A Full-Rate Full-Diversity 2x2 Space-Time Block Code with Linear Complexity for the Maximum Likelihood Receiver

From engineering point of view, the simplicity of the decoder is a very important factor in designing different space-time block codes (STBCs) in wireless communications systems. On the other hand, full-diversity is an important factor which causes STBCs to have valid performance in terms of bit error rate (BER). High symbol transmission rate is also a significant factor in designing STBCs. Regarding these three characters, this paper proposes a full-rate STBC which benefits from a linear complexity for the optimum receiver and full-diversity properties. This code is designed for two transmit antennas and the complexity of its optimum receiver is linear for any arbitrary number of receive antennas. Simulation results also show that the performance of the proposed code is close to the performance of the Golden code when 4-QAM constellation is considered, and it effectively outperforms the Golden code when BPSK constellation is employed.