摘要
面向控制领域的众多廉价的DSP和单片机均集成有PWM(脉冲宽度调制器)模块,在对PWM信号进行理论分析的基础上,分别得出了应用PWM来实现AM、FM和SSB三种模拟通信信号的调制与解调方法:在解调时可以应用PWM和外接的LPF(低通滤波器)实现对解调信号的D/A变换功能;在调制时则应用芯片CPU和PWM共同完成对信号的调制算法,其中的PWM和外接的BPF(带通滤波器)还具有实现D/A变换的功能。最后论文应用DSP56F803芯片对该方案进行了成功实现。
PWMs (Pulse Width Modulators) are integrated in many low-priced DSPs and microcontrollers aimed at the autocontrol area. Based on the theory analysis of PWM signal, modulation and demodulation methods using PWM were obtained separately for AM, FM and SSB. As for the signal demodulation, PWM and the external LPF(Low Pass Filter) work together to fulfill digital-to-analog conversion (D/A) of the demodulated signal. Oppositely the signal modulation algorithm is corporately implemented by the chip’s CPU and PWM units. In addition, the PWM and the external BPF (Band Pass filter) also play the role of D/A conversion function. Lastly, the above scheme was successfully realized using the chip DSP56F803.
出处
《电路与系统学报》
CSCD
北大核心
2005年第3期149-152,共4页
Journal of Circuits and Systems
