MMSE interference in Gaussian channels

• These results provide the engineering insight to the good performance of the Han and Kobayashi scheme on the interference channel. We show that the Han and Kobayashi scheme is optimal MMSE-wise. • The results can be easily extended to K MMSE constraint [Bustin and Shamai, submitted ISIT 2012]. • The engineering advantage of the MMSE disturbance measure over the mutual information measure in the Gaussian channel are demonstrated. • Single code I-MMSE tradeoff, bounded by the optimal superposition coding tradeoff [Bennatan, Shamai, Calderbank, <arXiv:1008.1766v1-2010>]. • Interesting challenges: optimization of I n (snr 2 ), under the MMSEcn(snr 1 ) constraint when block-length n is finite. For n = 1, conjecture: the optimal X is discrete [Shamai, ISIT 2011].