Diversity-Multiplexing Tradeoff of MIMO Systems with Antenna Selection

The diversity-multiplexing (D-M) gain tradeoff is a popular benchmark for measuring the performance of multi-input multi-output (MIMO) systems. This paper studies the fundamental D-M gain tradeoff of a pruned MIMO system where L_t transmit and L_r receive antennas are selected out of the full system with M_t transmit and M_r receive antennas (L_t les M_t and L_r les M_r). It is shown that a MIMO system with the optimal antenna selection (AS) has the same D-M tradeoff as the full system if the multiplexing gain is less than some threshold P, although it suffers from some diversity gain loss for the multiplexing gain larger than P. On the other hand, this paper quantifies, in terms of the D-M tradeoff, the gain of introducing additional transmit/receive antennas without increasing the number of RF chains and coding complexity. We also propose a fast and D-M tradeoff-optimal AS algorithm as a byproduct of our analysis.