The decoding process is said to be “hard” when the signal at the input, or output, of the decoder is binary, i.e., a signal with only two quantization levels.
Published in Chapter:
Efficient Discrete Simulation of Coded Wireless Communication Systems
Pedro J.A. Sebastião (Instituto de Telecomunicações, Portugal), Francisco A.B. Cercas (Instituto de Telecomunicações, Portugal), and Adolfo V.T. Cartaxo (Instituto de Telecomunicações, Portugal)
Copyright: © 2010
|Pages: 35
DOI: 10.4018/978-1-60566-774-4.ch007
Abstract
Simulation can be a valuable tool for wireless communication system’s (WCS) designers to assess the performance of its radio interface. It is common to use the Monte Carlo simulation method (MCSM), although this is quite time inefficient, especially when it involves forward error correction (FEC) with very low bit error ratio (BER). New techniques were developed to efficiently evaluate the performance of the new class of TCH (Tomlinson, Cercas, Hughes) codes in an additive white Gaussian noise (AWGN) channel, due to their potential range of applications. These techniques were previously applied using a satellite channel model developed by Lutz with very good results. In this chapter, we present a simulation method, named accelerated simulation method (ASM), that provides a high degree of efficiency and accuracy, namely for lower BER, where the application of methods like the MCSM is prohibitive, due to high computational and time requirements. The present work generalizes the application of the ASM to a WCS modelled as a stochastic discrete channel model, considering a real channel, where there are several random effects that result in random energy fluctuations of the received symbols. The performance of the coded WCS is assessed efficiently, with soft-decision (SD) and hard-decision (HD) decoding. We show that this new method already achieves a time efficiency of two or three orders of magnitude for SD and HD, considering a BER = 1x10-4 , when compared to MCSM. The presented performance results are compared with the MCSM, to check its accuracy.