Fast Fading Varying Channel Estimation And Equalization Techniques,

With the rapid development of highball, we demand that time-varying and fast-fading mobile communication channels can be estimated and equalized efficiently and robustly. In this thesis, several approaches are studied, including optimal parametric feedforward estimation of fading channels, basis expansion for estimation and equalization of channels, channel estimation based on pilot and data traffic channels and channel estimation using linear interpolation.The method of optimal parametric feedforward estimation of fading channels, which is used in TDMA systems originally, is modified to cope with matrix singularity because the number of pilot signals is small in WCDMA systems. In this modified algorithm, channel estimation is made by dispreading the received signal of DPCCH with a corresponding long Gold sequence and pilot OVSF, followed by averaging. When studying the basis expansion approach, a new scheme utilizing pilot signals is proposed, which takes full advantage of high processing gain of DPCCH. Utilizing Fourier transform, the frequencies and the coefficients of basis can be estimated.On account of the importance of channels, we also discuss the characteristic of time-varying and fast-fading mobile channels and introduce channel modeling and a method of high-speed simulation for fading channels by using table look-up technique.In addition, because these approaches are simulated on the basis of 3rd Generation Partnership Project (3GPP). We describe how to form signals of uplink in WCDMA systems...