User Selection Scheme based on Reference Frames

Abstract

For a multi-user (MU) massive multiple-input multiple-output (MIMO) system, its total throughput is directly related to the degree of mutual interference among user's channel vectors accessing the communication system. Selecting a group of users with the least mutual interference can maximize the total throughput, and thus, it is important to select users with low-mutual correlations. The paper designs two effective MU selection schemes with low-complexity. Specifically, based on channel characteristic, reference frames with low correlation are contructed. Then, the user whose channel is nearby an vector in the reference frame is selected, and different selected users are close to different vectors in the reference frame. Consequently, it can guarantee that the selected users have low mutual correlations. Comparing to the existing user selection schemes, the proposed algorithms exhibit better performance. Moreover, the schemes are more flexible, that is, the schemes can be applied into different environments, such as different number of antennas at base station (BS), different candidates, different number of selected users etc, based on different reference frames.

User Selection Methods for Overcoming Growing Number of Served Users in Massive MIMO Systems

“…Ref. [26] presents two multi-user selection schemes: a user selection algorithm based on correlation and a user selection algorithm based on orthogonal matching pursuit. These two algorithms are based on some designed fixed reference frames, which act as a dictionary to be compared with the correlation between the user channel in both proposed algorithms.…”

“…Ref. [26] compares the two proposed algorithms with the semi-orthogonal selection and the interchannel interference-based user selection. The performance is evaluated based on the throughput versus the signal-tonoise ratio.…”