摘要
在全数字化MPSK(多相移键控)解调中,有时存在着相当大的相对载波频偏,导致接收机不能正常工作。文中介绍了基于最大似然准则的FFT(快速傅里叶变换)频偏估计算法,分析了该算法的复杂度,并将该算法应用于MPSK信号载波恢复,达到对频偏进行有效估计并矫正的目的。首先给出了应用FFT频率估计器的MPSK信号载波恢复结构,以及在FPGA(现场可编程门阵列)上实现该算法的关键技术。在使用IP核的基础上,详细描述了FFT频率估计器在FPGA中的实现过程。最后分析了算法实现时需要的硬件资源和性能。
In fully digitized MPSK demodulators, sometimes there exists a rather large frequency-offset so that the demodulator can not work normally. In his paper, a maximum likelihood frequency estimator base on FFT is introduced, the complexity of the algorithm is analyzed. The frequency offset is estimated and compensated when the algorithm is applied to carrier recovery for MPSK signals. First the structure the FFF frequency estimator is given, as well as the key techniques for its implementation on FPGA devices. Second, base on the IP cores, the process to implement the FFT frequency estimator in FPGA devices is described in detail. Finally the performance and hardware burden of the implementation is discussed.
出处
《电子工程师》
2007年第2期31-34,共4页
Electronic Engineer
关键词
FFT
校频
FPGA
FFT
frequency estimation
FPGA
