Velocity estimation in cellular systems based on the time-frequency characteristics of the received signal

Estimating the velocity of the mobile units is of great importance in hierarchical cellular systems since the satisfactory handover of mobiles to macro or micro-cells depends on its present velocity. In this contribution, the first moment of the instantaneous frequency (IF) of the received signal, is proposed as a new velocity estimator. The performance of this estimator in the presence of Rayleigh fading, log-normal shadowing, and additive white Gaussian noise is compared with the conventional zero crossing rate (ZCR) estimator. Simulations show that the performance of the proposed estimator is superior to that of the ZCR velocity estimator, in the presence of additive noise. Also it has been shown that the IF velocity estimator is robust in the presence of shadowing.