Dual-mode antenna selection for spatial multiplexing systems with linear receivers

Wireless links with multi-antenna transmitters and receivers can be used to provide increased diversity and/or large data-rates. It has been shown that multi-antenna communication systems can simultaneously achieve the maximum diversity and maximum rate (or multiplexing) gain. This paper proposes a modified version of traditional spatial multiplexing that allows the wireless system to obtain maximum diversity and multiplexing gain with a linear receiver. This diversity-multiplexing gain tradeoff is optimized by switching between transmit selection diversity and spatial multiplexing. We show that this system model can be easily implemented when the transmitter has no form of channel knowledge by using a limited number of feedback bits from the receiver to the transmitter. Simulation results show gains compared to selection diversity and spatial multiplexing.