Linear Precoding for STBC to Account for Antenna Correlation in Next Generation Broadband Systems

The presence of strong channel correlations reduces the amount of the available diversity in the (multiple input multiple output) MIMO channel, leading to performance degradation. These correlations are long-term statistics that the transmitter can obtain either by exploiting channel reciprocity of by low-rate feedback from the receiver. In order to account for this correlation, a Linear Precoding technique has been proposed for the adaptation of Space-Time Block Codes (STBC). This technique works well for orthogonal STBC but fails in the case of non-orthogonal STBC. In this paper we present the adaptation of Linear Precoding to non-orthogonal STBC. Simulations in the case of ABBA codes are provided and comparisons are made with respect to beamforming.