The method and simulation model for the synthesis of barker-like code sequences

Noise immunity is one of the essential characteristics of modern wireless data reception/transmission systems. In wireless systems such as Wi-Fi, HiperLan, or Bluetooth, the signal is propagated by electromagnetic oscillations in the environment. However, unlike wiring systems, these oscillations are unprotected from external influences. Noise immunity is one of the essential characteristics of modern wireless data reception/transmission systems. Moreover, if several wireless systems work close enough to each other, there is a possibility of overlapping waves, which will damage the information signal. It is determined that for the tasks of control of unmanned aerial vehicles and mobile robotic complexes increasing the noise immunity of data transmission channels is an urgent problem. It has been investigated that Barker-like code sequences based on ideal ring bundles provide an increase in the power of the obtained sequences by optimizing the parameters of the ideal ring bundles used. It is determined that the increase of noise immunity during data reception and transmission is achieved by choosing the optimal ratios of the parameters of the ideal ring bundle. It is shown that the advantages of Barker-like code sequences such as the optimal ratio between the length of the sequence and its correcting ability, the ability to change the length of the sequence depending on the level of interference are widely used in modern wireless communication and telecommunications systems. The method of synthesis of Barker-like code sequences with the use of ideal ring bundles has been improved, which, by taking into account the ratios of the parameters of ideal ring bundles, provides the choice of the minimum bit code sequence that takes into account the level of interference. A simulation model of synthesis of Barker-like code sequences, noise generation, and error correction has been developed on the basis of the improved method of synthesis of Barker-like code sequences. The developed simulation model is used to study the processes of coding, decoding, detection, and correction of errors in the obtained Barker-like code sequences. It has been investigated that the use of synthesized Barker-like code sequences based on ideal ring bundles provides data recovery of damaged no more than 25 % of the bits of each codeword, and detects up to 50 % of damaged bits in each codeword. Keywords: Barker-like code sequence; ideal ring bundle; noise-tolerant coding; simulation model.

Introducing perforation when applying turbo codes

The problem of adapting the degree of redundancy introduced in the process of error-correcting coding to the changing characteristics of the data transmission channel is urgent. Turbo codes, used in a variety of digital communication systems, are capable of correcting multiple errors occurring in the data transmission channel. The article compares the decoding efficiency for various options for introducing perforation into the code sequence generated by the turbo code encoder. Based on the comparison results, recommendations were made on the most appropriate option for the introduction of perforation.

Physical layer synchronization algorithms for signal-code sequence increasing noise immunity of dvb-s2x standard vl-snr mode

The work is devoted to expanding the noise immunity of the DVB-S2X standard and the VL-SNR mode physical layer synchronization algorithms. The article proposes a signal-code sequence that increases the noise immunity of the signal, operating down to −11 dB signal-to-noise ratio, and a synchronization system for it.

SYNTHESIS OF BARKER-LIKE SEQUENCES WITH ADAPTATION TO THE SIZE OF THE INTERFERENCE

The method of synthesis of noise-resistant barker-like code sequences with the use of ideal ring bundles has been improved. The method for fast finding of such noise-like noise-resistant code sequences, which are able to find and correct errors in accordance with the length of the obtained code sequence, has been improved. An algorithm is implemented to quickly find such noise-resistant barker-like code sequences that are able to find and correct errors in accordance with the length of the obtained code sequence. A simulation model of noise-tolerant barker-like coding with the use of ideal ring bundles has been developed. The possibility of reducing the redundancy of noise-tolerant code sequences by cutting code sequences by a certain number of bits without losing the regenerative capacity of noise-tolerant codes has been investigated. Theoretical analysis of the possibilities of this approach and its effectiveness is performed. Several series of experimental studies of the reliability of the described method on different data samples were performed and its functional efficiency was confirmed. The analysis of the obtained data and identification of key factors influencing the result is carried out. The practical software implementation of the simulation model of noise-tolerant barker-like coding for finding and correcting errors in the obtained noise-tolerant barker-like code sequences is carried out. The used methods and algorithms of data processing, the main components for message processing and their purpose are described. The possibility of reducing the redundancy of noise-tolerant code sequences by reducing the code sequences by a certain number of bits without losing the reproducibility of noise-tolerant codes has been investigated. Theoretical analysis of the possibilities of this approach and its effectiveness is performed. Several series of experimental studies of the reliability of the described method on different data samples were performed and its functional efficiency was confirmed. The analysis of the obtained results is performed and the main factors influencing the obtained result are determined. The proposed noise-tolerant barker-like code sequences have practical value, because with the help of the obtained barker-like code sequence it is quite simple and fast to find up to 50 % and correct up to 25 % of distorted characters from the length of noise-tolerant barker-like code sequence.