In this paper, we propose two efficient symbol detection algorithms for space-frequency OFDM (SF-OFDM) transmit diversity scheme. When the number of sub-carriers in SF-OFDM scheme is small, the interference between adjacent sub-carriers is generated The proposed algorithms eliminate this interference in parallel or sequential manner and obtain a considerable performance improvement over the conventional detection algorithm. The bit error rate (BER) performance of the proposed detection algorithms was evaluated by the simulation. In the case of 2 transmit and 2 receive antennas, at BER=10-4 the proposed algorithms obtain about 3 dB gain. In the results of logic synthesis using 0.35 μm CMOS technology, the proposed SF-OFDM-PIC and SF-OFDM-SIC symbol detectors are composed of 28K and 26K logic gates, respectively. Since the proposed algorithms cancel the interference caused by the small number of sub-carriers and provide an excellent diversity advantage, SF-OFDM scheme with the proposed algorithms can be a good solution for the systems with the small number of sub-carriers such as wireless LANs.