Constrained TST MUSIC for joint spatial-temporal channel parameter estimation

This paper presents an improved tree-structured multiple signal classification (MUSIC) algorithm to jointly estimate the directions of arrival (DOA) and propagation delays in a CDMA system. The proposed algorithm makes use of one spatial (S)-MUSIC and two temporal (T)-MUSIC algorithms alternatively to estimate the group delays and the DOA, respectively. In contrast to the previous version, a constrained temporal filtering process and a constrained spatial beamforming process are addressed, which try to minimize the filtered output power under a set of judicious chosen linear constraints. Such a constrained filtering approach can effectively partition the incoming rays and suppress the propagation error in the tree-structured estimation scheme, thus in turn enhancing the overall performance. Furthermore, the pairing of the estimated DOA and delays is also automatically determined. Compared with previous works, the new approach calls for low computational complexity but exhibits superior performance, as shown in the furnished simulations.