CN102811192A - A Signaling Control Method in Orthogonal Frequency Division Multiplexing Technology - Google Patents

Abstract

A method for controlling signaling in orthogonal frequency division multiplexing technology includes that a system transmits a first monitoring period to UE (user equipment ) connected with the system in a public manner; the UE monitors page messages from a physical downlink control channel of the system within the first monitoring period; if the page messages are not monitored by the UE within the first monitoring period, the UE is set to monitor within the next monitoring period continuously; and if the page messages are monitored by the UE within the first monitoring period, the UE executes services according to the page messages. By applying the method, special signaling expense is reduced and power consumption of the integral system is further reduced.

Description

A Signaling Control Method in Orthogonal Frequency Division Multiplexing Technology

technical field

The present invention relates to the field of communication technology, and more specifically, to a signaling control method in OFDM technology.

Background technique

The orthogonal multi-subcarrier transmission of Orthogonal Frequency Division Multiplexing (OFDM) has the advantages of relatively small intersymbol interference, easy expansion, strong frequency selectivity, and flexible scheduling. Discontinuous reception (DRX) is a very effective power-saving mechanism because it reduces the time for the UE to monitor the control channel and increases the standby time for the user terminal (UE).

In the communication system, the DRX mechanism of the UE is realized through cooperation of various timers. The base station configures the timer for each UE respectively through air interface signaling. The basic principle of DRX used in the system is shown in Figure 1. The DRX cycle consists of an activation timer (On-duration) and a subsequent repeated period of possible sleep time waiting for DRX activation (Opprtunity for DRX).

The working process of the DRX mechanism is shown in FIG. 2 . The On-duration timer is the time period for the UE to search for the Physical Downlink Control Channel (PDCCH), that is, several consecutive PDCCH transmission subframes in one DRX cycle. During the validity period of the On-duration timer, if the UE receives its own correct PDCCH indication, it will receive the corresponding data packet and start the DRX inactivity timer (DRX-Inactivity timer) at the same time. The DRX-Inactivity timer is the time interval for the UE to wait for the PDCCH indication to be correctly received again after the UE correctly received the PDCCH indication last time. If the DRX-Inactivity timer expires and no new PDCCH indication is correctly received, it will enter the DRX state, and at this time, the DRX short cycle (Short DRX Cycle) is adopted, and the DRX short cycle timer (drx-ShortCycleTimer) is started. After the drx-ShortCycleTimer times out, the DRX long cycle (Long DRX Cycle) is enabled. If the On-duration timer is valid, if the UE does not correctly receive its own PDCCH indication, it will enter the DRX state.

The existing DRX technology can well meet the UE power saving requirement in the mobile communication system. Although the dedicated timer configuration mechanism is flexible, since a dedicated timer needs to be configured for each UE, a configuration message needs to be sent to the UE. The base station transmits multiple DRX timer configurations of each UE to the UE through the air interface, which requires certain dedicated signaling overhead. With the increase of the number of UEs, the overhead of dedicated signaling becomes larger and larger, affecting the operation of the entire system and correspondingly increasing the power consumption of the entire system.

Contents of the invention

Embodiments of the present invention propose a signaling control method in OFDM technology, which reduces proprietary signaling overhead and further reduces power consumption of the entire system.

The technical scheme of the embodiment of the present invention is as follows:

A method for controlling signaling in OFDM technology, the method comprising:

The system sends the first listening period to the user terminal UE that establishes a connection with the system in a public manner;

The UE monitors the paging message from the system physical downlink control channel PDCCH in the first monitoring period. If the UE does not hear the paging message in the first monitoring period, the UE continues to monitor in the next first monitoring period; if the UE is in The paging message is monitored during the first monitoring period, and the UE performs services according to the paging message.

The UE monitoring the paging message from the system in the first monitoring period includes:

The UEs are grouped, and the system intermittently delivers DRX in groups;

The UEs in the same group monitor the paging message from the system at the same moment in the first monitoring period.

The UE monitoring the paging message from the system in the first monitoring period includes:

The system issues DRX to all at the same time;

All UEs monitor the paging message from the system at the same moment in the first monitoring period.

After performing the service according to the paging message, the UE further includes: the UE continues to monitor the paging message from the system PDCCH within the second monitoring period.

The first monitoring period is the smallest period among the monitoring periods of all UEs, and the first monitoring period is greater than or equal to the time of one radio frame.

The second listening period is determined by high-priority user frames.

It can be seen from the above technical solutions that, in the embodiment of the present invention, the system sends the first listening period to UEs that establish a connection with the system in a public manner, and the system does not need to send a different listening period to each UE separately. If the UE does not hear the paging message in the first listening period, the UE will continue to listen in the next first listening period; if the UE listens to the paging message in the first listening period, the UE will execute the paging message according to the paging message. business. The system sends the first listening period to the UE in a public way, reducing the overhead of proprietary signaling and further reducing the power consumption of the entire system.

Description of drawings

FIG. 1 is a schematic diagram of the basic principle of DRX in the prior art;

FIG. 2 is a schematic diagram of a DRX process in the prior art;

3 is a schematic flowchart of a signaling control method in OFDM technology according to an embodiment of the present invention;

FIG. 4 is a schematic diagram of UE DRX cycles after UE grouping in the present invention;

FIG. 5 is a schematic diagram of a DRX customization cycle according to an embodiment of the present invention;

Fig. 6 is a schematic diagram of a cycle according to an embodiment of the present invention;

FIG. 7 is a schematic diagram of state transition of a UE according to an embodiment of the present invention.

Detailed ways

In order to make the object, technical solution and advantages of the present invention more clearly, the present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

In the embodiment of the present invention, the communication system, hereinafter referred to as the system for short, sends the same first listening period to all UEs in a public manner. Since the monitoring period of all UEs is consistent, the system only needs to agree on the period with the UE in a public way, and the signaling overhead paid by the system is greatly reduced, thereby reducing the power consumption of the entire system.

Referring to accompanying drawing 3, it is a schematic flow chart of the control method of signaling in OFDM technology, which specifically includes the following steps:

Step 301, the system sends a first monitoring period.

According to the system, the first listening period is sent to the UE that establishes a connection with the system in a public manner. The present invention determines a unified monitoring cycle according to the service characteristics of the system and the response time requirement of the UE to the system. In the prior art, when multiple UEs exist, it is necessary to calculate for each UE the listening period corresponding to the UE. In the case of multiple UEs, the smallest listening period among the multiple UEs is selected as the first listening period, and then the first listening period is sent to the UEs connected to the system. The first monitoring period is greater than or equal to the time of one radio frame. The public way includes sending the first listening period to the UE through a system broadcast message.

Step 302, the UE monitors the paging message in the first monitoring period.

If the UE monitors the paging message in the first monitoring period, execute step 303; otherwise, return to step 302, that is, the UE continues to monitor in the next first monitoring period.

UEs can be grouped, and the first monitoring period of each group is the same, but the DRX delivery of different groups is not delivered at the same time, and the DRX delivery of each group is staggered in time. Referring to Figure 4, the UEs are divided into two groups, and the DRX of each group is delivered at intervals. Correspondingly, UEs in the first group monitor paging messages from the system at the same time according to the first monitoring period; UEs in the second group also monitor paging messages from the system at the same time according to the first monitoring period. The first group of UEs and the second group of UEs listen at different times.

The advantage of grouping UEs is that the number of UEs that can be paged per unit time increases correspondingly, which improves scheduling performance and saves terminal power at the same time.

In addition, DRX can also be delivered to all UEs at the same time, so all UEs monitor paging messages from the system at the same time in the first monitoring period.

Step 303, the UE performs services according to the paging message.

The UE implements related services according to the paging message.

Referring to Fig. 5, the UE is in the Sleep state after being connected to the system. Thereafter, the UE monitors the paging message according to the first monitoring period T1. After the UE listens to the paging message, it enters the Active state and continuously monitors the PDCCH message for T1. If the UE is not scheduled within T1, that is, it does not receive a PDCCH indication message related to itself, it continues to enter the Sleep state.

If the UE is scheduled within the time period T1, the service data transmission process will start, and this process will last for the scheduled time T2, and the duration of T2 is related to the actual execution process of the service.

After the UE receives the DCI instruction from the system to stop the service transmission process, the UE still continuously monitors the PDCCH message in the second monitoring period T3. If the UE is scheduled within T3, continue service transmission. If the UE is not scheduled within T3, the UE enters the Sleep state. T3 is determined by high priority user frames. For example, if most high-priority users can basically complete the transmission within n frames, then T3 is n frames, and after n frames, the UE continues to maintain the receiving state and waits for downlink control.

As shown in FIG. 6 , the UE that is paged in the first listening period enters an active state and waits for subsequent scheduling by the system. After the service of the UE ends (the DCI instruction is received to end the scheduling), the UE will continue to monitor the PDCCH in the second monitoring period. If the UE is not scheduled again during the second listening period, it enters the sleep state, and if the UE is scheduled again during the second listening period, it continues to complete service transmission. For the UE that has not been paged, continue to sleep and wait for the next listening time to come.

For the UE, the several moments shown in FIG. 7 are critical moments when the state of the UE changes. Firstly, in the first monitoring period, when the UE monitors the paging message at time t ₁ , if it detects the paging message from the system, the UE enters the Active state from the Sleep state, that is, the state of continuously monitoring the PDCCH.

Secondly, at time t ₂ when receiving the PDCCH indication message, the UE starts the service transmission process in the Active state, and enters the service activation sub-state in the Active state.

Again, at time _t3 when receiving the DCI indication service end, although the UE service process stops, it still continuously monitors the PDCCH indication message in the second monitoring period to ensure that the system can resume the service of the UE in time when the service is suspended by the system. Scheduling, that is, the subsequent monitoring state of the PDCCH in the Active state.

Finally, the time t ₄ is when the UE finishes monitoring the PDCCH message. If the UE does not hear its own PDCCH indication message until the time t ₄ during the PDCCH continuous monitoring process in the second monitoring period, it will enter the Sleep state.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the protection scope of the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims (6)

1. A control method for signaling in OFDM technology, characterized in that the method comprises: The system sends the first listening period to the user terminal UE that establishes a connection with the system in a public manner; The UE monitors the paging message from the system physical downlink control channel PDCCH in the first monitoring period. If the UE does not hear the paging message in the first monitoring period, the UE continues to monitor in the next first monitoring period; if the UE is in The paging message is monitored during the first monitoring period, and the UE performs services according to the paging message. 2. The method for controlling signaling in OFDM technology according to claim 1, wherein the UE monitoring the paging message from the system in the first monitoring period comprises: The UEs are grouped, and the system intermittently delivers DRX in groups; The UEs in the same group monitor the paging message from the system at the same moment in the first monitoring period. 3. The method for controlling signaling in OFDM technology according to claim 1, wherein the UE monitoring the paging message from the system in the first monitoring period comprises: The system issues DRX to all at the same time; All UEs monitor the paging message from the system at the same moment in the first monitoring period. 4. The signaling control method in OFDM technology according to claim 1, characterized in that, after the UE executes the service according to the paging message, it further comprises: the UE continues to Listen for paging messages from the system PDCCH. 5. The method for controlling signaling in OFDM technology according to claim 1, wherein the first listening period is the smallest period in the listening periods of all UEs, and the first listening period is greater than or equal to one radio frame time. 6. The signaling control method in OFDM technology according to claim 4, characterized in that, the second listening period is determined by a high-priority user frame.

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