mmFlexible: Flexible Directional Frequency Multiplexing for Multi-user mmWave Networks

TL;DR

mmFlexible introduces a flexible mmWave system enabling arbitrary directional frequency multiplexing using a novel delay-phased array architecture and a real-time estimation algorithm, significantly reducing latency.

Contribution

The paper presents a new delay-phased array architecture and FSDA algorithm for real-time frequency-direction response estimation in mmWave systems, enhancing flexibility and scalability.

Findings

Achieves 60-150% latency reduction over baselines

Enables arbitrary directional frequency multiplexing

Demonstrates effectiveness with mmWave channel traces

Abstract

Modern mmWave systems have limited scalability due to inflexibility in performing frequency multiplexing. All the frequency components in the signal are beamformed to one direction via pencil beams and cannot be streamed to other user directions. We present a new flexible mmWave system called mmFlexible that enables flexible directional frequency multiplexing, where different frequency components of the mmWave signal are beamformed in multiple arbitrary directions with the same pencil beam. Our system makes two key contributions: (1) We propose a novel mmWave front-end architecture called a delay-phased array that uses a variable delay and variable phase element to create the desired frequency-direction response. (2) We propose a novel algorithm called FSDA (Frequency-space to delay-antenna) to estimate delay and phase values for the real-time operation of the delay-phased array. Through evaluations with mmWave channel traces, we show that mmFlexible provides a 60-150% reduction in worst-case latency compared to baselines