JPS5850844A - Multidirectional synchronization system - Google Patents

Abstract

PURPOSE:To transmit a dial pulse signal from a subordinate station to a master station by transmitting a PCM signal, which is as much as six frames or its integral multiple, in such a way that it is arranged in a transmitted burst to be transmitted at a time when the transmitted burst of the subordinate station is constituted. CONSTITUTION:A PCM codes are received by a receiving terminal 1, and a frame synchronizing signal receiving circuit 2 detects multiframe synchronism to find a frame containing a dial signal in the 8-bit code, thereby transmitting it to a memory control circuit 7. On the other hand, a synchronizing signal in a signal from a master station is transmitted from a terminal 3, and transmitting timing counters 5-1-5-3 count timing to input the results to the circuit 7. The circuit 7 controls the counters so that one of memories 6-1-6-3 is used for reading-in operation, another memory is used for reading-out operation, and the remaining one is used as a stand-by memory. Signals read out of the memory are transmitted to the master station through an OR circuit 8, a transmitter 9, and an antenna 10.

Description

[Detailed Description of the Invention] The present invention provides PCM (Pulse Code Module)
This invention relates to a synchronization method for a time division multiplex radio system using a time division multiplexing radio system.

In a communication system that uses radio frequencies, communication between a specific central station (hereinafter referred to as the master station) and multiple opposing stations (hereinafter referred to as slave stations) is carried out in a pair. Using radio frequencies is preferable from the standpoint of effective use of radio waves, and conventionally a method using two-frequency division multiplexing and single band modulation has been put into practical use. However, considering the direction of digitalization of 2 communications, a time division multidirectional multiplexing system using a digital radio modulation system using a PCM modulation system as an audio modulation system has been devised and is about to be put into practical use.

In this case, since wireless transmission is performed using a pair of radio waves, continuous waves are used for transmission from the master station to the slave station, so there is no particular problem, but from the slave station to the master station.

Since each slave station transmits intermittently (burst-like), various considerations must be made regarding the transmission method.

FIG. 1 shows the timing of transmission by a master station and each slave station in an example of a 9-time division multidirectional multiplex radio system. Transmission from the master station to the slave stations is a continuous wave.

A frame synchronization bit F is inserted at regular intervals. Each slave station has 1. Detect this frame sync bit.

Based on this, if you count and transmit the timing of your own station's transmission to match the reception timing of the master station, each slave station will transmit a signal intermittently (hereinafter referred to as a transmission burst).
In some cases, it becomes unnecessary for the master station to transmit codes for detecting synchronization, reducing the number of code pits in the transmission burst, thereby making it possible to use radio waves more effectively.

The present invention relates to a time division multiplex communication system using such a transmission system. This relates to a code configuration method for each slave station. FIG. 2 shows the frame structure of PCM transmission using the well-known communication channel system, which was also recommended by the Consultative Committee on International Telegraph and Telephone (CCITT). In this frame configuration.

When one pulse amplitude harmonic (hereinafter referred to as a PAM wave) is encoded with 8 bits, 5 out of 6 frames represent the PAM wave encoded with all 8 bits, and 6
One of the frames.

One pit of the 8 bits is used to transmit a dial signal. Therefore, it is necessary for each slave station to construct a code so that the frame representing this signal can be detected at the master station.

The present invention provides a code structure for a multi-directional multiplex communication system that allows detection of a dial signal at a master station.

As mentioned above, the transmission of the dial signal is one frame in every six frames, so the transmission burst of each slave station consists of codes of six frames or an integral multiple thereof. If you decide in advance which part of the six frames (for example, the last frame) contains the frame in which the 8th pit of the 8-bit encoded code represents the dial signal, the parent When the station receives the transmission bursts from each slave station and rearranges them into a standard PCM code string, it is possible to identify the portion of the PCM code received from each slave station that includes a dial signal.

FIG. 3 shows an example of the code structure of a slave station transmission burst according to the present invention. In this embodiment, the transmission burst of the slave station consists of PCM codes for 6 frames.

This figure shows that six communication paths (the communication paths are hereinafter abbreviated as CH) are assigned to the corresponding slave station. ~f in the figure is an 8-bit P
It consists of 60H of CM code, that is, 48 bits,
f1 to f are 8-bit PCM codes.

It is assumed that f6 is a code in which all PAM l waves are encoded, and the eighth bit out of eight bits is used for transmitting a dial signal. Even if the number of channels is different for each slave station, if the order of arranging 8 to f6 is the same, the master station can receive the transmission burst from each slave station and transmit it according to the standard shown in Figure 2. It can be rearranged to PCM code structure.

Sl and S2 each consist of several bits, including guard bits before and after the transmission burst, synchronization bits for differential synchronization, monitoring bits, and the like.

FIG. 4 is an example of a circuit system diagram configuring the slave station transmission burst of the present invention, in which 1 is a receiving terminal for a signal from a PCM terminal station, 2 is a frame synchronization signal and a signal from among PCM code examples. A multi-frame synchronization signal detection circuit 3 receives a frame synchronization signal from the master station (corresponding to F in FIG. 1) received by the receiver of the slave station; Counter circuit for counting the transmission timing of the own station predetermined in 5-1 to 5
-3 is a memory circuit that temporarily stores the code from the PCM terminal; 6-1 to 6-3 are counter circuits for reading and reading out the memory; and 7 is a memory that controls reading and subsequent reading of the memory. The control circuit 8 is an OR circuit that collects the contents read from the memory.

9 is a radio transmitter, and 10 is a transmitting antenna.

Next, this operation receives the PCM code from the PCM signal receiving terminal, detects multi-frame synchronization in the frame synchronization signal receiving circuit, and detects the frame containing the dial signal in the 8-bit PCM code. The information is transmitted to the memory control circuit 7.

On the other hand, the frame synchronization signal included in the received signal from the master station is received from the terminal 3, the transmission timing of the own station is counted by the transmission timing counter, and the information is transmitted to the memory control circuit 7. In the memory control diagram, based on the above information, one of the three memories is used for reading the PCM code, the other one is used for reading the PCM code, and the remaining one is used for the timing. The memory counter is controlled accordingly. The PCM signal controlled and read by the memory counter is sent to the OR circuit 8. Wireless transmitter9. The signal is transmitted to the master station via the transmitting antenna 10.

FIG. 5 is an example of a master station receiving circuit that receives signals transmitted from the slave station, where 1 is a reception antenna, 2 is a radio receiver, and 3 is a frame synchronization information reception circuit from the master station transmitter. Terminal 4 is a counter that counts reception timing based on the frame synchronization information, 5-1.5-2 is a memory circuit that stores received codes in order to rearrange them, and 6-1
．． 6-2 is a counter for reading and reading memory;
7 is a memory control circuit for controlling the memory; 8 is a frame synchronization generation circuit for the PCM terminal; 9 is an OR circuit for synthesizing memory read outputs; and 10 is an output terminal for the PCM terminal.

Next, is this behavior from each slave station? Aerial transmitting bursts,
The codes received by the radio receiver and demodulated are temporarily stored in the memory 6-1.6-2 in order to be rearranged into a standard PCM terminal station code string. The memory is stored in a memory control circuit 8 based on the reception timing created by the reception timing counter 4 based on the frame bits from the transmitter.
The codes are rearranged in the memory specified by the memory counter 6-1, 6-2 controlled by the memory counter 6-1, 6-2, and read out by being specified by the memory counter. The read code is the P generated by the frame synchronization generation circuit 8 in the OR circuit.
It is combined with the frame synchronization signal for the CM terminal station and transmitted from the terminal 10 to the PCM terminal station.

As explained above, according to the present invention, when configuring a transmission burst of a slave station, P of 6 frames or an integral multiple thereof is
By transmitting the CM codes side by side in one transmission burst, the master station can distinguish the complaints containing the dial signal, and therefore it is possible to transmit the dial pulse signal from the slave station to the master station. Will.

In the detailed description of the present invention, the transmission burst was constructed using PCM codes for 6 frames.

Of course, the frame may be composed of frames that are an integral multiple of that number. .

[Brief explanation of the drawing]

Fig. 1 is a diagram showing a time chart of a transmission signal of a 9-time division multidirectional simultaneous radio system, Fig. 2 is a diagram showing a frame configuration of a PCM terminal station, and Fig. 3 is a diagram showing a frame configuration of a PCM terminal station. FIG. 4 is a diagram showing the code structure of the station transmission burst. FIG. 4 is a circuit diagram of a slave station that implements the code structure of FIG. 3. FIG. 5 is a circuit diagram of a master station that implements the code structure of FIG. 3. be. 5-1.5-2: Memory circuit, 6-1.6-2: Counter. Agent Patent Attorney Susuki 1) Toshiyuki Figure 1 Hemi sent 1 station, Iblind 22 Ma received 11 stations 22222=[222222[==
===ko===:, 2°nini
Ninini Figure 3

Claims (1)

[Claims] Wireless transmission between one master station and multiple slave stations is performed using a pair of radio waves using a digital modulation method, with continuous waves transmitted from the master station to the slave stations, and continuous waves from the slave stations to the master station. In a wireless communication method in which each slave station transmits intermittently in two time divisions,
When transmitting a 4-channel PCM code, each slave station transmits the signals of 6 frames of the p CM code or an integral multiple thereof to the master station on the channel assigned to it (7). A multidirectional multiplex code configuration system characterized by transmitting dial signals by