关键词: 正交复用二进制偏移载波, 循环谱, 多参数估计

Abstract: In the low signal-to-noise ratio environment, the problem of multi-parameter blind estimation for quadrature multiplexed binary offset carrier ( QMBOC) signals is existed. To solve this problem, a cyclic spectral estimation algorithm is proposed based on frequency domain cumulative averaging. First, the cyclic autocorrelation function of QMBOC signal is obtained from the signal model. The cyclic autocorrelation function is equivalent to the sum of the cyclic autocorrelation function of two subsignals. Then the cyclic autocorrelation function is used to derive the cyclic spectrum by Fourier transform, and the cyclic spectrum is averaged by frequency domain accumulation. Finally, the spectral peak is searched to realize the blind estimation of pseudo-code rate, subcarrier rate and carrier frequency according to the spectral line characteristics of the cyclic frequency section of QMBOC signal. The experimental results show that the proposed algorithm can effectively estimate multiple parameters of QMBOC signal at - 9.5 dB.

Key words: quadrature multiplexing binary offset carrier, cyclic spectrum, parameters estimation