Hybrid Beamforming and Waveform Design for Over-the-air Integrated Signal

TL;DR

This paper proposes a hybrid beamforming and integrated waveform design framework for V2X networks, aiming to improve resource efficiency and reduce interference through joint optimization of communication components.

Contribution

It introduces a novel over-the-air integrated framework with joint hybrid beamforming and waveform design considering practical constraints, solved via an alternating optimization approach.

Findings

Effective hybrid beamforming and waveform design demonstrated through numerical results.

Joint optimization reduces interference and improves resource management in V2X networks.

Proposed methods outperform traditional separated approaches.

Abstract

The future wireless communications are expected to provide new use scenarios with emerging techniques. This paper focuses on vehicle to everything (V2X) network, where vehicles should cooperatively implement information obtaining, data sharing, and information postprocessing. Conventionally, the above three operations are considered in different layers or separated waveforms, leading to unavoidable interference and inefficient resource management when the number of devices becomes large. In this paper, we exploit the hybrid beamforming to design a cost-effective over-the-air integrated framework, and further consider the integrated waveform design problem with the constant-modulus constrain (CMC) and similarity constraint (SC). To solve these non-convex problems, an alternating optimization (AO) approach is proposed to jointly optimize the digital precoder as well as the hybrid combiner, using the successive convex approximation (SCA) and Riemannian conjugate gradient (RCG) algorithm. Additionally, we use the semidefinite relaxation (SDR) method to handle the practical waveform design problem. Numerical results demonstrate the effectiveness of the proposed hybrid beamforming and waveform design.