Performance analysis of direction finding using lag redundancy averaging

The lag redundancy averaging (LRA) method for processing linear equispaced arrays is examined. LRA is a simple procedure for estimating Toeplitz covariance matrices, which can be computed efficiently by means of spatial fast Fourier transform (FFT) algorithms. The effect of LRA on the performance of the MUSIC method for uncorrelated sources is investigated. Closed-form expressions for the asymptotic bearing accuracy are obtained. It is shown, for the single source case, that the LRA method is asymptotically efficient. For two equipowered sources, it is shown that while the resolution threshold of the LRA method is superior to that of standard MUSIC, its asymptotic accuracy is inferior