Spectral Efficiency Scaling Laws in Dense Random Wireless Networks with Multiple Receive Antennas

TL;DR

This paper derives spectral efficiency scaling laws in dense wireless networks with multiple receive antennas, showing how different levels of channel state information and antenna configurations influence capacity growth as network density increases.

Contribution

It provides analytical expressions for spectral efficiency in large random networks considering various CSIR scenarios and antenna scaling laws, revealing the benefits of exploiting dominant interfering links.

Findings

Spectral efficiency scales linearly with network density when antennas grow super-linearly.

Exploiting CSIR for dominant interferers yields multiplicative gains in capacity scaling.

Linear scaling persists with antenna correlation if the correlation matrix rank grows super-linearly.

Abstract

This paper considers large random wireless networks where transmit-and-receive node pairs communicate within a certain range while sharing a common spectrum. By modeling the spatial locations of nodes based on stochastic geometry, analytical expressions for the ergodic spectral efficiency of a typical node pair are derived as a function of the channel state information available at a receiver (CSIR) in terms of relevant system parameters: the density of communication links, the number of receive antennas, the path loss exponent, and the operating signal-to-noise ratio. One key finding is that when the receiver only exploits CSIR for the direct link, the sum of spectral efficiencies linearly improves as the density increases, when the number of receive antennas increases as a certain super-linear function of the density. When each receiver exploits CSIR for a set of dominant interfering links in addition to the direct link, the sum of spectral efficiencies linearly increases with both the density and the path loss exponent if the number of antennas is a linear function of the density. This observation demonstrates that having CSIR for dominant interfering links provides a multiplicative gain in the scaling law. It is also shown that this linear scaling holds for direct CSIR when incorporating the effect of the receive antenna correlation, provided that the rank of the spatial correlation matrix scales super-linearly with the density. Simulation results back scaling laws derived from stochastic geometry.