The Research Of DOA Estimation In Wideband Coherent Signal

The Smart antenna is one of the key technologies in the third generation (3G) system. And it has the present focuses in signal processing field. So the DOA of users plays a very important role in smart antenna systems. The main work of this dissertation is summarized as :The traditional MUSIC algorithm cannot estimate the DOA of coherent signals . In this paper presented three decorrelate coherent sources method: the spatial smoothing and modified MUSIC and the spatial filtering. Although the spatial smoothing solved the problem of coherent sources, but aperture of array is reduced. Modified MUSIC algorithm has less compute and spatial filtering has stronger power of decorrelate coherent but need more compute and preliminary estimation, when Modified MUSIC algorithm is compared with spatial filtering algorithm. The ISM algorithm on the basis of spatial smoothing and the ISM on the basis of spatial filtering are proposed in this paper .The wideband signal are divided into parts of narrowband on the basis of ISM algorithm. Through decorrelate coherent sources and applied MUSIC algorithm in every sub-band, a new method DOA estimation of wideband coherent sources is produced. Theory analysis and simulation result show that new algorithms have better ability to the wideband coherent sources. But it needs more improved to decrease compute.