Context Information Based Initial Cell Search for Millimeter Wave 5G Cellular Networks

TL;DR

This paper proposes a context-aware analog beamforming approach for initial cell search in mmWave 5G networks, addressing angular errors and demonstrating performance comparable to hybrid beamforming.

Contribution

It introduces a novel analog beamforming receiver architecture utilizing multiple phase shifter arrays to mitigate angular errors during initial cell search.

Findings

Analog beamforming performance degrades with angular errors.

The proposed architecture achieves hybrid beamforming performance.

Context information can enable efficient initial cell search in mmWave 5G.

Abstract

Millimeter wave (mmWave) communication is envisioned as a cornerstone to fulfill the data rate requirements for fifth generation (5G) cellular networks. In mmWave communication, beamforming is considered as a key technology to combat the high path-loss, and unlike in conventional microwave communication, beamforming may be necessary even during initial access/cell search. Among the proposed beamforming schemes for initial cell search, analog beamforming is a power efficient approach but suffers from its inherent search delay during initial access. In this work, we argue that analog beamforming can still be a viable choice when context information about mmWave base stations (BS) is available at the mobile station (MS). We then study how the performance of analog beamforming degrades in case of angular errors in the available context information. Finally, we present an analog beamforming receiver architecture that uses multiple arrays of Phase Shifters and a single RF chain to combat the effect of angular errors, showing that it can achieve the same performance as hybrid beamforming.