DOA Estimation of Linear Dipole Array With Known Mutual Coupling Based on ESPRIT and MUSIC

Abstract

In this paper, multiple signal classification and estimation of signal parameters via rotational invariance technique (ESPRIT) algorithms are proposed to estimate the direction of arrival (DOA) of multiple incident signals under known mutual coupling among elements of the antenna array. These algorithms use the same subspace based techniques to achieve the separation of the eigenvectors into two subspaces: the signal space and the noise space. However, ESPRIT only uses the signal space. The performance of subspace based DOA estimation algorithm is evaluated using uniform linear arrays of dipole elements. The simulation results show the exact number of samples and elements, signal‐to‐noise ratio and spacing between the antennas elements used are the most important parameters in the algorithms, to sustain the accuracy of the DOA of the incident signals. The problem of calculating mutual coupling coefficient of the array elements is formed into a matrix has been considered. It is shown from the simulation results that the performance of the DOA estimation techniques considering the mutual coupling effect can be improved by the proposed compensation method. The different results obtained are in good agreement with those of the literature.

Adaptive Beamforming Algorithm Based on MVDR for Smart Linear Dipole Array with Known Mutual Coupling

“…A beamformer is a collection of antennas which are linearly arranged so that their output can be steered electronically. The received signal at these antennas is used to compute the complex weights which are adaptively updated based on signal samples [6]. The first part of the presented design is begun by calculating the covariance matrix.…”

“…In practice, interactions between the HWD antennas will result in mutual coupling, which distorts the ideal steering vector significantly. In this situation, the true steering vector should be modified, then the received signal x M (t) is give by [6]: We can write formula (1) in the following form:…”

“…In order to calculate the mutual coupling matrix C, we consider that the interactions between the HWD antennas of the array will result in mutual coupling, and the array is composed of M coupled HWD antennas, which we classically model as a M port network. C can be written as [6,15]:…”

“…The total far field radiation patterns of linear array of HWD antennas is the product of the element factor E(θ) and array factor (AF) [6,26,27]. AF depends on the geometric arrangement of the array elements, the spacing of the HWD antennas (d), and the weights w obtained by the MVDR algorithm.…”

“…Adaptive beamforming is a technique of combining the weighted received signals on an array of HWD antennas to achieve maximum reception in the direction of desired user while signals from other directions are rejected [4]. These antennas are located near each other, and thus the effects of mutual coupling become more significant [5,6]. This is because when an antenna is radiating, some of the energy in one antenna is coupled into an adjacent antenna [7,8].…”