Antenna Selection for MIMO Systems with Sequential Nulling and Cancellation

Multiple-input multiple-output (MIMO) wireless systems have been drawing a lot of attention recently due to significant gain in capacity or diversity improvement. However it may be desirable to use only subset of the available transmit and/or receive antennas to reduce the implementation cost and complexity. In this paper we propose a selection criterion (metric) for antenna subset in spatial multiplexing mode when sequential nulling and successive cancellation techniques are used in receiver such as VBLAST. We assume to use fixed modulation/demodulation and uniform power allocation per independent substream for each transmit antenna. Therefore the symbol error rate (SER) is a more important performance measurement than the capacity. Based on minimum signal to noise ratio (SNR), we derive optimal selection criteria for several different transmit/receive structures. Further, we show how the channel state information (CSI) known to transmitter is used for the antenna selection. Performance analysis and simulations that validate our proposal are also provided.