新的OFDM系统载波频偏盲估计算法

针对现有频偏估计算法复杂度高的问题，提出一种新的基于恒模信号的盲估计算法。假定信道变化缓慢，紧邻OFDM符号将产生相同信道响应，通过衡量它们之间的幅度差异，推导出一种目标函数，采用曲线拟合法对目标函数进行拟合并求得最小值时，即得到最接近真实值的CFO估计值。仿真结果表明，所提算法与现有PDE-F1]算法和PDE-T2]算法相比，提高了估计精度，降低了复杂度，尤其在窄带噪声和接收信号增益不断变化的环境下，该算法具有更好的适用性和稳定性。

New kind of carrier frequency offset estimation algorithm for OFDM systems

In view of high complexity of the existing frequency offset estimation algorithms, we propsed a new blind estimation algorithm based on constant modulus signal. It was assumed that the channels change slowly, the adjacent OFDM symbols would generate the same channel responses, by measuring the amplitude difference between them, a kind of objective function was derived. By using the curve fitting method, the minimum value of the objective function was obtained At this point, the value of CFO estimation was closest to the true value. Simulation results show that the proposed algorithm is better than the existing PDE-F1] algorithm and PDE-T2] algorithm, improving estimation accuracy, reducing the complexity. The algorithm has better applicability and stability under the conditions of constantly changing variations of narrow band noise and received signal gain.