Iterative SVD-based frequency offset estimation with decorrelation for wireless sensor networks

This paper proposes an iterative frequency offset estimation scheme for wireless sensor networks with direct-sequence spread spectrum. The proposed scheme is able to estimate large frequency offset that may occur at the receiver on devices with a sensor by iterating singular value decomposition (SVD)-based frequency offset estimation. In the proposed estimation scheme, a decorrelator is inserted in the iteration cycle that reduces the correlation between the received signals in order to improve the estimation performance, even in multipath fading channel with co-channel interference. It is confirmed by computer simulation that the proposed estimation scheme achieves exact frequency offset estimation in the channel, even when the frequency offset normalized by the symbol duration is 7 × 10¹.