Cost-Effective Millimeter Wave Communications with Lens Antenna Array

TL;DR

This paper explores cost-effective millimeter wave communication systems using lens antenna arrays, demonstrating that they can achieve near-optimal capacity with fewer RF chains and lower complexity, outperforming existing designs in efficiency.

Contribution

It introduces a novel lens antenna array technique that leverages angle-dependent energy focusing and channel sparsity for efficient mmWave communication.

Findings

Lens arrays achieve capacity-optimal performance with few RF chains.

Significant improvements in spectrum and energy efficiency over existing methods.

Effective for wide-band frequency-selective channels.

Abstract

Millimeter wave (mmWave) communication is a promising technology for the fifth-generation (5G) wireless system. However, the large number of antennas used and the wide signal bandwidth in mmWave systems render the conventional multi-antenna techniques increasingly costly in terms of signal processing complexity, hardware implementation, and power consumption. In this article, we investigate cost-effective mmWave communications by first providing an overview of the main existing techniques that offer different trade-offs between performance and cost, and then focusing our discussion on a promising new technique based on the advanced lens antenna array. It is revealed that by exploiting the angle-dependent energy focusing property of lens arrays, together with the angular sparsity of the mmWave channels, mmWave lens-antenna system is able to achieve the capacity-optimal performance with very few radio-frequency (RF) chains and using the low-complexity single-carrier transmission, even for wide-band frequency-selective channels. Numerical results show that the lens-based system significantly outperforms the state-of-the-art designs for mmWave systems in both spectrum efficiency and energy efficiency.