... the achievable data rate as well as results in large pro-cessing latency. And an adaptive transmission requires com-plex parameter estimation, prompt, and accurate feedback and duplex channel.7. ... H. Sampath, S. Talwar, J. Tellado, V. Erceg, and A. Paulraj, A fourth-generation MIMO- OFDM broadband wireless system:design, performance, and field trial results, ” IEEE Communica-tions Magazine, ... com-plex gain ish = h + αζ, where the h is the real channel com-plex gain, α is a factor, and ζ is a complex Gaussian variablewith zero mean and a variance of 1. The relative channel in-accuracy...