On the Modified PN Code Tracking Loop with Multiuser Detection and Multipath Interference Cancellation

• Main Authors: Yu-hui Lin, 林育輝
• Other Authors: Chin-peng Li
• Format: Others
• Language: zh-TW
• Published: 2004
• Online Access: http://ndltd.ncl.edu.tw/handle/14722796235182723164

碩士 === 國立中山大學 === 通訊工程研究所 === 92 === A non-coherent PN code tracking loop with multi-user detection and simplified multi-path interference cancellation (MPIC) is proposed for direct sequence spread spectrum communications system. A decorrelator decision-feedback detector (DDFD) is first applied on the incoming signal to mitigate the multi-user interference. Then, a simplified multi-path interference cancellation (MPIC) is further used to increase signal quality. Finally, a modified code tracking loop (MCTL) is adopted for non-coherent PN code tracking. Mathematical expressions of the S-curve and tracking jitter are derived. Mean time to lose lock is also compared with traditional tracking loops. From the numerical results, we know the proposed PN code tracking loop can efficiently mitigate the interference from multi-user and multi-path and improve the performance of code tracking loop.