基于软件无线电的调频立体声激励器的设计与实现

Design and Realization of FM Exciter Based on Software Defined Radio

与传统采用模拟方式实现调制解调技术相比,全程数字化处理的调制器对信号处理的精度以及设备稳定性都有很大的提高。笔者在自行开发基于DSP+FPGA+DDS(带有IQ调制通道)结构的通用数字调制平台上,采用正交调制的方式实现了全数字调频激励器,这样避免了使用模拟方式造成的射频输出稳定性和同一性的下降,同时由于带有IQ调制通道的DDS对采样频率的内插提升,射频输出也无需再附加复杂的跟踪滤波器。

Compared with the conventional analog modulation, the adoption of full digitalization makes great progress in signal process precision of the device and performance and stability of the modulator. We design a general digital modulation platform based on DSP ＋ FPGA ＋ DDS （with IQ modulation channel） structure. Based on the research results, we use the means of orthogonal modulation to realize full digital FM exciter so as to avoid the distortions in radio frequency stability and consistency caused by using analog means. Meanwhile, because of the interpolation increase to the sample frequency by DDS with IQ modulation channel, there is no need to adding additional complicated tracking filter again.