The Research Of Spatial Spectrum Estimation Algorithm In Smart Antenna

In this paper, firstly, the author illustrates the principles of smart antenna and adaptive beam forming, and then introduces some typical adaptive algorithms, the LMS ,CMA and RLS algorithms are analyzed and discussed and simulate them in the computer to prove their capability. but they have the disadvantage of high complexity, so they are not fit for practice. The paper analyses the conventional method rejecting spatial smoothing coherent interfering signals, which is spatial smoothing technique. Analyzing the forward-backward covariance algorithm. As a result, the computation effort of the spatial smoothing algorithm can be reduced. Another main studied topic of smart antenna is the direction of arrival (DOA) of spatial signals. The performance of MUSIC algorithm with source number over or under estimated is analyzed in this paper. Under error source number existing condition, a new algorithm is suggested in this chapter. The performance of the new algorithm is much better than that of MUSIC algorithm. In the last chapter, based on the theoretical analysis of MMUSIC algorithm, a new modified MUSIC algorithm is presented. It can estimate the DOA of coherent signals and adjacent signals with small SNR effectively. Computer simulation confirms the new method more efficient than MMUSIC algorithm. At the end, this paper studies the problem of the DOA in the presence of the most signals in the communication system have the cyclostationary property. The Cycle-MUSIC algorithm obtains some significant conclusions.