Spectrum Allocation with Adaptive Sub-band Bandwidth for Terahertz Communication Systems

TL;DR

This paper proposes an adaptive sub-band bandwidth spectrum allocation method for terahertz communication systems, demonstrating significant throughput improvements over traditional equal bandwidth approaches, especially under power constraints and in multi-connectivity scenarios.

Contribution

It introduces a novel adaptive sub-band bandwidth allocation strategy for THz systems, optimizing spectrum division and power to enhance throughput and outperform existing methods.

Findings

Adaptive sub-band bandwidth significantly increases throughput.

Optimized spectrum allocation benefits are maximized under power constraints.

Proposed strategies outperform state-of-the-art in multi-connectivity THz systems.

Abstract

We study spectrum allocation for terahertz (THz) band communication (THzCom) systems, while considering the frequency and distance-dependent nature of THz channels. Different from existing studies, we explore multi-band-based spectrum allocation with adaptive sub-band bandwidth (ASB) by allowing the spectrum of interest to be divided into sub-bands with unequal bandwidths. Also, we investigate the impact of sub-band assignment on multi-connectivity (MC) enabled THzCom systems, where users associate and communicate with multiple access points simultaneously. We formulate resource allocation problems, with the primary focus on spectrum allocation, to determine sub-band assignment, sub-band bandwidth, and optimal transmit power. Thereafter, we propose reasonable approximations and transformations, and develop iterative algorithms based on the successive convex approximation technique to analytically solve the formulated problems. Aided by numerical results, we show that by enabling and optimizing ASB, significantly higher throughput can be achieved as compared to adopting equal sub-band bandwidth, and this throughput gain is most profound when the power budget constraint is more stringent. We also show that our sub-band assignment strategy in MC-enabled THzCom systems outperforms the state-of-the-art sub-band assignment strategies and the performance gain is most profound when the spectrum with the lowest average molecular absorption coefficient is selected during spectrum allocation.