JPH02206242A - Time division multiplex transmission system - Google Patents

Abstract

PURPOSE:To use a signal series subjected to DMI coding as it is (without inverse conversion to an original signal) as a transmission line code by superimposing a code rule violation code onto at least a signal series among plural signal series subjected to DMI coding. CONSTITUTION:A code rule violation superimposing circuit 11 at a sender side equipment 1 superimposes a code rule violation at a prescribed period onto only a 1st series in n-series of DMI code series synchronous with each other and the result is converted into a multiplexed signal series A by a multiplexer circuit 12. The signal series A sent to a receiver side equipment 3 via a transmission line 2 is demultiplexed into n-set of signal series by a multiplex demultiplex circuit 31. A code rule violation detection circuit 32 detects a code rule violation for a prescribed period superimposed at the sender side to control the timing of the clock signal of the multiplex demultiplex circuit 31 in a way that the signal series superimposed with the code rule violation is outputted as the 1st DMI code. A code rule violation elimination circuit 33 eliminates the code rule violation superimposed at the sender side as to the 1st DMI code series to reproduce an original signal.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention is used in the transmission of digital signals. In particular, DM
The present invention relates to a time division multiplex transmission method that time division multiplexes and transmits a plurality of I-encoded signal sequences.

〔overview〕

The present invention provides a time-division multiplexing transmission method in which multiple DMI-encoded signal sequences are time-division multiplexed and transmitted. By superimposing a coding rule violation on at least one signal sequence, the transmitting side can transmit multiple signal sequences as original signals. It multiplexes signals without inverse conversion, and allows the receiving side to demultiplex the multiplexed signals as they are.

[Conventional technology]

FIG. 4 shows signal waveforms in a conventional time division multiplex transmission system. Here, FIGS. 4(a) and 4(b) show individual signal sequences B1 to B before multiplexing, and FIG. 4(C) shows multiplexed signal sequence B.

Conventionally, in order to multiplex a plurality of n series of digital signals that are synchronized in frequency, a method has been used in which n digital signals are arranged bit by bit and multiplexed. This method is called a bit interleave method. In this method, a frame is generally constructed by arranging synchronization pulses at appropriate intervals so that n digital signals can be identified during demultiplexing.

Furthermore, in order to transmit multiplexed signals, it is common to convert them into appropriate transmission line codes in order to ensure stable transmission quality in digital transmission.

On the other hand, in order to flexibly configure a digital communication network, it is required to be able to directly send signals that have undergone digital signal processing such as demultiplexing to a relay transmission path.

For this purpose, even if the signal is converted to a transmission path code,
It is desirable to be able to perform signal processing such as demultiplexing.

[Problem that the invention seeks to solve]

However, in conventional time division multiplexing transmission systems, multiplexing processing is required before transmission line code conversion, so the coded signal before multiplexing processing is inversely transformed back to the original signal, and then the frame The drawback is that unless the pulses are time-divisionally superimposed, demultiplexing cannot be performed on the receiving side.

[Means for solving problems]

In the time division multiplex transmission system of the present invention, a transmitting side device is equipped with a coding rule violation superimposition circuit that superimposes a coding rule violation in a predetermined form on at least one of a plurality of signal sequences; a coding rule violation detection circuit that detects a signal on which a coding rule violation is superimposed and feeds a timing signal synchronized with the signal to a demultiplexing circuit; The present invention is characterized by comprising a code rule violation removal circuit that removes the code according to the reverse logic.

[For production]

By giving a coding rule violation to one signal sequence, multiple signal sequences can be multiplexed without inserting a special synchronization signal. Furthermore, since the DMI encoded signal sequence can be used as a transmission line code as it is (without being inversely converted to the original signal), the receiving side can directly demultiplex the received signal as it is. Furthermore, since the form of code rule violation is determined, the original code can be easily recovered on the receiving side.

〔Example〕

FIG. 1 is a block diagram of a time division multiplex transmission apparatus according to an embodiment of the present invention.

This device is a transmitter device 1 connected via a transmission path 2.
and a receiving device 3 , the transmitting device 3 includes a multiplexing circuit 12 that time-division multiplexes a plurality of n DME-encoded signal sequences, and the receiving device 3 receives signals transmitted from the transmitting device 1 . It includes a demultiplexing circuit 31 that receives and demultiplexes signals.

Here, the feature of this embodiment is that the transmitting side device 1 uses a coding rule violation superimposition circuit 11 that superimposes a predetermined form of coding rule violation on at least one of a plurality of signal sequences.
a coding rule violation detection circuit 32 in which the receiving side circuit 3 detects a signal on which a coding rule violation is superimposed and outputs a timing signal synchronized with the signal to the demultiplexing circuit 31; Sign rule violation superimposition circuit 1
The present invention also includes a coding rule violation removal circuit 33 that removes coding rule violations according to the inverse logic of the form used in No. 1.

FIG. 2 shows signal waveforms in this example, where (a) to C) show individual digital signals before multiplexing, and (
d) shows a multiplexed signal.

The n DMI code sequences synchronized with each other are shown in Figure 2 (a
) is the only sequence shown in the sign rule violation superimposition circuit 11.
As a result, violations of the sign rule at a constant period are superimposed. The first sequence in which the coding rule violation is superimposed and the other n-1 signal sequences A2 to A2 in which the coding rule violation is not superimposed are processed by the multiplexing circuit 12 as shown in FIG. 2 (6). It is converted into a multiplexed signal sequence A as shown in FIG.

The signal sequence A transmitted to the receiving side device 3 via the transmission path 2 is separated into n signal sequences by the demultiplexing circuit 31. The coding rule violation detection circuit 32 detects a fixed period coding rule violation superimposed on the transmitting side, and demultiplexes the signal sequence so that the signal sequence on which the coding rule violation is superimposed is output as the first DMr code. The timing of the clock signal of 31 is controlled.

The coding rule violation removal circuit 33 removes the coding rule violation superimposed on the transmitting side for the first DMI code sequence and reproduces the original signal.

FIG. 3 shows a state transition diagram of a code rule violation used by the code rule violation superimposition circuit 11 and the code rule violation removal circuit 33.

〔Effect of the invention〕

As explained above, the time division multiplex transmission method of the present invention is
A frame pulse is superimposed on a multiplexed signal by periodically giving a coding rule violation to one DMI code sequence. This has the effect that n mutually synchronized signals converted into DMI codes as transmission path codes can be multiplexed and demultiplexed without being inversely converted to original signals. Furthermore, since the form of code rule violation is determined, the original code can be easily recovered on the receiving side. In addition, since DME codes are used as transmission path codes, it is easy to superimpose coding rule violations after encoding and to detect coding rule violations, and this can be achieved with a relatively small circuit. .

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a time division multiplex transmission apparatus according to an embodiment of the present invention. FIG. 2 is a diagram showing signal waveforms. FIG. 3 is a state transition diagram of code rule violation. FIG. 4 is a diagram showing signal waveforms in the conventional method.

Claims (1)

[Claims] 1. A transmitting side device and a receiving side device connected via a transmission path, the transmitting side device including a multiplexing circuit that time-division multiplexes a plurality of DMI encoded signal sequences. In a time division multiplex transmission system, the receiving device includes a demultiplexing circuit that receives and demultiplexes signals transmitted from the transmitting device, and the transmitting device transmits at least one of the plurality of signal sequences. includes a coding rule violation superimposition circuit that superimposes a coding rule violation in a predetermined form on the signal, and the receiving side circuit detects the signal on which the coding rule violation is superimposed and transmits a timing signal synchronized with the signal to the demultiplexing circuit. and a coding rule violation removal circuit that removes the predetermined form of coding rule violation from the signal on which the coding rule violation is superimposed, according to its inverse logic. Time division multiplex transmission method.