一种基于循环谱的时频混叠信号参数估计方法

时频混叠信号的参数估计是通信信号领域一个新兴课题，它是对混合信号进行分离，识别与解调等后续处理的基础。信号经过调制、成形及采样后具备循环平稳的特性。本文基于时频混叠信号的循环平稳特性，计算其循环谱并用形态学滤波的思想提取含有载频与码元信息的截面的谱峰，而后进行搜索从而实现估计。解决了参数配对的问题，并且由形态学滤波在提取谱线时能有效降低背景色噪声。同时探究了多径与多普勒频移信道下该算法对估计精度的影响。经仿真验证，该算法能实现BPSK与8QAM任意任何后的载频与码元速率估计，具有抗噪声，精确度高等优效性。

A Method for Parameters Estimation of Time-Frequency Overlapped Signals based on Cyclic Spectrum

The parameters estimation of time-frequency overlapped signals is a new subject of communication signals process, it is the base of subsequent processes, such as separation,modulation recognition and signal demodulation of co-channels signals. It shows that signals reflect cyclostationary character after modulation, pulse formation and sampling. This paper presents a method which based on cyclostationary of time-frequency signals, after calculating the cyclic spectrum and making use of mathematic morphology to pick up discrect spectrum-line and estimate modulation parameters, including carrier frequency and chip rate. This algorithm solves the problem of parameter pairs,and make use of mathematic morphology can reduce the background noise effectively. At the same time doing some research about accuracy in the multipath fading