A VLSI Design of a Tomlinson-Harashima Precoder for MU-MIMO Systems Using Arrayed Pipelined Processing

This paper presents a VLSI design of a TomlinsonHarashima (TH) precoder for multi-user MIMO (MU-MIMO) systems. The TH precoder consists of LQ decomposition (LQD), interference cancellation (IC), and weight coefficient multiplication (WCM) units. The LQ decomposition unit is based on an application specific instruction-set processor (ASIP) architecture with floating-point arithmetic for high accuracy operations. In the IC and WCM units with fixed-point arithmetic, the proposed architecture uses an arrayed pipeline structure to shorten a circuit critical path delay. The implementation result shows that the proposed architecture reduces circuit area and power consumption by 11% and 15%, respectively. key words: multi-user MIMO, Tomlinson-Harashima precoding, LQ decomposition, interference cancellation