The modified CP-AFC with multi-stage tracking mode for WCDMA reverse link receiver
In this paper, we propose a modified CP-AFC (Cross-Product Automatic Frequency Control) algorithm to enhance coherent signal detection for WCDMA reverse link receiver. We introduce a moving average filter at the FDD input to decrease the noise effect by increasing the number of cross-products, since pilot symbol in WCDMA is not transmitted continuously. We also add normalization algorithm to overcome the conventional CP-FDD's sensitivity to the variance of input signal amplitude and to increase the linear range of S-curve. For rapid frequency acquisition and tracking, we adopt a multi-stage tracking mode. We applied the proposed algorithm in the implementation of WCDMA base station modem successfully.
cp-afc multi-stage tracking wcdma base station modem frequency synchronization