Abstract : In a short while wireless communication become widely used and one of the main transmission systems at all kind, new generations shows up with new techniques, Massive MIMO antenna is what we focus on in this paper and specifically, the downlink of linearly pre-coding multi-user of Multi-input Multi-output Orthogonal Frequency Division Multiplexing (MIMO-OFDM) system that has been studied using The Regular Zero Forcing (RZF) to adequate the Bit Error Rate (BER), and in addition, the Minimum Mean Square Error (MMSE) were taken into consideration and compared with RZF. By properly adjusting the RZF precoding design parameters and use its equations fine, using MATLAB application, the results of the simulation shows that the BER can be improved depending on the regularization parameter of RZF. At SNR 20 and when the regularization parameter is equal to 1 can get the better BER performance to be 〖10〗^(-6) and this value began to increase dramatically as this parameter increase and reach to BER 〖10〗^(-1) at regularization parameter equal to 1000 which represent the worst performance at SNR 20. Moreover, we notice that there is some common points between number of users (UE) antennas and Base Station (BS) antennas, taking in count that the antenna at each user is single antenna and for BS is Multi antennas.