This repository contains MATLAB code for simulation of the downlink precoding of Massive MIMO system. I proposed two optimizations for downlink precoding under the use of 1-bit DAC and imperfect CSI.

Note: Change the parameters to make the system correspond to your need. I have been playing around with these parameters. So the current parameters setting are NOT consistent with the sample output. Several parameters that need more attention:

• Num_BS_Antennas: The numebr of antennas at the base station.

• Num_UE: The number of UEs, assume each UE just has a single antenna.

• SNR: The range of SNR we simulate.

• Symbols: The constellation points specified to the modulation scheme chosen.

• f_dop: The doppler spread of the channel.

• f_symb: The sampling rate of channel matrix.

• multi: The weight of additive estimation error to channel estimation.

Figure taken from Jacobsson S, Durisi G, Coldrey M, et al. Quantized Precoding for Massive MU-MIMO[J]. 2016

• main.m: The entry function for robust ZF precoder.

• main_linear.m: The entry function for comparing three conventional precoders.

• Transmit.m: Complete source data generation, modulation, precoding, transmission and detection.

• Transmit_linear.m: Same functionality as transit.m, but designed for the conventional precoders.

• MF_Precoder.m: Conventional Matched Filter Precoder. Aim to maximize the SNR at receiving end.

• ZF_Precoder.m: Conventional Zero Forcing Precoder. Aim to eliminate the interference among users.

• WF_Precoder.m: Conventional Wiener Filter Precoder. Aim to minimize MSE between sending sequence and received sequence.

• Gen_Channel2.m: Generate a Rayleigh and flat-fading channel given doppler spread and sampling rate.

• Robust_CSI.m: Implementation of robust CSI algorithm.

• Robust_DAC.m: Implementation of robust 1-bit DAC algorithm.

• Robust_ZF_Precoder.m: Integrate Robust_CSI and Robust_DAC. Implement robust ZF precoder.

• Quantize_x.m: Simulate DAC, realize quantization.

• Decider.m: Detect the received constellation point.

Comparison between MF, ZF, WF precoders: