An Improved Music Algorithm for Carrier Frequency Offset Estimator in the Uplink of IFDMA System

The carrier frequency offsets (CFOs) in the uplink of interleaved frequency division multiple access (IFDMA) system destroy the orthogonality between users, resulting in severe multiple access interference (MAI). An improved MUSIC (multiple signal classification) algorithm is proposed to estimate CFO in this paper. In contrast to conventional MUSIC schemes which require multi-dimensional search over the parameter space, a signal structure based deterministic estimation algorithm with MUSIC is proposed for estimating the CFOs of all users simultaneously in the uplink of IFDMA system, using only one IFDMA block. Diversity schemes are also presented to improve the estimation performance. The algorithm is attractive owing to the low computational complexity and exhibiting effectiveness in frequency selective channels. The performance of the proposed scheme is confirmed by computer simulations.