Application of antenna arrays to mobile communications. II. Beam-forming and direction-of-arrival considerations

Abstract

Array processing involves manipulation of signals induced on various antenna elements. Its capabilities of steering nulls to reduce cochannel interferences and pointing independent beams toward various mobiles, as well as its ability to provide estimates of directions of radiating sources, make it attractive to a mobile communications system designer. Array processing is expected to play an important role in fulfilling the increased demands of various mobile communications services. Part I of this paper showed how an array could be utilized in different configurations to improve the performance of mobile communications systems, with references to various studies where feasibility of an array system for mobile communications is considered. This paper provides a comprehensive and detailed treatment of different beam-forming schemes, adaptive algorithms to adjust the required weighting on antennas, direction-of-arrival estimation methods-including their performance comparison-and effects of errors on the performance of an array system, as well as schemes to alleviate them. This paper brings together almost all aspects of array signal processing. It is presented at a level appropriate to nonexperts in the field and contains a large reference list to probe further.

Displaced Sensor Array for Improved Signal Detection Under Grazing Incidence Conditions

“…A common subspace-based DOA estimation algorithm is MUSIC (MUltiple SIgnal Classification) [14]. This method is based on the eigen-decomposition of the covariance matrix R into a signal subspace and noise subspace.…”

“…The adaptive beamforming algorithm optimizes the array output beam pattern such that maximum radiated power is produced in the directions of desired mobile users and deep nulls are generated in the directions of undesired signals representing co-channel interference from mobile users in adjacent cells. Prior to adaptive beamforming, the angles of arrival of narrowband sources from desired mobile users must be estimated using a direction of arrival (DOA) estimation algorithm [14]. This paper deals with the first part of the smart antenna system with an emphasis on estimating the angles of arrival of narrowband sources arriving at close to the array endfire direction, i.e., grazing incidence with respect to the array axis.…”

Introduction of Frequency-Domain Signal Processing to Broadband Single-Carrier Transmissions in a Wireless Channel

“…The presence of co-channel interference (CCI) degrades the transmission performance. The AAA technique [63], [64] can be used to suppress the CCI and increase the received signal-to-interference plus noise power ratio (SINR). AAA using the pre-FFT weight originally proposed for OFDM signal transmission can be applied to SC with FDE [65].…”

Design of a Sparse Antenna Array for Communication and Direction Finding Applications Based on the Chinese Remainder Theorem

“…Both of these research directions have not utilized the directional modulation ability of multiple transmit antennas to achieve the function of direction finding. The major work on direction finding has focused on space-time processing by multiple receiving antennas [9][10][11]. However, the receiver equipped with multiantenna can not meet the requirement of miniaturization such as communication and tracking system for Micro Aerial Vehicle [12].…”