DOA ESTIMATION IN DS-CDMA SYSTEMS OVER FREQUENCY-SELECTIVEFADING CHANNELS USING DECORRELATING DETECTOR AND APERTUREEXTENDEDMUSIC ALGORITHM

摘要

In the paper, we develop an effective direction of arrival(DOA) estimation method for the synchronous DSCDMAsystems over frequency-selective fading channels.The approach is applied in array antenna receiver at basestation. To effectively suppress multiple accessinterferences (MAI) and estimate DOAs in multipathCDMA channel, multiple parallel code-matched filterswith multipath delay and a decorrelating multiuserdetector are used to detect each path of desired signal foreach mobile user. In the output of the detector, acumulant-based aperture-extended MUSIC algorithm isdeveloped to estimate each resolvable direction ofmultipath users. The method can adapt to a larger numberof mobile users in practical systems by perfect MAIsuppression. Also, each sub-path signal DOA can beaccurately estimated with higher resolution than theprevious methods because array aperture is extended. Bythe use of higher order cumulant, it also has advantage ofeliminating the spatially colored Gaussian noise orcorrelative noise in wireless channels.