Comparative study of turbo equalization schemes using convolutional, convolutional turbo, and block-turbo codes

Turbo equalizers have been shown to be successful in mitigating the effects of inter-symbol interference introduced by partial response modems and by dispersive channels for code rates of 1 2. In this contribution, we comparatively studied the performance of a range of binary phase-shift keying turbo equalizers employing block-turbo codes, namely Bose–Chaudhuri–Hocquenghen turbo codes, convolutional codes, and convolutional turbo codes having high code rates, such as = 3 4 and = 5 6, over a dispersive five-path Gaussian channel and an equally weighted symbol-spaced five-path Rayleigh fading channel. These turbo equalization schemes were combined with an iterative channel estimation scheme in order to characterize a realistic scenario. The simulation results demonstrated that the turbo-equalized system using convolutional turbo codes was the most robust system for all code rates investigated.