Abstract:

An algorithm of multiple frequency offsets estimation for distributed multiple input multiple output orthogonal frequency division multiplexing (MIMO-OFDM) systems was discussed. Accounting for the difficulty and lack of blind estimation methods, the scheme uses the deconvolution blind source separation (BSS) to distract the effect of multipath and ambiguity and obtain the frequency offset signals by considering that the characteristics of the multipath signal model is similar to the signal in BSS. The multidimensional frequency estimation problem is thus turned into multiple single dimension problems, and then the frequency offset value is obtained by a single frequency offset estimation algorithm. Simulations indicate that the proposed algorithm has better performance in estimating the frequency offsets than pilots-aided ones. Under signal noise ratio (SNR) of 5 dB, the mean square errors of the carrier frequency offset (CFO) reaches to 10^-6.

Key words: distributed multiple output orthogonal frequency division multiplexing, multiple frequency offsets, blind source separation, deconvolution