JPH0115181B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a time division multiplexing multi-directional radio system between one master station and N slave stations, and in particular, the master station and the slave stations encode input signals for each opposing station. Time division multiplexing
The present invention relates to a time division multiplexing multidirectional radio system having separate time division carrier end station devices (hereinafter referred to as carrier ends).

If the transmission capacity between one master station and N slave stations is small, and the distance between the master station and each slave station is not large, then Time-division multiplexed communication channel signals are transmitted simultaneously using continuous mode wireless signals, and each slave station transmits the communication channel signals from each slave station to the master station using time-division mode wireless signals that are transmitted in bursts. Time-division multiplexing multidirectional wireless systems have recently become popular.

FIG. 1 is a block diagram of a conventional time division multiplexing multidirectional radio system, and FIG. 2 is a time chart for explaining its operation.

P in the figure is one master station, C ₁ to _{C 3} are three slave stations,
1 is the radio section of the master station P, 2, 2', 2'' are the slave stations
C ₁ to C ₃ radio units; 3 is a carrier end signal processing unit that processes time-division carrier end signals of communication signals between the master station P and each slave station C ₁ to _{C 3} ; 4, 4′, 4″ are carrier end signal processing units; Carrier-end signal processing units 5, 5', and 5'_' process time-division carrier-end signals of communication signals with the master station P of the _three slave stations _{C1 to C3} ;
The carrier end encodes the communication signals with C ₂ and C ₃ , performs frame synchronization, and multiplexes and demultiplexes the time-division communication channels. 6, 6', and 6'' are the master stations of slave stations C ₁ , C ₂ , and C ₃ . S ₁ to S ₇ are the time-division carrier terminals that transmit and receive the communication channel in which the communication signal with P is encoded and frame-synchronized.
τ 1 and τ ₂ are the synchronization signals of each of the 7 communication channels for a frame, and τ ₁ and τ 2 are the propagation delay times until the wireless signal reaches the slave stations C ₁ and C ₂ from the master station P, and α is the propagation delay time of each slave station. The delay time m inside the device represents the number of data bits of each communication channel.

To explain, as an example, in a system where only seven slave stations are installed in total, two slave stations C ₁ ,
Let me explain about _C2 . The synchronization signals S ₁ to S ₇ of each channel for one frame consisting of the seven communication channels of all slave stations are composed of, for example, 1 bit, and the synchronization signal S ₁ of the communication channel of slave station C ₁ is frame synchronized. The following describes the case where the reference bit is set as the reference bit. Of course, the synchronization signals S ₁ to S ₇ of each channel need not be one bit. Synchronization signal for each channel S ₁ ~ _{S 7}
is each m to be sent from the master station P to the slave stations C ₁ , C ₂ ...C ₇
For bit channel data, radio section 1:
So-called speed conversion is performed by creating empty bits at 2, 2', and 2'' and inserting synchronization bits.Now, the master station P sends a message to the slave stations _C1 and _C2 as shown in Fig. 2A. Data for slave station C ₁ is inserted between the synchronization signal S ₁ of _the communication channel of station C 1 and the synchronization signal S ₂ of the communication channel of slave station C ₂ , and the synchronization signal S ₂ and the synchronization signal S ₃ are inserted. During this period, a signal with data inserted for slave station C ₂ is transmitted, and is received by slave stations C ₁ and C ₂ with a delay of propagation delay times τ ₁ and τ ₂ , as shown in Fig. 2B and C. Ru.

Upon receiving the reference synchronization bit _S1 from the master station P, all the slave stations C ₁ , C ₂ ...C ₇ immediately send a (1+m) bit channel to the master station P into which one bit of the synchronization signal for transmission is inserted. Data for 7 stations (1+m) x 7 bits is transmitted as a frame period. In this case, each data received by the master station P from the slave stations C ₁ and C ₂ is
As shown in Figure 2 D and E, the round-trip propagation delay time
It is delayed by the sum of 2τ ₁ , 2τ ₂ and the delay time α within the device of each slave station (2τ ₁ +α) and (2τ ₂ +α).
In this case, the slave station _C1 adjusts the time using a delay line, clock counter, etc. that provides a delay time of 2(τ ₂ −τ ₁ ), and the master station P adjusts the time as shown in FIG. The data received from slave stations C ₁ and C ₂ are made so that they do not overlap with each other and that there is no idle time. Of course, even if the slave stations C ₁ and C ₂ are equidistant from the master station P and the propagation delay times τ ₁ and τ ₂ are equal, a delay element is provided on one of them to prevent them from overlapping. The relationship between the radio section of each station and the carrier end is that at the master station P, each slave station C ₁ ,
Carrying ends 5, 5' of the time division channel opposite C ₂ and C ₃ ,
The data of each channel from each carrier end 5, 5', 5" is speed-converted by the radio part 1 via the carrier end signal processing part 3, and the signal shown in FIG. 2A is obtained. As shown in the column, the signal for the carrier end 5 is multiplexed between the synchronization signal _S1 and the synchronization signal _S2 , and the signal for the carrier end 5' is multiplexed between the synchronization signal _S2 and the synchronization signal _S3 . ₁ , _C2 , _C3
transmitted to. In addition, in the case of reception from the master station P, the received signal is speed-converted in the radio section 1, and then separated into each slave station in the carrier end signal processing section 3, and the data from the slave station _C1 is sent to the carrier end 5. , the data from the slave station _C2 is passed to the carrying end 5'. The slave stations C ₁ and C ₂ perform bit synchronization and frame synchronization with the signal sequence shown in FIG. The processing units 4 and 4' separate the channel data from the carrier end ₅ of the master station P, and separate the channel data from the carrier end ₅ of the master station P at the carrier end corresponding to each slave station C _{1 and C 2, for example, the slave station C 1 .} give it to The transmission of slave stations C ₁ , C ₂ , C ₃ is as follows:
As mentioned above, as soon as the radio units 2, 2', 2'' receive the reference synchronization signal _S1 of each channel, the carrier ends 6, 6',
Each data from 6″ is sent to the carrier end signal processing unit 4, 4′,
Speed conversion is performed in the radio sections 2, 2', and 2'' via the 4'', and 1 bit of synchronization bit _S1 , _S2 , _S3 for each transmission is added, and the data determined for each slave station is It is transmitted to the master station P with a delay given by a lay line or the like.
In this way, wireless communication between one master station and N slave stations, so-called multidirectional wireless communication, becomes possible in a time-division manner.

However, in this conventional example, the master station P has each slave station
It is necessary to have separate carrier ends 5, 5', and 5'' corresponding to C ₁ , C ₂ , and C ₃ , and each carrier has a so-called channel section that encodes and decodes the input speech signal of each station, and A multiplexing/demultiplexing unit is required to perform frame synchronization, multiplexing, and demultiplexing with communication channels of other stations of similar size, and both units are mounted in one housing and share a power source. Even so, the carrier end device is large and expensive.The master station P has to install this large and expensive carrier end device separately for each slave station C ₁ , C ₂ , and C ₃ . There are drawbacks.

An object of the present invention is to enable a master station P to share code processing for multiplexing and demultiplexing speech signals with N slave stations C ₁ , C ₂ , and C ₃ using only one set of carrier ends. An object of the present invention is to provide a time division multiplexing multidirectional radio system having a compact and inexpensive configuration.

In order to achieve the above object, the present invention has a configuration in which N slave stations C ₁ , C ₂ , C ₃ are arranged for one master station P, and For the slave station, the radio signal of the communication channel output from the carrier terminal equipment 10, which encodes the input signal, performs frame synchronization, and time-division multiplexing, is transmitted simultaneously and continuously from the radio unit 1 at the same frame period as that of the output. The synchronization signal of the signal received by the radio section 9, 9', 9'' of the slave station is transmitted from the slave station to the master station in continuous mode.
S ₁ , S ₂ , and S ₃ transmit a communication channel signal, which is an encoded communication signal input to each slave station, in a time division mode in which it is transmitted in a burst format, and the master station P and the slave station C ₁ , C ₂ , and C ₃ are time-division multiplex multidirectional radio systems having a carrier terminal device 10 as a master station that encodes and processes call signals for each opposing station, and carrier terminal devices 11, 11', and 11'' as slave stations. , each radio unit 9, 9', 9'' of the slave station C ₁ , C ₂ , C ₃ and each carrier terminal device 11, 1
1' and 11'', respectively, are provided with pseudo signal generators that generate synchronization bits S ₁ to S ₇ at a predetermined frame period, and the output of the pseudo signal generator of the radio section forces the carrier terminal equipment. The synchronization bits S ₁ to S ₇ of the output of the pseudo signal generator of each carrier terminal device 11, 11', 11'' are reset to the output of the pseudo signal generator of each radio section 9, 9'', 9''. By synchronizing with the synchronization bits S ₁ to _{S 7} of the master station and synchronizing the transmission timing of the burst signal transmitted to the master station of each slave station with the transmission timing of the frame synchronization signal of the carrier terminal device 10 of the master station, Multiplexing and communication of communication signals between the master station P and N slave stations using a set of carrier terminal equipment 10 and radio section 1
Configure so that separation processing is shared.

An embodiment of the present invention will be described below with reference to the drawings.
FIG. 3 is a block diagram of a time division multiplexing multidirectional radio system according to an embodiment of the present invention, and FIG. 4 is a time chart for explaining its operation. Components with the same functions as those in FIGS. 1 and 2 are indicated by the same symbols.

In the block diagram of FIG. 3, 1 is the radio section of the master station P, 9, 9', 9'' are the radio sections of the three slave stations C ₁ , C ₂ , C _3. 7 is the radio section of the master station P. Carriage end signal processing section,
8, 8', 8'' are the carrier end signal processing units of the slave stations C ₁ , C ₂ , C _3. 10 is the carrier end of the master station P, 11, 11',
11'' indicates the carrying end of the slave stations C ₁ , C ₂ , and C ₃ .

In the radio sections 9, 9′, 9″ of slave stations C ₁ , C ₂ , C ₃ ,
In the conventional example, the synchronization signals S ₁ to _{S 7} of the continuous mode reception signal from the master station P are extracted and reproduced using a phase synchronization circuit PLL, etc., and bit synchronization and frame synchronization are achieved, but in the case of the present invention, , and further slave stations C ₁ , C ₂ , C ₃
As shown in FIG.
A pseudo signal generator that generates pseudo-random synchronization bit signals S ₁ to _{S 7} with a period equal to the frame period of the carrier end of the master station using the extracted frame clock 1, and slave stations C ₁ and C ₂ . , C ₃ carrying end 11, 11', 1
1'' is provided with a similar pseudo signal generator using a frame clock 2 that determines the frame synchronization,
A reset signal is generated in the pseudo signal generator of the radio section, and the reset signal is used to forcibly reset the synchronization pulse generating section of the pseudo signal generator at the carrier end 11, 11', 11'' of the slave station. and carrying end 11,1
The outputs of the pseudo signal generators 1' and 11'' are sent to the radio section 9,
In synchronization with the output of the pseudo signal generator 9′, 9″,
The transmission timings of the burst signals transmitted to the master station P of the slave stations C ₁ , C ₂ , and C ₃ are mutually synchronized and frame synchronized. The method for achieving this frame synchronization will be explained later.

Next _, using _the time chart _{shown in} FIG.
The transmission synchronization bits S ₁ to _{S 7} that generate 1″... are
A case where mutual frame synchronization is not achieved and a case where frame synchronization is achieved will be explained.

4A shows the continuous mode signal sent from the master station P to each slave station C ₁ to C ₇ , which is the same as that shown in FIG. 2A, and FIG. _C1 , _C2
The timing of the received signal is shown in D, E, and
I, J indicate the state when the frame synchronization of the transmission timing of the burst signal to be transmitted from the slave stations C ₁ and C ₂ to the master station P is synchronous and asynchronous, and F, G,
K and L are burst signals received by the master station P from the slave stations C ₁ and C ₂ . H and M in the figure show signal arrangements during frame synchronization and asynchronous time when burst signals received from slave stations C ₁ and C ₂ of the master station P are supplied to the carrier end 10 having the same frame configuration.

In the case of frame asynchronization shown in D and E of the same figure,
Synchronization bit S ₁ of slave station carrier end 11, 11', 11''...
S ₇ and the synchronization bits S ₁ to _{S 7} of the radio sections 9, 9', 9'', etc. are not in frame synchronization with each other, so when the synchronization bit S ₁ is received, the transmission signal is immediately transmitted, so the diagonal lines in the diagram The signal received by the master station P is made so that the slave stations C ₁ , C ₂ . , G, and the symbol arrangement when supplying this to the conveying end 10 is shown in the figure H.
It will be like this. S ₇ and S ₃ in H in the same figure are shown in F and G in the same figure. S ₇ and S ₃ . The timing of S ₇ and S ₃ in H in the figure does not match the frame synchronization signal of the carrier end 10, so
Correct reception separation cannot be performed at the carrier end 10. In the case of frame synchronization shown in I and J of the same figure, slave station C ₁
At the carrier end 11, the synchronization bit _S1 from the master station is connected to the slave station.
Since frame synchronization is established with respect to the synchronization bit _S2 from the master station at the carrier end 11' of _C2 , the synchronization bit _S1
When it receives the transmission signal, it immediately transmits the transmission signal, but as shown in the shaded area in the figure, for the part assigned to its own station, that is, the slave station C ₁ , the slave station C ₂ transmits the transmission signal between the synchronization bits S ₁ and S ₂ .
In this case, the synchronization bits S ₂ and S ₃ are transmitted. The signal received by the master station P is K in the same figure.
When this signal is supplied to the carrier end 10, the signal arrangement is as shown in M in the figure, which matches the timing of the frame synchronization signal of the carrier end 10, so that correct reception and separation can be performed at the carrier end 10. . Since the transmission timing of the burst signal transmitted by each slave station matches the transmission timing of the frame synchronization signal of the carrier end 10 of the master station P, only one carrier end 10 of the master station P can transmit seven slave stations _C1. , C ₂ … Separate the signals from C ₇ .
This allows multiplexing. In reality, the signal in Figure M is synchronized by the synchronization bit of the master station carrier end 10 due to the propagation delay time.
Since S ₁ to S ₇ do not match as they are, the reset signals of each slave station are delayed by a considerable amount and the times are adjusted so that they match. Similarly, in the radio sections 9, 9', and 9'' of each slave station, bit synchronization is achieved by varying the phase of the clock so that the phase of each bit matches. ₁ , _C2 , and _C3 in continuous mode, there is no problem since the carrier end 10 and the radio section 1 are naturally in bit synchronization and frame synchronization as in the conventional example.
Through the above-described operation, a set of carrier terminals 10 of the master station P commonly performs code processing of speech signals with each of _the slave stations C ₁ , C ₂ , and C ₃ . ₂ and _C3 will be able to communicate.

Next, the synchronization bits S ₁ to _{S 7} generated at the carrier ends 11, 11', 11'', etc. in the slave stations and the radio sections 9, 9',
9, ″… synchronization bits S ₁ to _{S 7} received from the master station P
This section explains how to achieve mutual frame synchronization with.

There is a method for achieving frame synchronization using pseudo signal generators (hereinafter referred to as PN generators) using respective frame clocks on the carrier end side and the radio section side.

FIG. 5 is a circuit diagram for performing frame synchronization using a PN generator, and FIG. 6 is a time chart for explaining the operation.

In the figure, Q ₁ to Q ₃ and Q ₁ ′ to _{Q 3} ′ are D-type flip-flops (hereinafter referred to as FF), Q ₄ and Q ₄ ′ are exclusive OR circuits (hereinafter referred to as EX-OR), and Q ₅ is Showing a NAND circuit.

Figure 5 shows a PN generator circuit consisting of FF Q ₁ to Q ₃ and EX-OR Q ₄ , and FF Q ₁ ′ to _{Q 3} ′ and EX-OR.
- The PN generator circuit consisting of OR Q ₄ ′ is,
Both are three-stage PN generators, and are synchronizing pulse generating circuits that repeatedly generate 7-bit patterns of frame clocks 1 and ₂ between the two arrows in FIG. Q ₃ repeatedly generates synchronization pulses S ₁ to _{S 7} for one frame on the transport end side, and
Q ₁ ′ to Q ₃ ′ are synchronization pulses for one frame on the radio side
S ₁ to S ₇ occur repeatedly.

A, B, C and D of the time chart in Figure 6,
E and F are state transitions of Q ₁ to Q ₃ of FF and
It represents the state transition from Q ₁ ′ to Q ₃ ′. Figure G shows a frame clock 1 on the carrier end side and a frame clock 2 on the radio section side. Frame clock 1 and frame clock 2 each generate one frame's worth of synchronization pulses S ₁ -
S ₇ is occurring. Frame clock 1 on the transport end side
Since the frame clocks 1 and 2 on the radio section side are bit synchronized, it is possible to synchronize both frame clocks 1 and 2 using a delay line or the like, so it is assumed that they are synchronized. Center of Figure 6, Figure H
The left side of A shows a state where the synchronization pulse of the output of the PN generator on the carrier end side and the synchronization pulse of the output of the PN generator on the radio section side are not synchronized.

Now, we will explain the process of synchronizing both synchronization pulses by resetting the PN generator on the carrier end side using the output of the PN generator on the radio section side.

The outputs of Q ₁ ′, Q ₂ ′, and Q ₃ ′ of the FF of the PN generator on the radio section shown in D, E, and F in Figure 6 are all code “1”.
, that is, at the timing of signal A of the output of HQ ₅ in Figure 6, the signal shown in Figure H appears at the output of NAND circuit Q ₅ , which is sent to the FF of the PN generator on the carrier end
The reset signal is supplied to _Q1 to _{Q3 of} When Q ₁ to _{Q 3} of the FF on the carrier end side receive a reset signal, the reset signal takes priority, and regardless of the state of the D input of FF Q ₁ to _{Q 3} , the reset signal causes Q _{1 to Q 3} of the FF to be reset.
Each output of _Q3 has the code "1". In other words, at the output of NAND circuit _Q5 , at the falling edge of signal A shown in Figure H.
Each output of FF Q ₁ to _{Q 3} becomes code “1”. As a result, Q ₁ to _{Q 3} of the FF of the PN generator on the carrier end side
outputs signals as shown by dotted lines in Figure 6 A, B, and C, and outputs signals Q ₁ ', Q ₂ ', and Q ₃ ' of the PN generator FF on the radio section side shown in Figure 6 D, E, and F. The output will be the same. Therefore, the PN generator on the carrier end side resets the PN on the radio section side by the reset signal generated by the PN generator on the radio section side.
This means that it is synchronized with the generator.

In this way, each slave station of the system of the embodiment shown in FIG.
Each radio section 9, 9', 9'' of _C1 to _C7 transmits a synchronization bit S at a constant frame period using the output signals of Q1 _' , _Q2 ', _Q3 ' of the FF of each PN generator. ₁ to _S7 and forcibly synchronize the outputs of the PN generators at each transport end 11, 11', 11''...
Each carrier end 11, 11', 11'' receives a burst signal of a communication channel which encodes a communication signal input to each slave station in synchronization with the output of _Q1 to _Q3 of the FF of its own PN generator. The transmission timing is determined, and each radio section 9,
9', 9''... to the master station P. In other words, the slave station
In C ₁ , the synchronization bit S ₁ of the radio section 9 and its carrying end 11
frame synchronization with synchronization bit S ₁ of the slave station.
In C ₂ , synchronization bit S ₁ of radio section 9' and its carrying end 1
It is sufficient to synchronize the frame with the synchronization bit _S2 of 1' and transmit it to the master station P, and the master station P can communicate with each slave station _C1 to _C7 using only one carrier end 10. becomes.

As explained in detail above, according to the present invention, the carrier end of the master station can be shared in a time-sharing manner for multi-directional communication with each slave station, so that the master station only needs one carrier terminal device. This has the effect of realizing a compact and inexpensive time-division multiplexing multidirectional radio system.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a conventional time division multiplexing multidirectional radio system, FIG. 2 is an operation time chart of the conventional example, and FIG. 3 is a block diagram of a time division multiplexing multidirectional radio system according to an embodiment of the present invention. FIG. 4 is a time chart for explaining the operation of the embodiment of the present invention, FIG. 5 is a circuit diagram of a PN generator that performs frame synchronization, and FIG.
The figure is an operation time chart of the PN generator that performs frame synchronization. In the figure, 1, 2, 2', 2'', 9, 9', 9'' are radio sections, 3, 4, 4', 4'', 7, 8, 8', 8'' are carrier end signal processing sections, 5, 5', 5'', 6, 6', 6'', 1
0, 11, 11', 11'' are the carrier ends, P is the master station, C ₁ ,
C ₂ and C ₃ are slave stations, S ₁ to _{S 7} are synchronization bits, Q ₁ to _{Q 3} ,
Q ₁ ′ to Q ₃ ′ are D flip-flops, Q ₄ , Q ₄ ′ are EX-
OR, Q ₅ is a NAND circuit.

Claims (1)

[Claims] 1. N slave stations C ₁ , C ₂ , C ₃ for one master station P
is arranged, and from the master station to the slave station, the radio signal of the communication channel of the output of the carrier terminal equipment 10, which encodes and time-division multiplexes the input signal, is transmitted simultaneously and continuously in the same frame period as the output. The communication channel signal of each slave station is transmitted in a continuous mode, and the communication channel signal of each slave station is transmitted in burst form from the slave station to the master station using synchronization signals S ₁ , S ₂ , and S _{3 of} the signals received by the slave station. Transmission is carried out in time division mode 9, 9', 9'', and the master station and the slave station are time division multiplexed with carrier terminal equipment 10; In the multi-directional radio system, a synchronization bit is sent to each radio unit 9, 9', 9'' of the slave stations _C1 , _C2 , _C3 and each carrier terminal device 11, 11', 11'' at a predetermined frame period. A pseudo signal generator for generating signals S ₁ to _{S 7} is provided, and the output of the pseudo signal generator of the radio section forcibly resets and controls the pseudo signal generator of the carrier terminal equipment to generate pseudo signal generators of the carrier terminal equipment. The output of the signal generator is synchronized with the output of the pseudo signal generator of the wireless section and the timing of transmitting the burst signal to be transmitted to the master station of each slave station is the timing of transmitting the frame synchronization signal of the carrier terminal device of the master station. A time-sharing method characterized in that the master station P can perform multiplexing and demultiplexing of call signals with N slave stations in common by using a set of carrier end station equipment 10 and radio unit 1. Multiplexed multidirectional wireless system.