Wcdma Downlink Interference Suppression Receiver Research And Low-power Asic Design Methodology Discussed

The paper firstly introduces the Multiple Access Interference(MAI) suppression techniques used in DS/CDMA and the most effective one is the Multi-User-Detection(MUD) technique. Then it introduces the classification and evolution history of MUD and the principals of several classical MUD algorithms.The paper secondly analyses MAI suppression techniques used in WCDMA downlink, that is LMMSE adaptive equalization and Interference Cancellation(IC). It gives out the general structure of MAI suppression receiver according to the feature of WCDMA downlink. Then It analyses the principals, advantages and disadvantages of LMMSE and ICs, and discusses the feasibility of combining these two techniques together. At last, It gives out the detail structure of MAI suppression receiver which is applicable to be used in WCDMA downlink. The suggested receiver uses Successive Interference Cancellation (SIC) and Parallel Interference Cancellation (PIC) placed before and after LMMSE adaptive chip equalizer to cancel Multiple Code Interference(MCI) in multiple code transmission and MAI in single code transmission. It estimates the effective spreading code of interference users using Fast Hadamard Transformation, then achieves effective interference symbols after de-spreading, at last re-constructs and cancels the MAI.The paper thirdly researches the performance of multiple code transmission, LMMSE, IC, and the suggested receiver by computer simulations in WCDMA system. The simulations further demonstrate that the performance gain of the suggested receiver by using LMMSE and IC techniques together, and make certain the parameters of the receiver that affect performance much. The simulations also demonstrate that the suggested receiver can work in many environments to get stable gain, and have much applicable value.Because of the strict requirements of power consumption in Mobile Terminal, the paper introduces the low power ASIC design and estimation techniques at last. It mainly introduces the low power design and power estimation procedure of the base-band processor chip of CDMA2000-1x MT, and mainly discusses the clock gating techniques to improve the power comsumption of integrated circuit.