Abstract:The modified cyclic autocorrelation algorithm is proposed to estimate problems of the useful data period, entire symbol period, chip duration, and guard interval length in MC-CDMA signal. Firstly, the autocorrelation function of the received MC-CDMA signal is computed. Then, Fourier transformation and accumulation in frequency-domain are used. Finally, through detecting the interval of the peak pulses in different slices, parameters mentioned above can be estimated. In addition, a new method of estimating symbol period, the accumulative average method, is developed. By averaging amplitudes of the spectral lines in each column parallel to the delay axis, the symbol duration can be obtained. Cyclic autocorrelation expression of the MC-CDMA signal is derived theoretically, and it is proved that MC-CDMA signal with cyclic prefix has cyclostationary. The simulation results show that, the improved cyclic autocorrelation algorithm is effective in the low signal-to-noise cause.
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