A ROBUST DIRECTION OF ARRIVAL ESTIMATION SYSTEM FOR MILLIMETER-WAVE APPLICATIONS

Abstract

Millimeter-wave wireless communications systems are proving many advantages in comparison to systems operating at the lower frequency band thanks to their wide bandwidth, ability to provide high-speed and multimedia services. However, the transmission loss in the system is large, so it is necessary to have beam forming to compensate for this loss as well as to implement interference reduction techniques in order to increase system quality. In order to perform beam forming, determining the direction of arrival (DOA) of the incident wave of the radio signal source is a necessary condition. This paper proposes a millimeter-wave multi-antenna system for the estimation of DOA of radio signal in the azimuth plane operating at 28 GHz. The proposed system for determining the DOA of correlated and uncorrelated signals in millimeter-wave applications utilizes the digital intermediate frequency (IF) software-defined radio receiver architecture combining with a 90 degree phase shifter as an analog inphase-quadrature demodulator and multipath signal classification (MUSIC) algorithm associated with the improved spatial smoothing technique. The system is modeled and simulated to demonstrate the ability of determining the DOA of a radio signal operating at a center frequency of 28 GHz. The proposed system is modeled and simulated for the purpose of estimating the DOA of signal of interest at 28 GHz. The proposed solution is capable of estimating the DOA of the correlated and uncorrelated signals with high accuracy, an error of less than 1 degree, and a low number of samples (snap shots) by using software defined receiver architecture based on phase shifter and demodulation scheme by software, as well as superresolution algorithms.