Pulse Amplitude Modulation - Analog communication
- 5. PWM and PPM generation using MATLAB
- 6. PWM and PPM generation
- 8. • The basic theory behind Pulse width demodulation is that converting the PWM signal to PAM (Pulse Amplitude Modulation) signal. • PAM can be easily detected by suitable low pass filter.
- 9. • Input PWM wave is applied to Ramp generator and Synchronous Pulse generator • Synchronous pulse generator will generate a pulse waveform such that the pulse will end at the beginning of each PWM pulse • Ramp generator will produce a ramp signal whose amplitude is proportional to width of the PWM signal • Now apply these Ramp and Synchronous pulse to an Adder circuit which adds these signals together. • The next block is a positive Clipper with a specific voltage; Clipper clips the waveform at a particular level. • The output of clipper will be PAM signal, now the PWM signal gets converted to PAM signal. • The PAM can be demodulated by Low Pass filtering method. Thus our next block is Low Pass Filter.
- 11. PPM detection
- 12. PPM to PWM conversion Rising edge of PWM at each sampling instant Trailing edge of PWM at each rising edge of PPM