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arXiv · 1610.09247

Generalized I-MMSE for K-User Gaussian Channels

Samah A. M. Ghanem
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Abstract

In this paper, we generalize the fundamental relation between the mutual information and the minimum mean squared error (MMSE) by Guo, Shamai, and Verdu [1] to K-User Gaussian channels. We prove that the derivative of the multiuser mutual information with respect to the signal to noise ratio (SNR) is equal to the total MMSE plus a covariance term with respect to the cross correlation of the multiuser input estimates, the channels and the precoding matrices. We shed light that such relation is a generalized I-MMSE with one step lookahead and lookback, applied to the Successive Interference Cancellation (SIC) in the decoding process.

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Samah A. M. Ghanem. 2016-10-28. Generalized I-MMSE for K-User Gaussian Channels. https://arxiv.org/abs/1610.09247

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