KR19980039197A - Channel redundancy method using PN code - Google Patents

Abstract

The present invention can support the parity for error detection without additional bits by duplexing the channel by simultaneously transmitting two pieces of information in one channel, and by performing synchronization automatically when decoding the two pieces of information at the same time. The synchronization of each channel is also automatic, and a method of duplexing a channel using a PN code which can be easily encrypted by changing the encoding method if encryption is required is disclosed.

Description

Channel redundancy method using PN code

The present invention relates to a channel redundancy method using a PN code, and in particular, two information is simultaneously transmitted in one channel to duplicate the channel, and at the same time, the synchronization is automatically performed when decoding two pieces of information at the receiving side. The present invention relates to a channel duplication method using a PN code.

In the conventional channel duplication method, in order to transmit two pieces of information, each channel must be allocated and transmitted, or one channel must be sequentially transmitted alternately with a time difference. At this time, the information received side inevitably has a parallax on the side receiving the information, therefore, it is necessary to synchronize the information. Also, the information is errored due to the influence of noise in the transmission process. Thus, there is also a need for handling errors in the received information.

Accordingly, an object of the present invention is to provide a channel duplication method using a PN code that can duplicate a channel by encoding an input source to be transmitted using characteristics of a PN code.

According to an embodiment of the present invention, a channel duplexing method using a PN code includes encoding two channel information to be transmitted into a PN code, and adding the information encoded by the PN code to a modular 2 adder. Characterized in that it comprises the step of transmitting to the receiving side in one channel.

1 is a circuit diagram shown by explaining a method of encoding channel X. FIG.

2 is a circuit diagram shown by explaining a method of encoding channel Y. FIG.

Figure 3 is a circuit diagram shown by explaining the encoding method according to the present invention.

* Explanation of symbols for the main parts of the drawings

101,102,103,201,202,203: Shift register

104,204: Modulo 2 adder

105,106,107,205,206,207: Initial value setting line of the shift register

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

In order to encode the input source of the channel X, as shown in FIG. The output looks like this:

Initial state 1 1 1 Output

0 1 1 1

1 0 0 1

0 1 0 1

1 0 1 0

1 1 0 1

1 1 1 0

Meanwhile, in order to encode the input source of the channel Y, a three-stage shift register 201, 202, 303 and a module having the transmission input sources 207, 206, and 205 as inputs, respectively, as shown in FIG. When the circuit is constituted by the low adder 204, the output of the shift register 203 becomes as follows.

Initial state 1 1 1 Output

0 1 1 1

1 0 1 1

0 0 1 0

1 0 0 0

1 1 0 0

1 1 1 0

Here, the initial value of the shift register may be set to 0 or 1 as the signal line of (105, 106, 107, 205, 206, 207).

The output of channel X is (1 1 1 0 0 1 0 1 1 1 0 0 1 0 .....), and the output of channel Y is (1 1 1 0 1 0 0 1 1 1 0 1 0 0 .. Indefinite repetition. If one symbol is assigned to each channel in units of 7 bits, which is a period of the PN code, and each symbol is assigned to 7 bits shifted by one bit, 7 different symbols for each channel can be obtained. The following shows the bits of the symbols assigned to each channel.

Symbol Channel X Channel Y

A 1110010 1110100

B 0111001 0111010

C 1011100 0011101

D 0101110 1001110

E 0010111 0100111

F 1001011 1010011

G 1100 101 1101001

The symbol value of each channel generated by using the characteristics of the PN code and the mirror characteristics of the PN generator is added to the modulo diadder 301.

As shown in FIG. 3, when a new symbol combining the symbols of the channel X 302 and the channel Y 303 is transmitted, information of two channels can be simultaneously transmitted to one channel. The following shows the symbols to be transmitted, encoded in the above manner. In the following notation (X * Y), X denotes a symbol of channel X, Y denotes a symbol of channel Y, and * denotes that symbols of channel X and channel Y are encoded by the method proposed in the present invention. Means that.

(A * A) 0 0 0 0 1 1 0

(A * B) 1 0 0 1 0 0 0

(A * C) 1 1 0 1 1 1 1

(A * D) 0 1 1 1 1 0 0

(A * E) 0 1 0 0 0 0 1

(A * G) 0 0 1 1 0 1 1

(B * A) 1 0 0 1 1 0 1

(B * B) 0 0 0 0 0 1 1

(B * C) 0 1 0 0 1 0 0

(B * D) 1 1 1 0 1 1 1

(B * E) 0 0 1 1 1 1 0

(B * F) 1 1 0 1 0 1 0

(B * G) 1 0 1 0 0 0 0

(C * A) 0 1 0 1 0 0 0

(C * B) 1 1 0 0 1 1 0

(C * C) 1 0 0 0 0 0 1

(C * D) 0 0 1 0 0 1 0

(C * E) 1 1 1 1 0 1 1

(C * F) 0 0 0 1 1 1 1

(C * G) 0 1 1 0 1 0 1

(D * A) 1 0 1 1 0 1 0

(D * B) 0 0 1 0 1 0 0

(D * C) 0 1 1 0 0 1 1

(D * E) 0 0 0 1 0 0 1

(D * F) 1 1 1 1 1 0 1

(D * G) 1 0 0 0 1 1 1

(E * A) 1 1 0 0 0 1 1

(E * B) 0 1 0 1 1 1 0

(E * C) 0 0 0 1 0 1 0

(E * D) 1 0 1 1 0 01

(E * E) 0 1 1 0 0 0 0

(E * F) 1 0 0 0 1 0 0

(E * G) 1 1 1 1 1 1 0

(F * A) 0 1 1 1 1 1 1

(F * B) 1 1 1 0 0 0 1

(F * C) 1 0 1 0 1 1 0

(F * D) 0 0 0 0 1 0 1

(F * E) 1 1 0 1 1 0 0

(F * F) 0 0 1 1 0 0 0

(F * G) 0 1 0 0 0 1 0

(G * A) 0 0 1 0 0 0 1

(G * B) 1 0 1 1 1 1 1

(G * C) 1 1 1 1 0 0 0

(G * D) 0 1 0 1 0 1 1

(G * E) 1 0 0 0 0 1 0

(G * F) 0 1 1 0 1 1 0

(G * G) 0 0 0 1 1 0 0

Regarding the combined symbols of the received channels X and Y, referring to (X * Y) described above, it is possible to know which symbol is transmitted in each channel. For example, if the received symbol is 1 0 0 1 0 0 0, it corresponds to (A * B). Therefore, it can be seen that the symbol A is transmitted in channel X and B in channel Y. Therefore, since information sent from two channels can be known at the same time, information on the two channels is automatically synchronized during decoding.

In addition, the combined information automatically configures even parity since the number of 1s is always even according to the characteristics of the PN code.

As an advantage of the method proposed in the present invention, since one channel can be duplexed in the existing communication system without any change, it can be applied to the existing communication model. In addition, since the encoded symbol retains the characteristics of the PN code, parity bits for error processing are automatically included, so there is no need to use a separate parity bit.

In addition, when restoring each piece of information, synchronization occurs automatically. If you increase the number of shift registers, it is impossible to recover the information without knowing the PN code generator used.

Since the PN code uses an odd number of bits as bits of a symbol, it is difficult to apply the PN code to a commonly used 8-bit system scheme. However, if the parity bit is used, it becomes 9 bits, so that the method proposed in the present invention can be applied without any problem. In this case, the parity for information is applied twice.

Looking at the number of symbols is an odd number, because 000 cannot be used as the initial value of the shifter register. However, in the case of 000 in the encoding process, this can be solved by giving a separate unused code.

As described above, according to the present invention, since two types of information can be transmitted through one channel by encoding and transmitting the input source to be transmitted with a PN code, the channel can be duplicated and a parity function for processing an error is added. It also has an excellent effect with passwords.

Claims (1)

Encoding two channel information to be transmitted into a PN code, and transmitting the information encoded by the PN code to a receiver by adding a modular 2 adder to a receiving side through a PN code. Channel redundancy method.