Abstract: It is well known that channel estimation is important for overall performance of a VRVP-MQAM system. Therefore, the MMSE estimation based VRVP-MQAM scheme was studied and second order statistical characterization of the channel state information(CSI) imperfection over a Rayleigh flat-fading was derived. Then rate and power algorithms was proposed in two kinds of situations that are derived based on , the correlation coefficient between the estimated SNR and its true value. Finally, the proposed VRVP-MQAM scheme was simulated with a given Rayleigh flat fading channel. The simulation results and their comparison with an alternative rate and power algorithm which exploits an ideal CSI assumption show preliminarily that: Compared with ideal CSI(=1), the signal to noise ratio(SNR) of MMSE estimate error(=0.9) is 1 to 3 dB; When average SNR is 20 dB, the average spectral efficient(ASE) of MMSE CSI is 0.3 bps/Hz lower than that of the ideal CSI. Thus the application of VRVP-MQAM scheme will greatly improve in the future.