Robust transmission over wireless channel using a multiple antenna system

Two principal transmission techniques have been developed to take advantage of Multiple-Input Multiple-Output (MIMO) systems: Spatial Multiplexing and Diversity Transmission. In this paper we are combining space-time block code (STBC) with spatial multiplexing technique over space to take advantages of both schemes. At the receiver, a minimum mean square error (MMSE) detector with interference cancelation (IC) is integrated with the space-time decoder to reconstruct the desired signal effectively. Various algorithms are constructed for calculating best Rx. antenna and MMSE decoder is used for estimation of interfering terms and then space-time decoder is applied. ”Selecting a best Rx. antenna” depending on signal power (norm basis) of symbols s1 and s2 is giving good coding gain as compared to selection depending on signal power of interfering terms. But former is giving same diversity gain as compared to only MMSE method and later is giving slightly more diversity gain. Best antenna selection with spatially multiplexed data is giving 2 dB more gain as compared to best antenna selection with STBC data. Both of above methods are compared with MMSE decoder applied to whole data.