On an Orthogonal Space-Time-Polarization Block Code

Over the past several years, diversity methods such as space, time, and polarization diversity have been successfully implemented in wireless communications systems. Orthogonal space-time block codes efficiently combine space and time diversity, and they have been studied in detail. Polarization diversity has also been studied, however it is usually considered in a simple concatenation with other coding methods. In this paper, an efficient method for incorporating polarization diversity with space and time diversity is studied. The simple yet highly efficient technique is based on extending orthogonal space-time block codes into the quaternion domain and utilizing a description of the dual-polarized signal by means of quaternions. The resulting orthogonal space-timepolarization block codes have given promising results in simulations. In the example described in this paper, the achievable performance gain for two transmit and one receive antennas is approximately 6 dB at a bit error rate of 10 when compared with the Alamouti code. Index Terms polarization diversity, space-time processing, quaternions, block codes