Research Of Channel Estimation And SIR Estimation In WCDMA Physical Layer

WCDMA, as one of 3rd generation mobile communication technology, is mainly focused on the research of the ceaseless rising of quality of service (QoS), the increasing improving of industrial chain, the diversification and regionalization of service.In order to estimate the data channel information more accurately, this paper does not only use the information of the future slots, the current slot and even the history slots of pilot part, but also use the information of the estimated non-pilot part when making channel estimation to the data channel. More channel information is used, thus channel character can be better reflected. Simulation by increasing the average length of the sliding window improves the effect of channel estimation to a certain extent.In the power control, the error of SIR estimation directly affects the effect of the inner closed loop power control. The interferences to each path is treated as the interference from other users and thermal noise in the traditional SIR estimation algorithm, when estimating ISCP. Essentially, the inter-path-interference is ignored, so that the proposed algorithm can only work effectively in the case of lower Ec/N0 or only one path. Through the remodeling analysis to the system base-band signal, the effect of the inter-path-interference to the estimated SIR is quantified. Thus, an SIR estimation algorithm based on eliminating the inter-path-interference is proposed. Finally, it is verified by the computer simulation and the development on DSP chip that, the proposed algorithm is more accurate than the traditional algorithm. Accordingly, the proposed algorithm has great worth to the power control in HSPA service with higher Ec/N0.