A review of turbo coding with channel estimation for Single input Single output system in ultra-wideband channel

摘要

This paper describes a review of turbo coding with channel estimation for Single-input and Single output system in ultra-wide band (SISO-UWB) channel. The common decoding algorithms used in turbo codes are Bahl, Cocke, Jelinek and Raviv (BCJR) algorithm, Viterbi algorithm, and Soft Output Viterbi Algorithm (SOVA). In the application of channel estimation with turbo codes the techniques used are maximum posterior probability (MAP) decoder, Least Square (LS) estimation, Discrete Fourier Transform (DFT), and Maximum Likelihood (ML). These techniques can improve system performance by re-estimating the channel after iteration of each decoder. BCJR algorithm and sign-change-ratio (SCR) criterion are recommended for turbo codes decoding and stopping iteration respectively. Least Square (LS) estimation technique can be used to estimate the channel parameter of turbo codes maximum iteration. It is believed that the proposed combination method can minimize turbo codes stopping iteration and hence, prevent computation delay, wasted power consumption as the iteration stages keep increasing when it reaches the maximum peak of the performances.