Estimation of the nonstationary mean signal in wireless systems using wavelets

A new technique is described for estimating the nonstationary mean signal received at a mobile station in a Rayleigh fading environment. The estimate is based on samples taken at the midpoints between the local minima of the received envelope. The continuous wavelet transform is used to estimate the local minima. An estimate of the mean signal is obtained using a fixed number of local minima. This technique requires neither an estimate of the mobile speed nor an adaptive temporal averaging window, in contrast to other estimators. Simulations show that the mean signal is estimated well in a nonstationary environment with variable mobile speed