Cross-Layer Design for MIMO Systems

This work builds on previous results characterizing the diversity-multiplexing tradeoff region in multiple antenna wireless systems to find the point on this region that minimizes end-to-end distortion. Our goal is to find the optimal balance between the increased data rate provided by multiplexing versus the error protection provided by diversity. We first examine the distortion achieved by concatenating a vector quantizer with a multiple antenna channel. We show that in the high-SNR asymptotic regime we can find a closed form expression for the distortion exponent as a function of the optimal point on the diversity-multiplexing tradeoff curve. We also consider a numerical example for delay-constrained distortion. Our results show that the optimal operating strategy under delay constraints is substantially different than the optimal tradeoff strategy for average distortion.