Ad Hoc Network Duplexing, Multiplexing, and Multiple Access: Canonical Results for Two Limiting Topologies

Abstract

Wireless ad-hoc networks have seen much attention in recent years, for the numerous benefits they offer. There are still a number of open research questions regarding these networks, and this paper addresses the question of which duplexing, multiplexing, and multiple access (D/M/MA) techniques are preferable in ad hoc networks. These techniques have substantial impact on network performance, yet this particular topic has seen surprisingly little attention. In this paper, we investigate D/M/MA techniques in ad-hoc networks and specifically address how to allocate time/frequency resources to improve network performance. We provide a comparison of time, frequency, and time-frequency schemes in terms of a number of features, including throughput, relative range and capacity. To keep the analyses tractable, we conduct our study using two limiting or "extreme" topologies: full mesh and pure relay networks. Our results show that for a peak power constraint, in terms of data rate, range, or capacity, continuous single-carrier waveforms are superior to bursted multi-carrier waveforms, and these schemes are attained with appropriate application of "hybrid" time-frequency division. Latency and throughput simulation results are provided for mesh networks, and analytical signal-to-noise-plus-interference ratio and simulation results for relay networks are also provided, to support our theoretically-based claims.