In this paper, performance analysis for different combining technique for receiver diversity in a MIMO system is presented. A general framework for diversity combining techniques in cooperative wireless communication system is also provided. Performance analysis of different diversity combining techniques i.e. selection diversity, equal gain combining and maximal ratio combining is calculated over Rayleigh fading channel for both BPSK (Binary Phase Shift Keying) and QPSK (Quadrature Phase Shift Keying) modulation. Monte Carlo simulations resulting in graphs showing the bit error rate v/s signal to noise ratio are provided to verify the results.