Studies On The Key Techniques Of WCDMA Systems

Channel coding and RAKE receiver are the key physical layer technologies onWCDMA system. In this paper, Equal Error Protection(EEP) issue of the Turbo codeinterleaver and GRAKE receiver refers to the finger selection algorithm in HSUPA hasbeen studied, and suggest the corresponding improvements in the structure or algorithm.Interleaver is an important component of Turbo code that makes the codewordsrandom, uniformity, but the randomized codewords after puncturing will appear theEqual Error Protection issue, which will affect the encoding and decoding performance.Paper by studying the features of Turbo code puncturing, the basic structure of a blockor random interleaver and the factors that may affect the interleaved performance, giventhe elimination of fixed points and has a Equal Error Protection forms, finally throughsimulation verify the correctness of the structure improved.HSUPA technology uses a smaller spreading factor, making the spreading gaindecreases, some scrambling poor autocorrelation, the use of the traditional RAKEreceiver technology in R99can not satisfy the system performance requirements. Thispaper discusses the GRAKE receiver principle, given the estimation and simplificationmethod of the combined weight. Finally, in-depth analysis of several finger selectionalgorithms, proposed a sub-optimal adaptive finger selection algorithm and simulationanalysis.