LOS MIMO Design based on Multiple Optimum Antenna Separations

TL;DR

This paper investigates optimal antenna separations in LOS MIMO systems with ULAs, providing multiple solutions for antenna separation product to enhance V2V communication over varying distances.

Contribution

It derives a general expression for multiple optimal antenna separation solutions, extending LOS MIMO design beyond the smallest separation case.

Findings

Multiple solutions for optimal antenna separation product are identified.

Designs tailored for a range of distances improve V2V communication performance.

The smallest separation solution is not the only optimal choice in LOS MIMO systems.

Abstract

The use of multiple antennas in a transmit and receive antenna array for MIMO wireless communication allows the spatial degrees of freedom in rich scattering environments to be exploited. However, for line-of-sight (LOS) MIMO channels with uniform linear arrays (ULAs) at the transmitter and receiver, the antenna separations at the transmit and receive array need to be optimized to maximize the spatial degrees of freedom and the channel capacity. In this paper, we first revisit the derivation of the optimum antenna separation at the transmit and receive ULAs in a LOS MIMO system, and provide the general expression for the optimum antenna separation product, which consists of multiple solutions. Although only the solution corresponding to the smallest antenna separation product is usually considered in the literature, we exploit the multiple solutions for a LOS MIMO design over a range of distances between the transmitter and receiver. In particular, we consider the LOS MIMO design in a vehicle-to-vehicle (V2V) communication scenario, over a range of distances between the transmit and receive vehicle.