A fine frequency deviation estimation algorithm(FFDE)is proposed to improve the low accuracy of the existing frequency deviation estimation algorithm for time-domain synchronous orthogonal frequency division multiplexing(TDS-OFDM)systems. The algorithm correlates the adjacent frame headers in receiving sequences with local PN sequences
respectively
and then the correlation results are conjugatively multiplied.The argument of the product is divided by the time interval between the adjacent frame headers to get the frequency deviation estimation. The algorithm has advantages of low computation complexity
accurate estimation
strong capabilities of suppressing channel noises and multipath interferences. The analytical results show that the algorithm has an extremely low bound of estimation error variance. The normalized estimation error variance is lower than 10
-11
under the channel conditi
on of additive white Gaussian noise within the normal signal to noise ratio(SNR)range. Simulation results are fully consistent with the analytical results. Simulations under multipath environment and SNR equal to 15 dB show that the standard deviation of estimation error is 0.5 Hz
which is only 0.03% of the subcarrier spaces of the system
and 1% of traditional methods.
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references
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