Abstract : The main objective is to obtain low and fixed complexity for orthogonal frequency division multiplexing system. For that Space frequency Block Coding is used in which the space and frequency diversities are combined together in order to fully exploit the multiple-input multiple-output (MIMO) channel capacity. Full-rate full-diversity (FRFD) space-time codes (STC) such as the Golden code are studied for that purpose. However, despite their larger achievable capacity, most of them present high complexity for soft detection, which hinders their combination with soft-input decoders in bit-interleaved coded modulation (BICM) schemes. This article presents a new low complexity soft detection algorithm for the reception of FRFD space-frequency block codes in BICM orthogonal frequency division multiplexing (OFDM) systems. The proposed detector maintains a reduced and fixed complexity, avoiding the variable nature of the list sphere decoder (LSD) due to its dependence on the noise and channel conditions. We can implement this detection process in Orthogonal Frequency Division Multiple Accessing system and can achieve a better bit error performance.