An Easy Rake Receiver for TD-SCDMA Smart Antenna

The application research on smart antenna (SA) for CDMA system is consists of two parts in general. One part is the research on mathematical methods in SA technology, i.e., how to isolate the array manifold parameter e^ja_m {e^{ja_m }} and then to get the weighting coefficient w _m for the SA receiving signal S(t)e^ja_m {S(t)e^{ja_m }} . The estimation of DOA is included in the above handling process. The other is how to extract the signal S(t)e^ja_m {S(t)e^{ja_m }} from SA receiver, which should be the focus of the research of SA application. Utilizing the feature of mid-amble sequence of TD-SCDMA system, a novel DOA estimation method based on mid-amble sequence (MDOA) is presented in this paper, by which the array manifold e^ja_m {e^{ja_m }} can be extracted directly from the SA receiving signal. Making use of the array manifold parameter e^ja_m {e^{ja_m }} obtained by the MDOA method, the simulation of downlink beam-forming shows that the proposed MDOA method is feasible. This method will result in the research of mathematical methods used in SA being completely abandoned. Also, a usable SA receiver for TD-SCDMA with beam-forming by amplitude weighting in base-band is given as well as the correctness proof by using spectrum searching method in base-band.