Multi-Antenna Communication in Ad Hoc Networks: Achieving MIMO Gains with SIMO Transmission

TL;DR

This paper demonstrates that in wireless ad hoc networks, using multiple receive antennas with SIMO transmission can linearly increase network throughput by effectively managing interference and boosting signal power, even with single-antenna transmitters.

Contribution

It shows that linear throughput scaling is achievable with SIMO in ad hoc networks, contrasting prior work that required MIMO for such gains.

Findings

Throughput scales linearly with number of receive antennas nR.

Receive antennas can suppress interference and enhance desired signals.

Results hold under various network conditions and relaxations.

Abstract

The benefit of multi-antenna receivers is investigated in wireless ad hoc networks, and the main finding is that network throughput can be made to scale linearly with the number of receive antennas nR even if each transmitting node uses only a single antenna. This is in contrast to a large body of prior work in single-user, multiuser, and ad hoc wireless networks that have shown linear scaling is achievable when multiple receive and transmit antennas (i.e., MIMO transmission) are employed, but that throughput increases logarithmically or sublinearly with nR when only a single transmit antenna (i.e., SIMO transmission) is used. The linear gain is achieved by using the receive degrees of freedom to simultaneously suppress interference and increase the power of the desired signal, and exploiting the subsequent performance benefit to increase the density of simultaneous transmissions instead of the transmission rate. This result is proven in the transmission capacity framework, which presumes single-hop transmissions in the presence of randomly located interferers, but it is also illustrated that the result holds under several relaxations of the model, including imperfect channel knowledge, multihop transmission, and regular networks (i.e., interferers are deterministically located on grids).