A Modified V-BLAST System for Performance Improvement Through Introducing Different Delay Offsets to Each Spatially Multiplexed Data Streams

This paper proposed a modified vertical-Bell Labs layered space-time (V-BLAST) system, where different delay offsets are intentionally applied to the spatially multiplexed data streams in order to improve bit error rate (BER) performance. The proposed system can use only one receive antenna to recover the transmitted information by zero forcing (ZF) detection, whereas the conventional synchronous V-BLAST system requires that M_r ges M_t (where M_t and M_r are the number of transmit and receive antennas, respectively). Compared with the conventional synchronous V-BLAST system, the modified system can achieve M_rth-order diversity using ZF detection. Although delay offsets in the system introduce an attenuation factor which decreases the instantaneous signal-to-noise ratio (SNR), the BER performance of the modified system with proper system parameters demonstrates a performance improvement over the conventional synchronous V-BLAST system.