Study of BER performance of BCJR algorithm for turbo code with BPSK modulation under various fading models

In Communication Systems, signals are transmitted through channel to the Receiver. Generally Receiver are built in order to recover the original message without any error. With the wired communication, the messages are recovered from the wired channel without any errors by considering only the transmitted message from transmit antenna. But now the trends are moved from the wired to wireless communication. In wireless channel, messages are faded or added to the noise. In such a case, the receiver infrastructure is designed not only to recover the message not only consider the transmitted signal from transmit antenna but also considers the noisy received signal received at receive antenna. To remove the error, caused due to noise and fading, arises from the channel, the various error control codes are used. Some of the error control codes are Hamming Code, Cyclic code, Convolution Code and Turbo Code. The first part of the paper presents the BCJR (Bahl — Cocke — Jelinek — Raviv) algorithm for Turbo code with BPSK modulation and analyzes the bit error rate performance of this algorithm with the AWGN noise over Rayleigh, Rician and Nakagami Fading Model. The second part of the paper presents comparison of BCJR algorithm for Turbo Code with the convolution code.