无线通信系统中的随机接入时间的示意图。如图3b所示，一个随机接入时间内，包括K个可选的前导。在第一随机接入时间发送的前导m与在第二随机接入时间发送的前导n的前导格式可以相同，也可以不相同；前导m与前导n承载的序列可以相同，也可以不相同；前导m与前导n所占用的频域资源可以相同，也可以不相同；前导m与前导n对应的时域位置可以相同，也可以不相同。前导m与前导n对应的时域位置相同是指前导m与前导n针对网络设备的同一接收波束，例如，网络设备的接收波束1可接收4个正交频分复用(Orthogonal Frequency Division Multiplexing，OFDM)符号，前导m可携带两个OFDM符号，前导n可携带两个OFDM符号，用户设备将前导m发送至接收波束1，在通过前导m接入失败且网络设备检测到前导m的情况下，接收波束1还可以接收两个OFDM符号，用户设备可将前导n继续发送至接收波束1，即前导m与前导n均针对接收波束1，前导m与前导n对应的时域位置相同。
下面结合本发明实施例中的附图4对本发明实施例提供的随机接入方法进行描述。
请参见图4，是本发明实施例提供的一种随机接入方法的通信示意图。需要说明的是，图4所示的实施例以一个小区内的一个网络设备和一个用户设备进行介绍，该实施例所示的方法包括但不限于如下步骤：
步骤S101：用户设备向网络设备发送第一随机接入前导；
具体地，用户设备在向网络设备发送随机接入前导之前，接收所述网络设备发送的下行RACH消息，所述下行RACH消息用于通知所述用户设备，可以发起随机接入。所述下行RACH消息包括随机接入的配置信息，所述配置信息可以包括前导初始接收目标功率(Preamble Initial Received Target Power)、基于前导格式的功率偏移量(Delta_Preamble)和功率爬坡因子(Power Ramping Step)等信息。其中，Preamble Initial Received Target Power表示所述网络设备期望接收到的随机接入前导的初始功率，所述用户设备利用该取值计算随机接入前导的发送功率，发起随机接入过程。Delta_Preamble与前导格式相关，其值可通过所述下行PACH消息指示，也可通过查表得到。Power Ramping Step表示每次接入失败后，下次接入时提升的发送功率。Preamble Initial Received Target Power、Delta_Preamble以及Power Ramping Step可用于所述用户设备计算所述网络设备期待接收到的前导接收目标功率(PREAMBLE_RECEIVED_TARGET_POWER)。
所述下行RACH消息还用于指示随机接入时间对应的前导数量为一个或多个，以及每个前导的前导格式，每个前导承载的序列等信息。
在一种可能实现的方式中，所述用户设备在第一时间，向所述网络设备发送第一随机接入前导，所述第一随机接入前导用于所述用户设备接入所述网络设备。其中，所述时间用于表示用户设备可以发起随机接入的时间，可以将其称为随机接入时间，也可以将其称为其它名称，随机接入时间的具体数值由所述网络设备设定。所述第一时间，可以理解为所述用户设备在接收到所述下行RACH消息之后的第一个可以发起随机接入的时间，也可以理解为所述用户设备在随机接入失败之后的第一个或某个可以发起随机接入的时间，还可以理解为任意一个可以发起随机接入的时间。
基于图3b所示的随机接入时间的示意图，所述第一随机接入前导为随机接入时间对应的K个可选的前导中的一个，具体为哪个，由所述用户设备选择。可选地，所述用户设备可根据所述下行RACH消息和所述用户设备到所述网络设备的路径损耗从所述第一时间对应的多个前导中选择一个作为所述第一随机接入前导。
在一种可能实现的方式中，所述用户设备第一次向所述网络设备发送第一随机接入前导，所述第一随机接入前导用于所述用户设备接入所述用户设备。
所述用户设备向所述网络设备发送的所述第一随机接入前导，所述网络设备可能会接收到，也可能接收不到。若所述网络设备检测到所述第一随机接入前导，则所述网络设备向所述用户设备发送针对所述第一随机接入前导的随机接入响应，所述随机接入响应包括所述第一随机接入前导的索引号、用于上行时间同步的调整信息、为所述用户设备分配的上行资源等。若所述网络设备未检测到所述第一随机接入前导，则所述用户设备不会接收到所述网络设备发送的针对所述第一随机接入前导的随机接入响应，此时，可认为所述第一随机接入前导未到达所述网络设备，所述用户设备通过所述第一随机接入前导接入所述网络设备失败。
步骤S102：在所述用户设备通过所述第一随机接入前导接入所述网络设备失败的情况下，所述用户设备向所述网络设备发送至少一个第二随机接入前导，所述至少一个第二随机接入前导中的每个第二随机接入前导的接入特征信息与所述第一随机接入前导的接入特 征信息不相同，所述接入特征信息包括时间长度、发送波束、随机接入资源中的至少一种；
具体地，在基于竞争的随机接入过程中，所述用户设备可通过如下过程来判断通过所述第一随机接入前导是否成功接入所述网络设备：
(1)所述用户设备在第一预设时间段内判断是否接收到所述网络设备针对所述第一随机接入前导的随机接入响应，若未接收到所述随机接入响应，则确定接入失败，其中，所述第一预设时间段为随机接入响应时间窗(Random Access Response window)；
(2)若成功接收到所述随机接入响应，则所述用户设备向所述网络设备发送消息3，消息3携带所述用户设备的标识；
(3)所述用户设备在第二预设时间段内判断是否接收到所述网络设备针对消息3发送的消息4，若未接收到消息4，则确定接入失败，其中，所述第二预设时间段为介质访问控制-冲突解决定时器(mac-Contention Resolution Timer)对应的时间段；
(4)若所述用户设备接收到消息4，则所述用户设备判断消息4中携带的用户设备的标识与在消息3中上报给所述网络设备是否相符，若相符则所述用户设备就认为赢得了此次的随机接入冲突,确定接入成功；若不相符，则确定随机接入失败。
其中，过程(1)和(2)对于基于非竞争的随机接入过程也适用。
根据上述过程，可根据以下几种情况来确定所述用户设备通过所述第一随机接入前导接入所述网络设备失败：
(1)所述用户设备向所述网络设备发送的所述第一随机接入前导未到达所述网络设备，导致所述网络设备未检测到所述第一随机接入前导；
(2)所述网络设备检测到所述第一随机接入前导，向所述用户设备发送了随机接入响应，但是所述用户设备未成功检测到所述随机接入响应；
(3)所述用户设备成功检测到所述随机接入响应，向所述网络设备发送了消息3，但是所述网络设备未检测到消息3，或消息3检测出错，或消息3连续出错的次数超过最大重传失败次数；
(4)所述网络设备成功检测到消息3，向所述用户设备发送了消息4，但是所述用户设备未检测到消息4；或所述用户设备检测到消息4，但是消息4携带的用户设备标识与消息3中的所述用户设备的标识不相符。
由上述可知，所述第一随机接入前导未到达所述网络设备，必然导致随机接入失败。鉴于此，所述用户设备需再次发送随机接入前导。在所述用户设备通过所述第一随机接入前导接入所述网络设备失败的情况下，所述用户设备向所述网络设备发送至少一个第二随机接入前导。所述至少一个第二随机接入前导用于所述用户设备重新接入所述网络设备。所述至少一个第二随机接入前导中的每个第二随机接入前导的接入特征信息与所述第一随机接入前导的接入特征信息不相同，所述接入特征信息包括时间长度、发送波束、随机接入资源中的至少一种。只要第二随机接入前导的这三种元素中的一种元素与第一随机接入前导的不相同，便可确定该第二随机接入前导的接入特征信息与第一随机接入前导的接入特征信息不相同。
在一种可能实现的方式中，所述用户设备在第二时间，向所述网络设备发送一个第二随机接入前导A。其中，所述第二随机接入前导A的接入特征信息与所述第一随机接入前 导的接入特征信息不相同，例如，所述第二随机接入前导A的时间长度比所述第一随机接入前导的时间长度长。所述第二时间的时间长度与所述第一时间的时间长度相同，所述第二时间为所述用户设备通过所述第一随机接入前导接入所述用户设备失败后的一个时间，并不一定是所述第一时间紧挨着的下一个时间。
可选地，在所述用户设备通过所述第二随机接入前导A接入所述网络设备失败的情况下，所述用户设备在第三时间，向所述网络设备发送另一个第二随机接入前导B。其中，所述第二随机接入前导B的接入特征信息与所述第一随机接入前导的接入特征信息不相同，且与所述第二随机接入前导A的接入特征信息不相同，例如，所述第二随机接入前导A的时间长度比所述第一随机接入前导的时间长度长，所述第二随机接入前导B的时间长度比所述第二随机接入前导A的时间长度长。按此重复，直到所述用户设备成功接入所述网络设备，或发送次数超过最大允许发送次数。最大允许发送次数由所述下行RACH信息指示。同理，所述第三时间为所述用户设备通过所述第二随机接入前导接入所述用户设备失败后的一个时间，并不一定是所述第二时间紧挨着的下一个时间。
可选地，所述用户设备在未确定通过所述第二随机接入前导A是否成功接入所述网络设备的情况下，向所述网络设备发送至少第一第二随机接入前导。具体为：所述用户设备在第三时间，发送第二随机接入前导B；在第四时间，发送第二随机接入前导C…直到所述用户设备成功接入所述网络设备，或发送次数超过最大允许发送次数。最大允许发送次数由所述下行RACH信息指示。该种可能实现的方式，可以应用于所述用户设备处于小区边缘或所述用户设备的信号强度较弱的场景中。该种可能实现的方式，可以有效降低接入时延，并提高随机接入的成功率。可以理解的是，所述用户设备在未确定所述用户设备通过所述第二随机接入前导接入所述网络设备失败的情况下，在第三时间，向所述网络设备发送所述第二随机接入前导B，此时，所述第三时间为所述第二时间紧挨着的下一个时间。例如，随机接入信道时间的大小为10ms，所述第二时间为11-20ms，那么所述第三时间为21-30ms，在21-30ms中，所述用户设备向所述网络设备发送所述第三随机接入前导。该种可能实现的方式由所述下行RACH信息配置，即由所述网络设备为所述用户设备配置该种能力，或所述用户设备具有该种能力，由所述下行RACH信息指示所述用户设备激活该种能力。
在一种可能实现的方式中，所述用户设备在第二次向所述网络设备发送一个第二随机接入前导A。其中，所述第二随机接入前导A的接入特征信息与所述第一随机接入前导的接入特征信息不相同，例如，所述第二随机接入前导A的时间长度比所述第一随机接入前导的时间长度长。
在所述用户设备通过所述第二随机接入前导A接入所述网络设备失败的情况下，所述用户设备在第三次向所述网络设备发送另一个第二随机接入前导B。其中，所述第二随机接入前导B的接入特征信息与所述第一随机接入前导的接入特征信息不相同，且与所述第二随机接入前导A的接入特征信息不相同，例如，所述第二随机接入前导A的时间长度比所述第一随机接入前导的时间长度长，所述第二随机接入前导B的时间长度比所述第二随机接入前导A的时间长度长。按此重复，直到所述用户设备成功接入所述网络设备，或发送次数超过最大允许发送次数。最大允许发送次数由所述下行RACH信息指示。
在一种可能实现的方式中，所述用户设备在第二次向所述网络设备发送至少一个第二随机接入前导，所述至少一个第二随机接入前导中每个第二随机接入前导的接入特征信息与所述第一随机接入前导的接入特征信息。该种可能实现的方式，可以有效降低接入时延，并提高随机接入的成功率。
上述几种可能实现的方式中，所述至少一个第二随机接入前导的数量可由所述下行RACH信息指示，避免所述至少一个第二随机接入前导的数量太多造成冲突。
若所述每个第二随机接入前导中的时间长度与所述第一随机接入前导的时间长度不相同，则所述每个第二随机接入前导的时间长度比所述第一随机接入前导的时间长度长。例如，所述第一随机接入前导的时间长度为1ms，第二随机接入前导A的时间长度为2ms，那么对于所述网络设备而言，所述第二随机接入前导A的能量更高，所述网络设备更容易接收到，提高了随机接入前导到达网络设备的概率，从而有利于提高随机接入的成功率。
可选地，所述用户设备选择一个时间长度比所述第一随机接入前导的时间长度长的前导，并将其作为所述第二随机接入前导A，具体所述第一随机接入前导与所述第二随机接入前导的时间长度差值不做限定。可选地，所述用户设备在所述第一随机接入前导的基础上，对其时间长度进行叠加或延长得到所述第二随机接入前导A，叠加的倍数和延长的长度在此不作限定，例如，所述第一随机接入前导的时间长度为1ms，对其进行1倍叠加得到时间长度为2ms的前导，将该前导确定为所述第二随机接入前导A。
需要说明的是，随机接入过程中所允许的随机接入前导的时间长度有限制，即存在时间长度阈值，一旦时间长度达到该时间长度阈值，则不再增加时间长度。该时间长度阈值的具体数值可由所述网络设备设定，可通过下行系统信息或RACH信息告知所述用户设备。
若所述每个第二随机接入前导的发送波束与所述第一随机接入前导的发送波束不相同，则所述每个第二随机接入前导的随机接入资源与所述第一随机接入前导的随机接入资源相同或不相同。所述至少一个第二随机接入前导中的任意两个第二随机接入前导的发送波束相同或不相同。
若所述每个第二随机接入前导的随机接入资源与所述第一随机接入前导的随机接入资源不相同，则所述每个第二随机接入前导的发送波束与所述第一随机接入前导的发送波束相同或不相同。所述至少一个第二随机接入前导中的任意两个第二随机接入前导的随机接入资源相同或不相同。
所述每个第二随机接入前导的发送功率与所述第一随机接入前导的发送功率相同或不相同，所述至少一个第二随机接入前导中的任意两个第二随机接入前导的发送功率相同或不相同。
可选地，所述第一随机接入前导与所述第二随机接入前导承载的序列不相同。
可选地，所述第一随机接入前导与所述第二随机接入前导占用的频域资源相同或不相同。其中，相同是指占用的子载波数量相同且占用的子载波的位置相同。
在一种可能实现的方式中，所述用户设备根据时间长度、发送功率、发送波束、随机接入资源的优先等级向所述网络设备发送所述至少一个第二随机接入前导。可以理解的是，对时间长度、发送功率、发送波束、随机接入资源这四种元素进行优先等级排序，在通过改变一种元素的随机接入前导接入失败后，选择优先等级更高的另外一种元素的随机接入 前导进行发送，例如这四种元素的优先等级顺序从高到低为发送波束、随机接入资源、发送功率、时间长度，在第一随机接入前导接入失败的情况下，选择发送波束与第一随机接入前导的发送波束不同的第二随机接入前导A(其它三种元素可与第一随机接入前导的相同)，在第二随机接入前导A接入失败的情况下，选择与第一随机接入前导或第二随机接入前导A的随机接入资源不同的第二随机接入前导B进行发送，以此类推，直到接入成功或发送次数达到最大次数。其中，第二随机接入前导B的发送波束与第二随机接入前导A的发送波束相同或不相同。
可选地，对这四种元素中至少两种元素的任意组合进行优先等级排序，即在通过改变一种组合的随机接入前导失败后，选择优先等级更高的组合的随机接入前导进行发送。
可选地，在通过改变一种元素的随机接入前导接入失败后，选择改变这四种元素中至少两种元素的随机接入前导进行发送。
图4所示的实施例，通过发送接入特征信息与上一次随机接入前导的接入特征信息不同的随机接入前导来解决未来无线通信网络中由于随机接入前导未到达网络设备而导致的随机接入失败的问题，能够提高随机接入前导到达网络设备的概率，从而提高随机接入的成功率。
请参见图5a-图5e，为本发明实施例提供的五种随机接入方式的举例示意图，图5a-图5e用横条纹表示用户设备发送的随机接入前导，用交叉条纹表示网络设备接收到的随机接入前导。下面将对这五种方式分别进行介绍，其中，发送次数以三次为例，并假设网络设备能检测到用户设备发送的随机接入前导。
方式一，可参见图5a，用户设备进行第一次发送，向网络设备发送第一随机接入前导；在第一随机接入前导失败后，进行第二次发送，向网络设备发送第二随机接入前导；在第二随机接入失败后，进行第三次发送，向网络设备发送第三随机接入前导。其中，第三随机接入前导的时间长度比第二随机接入前导的长，第二随机接入前导的时间长度比第一随机接入前导的长，三次发送的发送功率相同，假设发送功率为P。P的计算方法在此不作限定。可选地，发送功率P的计算公式为：
P＝min{P CMAX(i)，PREAMBLE_RECEIVED_TARGET_POWER+PL}
其中，P的单位是dBm；P CMAX(i)表示第i个子帧所述用户设备的最大允许传输功率，单位是dBm；PL表示用户设备估计的用户设备到网络设备的路径损耗(PathLoss)，单位是dB；PREAMBLE_RECEIVED_TARGET_POWER为网络设备期待接收到的前导接收目标功率，由介质访问控制(Media Access Control，MAC)层指定为Preamble Initial Received Target Power，Preamble Initial Received Target Power由网络设备发送的下行RACH消息指定。
方式二，可参见图5b，与方式一不同之处在于，方式二中每次发送随机接入前导的发送功率不相同，且第二次比第一次小，第三次比第二次小。第一随机接入前导的发送功率P1由用户设备根据路径损耗和下行RACH消息计算得到，第二随机接入前导与第一随机接入前导之间的发送功率差值由下行RACH消息计算得到，具体计算方式在此不作限定。可选地，第k次发送的第k随机接入前导的时间长度为T k，其发送功率P k可根据如下公式计 算：
P k＝min{P CMAX(i),PREAMBLE_RECEIVED_TARGET_POWER+PL}，
其中，P k的单位是dBm；P CMAX(i)表示第i个子帧所述用户设备的最大允许传输功率，单位是dBm；PL表示用户设备估计的用户设备到网络设备的路径损耗，单位是dB；PREAMBLE_RECEIVED_TARGET_POWER为网络设备期待接收到的前导接收目标功率，由MAC层指定为：Preamble Initial Received Target Power–10log10(T k/T 1)+(k–1)*Power Ramping Step。PREAMBLE_TRANSMISSION_COUNTER为重传次数，Power Ramping Step表示每次接入失败后，下次接入时提升的发送功率，由下行RACH消息指定。Preamble Initial Received Target Power由下行RACH消息指定。
方式三，可参见图5c，与方式一不同之处在于，方式三中每次发送随机接入前导的发送功率不相同，且第二次比第一次大，第三次比第二次大。提高发送功率可以解决由于用户设备与网络设备之间距离过远造成的接入失败。
方式四，可参见图5d，第二次发送的第二随机接入前导的时间长度与第一次发送的第一随机接入前导的时间长度相同，第二随机接入前导的发送功率高于第一随机接入前导的发送功率；第三次发送的第三随机接入前导的发送功率与第一次发送的第一随机接入前导的发送功率相同，第三随机接入前导的时间长度大于第一随机接入前导的发送功率。方式四先提高发送功率进行接入，若提高发送功率接入失败，则选择时间长度较长的随机接入前导进行接入，以提高接入成功率。
方法五，可参见图5e，与方式一的不同之处在于，方式五中第三次发送的随机接入前导的总时间长度更长，并且发送时间不连续。
需要说明的是，上述五种接入方式实施的场景为基于同一发送波束、相同的随机接入资源进行多次随机接入前导的发送。上述五种接入方式中，若通过第三次发送的随机接入前导接入网络设备失败，则进行第四次随机接入前导的发送并按此重复，直到成功接入或发送次数超过最大允许发送次数。其中，第四次发送的随机接入前导的时间长度可比第三次发送的随机接入前导的长，发送功率比第三次发送的随机前导的大；或第四次发送的随机接入前导的时间长度与第三次发送的随机接入前导的相同，发送功率比第三次发送的随机前导的大；或第四次发送的随机接入前导的时间长度比第三次发送的随机接入前导的长，发送功率与第三次发送的随机前导的相同；或第四次发送的随机接入前导的总时间长度比第三次发送的随机接入前导的总时间长度长，发送功率与第三次发送的随机前导的相同或比第三次发送的随机前导的大。
移动业务的发展对无线通信的数据速率和效率要求越来越高。在未来无线通信系统中，波束成型(Beamforming)技术用来将传输信号的能量限制在某个波束方向内，从而增加信号发送和接收的效率。波束成型技术能够有效扩大无线信号的传输范围，降低信号干扰，从而达到更高的通信效率和获取更高的网络容量。
然而，在采用波束成型技术的通信网络中，基站和用户设备均可以通过多个波束进行信号传输，可参见图6，是本发明实施例提供的一种波束示意图，应用在上行接入时，用户设备可通过3个发送波束进行发送，网络设备可通过3个接收波束进行接收，图6所示的波束的数量并不构成对本发明实施例的限定，具体数量视具体情况而定。
在通信过程中，首先需要将发送波束(Beam)和接收波束匹配，使得发送端到接收端的增益最大，否则无法获取比较高的通信效率。而且，为了达到全覆盖，要求基站波束进行扫描。因此，在用户设备与基站分别建立上行连接和下行连接时，需要进行波束扫描，以获取最佳发送-接收波束对。进一步地，用户设备使用随机接入进行上行连接时，需要考虑发送波束-接收波束不匹配带来的影响。也就是说，用户设备的发送波束与基站的接收波束不匹配，可能会造成随机接入失败。如图6所示，假设用户设备的发送波束2与网络设备的接收波束2’为最佳发送-接收波束对，但是用户设备通过发送波束1向接收波束2’发送，则可能会造成随机接入失败。
LTE系统中的随机接入重传方法不支持多波束扫描，无法满足未来无线通信系统的需求。鉴于此，本发明实施例中的随机接入前导可通过不同的发送波束发送，也可通过相同的发送波束发送；随机接入前导可针对不同的接收波束，也可针对相同的接收波束，尽可能达到发送波束与接收波束匹配，从而提高随机接入成功率。附图5a-附图5e所示的五种接入方式可假设在发送波束与接收波束匹配的情况下进行的，若一开始发送波束与接收波束不匹配，则用户设备需要波束扫描，切换发送波束和/或接收波束来尝试进行随机接入，确定匹配的发送波束和接收波束。在一种可能的实现方式中，网络设备的接收波束对应随机接入资源，或者时间上的位置(例如图7c中，两个接收波束B2和B3在时间相邻，记为t1～t4。如果网络设备没有“波束”的定义，那么不同接收波束是通过时间上的位置来区分，换言之，接收波束B2占用t1～t2，接收波束B3占用t3～t4)，或者频率上的位置。
下面将结合附图7a和附图7d分别对切换接收波束和切换发送波束进行介绍。
请参见图7a，是本发明实施例提供的一种针对不同接收波束的随机接入方式的举例示意图。如图7a所示，用户设备进行第一次发送，以发送功率P 1针对网络设备的接收波束B1发送第一随机接入前导。在第一随机接入前导失败后，进行第二次发送，以发送功率P 1针对网络设备的接收波束B1发送比第一随机接入前导的时间长度长的第二随机接入前导。在第二随机接入失败后，进行第三次发送，以发送功率P 2针对网络设备的接收波束B2发送向网络设备发送比第二随机接入前导的时间长度长的第三随机接入前导。其中，P 1和P 2由用户设备根据路径损耗和下行RACH消息计算得到，两者可以相同，也可以不相同。换言之，用户设备在采用时间长度更长的随机接入前导接入失败时，可切换接收波束进行发送，发送比上一次时间长度更长的随机接入前导。可选地，发送功率P 1中的路损，是根据网络设备发送到用户设备的第一个接收波束B1得到，发送功率P 2中的路损，是根据网络设备发送到用户设备的第二个接收波束B2得到。可选地，用户设备在切换接收波束时，可发送比发送功率更高的随机接入前导。可选地，用户设备在切换接收波束时，可发送比上一次时间长度更长且发送功率更高的随机接入前导。
需要说明的是，图7a示出两种接收波束(B1和B2，分别对应交叉纹和斜条纹)和一种发送波束(横条纹)，即针对不同的接收波束，基于同一发送波束。
可选地，用户设备可根据接收波束之间的空间位置关系来判断是否切换接收波束，例如接收波束2与接收波束1在空间上相邻，那么在针对接收波束1的随机接入前导接入失败之后，发送针对接收波束2的随机接入前导。可选地，用户设备可根据接收波束的接收质量来判断是否切换接收波束，例如用户设备判断出接收波束2可能获得比接收波束1更 好的接收质量，那么在针对接收波束1的随机接入前导接入失败之后，发送针对接收波束2的随机接入前导。
请参见图7b，是本发明实施例提供的一种针对不同发送波束的随机接入方式的举例示意图；如图7b所示，用户设备基于发送波束b1进行第一次发送，以发送功率P 1发送第一随机接入前导。在第一随机接入前导失败后，基于发送波束b1进行第二次发送，以发送功率P 1发送比第一随机接入前导的时间长度长的第二随机接入前导。在第二随机接入失败后，基于发送波束b2进行第三次发送，以发送功率P 2发送向网络设备发送比第二随机接入前导的时间长度长的第三随机接入前导。其中，P 1和P 2由用户设备根据路径损耗和下行RACH消息计算得到，两者可以相同，也可以不相同。换言之，用户设备在采用时间长度更长的随机接入前导接入失败时，可切换发送波束进行发送，发送比上一次时间长度更长的随机接入前导。可选地，用户设备在切换发送波束时，可发送比发送功率更高的随机接入前导。可选地，用户设备在切换发送波束时，可发送比上一次时间长度更长且发送功率更高的随机接入前导。
需要说明的是，图7b示出两种发送波束(b1和b2，分别对应横条纹和竖条纹)和一种接收波束(交叉条纹)，即针对不同的发送波束，基于同一接收波束。
可选地，用户设备在采用时间长度更长的随机接入前导接入失败时，可同时切换发送波束和接收波束。
可选地，用户设备可根据发送波束之间的空间位置关系来选择是否切换发送波束，例如发送波束2与发送波束1在空间上相邻，那么在基于发送波束1的随机接入前导接入失败之后，发送基于发送波束2的随机接入前导。可选地，用户设备可根据发送波束的传输质量来判断是否切换发送波束，例如用户设备判断出发送波束2可能获得比发送波束1更好的传输质量，那么在基于发送波束1的随机接入前导接入失败之后，发送基于发送波束2的随机接入前导。
请参加图7c，是本发明实施例提供的另一种针对不同接收波束的随机接入方式的举例示意图。与图7a的不同之处在于，这里的第三次发送的随机接入前导在网络设备的两个接收波束内进行，并且总时间比第二次发送的时间长度更长，两次发送时间不连续，这两次发送时间的具体间隔的时间宽度，用户设备可从PACH信息获知。需要说明的是，第三次发送的随机接入前导不限于在网络设备的两个接收波束内进行，可以在更多的接收波束内进行。
请参加图7d，是本发明实施例提供的另一种针对不同发送波束的随机接入方式的举例示意图。与图7b的不同之处在于，这里的第三次发送的随机接入前导通过用户设备的两个发送波束进行，并且总时间比第二次发送的时间长度更长，两次发送时间不连续，这两次发送时间的具体间隔的时间宽度，用户设备可从PACH信息获知。需要说明的是，第三次发送的随机接入前导不限于通过用户设备的两个发送波束进行，可以通过更多的发送波束进行。
附图7a-附图7d所示的四种随机接入方式基于附图5a，即发送功率不变，选择时间长度更长的随机接入前导进行随机接入。需要说明的是，附图5a-附图5e所示的五种随机接入方式与附图7a-附图7d所示的四种随机接入方式可任意组合，例如，附图7a所示的随机 接入方式与附图5c所示的随机接入方式组合，即改变接收波束、增加发送功率并选择时间长度更长的随机接入前导进行随机接入。
上述详细阐述了本发明实施例的方法，下面提供了本发明实施例的装置。
请参见图8，是本发明实施例提供的一种用户设备的结构示意图，该用户设备90可以包括收发器913。
所述收发器913，用于向网络设备发送第一随机接入前导，所述第一随机接入前导用于所述用户设备接入所述网络设备；
所述收发器913，还用于在所述用户设备通过所述第一随机接入前导接入所述网络设备失败的情况下，向所述网络设备发送至少一个第二随机接入前导，所述至少一个第二随机接入前导中的每个第二随机接入前导的接入特征信息与所述第一随机接入前导的接入特征信息不相同，所述接入特征信息包括时间长度、发送波束、随机接入资源中的至少一种，所述至少一个第二随机接入前导用于所述用户设备接入所述网络设备。
可选地，所述至少一个第二随机接入前导中的任意两个第二随机接入前导的接入特征信息不相同。
可选地，若所述每个第二随机接入前导的时间长度与所述第一随机接入前导的时间长度不相同，则所述每个第二随机接入前导的时间长度比所述第一随机接入前导的时间长度长。
可选地，若所述每个第二随机接入前导的发送波束与所述第一随机接入前导的发送波束不相同，则所述每个第二随机接入前导的随机接入资源与所述第一随机接入前导的随机接入资源相同或不相同。
可选地，若所述每个第二随机接入前导的随机接入资源与所述第一随机接入前导的随机接入资源不相同，则所述每个第二随机接入前导的发送波束与所述第一随机接入前导的发送波束相同或不相同。
可选地，所述每个第二随机接入前导的发送功率与所述第一随机接入前导的发送功率相同或不相同，所述至少一个第二随机接入前导中的任意两个第二随机接入前导的发送功率相同或不相同。
所述收发器913，具体用于根据所述时间长度、所述发送功率、所述发送波束、所述随机接入资源的优先等级向所述网络设备发送所述至少一个第二随机接入前导。
需要说明的是，上述收发器913用于执行图4所示实施例中的步骤S101和步骤S102，还用于实现用户设备90与卫星等网络设备之间的通信或数据传输，
收发器913还可以是收发电路或通信模块等。用户设备90还包括处理器914、电源911、用户接口912、显示系统915、传感系统916和音频系统917。需要说明的是，该用户设备90可以表示图4中所述的用户设备，图8所示的用户设备的结构并不构成对本发明实施例的限定。
处理器914，可以是中央处理器(Central Processing Unit，CPU)，通用处理器，数字信号处理器(Digital Signal Processor，DSP)，专用集成电路(Application-Specific Integrated Circuit，ASIC)，现场可编程门阵列(Field Programmable Gate Array，FPGA)或者其他可 编程逻辑器件、晶体管逻辑器件、硬件部件或者其任意组合。其可以实现或执行结合本发明公开内容所描述的各种示例性的逻辑方框，模块和电路。所述处理器也可以是实现计算功能的组合，例如包含一个或多个微处理器组合，DSP和微处理器的组合等等。
其中，电源911为用户设备90各项功能的实现提供电力保障。用户接口912用于用户设备90与其它设备或装置相连接，实现其它设备或装置与用户设备90的通信或数据传输。显示系统915用于信息的输出显示以及接收用户输入的操作。传感系统916包括各种传感器，例如温度传感器、距离传感器等。音频系统917用于音频信号的输出。
请参见图9，是本发明实施例提供的一种网络设备的结构示意图，该网络设备100可以包括收发器1012。
所述收发器1012，用于向网络设备发送第一随机接入前导，所述第一随机接入前导用于用户设备接入所述网络设备；
所述收发器1012，还用于在所述用户设备通过所述第一随机接入前导接入所述网络设备失败的情况下，向所述网络设备发送至少一个第二随机接入前导，所述至少一个第二随机接入前导中的每个第二随机接入前导的接入特征信息与所述第一随机接入前导的接入特征信息不相同，所述接入特征信息包括时间长度、发送波束、随机接入资源中的至少一种，所述至少一个第二随机接入前导用于所述用户设备接入所述网络设备。
所述收发器1012，还用于向所述用户设备发送下行RACH信息。
需要说明的是，网络设备100在接收到第一随机接入前导，但用户设备通过第一随机接入前导接入失败的情况下，收发器1012执行上述过程。实际应用中，网络设备100可能接收到第一随机接入前导，可能接收不到第一随机接入前导；可能接收到第二随机接入前导，可能接收不到第二随机接入前导。不过，网络设备100可接收用户设备发送的不同时间长度的随机接入前导，不同前导格式的随机接入前导，不同发送功率的随机接入前导。
网络设备100还包括处理器1011和以及天线。需要说明的是，实际应用中收发器1012不限于两个，天线也不限于两个，该网络设备100的结构并不构成对本发明实施例的限定。
处理器1011主要包括四个部件：小区控制器、话音信道控制器、信令信道控制器和用于扩充的多路端接口。处理器1011负责所有的移动通信接口管理，主要是无线信道的分配、释放和管理。收发器1012包括接收机和发射机，对于用户设备而言，可以通过发射机进行上行数据的发射，通过接收机对下行数据进行接收。
本发明实施例还提供一种计算机存储介质，用于储存为上述用户设备所用的计算机软件指令，其包含用于执行上述方面所设计的程序。
本发明实施例还提供一种计算机存储介质，用于储存为上述网络设备所用的计算机软件指令，其包含用于执行上述方面所设计的程序。
需要说明的是，对于前述的各方法实施例，为了简单描述，故将其都表述为一系列的动作组合，但是本领域技术人员应该知悉，本发明并不受所描述的动作顺序的限制，因为根据本发明，某些步骤可以采用其他顺序或者同时进行。其次，本领域技术人员也应该知悉，说明书中所描述的实施例均属于优选实施例，所涉及的动作和模块并不一定是本发明所必须的。
在上述实施例中，对各个实施例的描述都各有侧重，某个实施例中没有详述的部分，可以参见其他实施例的相关描述。
本发明实施例方法中的步骤可以根据实际需要进行顺序调整、合并和删减。
本发明实施例装置中的单元可以根据实际需要进行合并、划分和删减。本领域的技术人员可以将本说明书中描述的不同实施例以及不同实施例的特征进行结合或组合。
通过以上的实施方式的描述，所属领域的技术人员可以清楚地了解到本发明可以用硬件实现，或固件实现，或它们的组合方式来实现。当使用软件实现时，可以将上述功能存储在计算机可读介质中或作为计算机可读介质上的一个或多个指令或代码进行传输。计算机可读介质包括计算机存储介质和通信介质，其中通信介质包括便于从一个地方向另一个地方传送计算机程序的任何介质。存储介质可以是计算机能够存取的任何可用介质。以此为例但不限于：计算机可读介质可以包括随机存取存储器(Random Access Memory，RAM)、只读存储器(Read-Only Memory，ROM)、电可擦可编程只读存储器(Electrically Erasable Programmable Read-Only Memory，EEPROM)、只读光盘(Compact Disc Read-Only Memory，CD-ROM)或其他光盘存储、磁盘存储介质或者其他磁存储设备、或者能够用于携带或存储具有指令或数据结构形式的期望的程序代码并能够由计算机存取的任何其他介质。此外。任何连接可以适当的成为计算机可读介质。例如，如果软件是使用同轴电缆、光纤光缆、双绞线、数字用户线(Digital Subscriber Line，DSL)或者诸如红外线、无线电和微波之类的无线技术从网站、服务器或者其他远程源传输的，那么同轴电缆、光纤光缆、双绞线、DSL或者诸如红外线、无线和微波之类的无线技术包括在所属介质的定影中。如本发明所使用的，盘(Disk)和碟(disc)包括压缩光碟(CD)、激光碟、光碟、数字通用光碟(DVD)、软盘和蓝光光碟，其中盘通常磁性的复制数据，而碟则用激光来光学的复制数据。上面的组合也应当包括在计算机可读介质的保护范围之内。
总之，以上所述仅为本发明技术方案的较佳实施例而已，并非用于限定本发明的保护范围。凡在本发明的精神和原则之内，所作的任何修改、等同替换、改进等，均应包含在本发明的保护范围之内。

Claims (14)

  1. 一种发送随机接入前导的方法，其特征在于，包括：
    用户设备向网络设备发送第一随机接入前导，所述第一随机接入前导用于所述用户设备接入所述网络设备；
    在所述用户设备通过所述第一随机接入前导接入所述网络设备失败的情况下，所述用户设备向所述网络设备发送至少一个第二随机接入前导，所述至少一个第二随机接入前导中的每个第二随机接入前导的接入特征信息与所述第一随机接入前导的接入特征信息不相同，所述接入特征信息包括时间长度、发送波束、随机接入资源中的至少一种，所述至少一个第二随机接入前导用于所述用户设备接入所述网络设备。
  2. 如权利要求1所述的方法，其特征在于，所述至少一个第二随机接入前导中的任意两个第二随机接入前导的接入特征信息不相同。
  3. 如权利要求1所述的方法，其特征在于，若所述每个第二随机接入前导的时间长度与所述第一随机接入前导的时间长度不相同，则所述每个第二随机接入前导的时间长度比所述第一随机接入前导的时间长度长。
  4. 如权利要求1所述的方法，其特征在于，若所述每个第二随机接入前导的发送波束与所述第一随机接入前导的发送波束不相同，则所述每个第二随机接入前导的随机接入资源与所述第一随机接入前导的随机接入资源相同或不相同。
  5. 如权利要求1所述的方法，其特征在于，若所述每个第二随机接入前导的随机接入资源与所述第一随机接入前导的随机接入资源不相同，则所述每个第二随机接入前导的发送波束与所述第一随机接入前导的发送波束相同或不相同。
  6. 如权利要求1-5所述的方法，其特征在于，所述每个第二随机接入前导的发送功率与所述第一随机接入前导的发送功率相同或不相同，所述至少一个第二随机接入前导中的任意两个第二随机接入前导的发送功率相同或不相同。
  7. 如权利要求1所述的方法，其特征在于，所述用户设备向所述网络设备发送至少一个第二随机接入前导，包括：
    所述用户设备根据所述时间长度、所述发送功率、所述发送波束、所述随机接入资源的优先等级向所述网络设备发送所述至少一个第二随机接入前导。
  8. 一种用户设备，其特征在于，包括：处理器和收发器，
    所述收发器，用于向网络设备发送第一随机接入前导，所述第一随机接入前导用于所述用户设备接入所述网络设备；
    所述收发器，还用于在所述用户设备通过所述第一随机接入前导接入所述网络设备失败的情况下，向所述网络设备发送至少一个第二随机接入前导，所述至少一个第二随机接入前导中的每个第二随机接入前导的接入特征信息与所述第一随机接入前导的接入特征信息不相同，所述接入特征信息包括时间长度、发送波束、随机接入资源中的至少一种，所述至少一个第二随机接入前导用于所述用户设备接入所述网络设备。
  9. 如权利要求8所述的用户设备，其特征在于，所述至少一个第二随机接入前导中的任意两个第二随机接入前导的接入特征信息不相同。
  10. 如权利要求8所述的用户设备，其特征在于，若所述每个第二随机接入前导的时间长度与所述第一随机接入前导的时间长度不相同，则所述每个第二随机接入前导的时间长度比所述第一随机接入前导的时间长度长。
  11. 如权利要求8所述的用户设备，其特征在于，若所述每个第二随机接入前导的发送波束与所述第一随机接入前导的发送波束不相同，则所述每个第二随机接入前导的随机接入资源与所述第一随机接入前导的随机接入资源相同或不相同。
  12. 如权利要求8所述的用户设备，其特征在于，若所述每个第二随机接入前导的随机接入资源与所述第一随机接入前导的随机接入资源不相同，则所述每个第二随机接入前导的发送波束与所述第一随机接入前导的发送波束相同或不相同。
  13. 如权利要求8-12所述的用户设备，其特征在于，所述每个第二随机接入前导的发送功率与所述第一随机接入前导的发送功率相同或不相同，所述至少一个第二随机接入前导中的任意两个第二随机接入前导的发送功率相同或不相同。
  14. 如权利要求8所述的用户设备，其特征在于，所述收发器具体用于根据所述时间长度、所述发送功率、所述发送波束、所述随机接入资源的优先等级向所述网络设备发送所述至少一个第二随机接入前导。
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CN108391319A (zh) 2018-08-10
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