CN114244476B

CN114244476B - Data coding transmission method based on multiplying power code

Info

Publication number: CN114244476B
Application number: CN202111603899.2A
Authority: CN
Inventors: 秦柏林
Original assignee: Individual
Current assignee: Individual
Priority date: 2021-12-25
Filing date: 2021-12-25
Publication date: 2024-03-15
Anticipated expiration: 2041-12-25
Also published as: CN114244476A

Abstract

The multiplying power code is a novel data transmission code, and is used for generating a repair packet by constructing an exclusive OR function equation set, sending source data and repair data during data transmission, and decoding the source data only by receiving half of correct data at a receiving end. Two bytes of source data are in a group, 4 bits are used as a source symbol, a repair symbol is calculated by the source symbol through an exclusive OR equation, the source symbol and the repair symbol are numbered from 0 to 7, 0 to 3 are the source symbols, and 4 to 7 are the repair symbols, so that 8 bytes are formed; the highest bit of each byte is an odd check bit, and then 3 bits are serial numbers; a byte with a value of 0 is added as a unit interval identification. The receiving end receives 8 bytes from 0, judges whether the first four bytes are correct or not according to the check value, and obtains source data; if one or more of the bytes are wrong, taking out the correct bytes in the 4 bytes, wherein the total number of the correct bytes is more than or equal to 4, and calculating the source data through an equation set; if the correct byte is less than 4, decoding is not possible.

Description

Data coding transmission method based on multiplying power code

Technical Field

The method is suitable for data transmission and data storage.

Background

Whether wired or wireless, efforts are constantly being made to find a way to transmit data reliably in one direction, from the earliest hamming code to the latest fountain code. At present, a response retransmission mechanism is widely used in the field of wired and wireless network communication, and the mode causes extremely low data transmission efficiency under the condition of poor channel quality; acknowledgement acknowledgements themselves in the acknowledgement mechanism may also be lost due to data errors, which may result in the sender always waiting for acknowledgement information at the receiving end. In engineering application, we have hard to explore, hope to find a unidirectional reliable transmission coding method, and turbo codes and fountain codes are created. In the practical use of both codes, too many inconveniences are found, for example: the turbo code binds the channel quality, the fountain code does not protect the packet sequence number and the transmission meta information, the meta information which needs to be encoded during decoding, if the key data are transmitted by the channel, the data can be in error, therefore, the new code is designed to solve the problems, namely, the channel quality is irrelevant, the meta information is protected, and meanwhile, the decoding end does not need any information of the encoding end. The binary data is known to be transmitted in a wired or wireless way, the 0,1 error probability is always 50%, the basic error rate does not exceed 50%, and therefore, the redundancy is 50% of the data quantity, decoding can be guaranteed under the condition that the error rate is not more than 50%, the error rate of the existing communication equipment is lower than 50% (the receiving and transmitting rate is reduced when the error rate is higher than 50%), and the reliable unidirectional transmission is similar.

Disclosure of Invention

Mathematical principle of encoding and decoding

The exclusive or expression is known to have the following characteristics:

A XOR B＝D

A＝D XOR B

it is necessary to transmit data in units of 2 bytes and one unit is divided into 4 source symbols, each of which is 4 bits long. The source notation we describe as A B C D to construct algebraic equations

X1∧X2∧X3∧X4＝R1

X1∧X3∧X4＝R2

X1∧X2∧X4＝R3

X2∧X3∧X4＝R4

Solving the equation to obtain

X1＝R1∧R4

X2＝R1∧R2

X3＝R1∧R3

X4＝R2∧R3∧R4

The source symbol number i=4 at the transmitting end and the repair symbol number j=4 at the receiving end, and the necessary condition for decoding is (i+j) > =4; we consider two extreme cases:

1、i＝0,j＝4

the source code can be decoded by the following formula:

X1＝R1∧R4

X2＝R1∧R2

X3＝R1∧R3

X4＝R2∧R3∧R4

2、i＝4,j＝0

directly obtaining source data without decoding removes the two extremes above, leaving now the case (i+j) > = 4, i >0, j <4

The number of source symbols to be solved is 4-i, the number of unknown repair symbols is 4-j, for the unknown repair symbol equation, we can obtain a system of reduced element equations by exchanging any source symbol value known on the left with the unknown repair symbol on the right, and all the wrong or lost source symbols can be obtained by the elimination method. Therefore, 8 symbols we transmit can decode the source symbol as long as any 4 symbols are received correctly. For practical application, the data to be transmitted is encoded according to 2 byte groups, and a large amount of encoded data is formed into a large data packet to be transmitted.

Coding format description

The encoding format is shown in fig. 1, and the source data has two bytes and 9 bytes after encoding. The first byte is 0 to identify the data unit header, and at the same time, if an error occurs in the middle, the first byte is used to find the data start position again at the decoding end. The next 4 bytes are the source symbol and the last 4 bytes are the repair symbol. The byte structure of the source symbol and the repair symbol is: the first bit is an odd parity bit, the odd number 1 of the 7 bits is 0, and the even number 1 is 0. Therefore, all bytes of source and repair symbols are not all 0 at all times. Bits 2 through 4 are used as sequence numbers (0-7) to identify the corresponding equation variables, with the last 4 bits being used as the source symbol or repair symbol. The purpose of the design is to facilitate the identification of the source symbol and the repair symbol and the corresponding equations thereof, and simultaneously, whether the source symbol or the repair symbol is transmitted correctly can be judged; error discarding, correctly used for decoding, if the total number of source symbols and repair symbols is greater than or equal to 4, then decoding, otherwise, discarding without decoding.

Overview of practical applications of encoding and decoding

In the above, we describe the mathematical principles of encoding and decoding and the encoding format in detail, and then we describe the practical application flow in detail. As shown in fig. 2, the data in the transmission buffer queue is taken out and encoded, the encoded data forms an MCS transmission size, and the MCS transmission size is sent to a transmitting device, where the transmitting device may be a wireless modulator or a network communication transmitting device; the receiving device receives the data, judges the initial position of the decoded data by checking whether the first byte is 0, reads 8 bytes from the first byte which is 0 for decoding, puts the decoded data into a receiving buffer, and gives the decoded data to an upper layer communication protocol for processing.

Drawings

Fig. 1 is a detailed codec format and description.

Fig. 2 is an actual codec usage flow.

Claims

1. The data coding transmission method based on the multiplying power code is characterized in that an exclusive OR function equation set is constructed to generate a repair packet, source data and repair data are sent during data transmission, and a receiving end can decode the source data only by receiving half of correct data; two bytes of source data are in a group, 4 bits are used as a source symbol, the source symbol calculates a repair symbol through an exclusive OR equation, the source symbol and the repair symbol are numbered from 0 to 7, 0 to 3 are the source symbols, 4 to 7 are the repair symbols, 8 bytes are formed, the highest bit of each byte is a parity check bit, then 3 bits are serial numbers for identifying a corresponding equation, and the last 4 bits are data bits; adding a byte in front of the source symbol to form unit data, wherein the added byte value is 0 and is used as a unit data interval mark; the receiving end receives 8 bytes from 0, judges whether the first four bytes are correct or not according to the check value, and obtains source data; if one or more of the bytes are wrong, the correct bytes in the 4 bytes are taken out, the total number of the correct bytes of the source symbol and the repair symbol is more than or equal to 4, and the source data is calculated through an equation set; if the correct total number of bytes is less than 4, the set of data is discarded.