JPS59231926A - Signal transmission system - Google Patents

Abstract

PURPOSE:To reduce the effect of noise by applying linear convertion to noise mixed in a transmission code via the Hadamard transformation device. CONSTITUTION:A transmission code word A becomes a transmission code word B while being subject to the effect of noise and reaches a reception system. The code word B is fed to the Hadamard transformation device 3, where a reception code word C is obtained, and even if impulse noise is included in the code word B, since the impulse noise is converted linearly, the noise is spread over the entire code word C and the effect of noise is mitigated. Further, a reception code word D is obtained by eliminating the noise from the code word C by means of a threshold value circuit 4 and the code is restored into an original signal by leading the code word D to a decoding processing section 5.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a noise C2-affected (two-way transmission system).

[Technical background of the invention and its problems]

Normally, in a transmission system that suppresses noise by linear conversion, even if the code word is a binary code, the transmission code is not a binary code, so a transmitter with a large peak voltage is required. In addition, there was a problem in that almost no information could be recovered from especially impulse-like noise.

[Purpose of the invention]

An object of the present invention is to provide a signal transmission system that eliminates the above drawbacks.

[Summary of the invention]

According to the present invention, a binary code is used as a transmission code. This binary code signal subjected to noise on the transmission path is supplied to a Hadamard transform device that linearly transforms it into another binary code signal. Then, the output of this Hadamard transform device is subjected to threshold processing (from the second step, the received code is obtained.

〔Effect of the invention〕

According to the present invention, since the noise mixed with the transmitted code (2) is passed through the Hadamard transform device (2) linearly transformed,
In particular, in order to make even ('''-invernus noise) average (bidispersion) in the received code signal, it is subjected to threshold processing (it is hardly affected by the didispersion noise).

Furthermore, on the transmitting side, since encoding can be performed using the transmission code from the beginning, there is no need for linear transformation at the time of transmission.

[Embodiments of the invention]

First, a detailed explanation of non-invention will be given.

A 4″-order (normalized) Hadamard matrix, when multiplied by 3, it becomes an identity matrix (one with two properties, i.e., HI Hl
There exists Hl = I. For example, assuming a 16th order Hadamard matrix, HI Hl kLs = H' = I Normalized Hadamard matrix H (= has the property that H('H) = I, so HI Hl Hs = I υ HI Hl = 'Hs 'H3 'H2=Hl.

By using the Ho and -H10 row vectors as codewords and applying the two-linear transformation H2, the 'Hs and -tH3 row vectors are obtained.

Figure 1 (2) shows an embodiment of the present invention. Here, the row vectors of the 16th-order Hadamard matrix H1, -H mentioned above are used as transmission codewords. In this case, the transmission codewords each consist of 16 bits and have 32 types. Therefore, the original signal is in 5-bit units (
2 encoding processing unit 1 (=transmission code word A of the corresponding row vector is supplied and converted into 2, and then guided to the transmission path 2.

The transmitted code word A generally reaches the reception system (=) due to the influence of noise on the transmission path 2. It performs a code word linear transformation H2 consisting of a vector affected by this noise, and can be realized only by addition and subtraction. Since Ht H2 = 1H3 as mentioned above, this Hadamard transform device 3 (from the second lii,
A received code I codeword C consisting of a row vector of and -tH8 is obtained. Here, even if the transmitted code word B contains impulse-like noise as shown in the figure, this impulse-like noise is also linearly transformed, so the entire received code word C (= the noise is dispersed). Therefore, the received code word C is passed to the threshold circuit 4 (2) A received code word from which noise is removed is obtained. (If the original signal (2) is derived, the original signal (2) can be restored. That is, the encoding processing unit 1 and the Hadamard transform device 3
Since the encoding and linear transformation used in are already known, the decoding processing unit 5 uses input (received)
It is possible to restore the original signal in units of 5 bits from 3 row vectors (16 bits each).

When communicating via a plurality of transmission paths, the above-mentioned received code wording may be supplied as is to the next transmission path 12. In this case, the Hadamard transform device 1 of the reception system of the transmission line 12
As for 3, linear transformation 'H2 is applied, and "H3'H
Since 2=Hi, the threshold circuit 14 obtains a received code word consisting of HI, L row vectors. Further (- When communicating this via transmission path n (-), the Hadamard transform device n described above is used as the Hadamard transform device n of the receiving system.
It can be the same as.

[Brief explanation of drawings]

FIG. 1 is a diagram showing an embodiment of the present invention. 1... Encoding processing unit 2...Transmission line 3...Hadamard conversion device 5...Threshold circuit 6...Decryption processing unit

Claims (1)

[Claims] A signal transmission method (=) in which communication is performed using a row or column vector of a 4fi-order Hadamard matrix as a code word, characterized by the provision of a Hadamard transform device that linearly transforms a code word via a transmission path into another code word. signal transmission method.