The Performance of Turbo Codes on a Rayleigh Fading Channel for Wireless Communication Systems

To counteract the unavoidable noisy channel problem, error control coding is necessary which presently giving way to turbo codes. Due to high complexity and bandwidth requirement of the traditional approach, turbo codes are evolved. Turbo codes offer great reliability of communications over Rayleigh fading channels where AWGN is problematic. This paper provides a description of Softinput soft-output (SISO) turbo decoder based on soft-output Viterbi algorithm (SOVA). The performance and design of turbo codes using Non coherent DPSK signaling on the Rayleigh fading channel is considered. The bit error rate (BER) performances of AWGN and Rayleigh fading Channels are compared. Simulation results ar provided for bit error rate performance using constraint lengths of K=3, over Rayleigh fading channel, show improvements of 0.4 dB for SOVA at BER 10-4.