Contents
What is an impulse signal?
In signal processing, the impulse response, or impulse response function (IRF), of a dynamic system is its output when presented with a brief input signal, called an impulse. More generally, an impulse response is the reaction of any dynamic system in response to some external change.
What is a periodic pulse train?
A periodic pulse train with period T0 consists of rectangular pulses of duration T. The duty cycle of a periodic pulse train is defined by T/T0. An application of the periodic pulse train is in the practical sampling process.
How is the length of a pulse modulated?
In pulse-duration modulation (PDM), the samples of the message signal are used to vary the duration of the individual pulses. This form of modulation is also referred to as pulse-width modulation or pulse-length modulation. The modulating wave may vary with the time of occurrence of the leading edge, the trailing edge, or both edges of the pulse.
How is pulse number modulation related to ppm?
Pulse number modulation (PNM) Related to PPM in the sense that we are using pulses with fixed amplitude and width. In this modulation scheme, however, many pulses are transmitted in every time slot, and the number of pulses present in the slot represents the number being transmitted.
How is the trailing edge of a pulse varied?
In Fig. 6d the trailing edge of each pulse is varied in accordance with the message signal. In PDM, long pulses expend considerable power during the pulse while bearing no additional information.
What are the different types of pulse amplitude modulation?
Board space and skew problems will be eliminated and the interference problem can be easier to solve. There are many possible modulation schemes, such as pulse amplitude modulation (PAM), pulse position modulation (PPM), pulse number modulation (PNM), pulse width modulation (PWM) and pulse density modulation (PDM).