A Study Of Detection Algorithm For Space-time Coding

Space-time coding technology which combine channel coding and antenna diversity techniques can improve spectral efficiency with multi-elements antenna array and has been a research hotspot in the telecommunication field recently. Space-time coding technology ,which based on multi-antenna at the transmitter, is a new coding/signal processing technique applied to wireless communication systems.In the traditional space-time coding techniques, the layered space-time codes (BLAST) and space-time block code (STBC) is a more extensive study of two methods of space-time coding. For one thing, layered space-time code structure provide higher spectrum efficiency, but it possesses the bad performance of anti-fading. For another, space-time block code has a good anti-fading performance, simple structure and can achieve full implementation transmit diversity gain. However, STBC coding rate limit by the transmitting antenna.In this paper, based on trellis coded modulation (TCM) of layered space time block coding scheme, layered space-time codes and space-time block codes are given to overcome bad anti-fading performance of the layered space-time codes and the characteristics of low-rate coding of space-time block codes because of the introduction of redundancy. Moreover, two different schemes of the decoding algorithm were presented to deal with this situation.In the first scheme, the received data were processed by linear transform, and then the number of available receiving antenna were virtually doubled in the proposed scheme. Furthermore, a group interference suppression measurement of singular value decomposition (SVD) is employed to separate the signal of different subgroups. In addition, the proposed decoding scheme can reduce the complexity of receiver, because it is beyond minimum permissible limit of the conventional SVD algorithm.In the second scheme, a group interference suppression technology without matrix inverse is introduced, by exploiting the properties of measurements. For one thing, the signal can be efficiently separated one from another layer using the TCM-LSTBC scheme and the new group interference suppression. For another, the new channel matrix remains the character of Alamouti matrix. Then the complexity of receiver is decreased in decoding stage.The final simulation results demonstrate that the presented method is superior in BER and the favorable performance of the proposed TCM-LSTBC scheme.