A Selective Decision-Feedback Detector for Space-Time Block Code with Combined Diversity and Spatial Multiplexing

Selective decision feedback detection (SDFD) is investigated for decoding the space-time block code which provides both diversity gain and spatial multiplexing gain. In SDFD, the system matrices are formulized with the real and imaginary parts decoupled before the channel matrix is Q-R decomposed (QRD). With a column permutation of the channel matrix, two candidates for the solution are obtained. The candidate with the lesser mean square error is selected as the detector output. SDFD is simpler than the sphere detector, while the error performance in certain conditions is very close to that provided by the optimum detector.