Research Of Channel Estimation And SIR Estimation In WCDMA System

Cellular mobile communication technology in recent years is developing very fast, and has already come to the third generation technology stage (3G) marked with wide-band and multimedia services. At present the mainstream of the 3G includes WCDMA, CDMA2000 and TD-SCDMA.This paper focuses on the WCDMA channel estimation and SNR estimate technical research.Channel estimation is one of the key technologies to improve the receiving performance of the wireless data transmission, as a method to recover the fading channel parameters. This paper discusses and simulates the present common channel estimation algorithms. Aiming at WMSA, three improved algorithms are put forward in the compressed mode. We also analysis and simulation the three algorithms in different channel environment in order to got the best of channel estimation algorithm, which has the best performance.Due to the near-far effect and the interference, power control whether effective directly determines the WCDMA system is available and largely determines the WCDMA system performance. For system capacity, covering, service's QoS, power control also has important influence. Signal-to-interference (SIR) estimate error directly affects the effect of inner power control. Based on the related literature, this paper presents a signal-to-interference ratio estimation algorithm and simulates the performance in signal-path channel. Revise the factors affecting finger signal power. Adopt IIR filter for the smooth processing in order to ensure the stability of finger noise power estimation. At last, we discusses the case of multi-path channel environment, in which we should use the noise power estimation results from the strongest path, instead of independent path results.All of the above algorithms have realized in the DSP in picochip (Beijing) Technology Co., LTD and meet the system performance requirements.