Heterogeneous Massive MIMO: A Cost-Efficient Technique for Uniform Service in Cellular Networks

TL;DR

This paper proposes heterogeneous massive MIMO (HmMIMO), combining co-located and distributed antennas to improve spectral efficiency at cell edges while reducing infrastructure costs.

Contribution

It introduces a novel HmMIMO paradigm that integrates cellular and cell-free approaches, balancing performance and complexity.

Findings

Achieves better user spectral efficiency at cell edges.

Reduces implementation costs compared to traditional cell-free MIMO.

Maintains a central base station with large antenna array.

Abstract

Massive multi-input multi-output (MIMO) has evolved along two tracks: cellular and cell-free, each with unique advantages and limitations. The cellular approach suffers from worse user spectral efficiency at cell edges, whereas the cell-free approach incurs high implementation costs due to a large-scale distributed infrastructure. This paper introduces a novel networking paradigm, termed heterogeneous massive MIMO (HmMIMO), which seamlessly integrates co-located and distributed antennas. Differing from two conventional paradigms, HmMIMO remains a base station with a large antenna array at the center of each cell, aided by distributed antennas deployed at cell edges. Our findings demonstrate that this paradigm achieves a favorable trade-off between performance and implementation complexity.