On the Distribution of an Effective Channel Estimator for Multi-Cell Massive MIMO

Abstract

Accurate channel estimation is of utmost importance for massive MIMO systems to provide significant improvements in spectral and energy efficiency. In this work, we present a study on the distribution of a simple but yet effective and practical channel estimator for multi-cell massive MIMO systems suffering from pilot-contamination. The proposed channel estimator performs well under moderate to aggressive pilot contamination scenarios without previous knowledge of the inter-cell large-scale channel coefficients and noise power, asymptotically approximating the performance of the linear MMSE estimator as the number of antennas increases. We prove that the distribution of the proposed channel estimator can be accurately approximated by the circularly-symmetric complex normal distribution, when the number of antennas, M , deployed at the base station is greater than 10. INDEX TERMS Massive MIMO, multi-cell, pilot-contamination, channel estimation.

Energy Efficiency-Oriented Resource Allocation for Massive MIMO Systems with Separated Channel Estimation and Feedback

“…The foreseen demand increasing in data rate has triggered a research race for discovering new ways to enhance the spectral efficiency of the next generation of mobile and wireless networks [1]. Benefiting from spatial multiplexing, massive MIMO systems can enjoy asymptotically orthogonal channels, arbitrary small transmit power, and negligible noise, thus providing significant performance gains in terms of spectral efficiency (SE), security, and reliability compared with conventional MIMO [2].…”