多分量相移键控信号码速率盲估计

Blind Estimation of Symbol Rates of Multi-component Phase-Shift Keying Signals

为解决单通道接收机同时截获到同一频带范围内的多分量相移键控信号的参数估计问题,提出了一种不经信号分离直接提取各独立信号分量码速率的盲估计算法.从理论上推导了多分量相移键控信号的二阶共轭循环自相关具有线性特性,因此可以不受干扰地提取各信号分量的码速率;进而提出了简单而有效的谱峰增强方法,与基于二阶共轭循环自相关获得的谱峰相比,用此法获得的谱峰更为清晰.仿真实验表明:用提出的算法,当双分量信号功率比为11且信噪比为-5 dB时,码速率估计的正确率可达98%;尤其是在单分量环境下,该算法比现有算法的性能提高4 dB以上.

To solve the parameter estimation problem of multi-component phase-shift keying （PSK） signals intercepted simultaneously by a single-channel receiver in the same bandwidth, a new blind estimation algorithm was proposed. With this algorithm, blind signal separation is avoided and the symbol rate of each independent signal can be estimated directly. The linearity of the 2nd-order conjugated cyclic correlation for a multi-component PSK signal was derived theoretically, so that the symbol rate of each independent signal can be extracted without interference. In addition, a simple and effective method was proposed to evhance spectrum peaks. Compared with spectrum peaks obtained based on the 2nd-order conjugated cyclic correlation, spectrum peaks obtained by the proposed method are legible. The simulation results indicate that with the proposed algorithm the correct probability of symbol rates can reach 98% when the power ratio of a two-component signal is 1 to 1 and the signal-tonoise ratio （SNR） is -5 dB. Especially in a single-component signal case, the proposed algorithm can bring more than 4 dB performance improvement compared with the existing algorithm.