JPH01173927A - Diversity communication equipment - Google Patents

Abstract

PURPOSE:To secure stable communication even when a wave propagation characteristic is unstable and fluctuates remarkably by comparing the quality of the reception signals of two transmitter/receivers, connecting transmission information to the transmitter part of the transmitter/receiver with superior quality, and setting the transmitter part at a transmittable state. CONSTITUTION:Detecting circuits to detect the quality of the reception signal are included in the transmitter/receivers 101 and 201, respectively. Here, when the quality information of the reception signal appearing on a terminal 107 is higher than that appearing on a terminal 207, by selecting the transmitter/receiver 101 by comparing those quality information at a control circuit 14, a control circuit controls switches 12 and 13, and introduces the transmission information from the terminal 101 to a terminal 104, and also, by controlling the transmitter part of the transmitter/receiver 101 at the transmittable state from a control terminal 100, the above stated transmission information is transmitted at the transmission timing of ping-pong transmission, and also, the reception signal obtained at a terminal 105 is connected to an output terminal 11. Simultaneously, the control circuit 14 controls the transmitter part of the transmitter/receiver 201 via a control terminal 206, and sets it at a transmission prohibiting state. In such a way, the stable communication can be secured.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a diversity communication device for improving the communication quality in wireless communication, and particularly to a communication device for mobile communication that uses the same frequency. The present invention relates to a tie-versity communication device used in a so-called ping-pong communication system, which achieves seemingly simultaneous two-way communication by periodically and alternately transmitting and receiving data.

(Prior Art) Diversity communication methods have been widely used as a method for improving the communication quality of wireless communication. Diversity communication systems set up multiple propagation paths with low correlation to each other, and combine the resulting multiple received signals to ensure stable communication even when propagation conditions change. This is a method of selecting.

Typical methods for setting a plurality of propagation paths with low correlation include space diversity, in which a plurality of transmitting and receiving antennas are set apart from each other, and frequency diversity, in which a plurality of communication channels with different radio frequencies are set. However, since the latter requires a wide frequency band, it is rarely used except in special cases. The former space diversity includes a method of using a plurality of receiving antennas, a method of using a plurality of transmitting antennas, and a method of using a plurality of both transmitting and receiving antennas. Of these, naturally, the greater the number of antennas, the better the communication quality is expected to be.

(Problems to be Solved by the Invention) However, what is widely used for -m is reception diversity in which a plurality of reception antennas are used.

The reason for this is that with receive diversity, the receiving side can combine and select received signals while checking the quality of the received signals, whereas with transmit diversity, the quality of the received signals is generally not known on the transmitting side. Because there is no antenna, it is not possible to switch the transmitting antenna, and even if it is to be combined, the phase of the transmission must be controlled so that the radio waves emitted from multiple antennas are combined in the same phase on the receiving side, which is extremely difficult. Due to difficulties. However, the requirement for transmit diversity is significant. For example, in the case of communication between a large base station and a mobile slave station, the base station can have multiple antennas installed, but the antennas on the mobile slave station It is difficult to install multiple antennas due to space limitations. Therefore, it would be advantageous if communication quality from the slave station to the base station can be obtained using receive diversity, while communication quality from the base station to the slave station can be balanced using transmit diversity. .

An object of the present invention is to provide a diversity communication device that solves the above problems and realizes transmission space diversity.

(Means for Solving the Problems) The present invention provides means for solving the above-mentioned problems by periodically and alternately performing transmission and reception between wireless stations using the same frequency. , in a ping-pong communication system that realizes two-way communication, the diversity communication device that performs transmission and reception includes a first transceiver connected to a first antenna, and a second transmitter/receiver connected to a second antenna. a transmitter/receiver, a first switch that selects either the output of the first transmitter/receiver or the second transmitter/receiver and takes it out as a received output; The receiver section of the first and second transceivers each includes a detection circuit for detecting the quality of the received signal, and Each of the transmitter sections of the second transceiver has a function of intermittent transmission output, and the control circuit compares the received signal quality detected by both the detection circuits, and based on this comparison, the first A switch is controlled to select the reception output of the transceiver showing good reception quality, and a second switch is controlled based on the comparison to select the reception output of the transceiver showing good reception quality. It is characterized in that transmission information is connected to the transmitter section, and the transmitter section is put into a transmittable state.

(Example) Next, the present invention will be explained with reference to the drawings.

Fig. 2 is a system configuration diagram showing the operation of the ping-pong communication method, and Fig. 3 is a time chart showing the operation of the ping-pong communication method. 3.4 is used to perform two-way communication. At this time, in the ping-pong communication method, transmitter/receiver 1
Communication from transmitter/receiver 2 to 1 is also the same as vice versa.
2 also uses radio waves with the same carrier frequency f, and can share one antenna for transmission and reception.

This ping-pong communication method will be explained using FIG. means that it is in the receiving state. Sending/receiving t
The information from ill to 2 is DI of code 6, D2. It is transmitted intermittently like D3 and is received by the transmitter/receiver fi2 which is in the receiving state at that timing. Conversely, information from the transceiver 2 to the transmitter/receiver 1 is transmitted through Ul, U2 . It is transmitted intermittently like U3 and received by the transceiver 1. As is clear from this figure, each transmitter/receiver does not transmit and receive at the same time, so one antenna can be shared. Also, since both opposing receivers transmit alternately, the same carrier frequency can be used for bidirectional communication. In addition, when the transmitted information is a continuous signal such as voice, the transmitted information is written to the buffer memory once, and when read from there, it is read out intermittently at twice the writing speed, so that the information can be overwritten. It can be transmitted without any shortage. On the receiving side, the transmitted information can be continuously reproduced by writing intermittently into the buffer memory at the receiving speed and reading from it continuously at half the writing speed.

The above is the operation of the ping-pong communication system, but what is important for this invention is that, as explained earlier, the same antenna can be used for transmission and reception, and the same carrier frequency can be used for bidirectional transmission. be. This is because the propagation characteristics of radio waves from transmitter/receiver R1 to R2 and the propagation characteristics in the opposite direction match due to their principle of reversibility, and the propagation characteristics in the reverse direction can be estimated from the propagation characteristics in one direction. This is because it can be done.

Next, the present invention will be explained with reference to FIG.

FIG. 1 is a block diagram showing an embodiment of the present invention, and reference numerals 101 and 201 are first and second transceivers, respectively, which perform ping-pong transmission and reception. It is connected to the first antenna 103 and the second antenna 203.

The antennas 103 and 203 are installed at different positions to perform space diversity transmission and reception. Further, a terminal 10 is an input terminal for transmission information, 11 is a reception output terminal, a switch 13 is a first switch, a switch 12 is a second switch, and 14 is a control circuit. The transmitter/receiver 1fi101, 201 each includes a detection circuit for detecting the quality of the received signal, and the terminals 107, 207 are output terminals for the detection results, respectively.

Further, the transmitter/receiver fi 101 and 201 each have a function of intermittent transmission output in the transmitter section, and terminals 106 and 206
is a control terminal to which a signal for controlling the transmission function of each transceiver is input. Terminals 104 and 204 are transmission information input terminals of the transceivers 101 and 201, respectively, and terminals 105 and 205 are transmission information input terminals of the transceivers 101 and 201, respectively.
This is the received signal output terminal.

Now, the radio waves arriving at antenna 103 are transmitted to antenna 203.
If the radio wave is stronger than that arriving at terminal 10,
7 indicates that the quality information of the received signal appearing at terminal 207 is of higher quality than the quality information appearing at terminal 207.

When this quality information is compared in the control circuit 14 and the transmitter/receiver 101 is selected, the control circuit controls the switches 12 and 13 to guide the transmission information from the terminal 10 to the terminal 104.
In addition, the control terminal 106 controls the transmitter unit of the transceiver 101 to be in a transmittable state to transmit the previous transmission information at the transmission timing of the ping-pong transmission, and the terminal 105
Output the received signal obtained to '! a: -'7' 11
'\Connecting. At the same time, the control circuit 14 controls the transmitter section of the transceiver 201 through the control terminal i' 206 to prohibit transmission.

Conversely, whether the radio waves arriving at the antenna 203 or the antenna 103
, the control circuit 14 causes the switch 12.13 to select the transmitting/receiving 111201, so that the transmitting/receiving U, ! The transmitter unit 201 is controlled to be in a transmittable state, and the transmitter unit of the transceiver 101 is set to be in a transmitting prohibited state. Based on the principle mentioned above, when transmitting is performed by selecting the antenna with the better reception tS condition, compared to the case where the antenna for the song is selected at the antenna position on the side of the muntin in the 1st pass. Good reception 1, ν property or transmission fλ
Space diversity can be achieved.

Although not specifically shown in the description of the above embodiments, selection of the reception output by a switch can be performed on the output side of the intermediate frequency amplification stage, or can be performed on the demodulation output of the subsequent stage. Further, as a method for detecting received signal quality, widely used methods such as a method of detecting received signal strength, a method of measuring out-of-baseband noise of demodulated output, etc. can be used.

(Effects of the Invention) As explained above, according to the present invention, space diversity in transmission and reception can be realized, and stable communication can be ensured, especially when radio wave propagation characteristics are unstable and fluctuate rapidly, such as in mobile communication. It is possible to obtain a communication device that can perform

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention, FIG. 2 is a configuration diagram explaining the operation of the ping-pong communication system, and FIG.
The figure is also a time chart explaining the operation of the ping-pong communication system. In the figure, 101 and 201 are transceivers, 103 and 20
3 is an antenna, 14 is a control circuit, 10 is an input terminal for transmission information, 11 is a reception output terminal, and 12 and 13 are switches.

Claims (1)

[Claims] A diversity communication device that performs the transmission and reception in a ping-pong communication system that realizes two-way communication by periodically and alternately performing transmission and reception using the same frequency between radio stations. a first transceiver connected to the first antenna, a second transceiver connected to the second antenna, and outputs of either the first transceiver or the second transceiver. It consists of a first switch that selects and takes out the received output, a second switch that distributes the transmitted information to either the first transmitter/receiver or the second transmitter/receiver, and a control circuit. Each of the receiver sections of the transceiver includes a detection circuit for detecting the quality of a received signal, and the transmitter sections of the first and second transceivers each have a function of intermittent transmission output, and the control circuit includes: The received signal quality detected by both detection circuits is compared, and based on this comparison, the first switch is controlled to select the receiving output of the transmitter/receiver that shows good reception quality, and the comparison is performed. The second switch is controlled based on the second switch to connect transmission information to the transmitter section of the transceiver that exhibits good reception quality, and to put this transmitter section into a transmittable state. Diversity communication device.