Blind estimation algorithm of multi-carrier CDMA sub-carrier frequencies and its performance analysis
多载波CDMA子载波频率盲估计算法及其性能分析*

Aiming at the practical application of spectrum sensing and multi-carrier CDMA signals demodulation, this paper proposed a method to estimate sub-carriers frequency of multi-carrier CDMA signals utilizing higher-order cyclic cumulants based on the cyclic stationary characteristic of multi-carrier CDMA signals. Because higher-order cyclic cumulants could effectively suppress stationary noise and non-stationary Gaussian noise, through theoretical analysis, it could prove that the fourth-order cyclic cumulant of the multi-carrier CDMA signal using BPSK modulation only exist in the cycle frequency of sub-carrier frequencies under the above noise background, so it could estimate the sub-carrier frequency of multi-carrier CDMA signals by detecting the of peak of cyclic frequencies. Duo to the fact that the multi-carrier CDMA signal could use different window function to reduce spectral leakage, by using several common window functions in the algorithm simulation, found that the algorithm is not sensitive to the changes of the window function, with highly robustness. Simulation results have verified the correctness and effectiveness of the algorithm.