Wyniki 1-4 spośród 4 dla zapytania: authorDesc:"Anatoliy Platonov"

Analysis of adequacy of power-bandwidth efficiency and mse of transmission as the measures of communication systems performance

  Approaching of the power-bandwidth efficiency of wireless communication systems (CS) to the theoretical limit is considered now as the urgent task of communication and information theory [1]. However, choice of the commonly accepted criterion of CS performance remains open problem. The reason is existence of a number of qualitatively different measures of efficiency intricately connected by different forms of trade-offs [2, 3]. Also mass production of individual cellular and local communication units radically increased the role of the market and deployment criterions such as sizes, complexity, cost, energy consumption of the units and others [3]. Development of analytical tools enabling optimal conjunction of these criterions and formulation of cross- group criterions meets great difficulties, and different approaches to the solution of this task are proposed [2, 3]. Recently, the basic and most widely used criterions of the CS performance are: - bandwidth efficiency (B) determined by the number of bits R/F0 transmitted per second per Hertz of the channels bandwidth (R is the bit-rate of transmission, F0 is the channel bandwidth); - power efficiency (P) determined by the "energy of bit" Ebit =WsignT bit =Wsign / R, or by "normalised" SNR E bit/Nx , where W sign is power of the signal at the channel output, and Nx /2 is the double-side spectral power density of the channel noise; - bit error rate (BER) determined as the probability of erroneous transmission of a single bit. In the previous decades, main attention was paid to improvement of the B-efficiency considered as the basic criterion due to the rapidly growing number of users and limited spectral resources [4]. Transition to GHz diapason has weakened the bandwidth limitations. In turn, rapidly growing (by 10-15% per year) energy consumption of communication systems radically increased the requirements to their power efficiency [2]. The third criterion - bit error rate [...]


  The paper discusses difficulties in evaluation of performance of the local wireless communications systems (CS) transmitting the signals from analog sources (ACS). These systems can be considered as a special class of the remote measurement systems, and quality of transmission can be assessed by the mean square error (MSE) of the recovered signals. Currently, both the analog and digital signals are transmitted using digital technologies, and performance of digital CS (DCS) is assessed by the group of particular criterions. This makes impossible a development of the strict analytical approach to DCS optimization that can be done for ACS on the basis of MSE criterion. The latter one enables design of top performance ACS transmitting the signals with maximal energy-spectral efficiency.1 1. INTRODUCTION The most actual task in design of the battery supplied ACS is a reduction of their energy consumption. The not less important task is optimal utilization of the channel bandwidth, as well as a reduction of interchannel interference, security of the signals and data transmission, greater coverage, decrease of the complexity and cost of CS, and others. Nowadays, communications employ only digital technologies for the signals transmission. Apart from the basic criterions, quality of transmission and performance of DCS as a whole are assessed by a large number of additional criterions important for applications of the systems [1], (see also Sect. 2). All the criterions are mutually connected by plural tradeoffs [2]. This disables a development of the systematic analytical approach to the search of optimal balance between different demands to DCS, and makes impossible adequate comparison of their performance. The result is the lack of systematic approach to design of DCS optimally utilizing resources of their transmitters, receivers and channels, and most relevant to the aims and scenario of the suggested applications. In turn, re[...]


  Nowadays, digitizing and coding is of the signals transmission, independen sources of signals analog or digital. However, in 1965 1970s, communication systems (CS) wi channels transmitting without coding w intensive research carried out in two directions. The first one (e.g. [1]-[7]) was concentrated on development of optimal FCS transmitting signals from sources iteratively with the performance attaining the Shannon’s limits. Objective of the second d [8]-[11]) was a development of FCS iteratively ting discrete signals (code blocks) over channel with substantially decreased e Each directions had independent and ve results, periods of greater or weaker attention but co mon difficulty was (and remains) the lack of impleme tation. The single example of practical application FCS is automatic repeat request (ARQ) The paper is devoted to the analysis of reasons which blocked application of the results of these r searches. As our investigations show, these reasons have Poznań, 21 ZAGADNIENIACH OPTYMALIZACJI SYSTEM NYCH KANAŁEM ZWROTNYM I IMPLEMENTACJA FEEDBACK COMMUNICATION SYSTEM systemów przesyłania omówione relacje i SPS z kasygnały resents communication FCS kanały zwrotne, Kailatha, transmisja , efektywność without coding, a single method ntly from are the 1965- with feedback were the subject of the analog f direction (e.g. transmit- ) analog forward error probability. verified analytical comthe implementation. of uest transmission. reasons, rerches. common source, and its removal of research in both directions applicable in practice. The paper is organized as follows. Sect. 1 devoted to the analysis and solution implementation of adaptive FCS transmitting analog i put signals (AFCS). In Sect. 3, in implementation of FCS transmitting discrete input signals (DFCS) have the same source, and can be r moved in the same way as in AFCS. of the code blocks transmission is discussed in Sect. 4 Brief [...]


  DESIGN AND TUNING OF HARDWARE IMPLEMENTATION OF ANALOG FEEDBACK COMMUMMUNICATION SYSTEM Streszczenie: W referacie omówiono podstawowe etapy projektowania i testowania prototypu wysokoefektywnego analogowego systemu telekomunikacyjnego z kanałem zwrotnym (AFCS) przeznaczonego do przesyłania sygnałów analogowych przez kanał z szumem. System zapewnia maksymalną energetyczną i widmową efektywność transmisji przy minimalnym średniokwadratowym błędzie (MSE) odtworzenia wartości sygnału. Prototyp realizuje opracowany wcześniej optymalny algorytm AFCS transmisji. Zmierzone charakterystyki systemu porównano z teoretycznie osiągalnymi1. Abstract: The paper discusses the main stages of real design of the hardware prototype of highly-efficient analog feedback communication system (AFCS) transmitting signals from analog sources. The system ensures maximal power and bandwidth efficiency of transmission and minimal mean square error (MSE) of the recovered signals. The design implements optimal AFCS algorithm, which was developed earlier. The measured characteristics of the system are compared with theoretically achievable. Słowa kluczowe: analogowa transmisja, adaptacyjna modulacja, AFCS, optymalizacja, projektowanie Keywords: analog transmission, adaptive modulation, AFCS, optimization, design 1. INTRODUCTION In his first work on information theory [1], C. Shannon stressed that difference between the analog and digital communication systems (CS) concerns only fidelity criteria and internal architectures. In the years 1960- 1970s, analog transmission was the subject of not less intensive researches than digital ones ([2]-[4] and other works). The obtained results unambiguously proved a capability of analog CS with feedback channels (AFCS) to transmit signals without coding with a bit rate equal to the capacity of the forward channel. However, research 1 The work was supported in part by the grant SDZP 214108 (GEKON) of Polish Nationa[...]

 Strona 1