Abstract: Wide Code Division Multiple Access (WCDMA) a third generation wireless communication system that has high bandwidth and offers multimedia communication capabilities for global mobile communications but the performance of WCDMA is degraded with various factors such as interference, fading and scattering. Diversity is a technique which is used to mitigate the fading problem in wireless channel at a relatively low cost .This paper gives the review of different diversity techniques to mitigate the fading problem and for improving the overall performance of the communication system. In different diversity techniques, space diversity technique is an important technique and maximum ratio combining (MRC) is the most effective technique which is a part of space diversity technique. MRC produces an output signal to noise ratio (SNR) equal to the sum of the individual SNRs.

Keywords: WCDMA, Diversity Techniques, Selection Combining, Maximum Ratio Combining.