# Millimeter Wave communication with out-of-band information

## TL;DR

This paper explores leveraging out-of-band information from lower frequency signals and sensors to reduce overhead and improve configuration in millimeter wave communication systems, especially in high mobility scenarios.

## Contribution

It introduces the concept of out-of-band information aided mmWave communication and analyzes strategies to utilize side information for efficient link configuration.

## Key findings

- Overhead can be significantly reduced using out-of-band information.
- Strategies for leveraging sub-6 GHz signals are analyzed.
- Challenges in using out-of-band signals are discussed.

## Abstract

Configuring the antenna arrays is the main source of overhead in millimeter wave (mmWave) communication systems. In high mobility scenarios, the problem is exacerbated, as achieving the highest rates requires frequent link reconfiguration. One solution is to exploit spatial congruence between signals at different frequency bands and extract mmWave channel parameters from side information obtained in another band. In this paper we propose the concept of out-of-band information aided mmWave communication. We analyze different strategies to leverage information derived from sensors or from other communication systems operating at sub-6 GHz bands to help configure the mmWave communication link. The overhead reductions that can be obtained when exploiting out-of-band information are characterized in a preliminary study. Finally, the challenges associated with using out-of-band signals as a source of side information at mmWave are analyzed in detail.