Increasing Demand For High Data Rate Services And High Spectral E±Ciency Are The Key Drives For The Continued Technology Evolution In Wireless Communications. The Code Division Multiple Access (CDMA), Orthogonal Frequency Division Multiple Access (OFDM) And A Combination Of The Same In The Form Of MC-DS-CDMA And MC-CDMA Are The Set Of Multiple Access/Multiplexing Mechanisms Evolving As The Order Of The Day In Wireless Communications. The CDMA Technology Is Employed As The Primary Access Mechanism In The 3rd Generation Cellular Systems. Ultra Spectral Modulation (USM) Is Likely To Use CDMA As The Access Mechanism For The 4th Generation Cellular. The Transceiver Design Greatly E®Ects A Wireless Communication System Per- Formance And Design. There Is A Good Scope For Optimizing The System Design To The Channel Conditions And Thereby Enhance The System Capacity. One Of The Factors That Introduces Performance Degradation Is The Delay Due To O®Set Time Between The Uplink And Downlink Slots Of TDD-CDMA, And The Feedback Delay In FDD-CDMA Systems Working In Time Varying Channel Conditions. Another Factor Which Decides The System E±Ciency Is The Training Overhead Required For The Chan- Nel Estimation. The Way The CDMA Band 3G Cellular Systems Are Standardized , These Systems Do Not Properly Exploit The Scope For Capacity Optimization. The Relative Mobility Between The Transmitter And Receiver Causes A Doppler Spread. In W-CDMA, This Doppler Spread Is Typically Less Than 300 Hz Which Is Much Less Than The Symbol Transmission Rate, Resulting In Slow Fading. This Feature Can Be Exploited In Fading Estimation And Mitigation With The Help Of Channel Prediction. In This Thesis, A Few Schemes Are Proposed To Improve The