JPH0732385B2 - Wireless communication system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Outline] In a wireless communication system requiring microwaves and millimeter waves indoors or the like, a plurality of antennas are connected to a node transmitter / receiver in a loop so as to connect with a terminal transmitter / receiver. To communicate with a burst signal, and to process the burst signal with the best received signal quality among multiple burst signals of the same content, and to obtain good communication quality even in an environment where the radio wave propagation condition is poor. This ensures the reliability and improves the reliability of the antenna system.

[Industrial application field]

The present invention relates to a wireless communication system for performing communication between terminal devices or between a terminal device and a center.

Between terminal equipment such as data terminal equipment and videophone terminal equipment,
Alternatively, in a system that communicates with a center equipped with a host computer or the like, a wireless system has been developed in which terminal devices can be easily arranged and moved. For example,
A communication method using infrared rays, a communication method using microwaves, and the like are known. When infrared rays are used, the communication distance cannot be lengthened as compared with the case where microwaves are used. Further, in a wireless communication system using radio waves such as microwaves, the reception level fluctuates greatly due to multiple reflections of radio waves indoors.

[Conventional technology]

In wireless communication systems indoors such as in offices, an antenna is installed on the ceiling to connect with the node transceiver, and a terminal transceiver equipped with a small antenna is placed on a desk or the like to provide the node transceiver. And the terminal transceiver device, for example, wireless communication is performed in a frequency band of about 50 GHz. In that case, if the terminal device including the terminal transceiver is equipped with a power source, it becomes a complete mobile terminal device. Also, if one antenna installed on the ceiling cannot cover the interior of the room, a plurality of antennas will be distributed.

[Problems to be solved by the invention]

Since microwaves and millimeter waves are used for indoor wireless communication, the reception level of the antenna becomes unstable due to the effects of multiple reflections of indoor radio waves and movement of people. Therefore, since high-speed data communication causes many errors, only relatively low-speed data communication is performed. Further, in the conventional example in which a plurality of antennas are arranged, the service area is simply shared by the respective antennas, and the data of the same contents are simultaneously transmitted from all the antennas.

The present invention, a plurality of antennas are distributed and connected in a loop, and by using each antenna in a time-division manner, the received burst signal with the best received signal quality is received and processed,
The purpose is to improve communication quality and reliability of the antenna system.

[Means for solving problems]

In the wireless communication system of the present invention, a plurality of antennas are distributed and connected in a loop, and each antenna is used in a time division manner. Are distributed on the ceiling or the like, are connected to the node transmission / reception device 1 in a loop, and the terminal transmission / reception device 3 having the antenna 4 is disposed on a desk or the like to perform communication by burst signals, and each antenna 2 is time-divisionally Use it to send burst signals of the same content so that they do not overlap in time,
In the terminal transmission / reception device 3, each antenna 2 is arranged on the time axis.
The burst signals from are received as arranged,
Further, burst signals from the terminal transmitting / receiving device 3 are simultaneously received by the respective antennas 2 and are sent to the node transmitting / receiving device 1.
Received burst signals of each antenna 2 are arranged and added on the time axis.

Since the node transmitter / receiver 1 and the terminal transmitter / receiver 3 repeatedly receive burst signals having the same content, the reception level of each burst signal is detected and the burst signal with the best received signal quality is detected. It is processed as a received signal.

[Action]

In the node transmission / reception device 1 and the terminal transmission / reception device 3, a plurality of burst signals having the same content are arranged and received on the time axis, and the reception burst signal of the maximum reception level is processed as a reception signal. It is possible to receive and process the burst signal in the optimum receiving state. Further, by connecting the antenna 2 in a loop, it is possible to switch the transmission / reception direction of the burst signal, so that it is possible to easily cope with a failure.

〔Example〕

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In this embodiment, a case will be described in which the quality of the received signal is judged at the incoming call level.

FIG. 2 is a block diagram of the first embodiment of the present invention.
Is a node transceiver, 11 is a transmitter, 12 is a receiver, 13 and 14
Is a changeover switch circuit (SW), 15-1 to 15-n are antennas, 16-1 to 16-n, 17-1 to 17-n are hybrid circuits, 18-1 to 18- (n-1), 19 -1 to 19- (n-1)
Is a delay circuit having a delay time of 1 burst length, 20-1 to
20-n is a circulator, 21 is a terminal transceiver,
22 is an antenna.

Changeover switch circuits 13 and 14 are hybrid circuits 16-1 and 17-
When the burst signal is transmitted from the transmission unit 11 after switching to the 1 side, the hybrid circuit 16-1 causes the circulator 20-1.
Is added to the antenna 15-1 via the antenna and the burst signal is transmitted at the frequency f ₁ . The burst signal delayed by one burst length by the delay circuit 18-1 is transmitted from the hybrid circuit 16-2 to the antenna 15 via the circulator 20-2.
-2, and is transmitted as the second burst signal at the frequency f ₁ . Similarly, after a delay time of n burst lengths from the antenna 15-n, a burst signal is transmitted at the frequency f ₁ and one frame ends.

In the terminal transmission / reception device 21, the antennas 15-1 to 15-n
Since the burst signal from is received in a state of being arranged on the time axis, the reception burst signal of the maximum reception level is selected and reception processing is performed.

Further, the burst signal of frequency f ₂ transmitted from the antenna 22 of the terminal transmitting / receiving device 21 is transmitted to each antenna 15-1 to 15-n.
Received by. The burst signal received by the antenna 15-1 is transmitted from the circulator 20-1 to the hybrid circuit.
It is added to the receiving unit 12 via 17-1.

The burst signal received by the antenna 15-2 passes from the circulator 20-2 through the hybrid circuit 17-2, is delayed by a delay circuit 19-1 for one burst length, and passes through the hybrid circuit 17-1 to the receiving section. Added to 12. Similarly, the burst signal received by the antenna 15-n is added to the receiving unit 12 via the (n-1) delay circuits. Therefore, the receiving unit 12 has antennas 15-1 to 15-
The burst signal received at n is arranged and added on the time axis, and the reception burst signal of the maximum reception level is selected and reception processing is performed.

The changeover switch circuits 13 and 14 are connected to the hybrid circuit 16 respectively.
When switched to the −n, 17-n side, the order of transmitting and receiving the burst signal with respect to the order of the antennas 15-1 to 15-n is opposite to the above case. Therefore, when a failure such as disconnection occurs in the delay circuit or hybrid circuit in the middle of the loop, by switching the changeover switch circuits 13 and 14,
The antenna can be used through a healthy circuit that exists on both sides of the obstacle.

FIG. 3 is a diagram for explaining the operation, and (a) shows a burst signal from the transmitter 11, which is sent out in one frame period. This burst signal is transmitted from the antenna 15-1 as shown in (b), and is transmitted from the antenna 15-2 by the delay circuit 18-1 after a delay time of τ1 as shown in (c). Further, as shown in (d), the signal is transmitted from the antenna 15-n after a delay time of τ (n-1) by (n-1) delay circuits. Therefore, the burst signals from the antennas 15-1 to 15-n are arranged on the time axis. Then, as shown in (e), the terminal transmission / reception device 21 receives the burst signals at different reception levels, and the burst signal having the maximum reception level is selected for each frame for reception processing.

The burst signal from the terminal transceiver 21 is transmitted from the antenna 22 at the frequency f ₂ and the antennas 15-1 to 15-
n are received almost at the same time. The burst signal received by the antenna 15-1 is applied to the receiving unit 12 via the circulator 20-1 and the hybrid circuit 17-1,
The burst signal received at 15-2 is transmitted to the circulator 20.
-2, the hybrid circuit 17-2, the delay circuit 19-1, and the hybrid circuit 17-1 are applied to the receiving unit 12, so that the first receiving burst signal is delayed by one burst length and then added to the receiving unit 12. become. And so on
The burst signal received by the antenna 15-n is added to the receiving unit 12 in the last arranged state on the time axis.

In the receiving unit 12, the burst signals of the same content arranged on the time axis have various reception levels within one frame as in (e), and the burst signal of the maximum reception level is selected and reception processing is performed. is there.

FIG. 4 is a block diagram of the transmitting unit. 23 is a multiplexing unit for multiplexing data, 24 is a speed converting unit, 25 is a modulating unit, 26 is an amplifying unit, and 27 is a switch unit for transmitting as a burst signal. , 28 are timing generators that generate various timing signals according to a clock. The multiplexing unit 23 multiplexes the data according to the clock, the speed conversion unit 24 performs speed conversion of the multiplexed data according to the timing signal from the timing generation unit 28, and adds the multiplexed data to the modulation unit 25. The data modulated by the modulation unit 25 is amplified by the amplification unit 26 and is sent out as a burst signal from the switch unit 27 controlled by the timing signal from the timing generation unit 28, as shown in FIG. It

FIG. 5 is a block diagram of the receiving unit. 29 is a band pass filter for removing unnecessary bands, 30 is a high frequency amplifying unit, 31 is a demodulating unit, 32 is a data reproducing unit, 33 is a level detecting unit, and 34 is timing. The generating unit, 35 is a memory, and 36 is a demultiplexing unit.

The received burst signal is applied to the high frequency amplification unit 30 via the band pass filter 29, the amplified output is applied to the demodulation unit 31 and demodulated, and the demodulation output is applied to the data reproduction unit 32 to reproduce the data by level identification. The reproduced and reproduced data is sequentially written in the memory 35 in response to the address signal from the timing generator 34.

The level detection unit 33 detects the level of the received burst signal by using the clock and the frame pulse. Since the reception level of the burst signal by each antenna is different, the maximum reception level within one frame is identified. , Information indicating the received burst signal having the maximum reception level is added to the timing generation unit 34. The timing generator 34
The read address signal of the memory 35 is formed according to the information, and only the reproduced data of the burst signal of the maximum reception level in one frame is read out from the memory 35 and is added to the demultiplexing unit 36 so that each data is reproduced. Is separated into

The transmitter / receiver in the terminal transceiver is also the fourth.
The structure is almost the same as the structure shown in FIGS.

If multiple terminal transceivers are installed,
It is possible to employ various communication methods that do not cause a transmission / reception collision. Further, instead of transmitting / receiving using the frequencies f ₁ and f ₂ , it is also possible to transmit / receive using vertical polarization and horizontal polarization.

FIG. 6 is a block diagram of the second embodiment of the present invention, in which circulators 41-1 to 41- are provided between the transmission unit 11 and the reception unit 12.
n are cascaded, and the antennas 42-1 to 42-n are connected to the circulators 41-1 to 41-n, respectively. Therefore, the antenna is connected to the node transmitting / receiving device 10 in a loop. Further, switch circuits 43-1 to 43-n are provided in the respective antennas 42-1 to 42-n. Antenna 42-
1 to 42-n are controlled by the switch circuits 43-1 to 43-n so as to be used in a time division manner,
A configuration using a diode such as a PIN diode or a Schottky diode as a switch element can be adopted, and is controlled by a control unit (not shown).

In this embodiment, burst signals of the same content are repeatedly transmitted from the transmitter 11 and a terminal transmitter / receiver (not shown). For example, the switch circuit 43-1 is turned off and the other switch circuits 43-2 are used. When 43 to 43-n are turned on, the burst signal from the transmitter 11 is transmitted to the circulator 41-
It is added to the antenna 42-1 via 1 and transmitted. The burst signal received by the antenna 42-1 is added to the receiving unit 12 via the circulators 43-1 to 43-n.

Next, the switch circuit 43-1 is turned on, and the switch circuit 43-
When only 2 is turned off, the burst signal from the transmitter 11 passes through the circulators 41-1 and 41-2 to the antenna 42-
2 is added and sent. The burst signal received by the antenna 42-2 is circulators 41-2 to 41-
It is added to the receiving unit 2 via n.

If only the switch circuit 43-n is turned off in the same manner, the burst signal from the transmission unit 11 will be transmitted to the circulator 41.
The burst signal which is added to the antenna 42-n via -1 to 41-n and is transmitted and received by the antenna 42-n is added to the receiving unit 12 via the circulator 41-n.

FIG. 7 is an explanatory view of the third embodiment of the present invention, which is 45,46.
Is a circulator, 47-1,47-2, ..., 48-1,48-2,
... is a hybrid circuit (H), 49-1, ..., 50-
1, ... are delay circuits (τ), 51-1, 51-2, ..., 52−
1, 52-2, ... Are antennas, and 53, 54 are non-reflective terminators.

When the changeover switch circuits 13 and 14 are in the illustrated state, the transmitter 11
The burst signal from the hybrid circuit 47-1 is applied to the hybrid circuit 47-1 via the circulator 45.
1 is added to the antenna 51-1 and transmitted. The burst signal delayed by one burst length by the delay circuit 49-1 is added to the antenna 51-2 via the hybrid circuit 47-2 and sent out.

The burst signal received by the antenna 52-1 is applied to the receiving unit 12 via the circulator 46, and the antenna 52-1
-2, the burst signal received by the hybrid circuit 48
-2 from the hybrid circuit 48-1 to the circulator 46-1.
Is added to the receiving unit 12 via.

Therefore, burst signals of the same content are sequentially transmitted from the antennas 51-1, 51-2, ..., Also, the antennas 52-1, 52-2 ,.
The burst signal received at .. is added to the receiving unit 12 while being arranged on the time axis.

When the changeover switch circuits 13 and 14 are changed, the transmitter 1
The burst signal from 1 is applied to the hybrid circuit 48-1 via the circulator 46, and the burst signal is transmitted first from the antenna 52-1 and after one burst length time, the burst signal is transmitted from the antenna 52-2. To be done. The burst signal received by the antenna 51-1 is added to the receiving unit 12 via the circulator 45, and the antenna 51-2
The burst signal received at 1 is added to the receiving unit 12 after the time of one burst length.

Therefore, since the antenna system is duplicated, even if a failure occurs in one of the antenna systems, the system does not go down. Further, in this embodiment, since transmission and reception are performed by using different antenna systems, it is possible to reduce transmission and reception interference.

FIG. 8 is a block diagram of a fourth embodiment of the present invention. Instead of the hybrid circuit of the embodiment shown in FIG. 7, directional couplers 55-1, 55-2, ..., 56- , 56-2, ... are used, and the same reference numerals as those in FIG. 7 denote the same parts. The operation is almost the same as that of the embodiment shown in FIG. Also, the directional couplers 55-1, 55-2, ..., 56-1, 5 in the embodiment
It is desirable that the coupling degree of 6-2, ... Is set to be smaller as the connection order from the node transmitting / receiving apparatus 10 is closer.

FIG. 9 is a block diagram of a fifth embodiment of the present invention, in which the same reference numerals as those in FIGS. 7 and 8 indicate the same portions, and 57-1,57.
-2, ..., 58-1,58-2, ... is a circulator, 59
-1,59-2, ..., 60-1,60-2, ... are switch circuits, and 61,62 are short-circuit parts that short-circuit one terminal of the circulator. When the changeover switch circuits 13 and 14 are switched to the illustrated state, the burst signal from the transmitter 11 is transmitted from the circulator 45 to the circulators 57-1 and 57 corresponding to the respective antennas.
-2, ..., is reflected by the short-circuit portion 61, and propagates again to the circulators 57-1, 57-2 ,. Therefore, the switch circuits 51-1, 52
When −2, ... Is selected and turned off, the burst signal is transmitted from the antenna corresponding to the switched circuit that is turned off.

Also, although the burst signals are simultaneously received by the antennas 52-1, 52-2, ..., The switch circuits 60-1, 60-2 ,.
By turning off only one of the above and turning on the other, the burst signal received by the antenna corresponding to the switch circuit which is turned off is added to the receiving unit 12 via the circulator 46.

FIG. 10 is a block diagram of a sixth embodiment of the present invention, in which circulators 63-1 to 63 corresponding to antennas 64-1 to 64-n are provided.
-N is connected in a loop between the circulators 45 and 46 of the node transmitting / receiving device 10, and switch circuits 65-1 to 65-n are provided in the antennas 64-1 to 64-n. The circulators 63-1 to 63-n are set so that the propagation directions are alternately opposite to each other. For example, when the changeover switch circuits 13 and 14 are switched to the illustrated state, the antennas located at odd numbers from the circulator 45 Can be used in a time-division manner, and if the changeover switch circuits 13 and 14 are switched to the opposite side to the state shown in the figure, the even numbered antennas from the circulator 45 can be used in a time-division manner.

Therefore, the antenna system of the embodiment shown in FIG. 6 has a functionally dual structure by switching between transmission and reception.

FIG. 11 is a block diagram of the seventh embodiment of the present invention, and shows a case where the antenna system for transmission and the antenna system for reception are provided as separate loops. The directional couplers 66-1 to 66-n and the delay circuits 68-1 to 68-n are connected to the changeover switch circuit 13 in a loop shape, and the directional coupler 67-1 is connected to the changeover switch 14 in a loop shape.
To 67-n and delay circuits 69-1 to 69-n are connected, and antennas 70- are connected to the directional couplers 66-1 to 66-n and 67-1 to 67-n.
1 to 70n and 71-1 to 71-n are connected.

The delay circuits 68-1 to 68-n and 69-1 to 69-n are respectively 1 /
A directional coupler 66-1 having a delay time of 2 burst lengths
.About.66-n and 67-1 to 67-n are such that the bonding directions are alternately opposite. Therefore, the changeover switch circuit 1 is changed to the illustrated state.
When 3 and 14 are switched, the burst signal from the transmission unit 11 is sequentially transmitted from the odd-numbered antennas, and two delay circuits are connected between the odd-numbered antennas. A burst signal that is sequentially delayed by one burst length is transmitted. Also, antennas 67-1 to 67-n
The signals received at odd numbers of 1 are sequentially delayed by one burst length and added to the receiving unit 12. When the changeover switch circuits 13 and 14 are switched to the opposite side to the state shown in the drawing, the coupling directions of the directional couplers 66-1 to 66-n and 67-1 to 67-n are alternately opposite. The antenna is used, and burst signals are transmitted and received.

FIGS. 12 and 13 are explanatory views of the antenna connection, and FIG. 12 shows a case where the antennas 72 are connected to different loops and distributed, and for example, the changeover switch circuits 13 and 14 (see FIG. 7,
(See FIG. 8), it is possible to switch between upper and lower transmission and reception. Further, FIG. 13 shows the case where the antenna 73 is connected to the loops arranged in parallel, and the antennas connected to one loop and the other loop can be arranged alternately.

〔The invention's effect〕

As described above, according to the present invention, the node transmitter / receiver 1 and the terminal transmitter / receiver 3 communicate with each other by a burst signal, and the node transmitter / receiver 1 has a plurality of antennas 2.
Are connected in a loop and distributed, and a switch circuit or a delay circuit is connected to each antenna 2 so that each antenna 2 is used in a time division manner, and a burst signal from the node transmitter / receiver 1 is transmitted from each antenna 2 from each antenna 2. The terminal transmission / reception device 3 transmits the burst signals having the best quality among the received burst signals having the same content, for example, the burst signal having the minimum interference and the maximum reception level. Therefore, even in an environment where the propagation characteristics of radio waves are unstable, such as indoors, it is possible to perform data communication with few errors. Further, by connecting in a loop, even if a failure occurs on the way, it becomes easy to switch the transmission / reception direction of the burst signal, and the communication can be continued without the system going down. If the antenna system is functionally or physically duplicated,
The reliability can be further improved.

[Brief description of drawings]

FIG. 1 is an explanatory view of the principle of the present invention, FIG. 2 is a block diagram of the first embodiment of the present invention, FIG. 3 is an operation explanatory view of the first embodiment of the present invention, and FIG. FIG. 5, FIG. 5 is a block diagram of the receiver, FIGS. 6 to 11 are block diagrams of the second to seventh embodiments of the present invention, and FIGS. 12 and 13 are antenna connection explanatory diagrams. Is. 1 is a node transceiver, 2 is an antenna, 3 is a terminal transceiver, 4 is an antenna, 10 is a node transceiver, 11
Is a transmitter, 12 is a receiver, 13 and 14 are changeover switch circuits, 15
-1 to 15-n are antennas, 16-1 to 16-n, 17-1 to 17-
n is a hybrid circuit (H), 18-1 to 18- (n-
1), 19-1 to 18- (n-1) are delay circuits (τ), 20-
1 to 20-n are circulators, 21 is a terminal transmitting / receiving device, and 22 is an antenna.

 ─────────────────────────────────────────────────── ─── Continuation of front page (56) Reference JP-A-53-120211 (JP, A) JP-A-55-77247 (JP, A) JP-A-60-21652 (JP, A)

Claims (1)

[Claims] 1. A node transceiver (1), a plurality of antennas (2) connected to the node transceiver (1) and distributed, and an arbitrary number of terminal transceivers (3).
And the antenna (4) of the terminal transceiver (3), the plurality of distributed antennas (2) are connected to the node transceiver (1) in a loop, and the node transceiver (1) ) From the node transmitter / receiver (3), the burst signal from the node transmitter / receiver (1) is sequentially added to the plurality of antennas (2) connected in a loop, The plurality of antennas (2) are transmitted from each antenna (2) so that they do not overlap in time due to time-divisional use, and the terminal transmitting / receiving device (3) outputs the received burst signals of the same content with the highest quality. When the best burst signal is selectively processed and the burst signal is sent from the terminal transceiver (3) to the node transceiver (1), the terminal transceiver ( ) Is received by the node transmission / reception device (1) so as not to overlap in time by the time divisional use of the plurality of antennas (2), and the burst signal of the same content has the best quality. A wireless communication method characterized by selective processing of burst signals.