Space time interleaving code

Multi input multi output system in frequency selective channel provides space and frequency diversity at the same time. Traditional space time codes suffer from rate loss or diversity order loss. Space time interleaving code (STIC) achieves full space and frequency diversity without rate loss. Random interleavers are embedded on different transmit antennas. Thus it is easy to apply the code to various number of transmit antennas. In order to simplify the complexity of STIC decoding, two kinds of iterative decoding structures were designed. One is passing extrinsic information between convolutional constraint and equalization constraint, the other is passing iteratively between summing constraint, convolutional constraint and equalization constraint. The simplified iterative decoders lower the receiver complexity from growing exponentially with the number of transmit antennas to growing approximately linearly with the number of transmit antennas. STIC not only achieves full rate full diversity but also makes it easy to implement in practice. Numerical experiments are implemented to prove the observations.