Date Added: May 2012
Recent works have established that MIMO systems optimized for Gaussian source signals may suffer unexpected performance loss when practical inputs are in fact discrete QAM sources. There is a practical need in the optimization of MIMO related systems of various networking scenarios to specifically target source signals of finite QAM alphabet. In this paper, the authors investigate the pre-coding optimization of wireless two-hop non-regenerative three-node MIMO relay networks driven by finite alphabet inputs. Exploiting a known optimal structure for the pre-coder at relay and a special convexity property, they propose an iterative two-step numerical optimization algorithm.