Modified Soft Output Viterbi Error Correcting Algorithm

employed for decoding digital signals. Bit Error Rate (BER) performance obtained using SOVA is very close to Shannon’s capacity limit in Additive White Gaussian Noise (AWGN) channel. The SOVA is three times less in complexity compared with Maximum a Posteriori (MAP) algorithm. Introducing a common scaling factor in the extrinsic information can improve performance of SOVA with minimal iteration. This paper presents the results of simulation of SOVA and a modified SOVA in AWGN and fading channel. The BER performance of Turbo codes is found to improve even in fading environment on using the modified SOVA. Input here the part of summary. Key words: BER, AWGN, SOVA, MAP, Turbo code