THE BASICS OF SELECTING THE OPTIMAL PARAMETERS OF ERROR-CORRECTING CODES FOR TELECOMMUNICATION SYSTEMS

2020 ◽  
Author(s):  
М.А. Быховский
Keyword(s):  
Communication Systems ◽  
Ldpc Code ◽  
Satellite Communications ◽  
Error Correcting Codes ◽  
Rs Codes ◽  
Transmission Reliability ◽  
Multidimensional Signal ◽  
Large Length ◽  
Parity Check Codes ◽  
Communications System

Рассмотрены основные принципы выбора параметров помехоустойчивых кодов для систем связи. Приведены формулы для вероятности ошибки декодирования разных кодов в зависимости от их длины и от вероятности ошибки демодуляции сигналов. Показано, что коды Рида-Соломона (RS) достаточно большой длины позволяют обеспечить высокую помехоустойчивость приема сообщений. Показано также, что в системе связи, в которой сообщения передаются с помощью многомерных ансамблей сигналов, а помехоустойчивые коды не используются, высокая помехоустойчивость приема сообщений обеспечивается при предельно малом отношении сигнал/шум на входе демодулятора. Выполнено сравнение параметров систем связи с кодами RS и спутниковой связи стандарта DVB-S2 с двоичными кодами с малой плотностью проверочных символов (LDPC). Показано, что высокая надежность передачи в системе обеспечивается при использовании с кода RS, имеющего существенно меньшую длину, чем у кода LDPC. The basic principles of selection of parameters of error- correcting codes for communication systems are considered. Formulas, that allow determining the probability of decoding errors of different codes depending on their length and the probability demodulation errors of signals, are given. It is shown that Reed-Solomon (RS) codes of a sufficiently large length make it possible to ensure high noise immunity of receiving messages. It is also shown that in a communication system in which messages are transmitted using multidimensional signal ensembles, and error-correcting codes are not used, messages can be transmitted at a given speed with an extremely small signal/noise ratio at the input of the demodulator. A comparison of the parameters of communication systems with RS codes and the DVB-S2 satellite communications system with binary low-density parity-check codes (LDPC) is performed. It is shown that high transmission reliability in the system is achieved by using an RS code having a significantly shorter length than the LDPC code.

scholarly journals MIMO-Filtered OFDM System Improvement Using Modified Concatenated RS/LDPC Codes

2021 ◽  
Author(s):  
Ghasan Ali Hussain
Keyword(s):  
Wireless Communication ◽  
Communication Systems ◽  
Ldpc Codes ◽  
Ldpc Code ◽  
Error Rates ◽  
Wireless Communication Systems ◽  
Ofdm System ◽  
Rs Codes ◽  
Concatenated Code ◽  
Ber Performance

Abstract In mobile communication systems, there are errors that will be generated in the digital signal due to fading and interference. Consequently, different techniques are used to improve the system's reliability and enhance the signal's robustness. Channel coding techniques are used to enhance the system reliability of 5G wireless communication systems . In the upcoming wireless technologies, LDPC codes are still introduced as an alternative to turbo codes. However, the error floor phenomenon is one of the biggest demerits of using LDPC code in the different communication systems that need low error rates. This paper uses RS codes with LDPC codes in a concatenated code to solve this demerit of LDPC codes. Meanwhile, a modified concatenated RS/LDPC codes are created using outer RS codes with inner LDPC codes then appended by interleaver, unlike the conventional concatenated codes that use the interleaver between both codes. Thereafter, the modified concatenated RS/LDPC codes were suggested to enhance BER performance for the f-OFDM system. The results showed that using the proposed concatenated code outperformed using single and familiar concatenated RS/LDPC code in terms of improving BER performance. Meanwhile, the proposed system achieved lower OOBE values than the conventional OFDM system. Therefore, the resulted system can be introduced as a competitor candidate for 5G wireless communication systems due to these features

INNOVATIVE METHOD OF SATELLITE COMMUNICATION

2019 ◽  
Author(s):  
Teodor Narytnik ◽  
Vladimir Saiko
Keyword(s):  
Communication Systems ◽  
High Speed ◽  
Satellite Communication ◽  
Radio Channel ◽  
Satellite Communications ◽  
Service Area ◽  
Satellite Systems ◽  
Orbit Satellite ◽  
Geometric Size ◽  
Distributed Satellite

The technical aspects of the main promising projects in the segments of medium and low-orbit satellite communication systems are considered, as well as the project of the domestic low-orbit information and telecommunications system using the terahertz range, which is based on the use of satellite platforms of the micro- and nanosatellite class and the distribution of functional blocks of complex satellite payloads more high-end on multiple functionally related satellites. The proposed system of low-orbit satellite communications represents the groupings of low-orbit spacecraft (LEO-system) with the architecture of a "distributed satellite", which include the groupings of the root (leading) satellites and satellite repeaters (slaves). Root satellites are interconnected in a ring network by high-speed links between the satellites. The geometric size of the “distributed satellite” is the area around the root satellite with a radius of about 1 km. The combination of beams, which are formed by the repeater satellites, make up the service area of the LEO system. The requirements for the integrated service area of the LEO system (geographical service area) determine the requirements for the number of distributed satellites in the system as a whole. In the proposed system to reduce mutual interference between the grouping of the root (leading) satellites and repeater satellites (slaves) and, accordingly, minimizing distortions of the information signal when implementing inter-satellite communication, this line (radio channel) was created in an unlicensed frequency (e.g., in the terahertz 140 GHz) range. In addition, it additionally allows you to minimize the size of the antennas of such a broadband channel and simplify the operation of these satellite systems.

Sign in / Sign up

Export Citation Format

Share Document