JPS5846094B2 - Meeting line configuration method for time division multiplexing phase modulation multidirectional wireless communication system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a configuration method for organizing meetings in a multidirectional wireless communication system using time division multiplex phase modulation. When connecting via a line, communication between each station is performed using a pair of transmitting and receiving radio waves, so in order to use radio waves efficiently, a multidirectional multiplex wireless communication system using radio waves in the ultra-high frequency band is applied. .

In addition, in terms of communication content, in addition to telephone transmission, applications such as data transmission have recently increased, and this trend will continue to increase in the future. As such, time division multiplexing using pulse code modulation is more suitable than frequency division multiplexing.

Therefore, it is necessary to adopt a time division multiplexing method in a multidirectional multiplex wireless communication system, and in this case,
It goes without saying that time division multiplexing is used to transmit signals from the master station to each slave station, but frequency division multiplexing and time division multiplexing are also used to transmit signals from each slave station to the master station. Either of these is possible.

However, the time division multiplexing method is advantageous because the configuration of the master station is simple, and it is considered effective to use the time division multiplexing method for signal transmission from each slave station to the master station. There is.

Among them, PSK modulation (Phase 5hi
ft Keing) system is generally used, and when this system is used, the following can be considered as a system for setting up a dedicated line for meetings in addition to communication paths such as telephone lines and data transmission lines.

(1) A method in which the meeting line signal is made into pulses, and the communication line signal is then inserted into the pulse train.

(2) For the carrier wave phase modulated by the channel signal,
A method that performs frequency modulation using a modulation depth within a range that does not cause errors in demodulating the channel signal.

However, all of these are unfavorable for the following reasons.

FIG. 1 is a time sequence diagram showing the configuration of time slots applied to a time division multiplexing phase modulation multidirectional wireless communication system. Signal transmission from a master station to each slave station is performed by time slot groups TS1 to TSn of multiple bits. This frame is repeated, and each time slot group TS□~TSn corresponds to each slave station 1~n, and the pulses inserted into each time slot group TS, ~TSn. A communication path signal is transmitted from the master station to each of the slave stations 1 to n by the signal.

In addition, time slot groups ts1 to ts are allocated to each of the slave stations 1 to n for signal transmission from each of the slave stations 1 to n to the master station, and the pulse signals inserted into these groups allow Communication path signals are transmitted from each slave station 1 to n to the master station.

a., time slot groups TS1 to TSn and tsl
The period of the time slots constituting ~tsn varies depending on the number of communication paths, but in the case of voice communication signals, the sampling interval during pulse modulation is 125μ8ee, so
125 μsec or an integral multiple thereof is appropriate.

According to the line configuration shown in FIG.

That is, although the master station is always transmitting, the transmission from the slave station to the master station is intermittent transmission according to the timing assigned to itself, and the above-mentioned method 2 cannot be used.

Also, if 1 above is applied, the bit rate of pulse modulation is set to 64 Kbit, for example, in order to interrupt the time slot for the meeting line into the time slot groups TS1 to TSnb and ts1 to tsn between the master station and the slave station. In this case, in the system shown in Figure 1, the pulse period of time slot groups ts1 to tsn becomes higher by nx 64Kbit (n is the number of slave stations), and the occupied frequency band when modulating the carrier wave is expanded, making effective use of radio waves. This results in disadvantages that are not favorable from the perspective of the user.

The present invention has the purpose of fundamentally eliminating such drawbacks,
In the multi-directional wireless communication system described above, a time slot for transmitting a meeting line pulse and a time slot for transmitting a meeting control pulse are provided in the signal transmission frame from the master station to each slave station. A characteristic feature is that a time slot for a meeting line common to each slave station is provided in the signal transmission frame from the slave station to the master station, and a pulse for meeting control is provided in a group of time slots assigned to each slave station. The present invention provides a meeting line configuration method for a time-division multiplexing phase modulation multidirectional wireless communication system.

Hereinafter, the present invention will be explained in detail with reference to FIG. 2 and subsequent figures showing embodiments.

The second transmission is a block diagram showing the configuration of the master station, in which a pulse train obtained by pulsing the communication line signal from the communication line input 1 is given to the multiplexer 2, and the audio signal of the meeting line 3 is pulsed by the pulse modem 4. The pulse train from the communication path input 1 and the pulse signal from the pulse modulator/demodulator 4 are combined by the multiplexer 2.

On the other hand, a radio frequency carrier wave is generated by a carrier wave generator 5, which is passed through a pulse phase modulator 6 to undergo pulse phase modulation using the output of the multiplexer 2, and then amplified by a transmission amplifier 7, which is then used as a shared antenna. The signal is sent to the antenna 9 via the receiver 8, and is thereby transmitted to each slave station.

In addition, the radio waves from each slave station are captured by the antenna 9, enter the frequency converter 10 via the antenna duplexer 8, are frequency-converted by the oscillation frequency of the local oscillator 11, become an intermediate frequency, and then It passes through the frequency amplifier 12 to the phase demodulator 13, where it is demodulated into a pulse signal, and after being distributed by the demultiplexer 14 into the communication line output 15 and the meeting line output, the meeting line output is sent to the pulse modulator/demodulator 4. After further demodulation into an audio signal at
It is sent to meeting line 3.

When the meeting line 3 is in operation, the switch 16 is turned on, which causes the control circuit 17 to operate and send a meeting control signal to the multiplexer 2. The operation of the multiplexer 2, demultiplexer 14, pulse modulator/demodulator 4 buttons, and control circuit 17 is regulated based on clock pulses from the pulse generator 18.

FIG. 3 is a block diagram showing the configuration of a slave station, which is the same as FIG. 2 except that a switch circuit 19 is inserted. In order to perform transmission only at the timing corresponding to the assigned one, the switch circuit 19 performs on/off operations based on the clock pulse from the pulse generator 18.

FIG. 4 is a time sequence diagram showing the configuration of time slots used for signal transmission between the button in FIG. 2 and the master station and slave stations in FIG. A time slot D for meeting control and a time slot E for meeting line are provided in one frame consisting of slot groups A1 to An. The meeting control time slot D is composed of n bits corresponding to the number of slave stations 1 to n.

In addition, for signal transmission from each slave station 1 to n to the master station, in one frame composed of a time slot group B8 to Bn consisting of a plurality of time slots allocated to each slave station 1 to n, A time slot F for a meeting line common to each slave station 1 to n is provided, and corresponds to a time slot E for a meeting line in the frame from the master station. The meeting control pulses C1 to Cn each have 1 bit each.

Therefore, in signal transmission from the master station to each slave station 1 to n (downward direction), the time slot group A□ to An transmits the communication path signal, and the meeting line time slot group E transmits the meeting audio signal of the meeting line 3. 9 meeting control time slots) D are transmitted, each slave station
Any one of them can be called for a meeting call.

In signal transmission from each slave station 1 to n to the master station (hereinafter referred to as upstream direction), the time slot group B1 to Bn transmits a communication path signal, and the meeting line time slot F transmits a meeting audio signal. The meeting control pulses C1 to Cn make it possible to call the master station for a meeting call.

However, the time slots Eb and F for meeting lines in the downward 9 direction and up direction are only for one line, and each slave station 1 to
n is shared, so if one of the slave stations 1 to n has a meeting call with the master station, another meeting call is impossible, and it is necessary to notify others that a meeting call is in progress. arise.

Therefore, each bit of the meeting control time slots In- and C1 to Cn in the downward direction and upward direction is as follows.
0" indicates a non-call state; 1" indicates a call state; a reversal from 0 to 1 indicates a call has been made, and a reversal from 1 to O indicates an end of call. At the same time, a response is indicated by the callee's inversion from ``0'' to 1''.

Therefore, for example, in FIG. 4, slave station 2 is connected to switch 1.
6 is turned on, the bit of the meeting control pulse C2 becomes "1" due to the operation of the control circuit 17, which is detected by the control circuit 17 of the master station, and the bell and buzzer (not shown in the figure) are activated. etc. to notify the incoming call, and when the master station switch 16 is turned on, the control circuit 17
As a result of the operation, the second bit of the downlink meeting control time slot (D) becomes "1", which is transmitted to the control circuit 1 of the slave station 2.
7 is detected, and the meeting call circuit is completed.

In addition, for other slave stations 1, 3 to nVC buttons, any bit in the downlink meeting control time slot)D is 1"
The control circuit 17 detects that the meeting line is busy, and uses a lamp or the like (not shown in the figure) to indicate that the meeting line is busy.

Note that if the second bit of the meeting control time slot D and the bit of C2 become 0'', the above state is dynamically canceled.

FIG. 5 shows a plurality of sets of downward meeting control pulses D and a plurality of upward meeting control pulses C1 to Cn, one of which is used for normal meeting control.
This is a time sequence diagram of an embodiment in which the other pulses are used for control of interrupt calls to enable interrupt calls in an emergency. In the example shown in the figure, the downlink meeting control pulse D1 is normally controlled,
2 is used for interrupt control, the first bit of the uplink meeting control pulses C1 to Cn is used for normal control, and the second bit is used for normal control.
is used for interrupt control.

Therefore, if the control circuits 17 of the master station and slave stations 1 to n are configured as described above, it becomes possible to make an interrupt call even during a meeting call in the event of an emergency situation, etc. In the example shown in the figure, During a normal meeting call between the master station and slave station 1, it became necessary to make an interrupt call to slave station 2, and the second bit of the meeting control pulse C2 was set to '1''. 2nd bit of downward direction meeting control pulse D2? &
As a result, an interrupt call is made using downlink and uplink meeting line time slots E and F.

At this time, any bit that the control circuit 17 of the slave station 1 applies to the downlink meeting control pulse D2 is '1'.
” and forcibly disconnects its own meeting call circuit.

In addition, the time slots E and F for each meeting line in the down direction and up direction in FIG. Control pulse D, C1 to Cn
is made up of a desired number of time slots, a code with a fixed number of bits is formed by these pulses, and this code corresponds to multiple sets of meeting line time slots. It becomes possible to select and use any one.

As described above, a meeting line can be configured by simply adding a few time slots to the conventional frame configuration, but especially in the embodiment shown in FIG. This is convenient for making a new call when you forget to turn it off even though S has ended, and you can use one meeting line efficiently.

Further, in the above description, the case where the phase modulation of the carrier wave is two-phase is taken as an example, but the present invention can be similarly applied to polyphase phase modulation such as four-phase or eight-phase.

As is clear from the above explanation, the present invention can be applied to slave stations that do not perform continuous transmission, and there is less need to increase the period of time slots, and the occupied frequency band due to carrier wave modulation can be reduced. This has great effects on multi-directional wireless communication systems, such as minimizing the size and making effective use of radio waves.

[Brief explanation of the drawing]

Fig. 1 is a time sequence diagram showing the configuration of time slots in a time division multiplexing phase modulation multidirectional wireless communication system, Fig. 2 and subsequent figures show embodiments of the present invention, and Fig. 2 is a block diagram showing the configuration of a master station. , FIG. 3 is a block diagram showing the structure of the slave station, FIG. 4 is a time sequence diagram showing the structure of time slots, and FIG. 5 is a time sequence diagram showing another embodiment. 1 to n...Slave station, 2...Multiplexer, 3...
Meeting circuit, 4... Pulse modulator/demodulator, 14... Demultiplexer, 15... Control circuit, 16... Switch, 19... Switch circuit, A1~An jBl~
Bn...Time slot group, C1 to Cn, D, D
I, D2 "" Pulse for meeting control, E, F...
・Time slot for meeting line.

Claims (1)

[Scope of Claims] 1. In a time-division multiplexing multi-directional wireless communication system composed of a master station and a plurality of slave stations, in a frame consisting of a pulse train that transmits a signal from the master station to each slave station, a communication line for a meeting line is provided. In addition to providing a time slot and a time slot for meeting control, a time slot for a common meeting line is provided in a frame consisting of a group of time slots corresponding to each slave station, in which a pulse train for transmitting a signal from each slave station to the master station is arranged. A meeting line configuration method for a time division multiplexing phase modulation multidirectional radio communication system, characterized in that a meeting control pulse is provided in a time slot group assigned to each slave station. 2. A plurality of sets of time slots for meeting control are provided in a frame consisting of a pulse train for transmitting a signal from a master station to each slave station, and a set of time slots is provided in a group of time slots assigned to each slave station. , wherein there are a plurality of meeting control pulses, one of the meeting control pulses is used for normal meeting control, and the others are used for interrupt call control. A meeting line configuration method for a time-division multiplexing phase modulation multidirectional wireless communication system. 3. A time slot for a meeting line provided in a frame consisting of a pulse train for transmitting signals from the master station to each slave station;
A plurality of sets of time slots for a meeting line provided in a frame consisting of a group of time slots corresponding to each slave station for arranging a pulse train for transmitting a signal from each slave station to the master station are made into mutually corresponding sets. , the plurality of sets of meeting control time slots provided in a signal transmission frame from the master station to each slave station, and meeting control pulses provided in a group of time slots allocated to each slave station. A meeting line configuration system for a time division multiplexing phase modulation multidirectional radio communication system according to claim 1, wherein a plurality of codes are formed to correspond to each of the meeting line time slots.