Multiple-Valued Signaling for High-Speed Serial Links Using Tomlinson-Harashima Precoding

The data rate of VLSI interconnections has been increasing following the demand for the high-speed operation of semiconductors, such as in CPUs. At high-speed data rates, achieving accurate communication without bit errors is difficult because of intersymbol interference (ISI). This paper presents high-speed data communication techniques for VLSI systems using Tomlinson-Harashima precoding (THP). Because THP can eliminate ISI by limiting the average and peak power of the transmitter signal, it is suitable for implementing advanced low-voltage VLSI systems. In this study, a 4-PAM (Pulse amplitude modulation) signal with THP was employed to achieve high-speed data communication in VLSI systems. Simulation and measurement results show that THP can remove the ISI without increasing the peak and average power of a transmitter signal. Furthermore, we clarify that multiple-valued signaling using THP is effective in reducing implementation costs to realize high-speed serial links.