Over View of Interference Cancellation Techniques in MU-MIMO

In the present and future situation in wireless communication the demand is increasing of good and high quality of communication. This is possible to the use of Multi-User MIMO systems. The Multi-User MIMO system downlink channels referred to as Broadcast Channel (BC) and uplink channels referred to as Multiple Access Channel (MAC). In MU-MIMO systems are caused interference and it is cancelled out by using transmission methods for broadcast channel. There are four transmission methods: Block Diagonalization, Tomlinson-Harashima Precoding, Channel Inversion, and Dirty Paper Coding for cancelled interference. In channel inversion method, Interference due to other Signals and inter-antenna interference become cancelled out and minimize noise enhacement. In the Block Diagonalization (BD) method, only the interference from other user signals is cancelled in the process of precoding. Dirty Paper Coding (DPC) is used to cancelled Gaussian noise and interference that is known to the transmitter. Tomlinson-Harashima Precoding (THP) in Decision Feedback Equalization is to cancel the post-cursor ISI error in the transmitter side, and in the DFE past transmit symbols are known without of errors.