Mobility

Doppler Spread Estimation in Mobile Communication Systems Using the Ambiguity Function of the Received Signals

Date Added: Aug 2009
Format: PDF

The Doppler spread of the received signal at the mobile unit antenna is proportional to its velocity. The estimation of the velocity of a mobile unit is of great importance as it is needed for effective handover and dynamic channel assignment in cellular systems and also for designing adaptive power control algorithms for Code-Division Multiple Access (CDMA) systems. Existing methods for estimating the Doppler spread of the received signals include the use of the Zero-Crossing Rate (ZCR)2 of the quadrature components of the received signal as well as the Rate Of Maxima (ROM)3, level crossing rate, and the auto-covariance of the envelope of the received signal.