Reduction of multipath propagation effects in microwave digital radio communication systems

The aim of this article is to create analytical models that estimate the continuity and effectiveness of digital radio communication systems using multipositional types of modulation (CAM-M, PM-M, FM-M, AM-M) and block coding according to the Reed–Solomon algorithm (RS) with hard decoding. In contrast to the well-known approaches to determining the noise immunity of systems that require computation model, new estimating models are presented that do not require knowledge of the spectrum coefficients, computer simulation training methods and graphical construction of interference curves for various types of modulation and coding parameters. The calculated ratios presented in the article include only the main parameters of the code (free distance, codeword length, relative code speed) and of the modulation type (modulation order, squared noise immunity). They make it possible to directly determine the theoretically required values of signalto-noise ratios (SNR) for input devices from given probabilistic errors based on RS signals, as well as to study the energy gain from coding (EGC), accessible and frequency-efficient systems. Based on the proposed rations, the calculations of the main characteristics of the communication channels for various parameters of the RS codes, the reliability of reception, types and orders of modulation are performed. Comparison of the results of calculation of noise immunity and system effectiveness given in the article with known similar characteristics obtained as a result of computer modeling confirms the correctness of the presented analytical models. The error of the constructed noise immunity curves does not exceed 0.1 dB in the operating range of the SNR. The materials presented in this article are original and can be used in the design, calculation and development of terrestrial and satellite systems.

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A generalized concatenated coding scheme for CDMA digital radio communication systems

10.1109/wncmf.1994.529149 ◽

2002 ◽

Author(s):

P. Kempf ◽

J. Khunjush

Keyword(s):

Communication Systems ◽

Radio Communication ◽

Concatenated Coding ◽

Digital Radio ◽

Coding Scheme

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Beyond the “Point of No Return”

Innovations in Organizational IT Specification and Standards Development ◽

10.4018/978-1-4666-2160-2.ch010 ◽

2012 ◽

pp. 166-182

Author(s):

Anique Hommels ◽

Tineke M. Egyedi

Keyword(s):

Communication Systems ◽

Dutch Government ◽

Radio Communication ◽

Emergency Communication ◽

Digital Radio ◽

Point Of No Return ◽

Innovation Project ◽

Radio Equipment ◽

Digital Communication Systems

This paper analyzes the role of ‘irreversibility’ in the decision-making process for a standard for the national Dutch emergency communication network. In the late 1980s, ETSI, the European Telecommunication Standards Institute, started the development of the so-called Tetra standard. Tetra is a standard for digital radio communication and is mostly applied in emergency communication (for police, ambulance, and fire brigade). In the early 1990s, several European governments decided to replace their analogue radio equipment for emergency communication by advanced digital communication systems. The Dutch involvement in Tetra started around 1992, but it took until November 2001 before the official governmental decision to launch the national C2000 network was taken. This paper argues that at that moment the ‘point of no return’ of the C2000 project had already passed (in the mid 1990s). We explain this using the concept of ‘constructed irreversibility’. We analyze a number of core decisions and choices of the Dutch government in the C2000 project that resulted in irreversibility. We conclude by discussing the disadvantages and the advantages of irreversibility in this innovation project.

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ИСПОЛЬЗОВАНИЕ РАЗВЕТВЛЕННОГО БИСПЕКТРАЛЬНО-ОРГАНИЗОВАННОГО КОДА В НЕСТАЦИОНАРНЫХ КАНАЛАХ СВЯЗИ С ЗАМИРАНИЯМИ

RADIOELECTRONIC AND COMPUTER SYSTEMS ◽

10.32620/reks.2019.1.05 ◽

2019 ◽

pp. 44-57

Author(s):

Виктория Владимировна Науменко ◽

Галина Анатольевна Проскура ◽

Александр Владимирович Тоцкий ◽

Валерий Борисович Шаронов

Keyword(s):

Gaussian Noise ◽

Communication Systems ◽

Noise Immunity ◽

Multipath Propagation ◽

Additive White Gaussian Noise ◽

Random Signal ◽

Lower Probability ◽

Radio Link ◽

Radio Waves ◽

Digital Radio

One of the main problems in modern wireless telecommunication systems and networks is the transmission and reception of signals in a multipath environment. Due to the nonideal impulse response of the communication channel, the frequency selective fading of the transmitted signal occurs. Diffraction and interference effects create a complex non-stationary structure of the electromagnetic field, which varies greatly in space and time. The method of branched BIS is organized - redundant coding, which allows you to receive and recognize a signal in a digital communication system in the presence of additive Gaussian noise, multipath propagation of radio waves, fading, random signal delays, as well as random changes in Doppler frequency shift. The advantages of the bispectral signal processing method include the ability to identify and evaluate the phase relationships of the spectral components in the observation, high noise immunity with respect to additive Gaussian noise and invariance to random signal time delays. The proposed method is based on solving the problem of multi-alternative detection and distinguishing of known triple signals against the background of interference according to test statistics – estimating the amplitude bispectrum by comparing the corresponding peak values of bi-amplitudes at the output of the matched bispectral filter. Since the bi-amplitude serves as a measure of the contribution of the frequency-phase dependences specified in a polyharmonic signal, the reception rule is to choose a triplet as the solution of a bispectrically organized signal, whose frequency dependencies are most similar to the frequency dependencies in the adopted oscillation. The aim of the work is to substantiate the advantages of using a branched bispectrically-organized code in digital radio communication systems in conditions of fading and multipath propagation of radio waves in comparison with the known redundant code. The results of computer statistical modeling of communication systems with the proposed coding method and the known one show a lower probability of symbol error for branched bispectrically-organized redundant coding under conditions of multipath radio propagation channels within the considered Rice and Rayleigh fade models. Computer simulations performed to show that the proposed method of branched bispectrically-organized redundant coding improves noise immunity in the propagation of radio waves in a channel with additive white Gaussian noise and also in a multipath radio link with fast and slow fading compared to the known frequency-redundant system-prototype.

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Beyond the "Point of No Return"

International Journal of IT Standards and Standardization Research ◽

10.4018/jitsr.2010120703 ◽

2010 ◽

Vol 8 (1) ◽

pp. 28-48 ◽

Cited By ~ 1

Author(s):

Anique Hommels ◽

Tineke M. Egyedi

Keyword(s):

Communication Systems ◽

Decision Making Process ◽

Radio Communication ◽

Emergency Communication ◽

Digital Radio ◽

Point Of No Return ◽

Innovation Project ◽

Radio Equipment ◽

Digital Communication Systems

This article analyzes the role of ‘irreversibility’ in the decision-making process for a standard for the national Dutch emergency communication network. In the late 1980s, ETSI, the European Telecommunication Standards Institute, started the development of the so-called Tetra standard. Tetra is a standard for digital radio communication and is mostly applied in emergency communication (for police, ambulance, and fire brigade). In the early 1990s, several European governments decided to replace their analogue radio equipment for emergency communication by advanced digital communication systems. The Dutch involvement in Tetra started around 1992, but it took until November 2001 before the official governmental decision to launch the national C2000 network was taken. This article argues that at that moment the ‘point of no return’ of the C2000 project had already passed (in the mid 1990s). We explain this using the concept of ‘constructed irreversibility’. We analyze a number of core decisions and choices of the Dutch government in the C2000 project that resulted in irreversibility. We conclude by discussing the disadvantages and the advantages of irreversibility in this innovation project.

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