Downlink performance analysis of a BPSK-based WCDMA usingconventional RAKE receivers with channel estimation

摘要

We consider the downlink of a Universal Mobile TelecommunicationnSystem terrestrial radio access-wideband code division multiple accessn(UTRA-WCDMA) system and we investigate the performance of thenconventional RAKE receiver. A multipath slowly Rayleigh fading channelnis assumed. For the purpose of channel tap weight estimation, a commonncontrol physical channel, that is either serial or parallel multiplexednwith the dedicated physical channels, is used. The receiver sensitivitynto imperfect knowledge of the path delays, to the number of pilotnsymbols, and to the power ratio of pilot to data channels is alsoninvestigated. The system performance is evaluated by means of bit-errornrates (BERs) derived using quadratic forms and characteristic functionsnfor a BPSK modulation. The mean-squared estimation error (MSEE) of thenchannel tap weights is also computed and compared to the classicalnCramer-Rao lower bound (CRLB). The mutual interference between pilot andndata symbols is taken into account