Blind equalization of space‐time‐turbo trellis coded/continuous phase modulation over Rician fading channels

Abstract

AbstractIn this paper, to improve bit error performance and bandwidth efficiency, we combine space‐time block codes (STBC), turbo trellis codes and continuous phase modulation and denote space‐time‐turbo trellis coded/continuous phase modulation (ST‐TTC/CPM). For high data transmission over wireless fading channels, STBC provide the maximal possible diversity advantage for multiple decoding algorithms. We present continuous phase modulation (CPM) for ST‐TTC signals, since CPM provides low‐spectral occupancy and is suitable for power and bandwidth‐limited channels. In our model, to utilize STBC efficiently, we need to estimate the channel parameters, which influence the signals having continuity property. Therefore, we develop a blind maximum likelihood channel estimation algorithm for signals propagating through a Rician fading channel. Here, Baum‐Welch (BW) algorithm, based on hidden Markov model (HMM), is modified to provide computationally efficient channel parameter estimation. We also investigate the performance of ST‐TTC/CPM in the case of no channel state information (CSI) for various Rician parameters K and Doppler frequency. Copyright © 2004 AEI.