Algorithm for the selection of error-correcting codes for the operation of radio communication systems in the shortwave range

Abstract

Introduction. One of the types of communication that exists and is actively being used at the present time are the systems of trunk-wire short-wave radio communication.

To ensure the necessary reliability of the transmission of information, it is necessary to apply noise-proof codes that are characterized by different indicators of code length, redundancy, etc. Increasing the redundancy of the code improves the reliability, but reduces the speed of the transfer of information. Depending on the task being solved, the question arises of solving the optimization problem of choosing the required jamming code. Therefore, the development of an algorithm that would provide the possibility of choosing the required noise immunity code to provide radio communication in the short-wave range under conditions of interference, depending on the solved problem, taking into account the parameters of the ionosphere and weather conditions, is an issue of relevance.

Theoretical analysis. To ensure the timely transmission of message flows, the radio communication system must have a certain level of bandwidth. When choosing a code for data transmission, the requirements for the reliability of the transmitted information and the speed of data transmission, which depend on the redundancy of the codes, the number of information elements, the length of the code, the number of verification elements, are monitored. The most common criterion for assessing the system's efficiency is to provide the necessary probability of correct signal reception and the probability of error detection in the code signal. These parameters depend on the condition of the radio channel, namely, the probability of distortion of one character in the binary channel, the minimum length of Hamming, the parameters of the code.

Algorithm. As a criterion for the algorithm, the ratio of the average value of the information quantity k / n to one code combination is selected. Control of this parameter allows adaptively to modify both the coding algorithm and the length of the code combination. This parameter affects both the maximum rate of transmission of information, and the probability of correct reception of the signal and the probability of error detection in the code signal and is within clearly defined limits.

The principle of the algorithm is to solve an optimization problem, namely, to locate such a noise immunity code, whose value k / n will be within these limits.

Conclusions. In the given article the algorithm of choice of interference-free codes for work of systems of radio communication in a short-wavelength range is developed, which provide the greatest bandwidth of a channel at the given error probability and the minimum speed of information transmission. This algorithm operates under conditions of interference and it can be used in other information transmission systems by adding other existing or new jamming codes.