A frequency-domain approach for estimating frequency offset and speed in 3G W-CDMA systems

In this paper, we propose a frequency-domain approach to estimate carrier frequency offset in a third-generation wideband code-division multiple-access (3G-WCDMA) system. The frequency-offset estimator, which is designed to operate in a multipath fading environment, does not require any prior knowledge about the correlation function of the fading process. The nature of the estimator is very conducive for the usage of binary search that greatly accelerates the estimation procedure. The algorithm has a low computational complexity in the order of O(N) and the dual features of estimating frequency offset and Doppler spread simultaneously. It is shown to have a wide estimation range. The performance is good even in low SNR, especially when selection diversity combining is used. It meets the Third Generation Partnership Project (3GPP) requirement of 0.1 ppm for the frequency-offset estimation even for short observation intervals.