Copyright © 2005 The Institute of Electronics, Information and Communication Engineers
Regular Section -- Letters -- Transmission Systems and Transmission Equipment for Communications |
A Velocity Estimation-Based Channel Estimator for WCDMA Forward Link Receiver
1 The authors are with the School of Information and Communication Engineering, Sungkyunkwan University, Suwon-City 440-746, Korea. E-mail: hjchoi{at}ece.skku.ac.kr
In this letter, we propose a new practical architecture of channel estimator that can compensate for the signal distortion due to variable mobile station velocity in WCDMA forward link. The proposed Channel Estimator consists of IIR filter for channel estimation and Velocity Estimator for selection of IIR filter coefficients matched to mobile station velocity. The combination of IIR filter and Velocity Estimator can overcome the divergence problem of IIR filter due to the mobile station velocity. The Velocity Estimator estimates the speed of mobile station velocity by observing power spectrum of the received signal and exhibits stable operation in low SNR environment. To improve the resolution of velocity estimation without additional complexity due to large FFT size, an interpolator is adopted in the velocity estimator. The proposed channel estimation architecture can not only be used for WCDMA forward link but also is applicable for CDMA-2000 system without major modifications. Also, the Velocity Estimator can be applied in the channel quality measurement for the selection of MCS (Modulation and Coding Scheme) level in HSDPA transmission.
Key Words: channel estimation, velocity estimation, WCDMA, FFT
Manuscript received January 4, 2005. Manuscript revised April 10, 2005.