JPH0452016B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a burst voice communication system, and more particularly to a burst voice communication system in which voice messages are communicated using a wireless line in a wireless transmission time shorter than the voice message time length.

The burst voice communication method is well known, in which multiple transmitting and receiving stations that share a wireless line on the same frequency channel communicate each voice message with a compressed band while shifting the communication time zone, that is, using the line in a time-division manner. ing.

According to such a burst voice communication method, the radio line required for communication is only one shared channel, resulting in high frequency utilization efficiency, and band compression transmission can substantially shorten communication time. There are various features such as making the communication time significantly shorter than the eavesdropping time, so-called interception time, and increasing the resistance to eavesdropping.

Voice messages transmitted from multiple transmitting/receiving stations communicating with each other in the burst voice communication system are converted into low-speed digital code strings by voice narrowband encoding processing on the transmitting side and stored in, for example, a semiconductor memory, with preset priority. They are read out at high speed according to their order. Therefore, this readout will be instantaneous or intermittent. The read digital code string is, for example, PAM (Pulse Amplitude).
The common carrier frequency is modulated by a pulse modulation method such as modulation, and the signal is outputted all at once in a time-division manner.

For example, the communication capacity is 16Kbit (kilobits)/
Assuming that a SEC (sec) transmission path is used by 10 transmitting and receiving stations, and a voice message is digitized and compressed at 1.6 Kbit/SEC, these 10
The communication time between each transmitting and receiving station is approximately 0.1 seconds, which is significantly shorter than the interception time, which is usually about 5 to 6 seconds, and the resistance to interception of communications can be significantly strengthened. As mentioned above, effective use of frequencies is a fundamental feature of the burst voice communication system.

However, in this type of conventional burst voice communication system, when two or more multiple subscribers (transmitting/receiving stations) use the same burst voice communication system, the priority order of multiple communications by these multiple subscribers is This operation is carried out manually between subscribers in accordance with preset control details. This method has disadvantages in that a reduction in communication capacity is unavoidable, and this control operation cannot be avoided in that it is unavoidable to be considerably complicated in response to the amount of communication.

In addition, if we try to centralize communication between each transmitting and receiving station and provide a control station to avoid this drawback, not only will the scale of the burst voice communication system become larger, but also communication security due to failure of the control station, human destruction, etc. Problems such as overall vulnerability and loss of confidentiality arise due to local increases in communication volume.

An object of the present invention is to eliminate the above-mentioned drawbacks, and to provide transmission request means that allows a plurality of transmitting/receiving stations constituting a burst voice communication system to automatically select a communication partner and make a call, thereby transmitting data at the same time. A burst voice communication method that can automatically avoid duplication of information and therefore basically prevent a decrease in communication capacity per unit time, and fundamentally eliminate the need for control operations for this purpose. Our goal is to provide the following.

The method of the present invention is a burst voice communication method in which multiple transmitting and receiving stations use the same frequency channel to communicate band-compressed voice messages with arbitrary parties, by dividing the frequency channel into a plurality of subchannels; The transmission request identifying means is configured to identify a predetermined priority order based on a combination of subchannels.

Next, the present invention will be explained in detail with reference to the drawings.
FIG. 1 is a block diagram showing an embodiment of a burst voice communication system according to the present invention.

Transmitting/receiving station (1) 1 to transmitting/receiving station (N) N are N transmitting/receiving stations that constitute the burst voice communication system according to the present invention, and each transmitting/receiving station has the same configuration. For example, transmitting/receiving station (1) 1 includes a transmitter 11, a transmission request signal generation circuit 12, a transmission/reception switch 13, an antenna 14, a transmission request station identification circuit 15, a receiver 16, and the like.

Among the configurations of each of these transmitting/receiving stations, the transmission request signal generation circuit 12 and the transmission requesting station identification circuit 15 are directly related to the present invention, and the others are the general configuration of a transmitting/receiving station in a normal burst voice communication system.

In the burst voice communication system, N transmitting/receiving stations as shown in FIG. 1 use the above-described time division method to occupy a communication line and communicate with other stations using each as a carrier wave.

The transmission request signal generation circuit 12 automatically performs priority order assignment and other controls in the operation of transmitting and receiving stations in the burst voice communication system, in contrast to conventional manual processing, and its operation is performed as follows. Ru.

That is, when the transmitting/receiving station (1) 1 wants to communicate with a desired transmitting/receiving station, the transmitter 11 sends a transmission command signal to the transmission request signal generation circuit 12 via the output line 1101, and outputs the transmission request signal. This signal is transmitted as a transmission request radio wave 1401 from the antenna 14 via the output line 1201 and the transmission/reception switch 13.

The above-mentioned transmission request signal is transmitted automatically after the end of communication if there is communication with any other transmitting/receiving station, or immediately if there is no communication with any other transmitting/receiving station, according to the communication priority order assigned in advance to each transmitting/receiving station. This is a signal requesting transmission from a station, and may be in any format as long as it meets this purpose and does not cause interference when multiple transmission request signals are sent at the same time. There is no problem.

FIG. 2 is a transmission request signal frequency allocation diagram showing the structure of the transmission request signal in the embodiment of FIG.

When each transmitter/receiver station in the embodiment of FIG. 1 wants to transmit, it transmits the identification frequency pair shown in FIG. 2P via the communication line, for example, for about one second.

The identification frequency pair P means a combination of two different frequency assignments for each transmitting/receiving station, and the identification frequency pair of each transmitting/receiving station is given a priority order for use of communication lines in advance. The frequency pair is output as a transmission request signal from each transmitting/receiving station to the communication line via the transmitting/receiving switch 13 and the antenna 14.

In the burst voice communication system, there are cases in which a voice message transmitted by one transmitting/receiving station can be received by all other transmitting/receiving stations, and cases in which only an arbitrary transmitting/receiving station can receive the voice message. In the former case, the identification frequency pair P is the frequency pair of the own station that wishes to transmit. A priority is assigned in advance to this frequency pair of the local station. The identification frequency pair P simply needs to be different for each transmitting/receiving station. For example, if there are 10 transmitting/receiving stations, GRP.1 shown in Fig. 2 is used.
The number of divisions between the frequency of GRP.2 and the frequency of GRP.2 is 3.
~4 is sufficient. In the latter case, the identification frequency pair P
It is necessary to handle the amount of information that allows identification of the own station and the other station at the same time. In this case as well, a priority is given in advance to the identification of the own station. The identification frequency pair P in this case is shown in Fig. 2, assuming that there are 10 transmitting and receiving stations, for example.
It is sufficient for the number of divisions of each of the GRP.1 frequency and GRP.2 frequency to be 9 to 10. It is obvious that the identification of the partner station may be added as a header of the voice message instead of being included in the information on the identification frequency pair P. In this embodiment, the partner station is identified by the header of the voice message. By making a transmission request in the form of an identification frequency pair, each transmission request can be accurately controlled by the function of the transmission request station identification circuit 15, which will be described later, even if it is sent simultaneously with other transmission request signals. The signal is input as a received signal 1402 to the transmission requesting station identification circuit 15 via the antenna 14 and the transmission/reception switch 13.

Under the control of a built-in station identification program, the transmission requesting station identification circuit 15 identifies the address information signal addressed to its own transmitting/receiving station, and then transmits the subsequent received contents to the receiver 16 via the output line 1501. In addition to receiving and processing this, if there is a transmission request signal with a higher priority than the transmission request signal from the own transmitting/receiving station, the own transmitting/receiving station requests transmission until the transmission based on this transmission request signal is completed and a transmission end sign is issued. A transmission request stop command signal is generated via output line 1502 to immediately stop transmitting the signal.

In this way, each transmitting/receiving station has a predetermined priority order and can automatically communicate with the desired transmitting/receiving station in a time-division manner using the same frequency band via transmission request signals with different code contents. It is carried out in a regular manner.

This type of transmission/reception system is based on RADA (Random
It can also be thought of as an application of the Access Discrete Address system to the burst voice communication system.

In the RADA method, a carrier wave with a relatively wide frequency band is divided into a plurality of slightly different frequency domain slots and time domain slots, and a station is selected by an address that is a combination of the slots. In the embodiment, a communication system essentially the same as the RADA system is implemented as a burst voice communication system by using identification frequency pairs assigned priorities as addresses.

In this way, it is possible to realize a burst voice communication system using the RADA system, which allows each transmitter/receiver station to automatically access any other party without causing a decrease in the communication capacity of the communication line.

The present invention provides a random access communication network composed of a plurality of burst voice communication devices that use the same frequency channel, in which after one of the transmitting and receiving stations emits radio waves, the transmitting and receiving station that wishes to send a message makes a transmission request. Both have the basic feature that in this case, when there are multiple transmitting/receiving stations making a transmission request, the transmission request is made via a coded identification frequency pair so that the desired station for communication is automatically selected. , it is possible to realize a transmission request that alleviates the influence of interference that occurs as a result of simultaneous use of the same frequency in wireless communication.

FIG. 3 is a block diagram showing an embodiment of the transmission requesting station identification circuit 15 in the embodiment of FIG.
Output line 13 from the transmitter/receiver switch 13 shown in FIG.
The received signal supplied via 01 is a radio frequency signal, on which are superimposed a transmission request signal emitted from each transmitting/receiving station and burst voice data (including address information, etc., if necessary). The received signal is transmitted to subchannel receivers 3011, 3012,
...301i, 301a, 301b, ...301j and the station identifier 305. Subchannel receivers 3011, 3012,...301i, 301
a, 301b, ... 301j are receivers corresponding to each subchannel obtained by dividing a predetermined frequency channel into a plurality of subchannels, and the receiving frequencies are f ₁ , f ₂ ... f _i , f _a , f in FIG. _b ,...f _j . Now, when a certain transmitting/receiving station transmits the identification frequency pair P, the frequency
The electric fields at f ₂ and f _b become stronger, and the other electric fields become relatively weaker. Therefore, the subchannel receiver 3012
The output levels of and 301b are high, and the other output levels are relatively low. Note that the subchannel receivers 3011...301j convert the received frequencies _f1 ... _fj to arbitrary intermediate frequencies _fIF , and the rectifiers 3021,
3022,...302i, 302a, 302b,...
302j. Rectifier 3021,...302
j rectifies the corresponding intermediate frequency and uses electric field strength determiners 3031, 3032, ... 303i, 303, respectively.
Output to a, 303b, . . . 303j. The electric field strength determiners 3031...303j generate a code "1" when a rectified signal corresponding to a predetermined electric field strength is input, and generate a code "0" in other cases.
Output to 04. The subchannel receiver 3011, rectifier 3021, and electric field strength determiner 3 described above
031 constitutes an electric field strength determination means for _f1 , one of the frequencies of GRP.1. Similarly, the subchannel receiver 301j, the rectifier 302j, and the electric field strength determiner 3
03j constitutes an electric field strength determination means for fj, one of the frequencies of GRP.2. In the determination of "1" and "0", the code "1" is output only when the rectified signal to be determined as "1" is continuously input for a predetermined period of time (for example, 0.2 seconds), and otherwise By outputting "0", malfunctions caused by burst audio data or noise are avoided. When the identification frequency pair P is supplied to the output line 1301 for about 1 second, only the outputs of the field strength determiners 3032 and 303b are "1" for about 0.8 seconds, and all others are "0".
The transmission request identifier 304 has i×j two-input AND
It has a gate function, and each AND gate function is composed of i number of GRP1 frequencies and j number of GRP2 frequencies as shown in Fig. 2. A total of i×j types of combinations are supported. The transmission request discriminator 304 detects the reception of the identified frequency pair P, and when P is a signal, if there is a transmission request signal with a higher priority than the transmission request signal of the own transmitting/receiving station, transmission is performed based on this transmission request signal. A transmission request stop command signal is generated via the output line 1502 so that the sending of the transmission request signal by the transmitting/receiving station is temporarily stopped until the end of the transmission is completed and a transmission end sign is issued.

If two sets of transmitting and receiving stations respectively transmit identification frequency pairs, P and Q, among the field strength determiners 303a...303j corresponding to GRP.2, only one determiner will output "1", and the others will output "1". Outputs “0”. Also, electric field strength determiner 303 compatible with GRP.1
1...303i, two determiners output "1", and the others output "0". Transmission request identifier 30
Reference numeral 4 denotes a pair of identification frequencies, and simultaneous detection of P and Q can be easily performed. The same holds true even if three or more identification frequency pairs are received simultaneously.

The station identifier 305 identifies the address information addressed to its own transmitting and receiving station from among the received signals supplied via the output line 1301 under the control of the built-in station identification program, and then transmits the subsequent received contents to the output line 150.
1 to the receiver 16. Furthermore, after the station identifier 305 similarly identifies the transmission end sign,
A call end message is output to the transmission request identifier 304 via the transmission line 3051.

In the embodiment shown in FIG. 1, it is clear that the transmission request signal generation circuit 12 and the transmission request station identification circuit 15 may be included in the transmitter 11 and receiver 16, respectively. All of these can be easily implemented without detracting from the spirit of the present invention.

As explained above, according to the present invention, in a random access wireless communication network constituted by a plurality of burst voice transmitting/receiving stations that use the same frequency channel, after a certain burst voice transmitting/receiving station finishes transmitting radio waves, the frequency is By dividing the message into multiple subchannels and using a transmission request identification signal defined by a pair of subchannels or three or more subchannels, a station desiring to send a message makes a transmission request. In the case of multiple burst voice transmitting/receiving stations, the burst voice transmitting/receiving station to be transmitted is automatically selected while avoiding the effects of interference.
This has the effect of realizing a burst voice communication system that can automatically process random access operations and significantly improve the reduction in communication capacity of wireless lines.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing one embodiment of the present invention;
FIG. 2 is a transmission request signal frequency allocation diagram showing the configuration of the transmission request signal in the embodiment of FIG. 1, and FIG. 3 is a block diagram showing one embodiment of the transmission request station identification circuit 15. 1,...N...Transmission/reception station (1)...(N), 11...Transmitter, 12...Transmission request signal generation circuit, 13...Transmission/reception switch, 14...Antenna, 15...Transmission request station identification Circuit, 16... Receiver, 3011, 301
2,..., 301i, 301a, 301b,...30
1j...Subchannel receiver, 3021,30
22,...302i, 302a, 302b,...30
2j... Rectifier, 3031, 3032,...303
i, 303a, 303b,...303j...Field strength determiner, 304...Transmission request identifier, 305...
...station identifier.

Claims (1)

[Claims] 1 Multiple transmitting/receiving stations to which priorities have been assigned in advance communicate band-compressed voice messages with arbitrary parties over wireless lines using the same frequency channel, and the wireless transmission time is shorter than the voice message time length. In a certain burst voice communication system, the frequency channel is divided into a plurality of subchannels, and a transmission request identification means is provided for identifying the priority order determined in advance based on the combination of the divided subchannels. Characteristic burst voice communication method.