The Experimental Research of DOA Estimation Based on Difference Co-array Method

In recent years, the difference co-array based method to calculate virtual antenna array with increased number of degrees of freedom started to receive the increasing attention. These methods are based on transforming of original (or physical) array into another array with higher number of antennas and used to step over the previously named limitation of super-resolution algorithms. This paper presents the practical research of using this method and its comparison to classic MUSIC direction-of-arrival estimation algorithm. To obtain experimental data, the simple five-channel direction finder was used. The receiver, in its turn, was connected to different array structures like conventional uniform linear array or linear sparse array with arbitrary antenna positioning. According to results it has been found that virtual antenna array based method shows better performance in angular resolution in comparison to MUSIC and has lower sidelobe level when sparse linear array is used. Nevertheless, due to high correlation between virtual antennas, the exact number of signal sources cannot be estimated.