Performance analysis of Dirty-Paper Coding over MIMO Keyhole Channels

In multiple input multiple output (MIMO) fading environment, the so called degenerate channels or keyholes may exist that exhibit low partial fading correlation at both ends of the link but still have poor rank properties, and hence low ergodic capacity. We analyze the performance of dirty-paper coding over MIMO keyhole channels. The keyhole condition, where the MIMO channel has only one degree of freedom, impairs the performance of the systems. Under these conditions, one may wish to design codes that are robust to this situation. We study the capacity and the probability of error of a MIMO system with BPSK over keyhole channel. We also prove the intuitive result that the capacity under keyhole condition can be improved using dirty paper coding