Question

Which of the following is false with respect to pulse position modulation?

(a) Can be transmitted in broadband

(b) Modulates a high frequency carrier

(c) Pulse is narrow

(d) Pulse width changes in accordance with the amplitude of modulating signal

The question was asked during a job interview.

Enquiry is from Pulse Modulation topic in section Digital Communication Techniques of Avionics

Answer 1

Right choice is (d) Pulse width changes in accordance with the amplitude of modulating signal

For explanation: In PPM, the pulses change position according to the amplitude of the analog signal. The pulses are very narrow. These pulse signals may be transmitted in a baseband form, but in most applications, they modulate a high-frequency radio carrier.