7
Applications to Mobile Communications and Radar/Sonar
In this chapter, the (non-relativistic) Doppler effect due to motion between transmitter and receiver and/or surrounding scatterers is described by a LTV system introducing time-varying delays. Since a non-relativistic analysis is carried out, time dilation existing between clocks in relative motion is neglected (Gray and Addison 2003). In the case of constant relative radial speed 
between transmitter and receiver, according to Lorentz transformations, the time-dilation factor 
is approximated to 1 where c is the medium propagation speed. Moreover, aberration effect is neglected. Applications to mobile communications and radar/sonar problems are considered when the transmitted signal is ACS. Conditions on the transmitted signal and channel parameters are derived under which the received signal can be modeled as GACS or SC.
