在D通道均匀DFT分析滤波器组基础上给出了一种新的信号正交分量的解调结构 ,为解调宽带信号 (B fc)的正交分量 ,系统采用两组D通道均匀DFT分析滤波器组通带互补方法 ,以克服单组滤波器中滤波器的非理想性所造成的信号失真。在频域中当信号频谱处于两个或更多个滤波器通道时 ,通过频谱组合办法直接得到实信号的正半谱或负半谱。在载波频率已恢复的情况下给出了IQ正交分量的解调算法。仿真证明该系统结构和算法的正确性和高效性

In this article a new demodulation structure based on D-channel Uniform DFT filter bank is given to obtain In-phase and Quadrature components (IQ) of the received signal. In order to get the IQ components for broadband signals, two D-channel Uniform DFT filter banks, whose ideal pass bands are set to be complementary, are used to reduce signal distortion caused by the non-idealness of filter in a single filter bank. When the signal spectrum falls into two or more channels, a method of spectrum assembling in frequency domain is used to obtain the positive or negative half spectrum. The demodulation algorithm for IQ components is given under condition that the carrier is recovered. Simulation proves that the system structure and algorithm are feasible and highly efficient.

TN911.7