A study on Dirty Paper Coding with a maximum beam in multiuser MIMO downlinks

This paper focuses on the signal processing algorithm for the downlink of Multi-User Multiple-Input Multiple-Output (MU-MIMO). In this paper, a novel transmission scheme is proposed for the cancellation of IUI (Inter-User Interference) in MU-MIMO downlinks. Compared with the conventional DPC with single receive antenna, the users in the proposed scheme are equipped with multiple receive antennas, even though the principle of the DPC (Dirty Paper Coding) in MU-MIMO is the same. For the users with multiple receive antennas, the maximum eigenvectors for all user channels are calculated first and then we select the user with the maximum eigenvector as the 1-st user. For the remaining users, the transmit weights are generated from the weights of previous selected users by using the algorithm which makes the each user gain as large as possible. We also use the DPC principle to cancel the IUI at the base station. Through computer simulations, we have shown that the proposed scheme achieves an excellent BER characteristic compared with the conventional DPC, especially when multiple receive antennas are used for each user.