Precoding-Based Full Rate Quasi-Orthogonal Space-Time Block Codes
基于预编码的全码率准正交空时分组码

Due to the high decoding complexity of the conventional full rate Quasi-Orthogonal Space-Time Block Code (QOSTBC) over eight transmit antennas, two precoding-based transmit schemes are proposed. The new QOSTBC is extended from the OSTBC over four antennas. With the precoding matrix constructed with the two phase feedbacks, the orthogonalization of channel matrix cancels the Inter-Symbol Interference (ISI). The Maximum Likelihood (ML) decoding of independent symbol is realized. An extra performance improvement is achieved with the interleaving at the transmitter. Meanwhile, the ML decoding of two joint symbols is carried out. Unlike the constellation rotation scheme for the full diversity, the precoding scheme improves the performance of QOSTBC with reducing ISI to the most extent. Simulation results show that two precdoing-based QOSTBCs outperform the conventional QOSTBC with constellation rotation and achieve the lower decoding complexity.