CMRLS-RAKE Receiver for Low Spreading Gain Systems

• Main Authors: Jih-Shin Lee, 李日新
• Other Authors: Shun-Hsyung Chang
• Format: Others
• Language: zh-TW
• Published: 2003
• Online Access: http://ndltd.ncl.edu.tw/handle/18948031929815542399

碩士 === 國立海洋大學 === 電機工程學系 === 91 === The development of the WCDMA tends to increase the data rate without bandwidth expansion by reducing the spreading gain. One of the solutions is to reduce the spreading gain, but the small spreading gain will cause interpath interfereence (IPI) due to imperfect autocorrelations of spreading sequence in multipath channels. The RAKE receivers which combined with constrained minimum mean square error (CMMSE) algorithm can support high data rate without bandwidth expansion and overcome IPI effectively, but training sequences and convergence speed is its fault. In order to improve these faults, we propose a RAKE receiver which combined with constant modulus recursive least square (CMRLS) called CMRLS- RAKE receiver. Under low spreading condition, comparing CMRLS- RAKE receiver and CMMSE-RAKE receiver. We found that former not only own the advantage of blind filtering technique and faster convergence speed, but also improve system performance in BER about ~ . According to those mention above, the CMRLS-RAKE receivers are more effectively and faster overcome IPI than the CMMSE-RAKE receivers.