Beamforming with Joint Phase and Time Array: System Design, Prototyping and Performance

TL;DR

This paper introduces the joint phase-time array (JPTA) architecture for mmWave beamforming, enabling multi-beam formation with a single RF chain, leading to significant system-level improvements like doubled uplink coverage.

Contribution

The paper presents a novel JPTA system design with prototype implementation, demonstrating multi-beam capabilities and performance benefits over traditional systems.

Findings

JPTA extends uplink coverage by 100%.

A single RF chain can serve four users simultaneously.

High-resolution delay elements are crucial for system performance.

Abstract

Joint phase-time arrays (JPTA) is a new mmWave radio frequency front-end architecture constructed with appending time-delay elements to phase shifters for analog beamforming. JPTA allows the mmWave base station (BS) to form multiple frequency-dependent beams with a single RF chain, exploiting the extra degrees of freedom the time-delay elements offer. Without requiring extra power-hungry RF chains, a BS with JPTA can schedule multiple users in different directions in a frequency-division multiplexing (FDM) manner. A BS with JPTA achieves various advantages over the traditional analog beamforming system. Simulation results show that JPTA can bring significant system-level benefits, e.g., extending uplink throughput coverage by 100%. To realize these system benefits of JPTA, high-resolution delay elements with a wide delay dynamic range are essential. With newly developed delay elements, we demonstrate that a single TRX RF chain can serve four users in four different directions in the mmWave band.