A comparison of smoothing approaches for angle measurement

For high-resolution active direction finding of completely correlated targets, one can use two approaches, i.e. frequency-domain smoothing and non-frequency-domain smoothing, such as spatial smoothing, or a multidimensional search of signal-subspace. A performance comparison of the two approaches is presented for the fluctuating target cases under an equal transmitted-energy constraint. both theoretical analysis and simulations are used to study the performance of the detection (determination of number of targets) and angle estimation. It is found that the frequency-domain smoothing can significantly outperform the non-frequency-domain smoothing under the equal transmitted-energy constraint