Abstract
In this work tracking analysis of the normalized least mean fourth (NLMF) algorithm is carried out in the presence of two sources of nonstationarites (carrier frequency offset between transmitter and receiver and random variations in the environment). The concept of energy conservation is used to carry out the analysis. Simulation results agree very closely with theory. The results show that, unlike in the stationary case, the steady-state excess mean-square error (MSE) is not a monotonically increasing function of the step size. Moreover the ability of the adaptive algorithm to track the variations in the environment is shown to degrade with increasing frequency offset.