Doppler shift is positive if mobile is moving away from direction

doppler-shift-is-positive-if-mobile-is-moving-away-from-direction

Doppler shift is positive if mobile is moving away from direction of arrival of the wave.

A. True

B. False

This question was addressed to me in unit test.

My enquiry is from Small- Scale Multipath Propagation topic in chapter Mobile Radio Propagation: Small – Scale Fading and Multipath of Wireless/Mobile

Right answer is B. False

Easiest explanation: Doppler shift is positive if the mobile is moving toward the direction of arrival of the wave, as the apparent received frequency is increased. And if the mobile is moving away from the direction of arrival of the wave, Doppler shift is negative.