A Fully Open-source Implementation of an Analog 8-PAM Demapper for High-speed Communications

TL;DR

This paper presents an open-source, analog 8-PAM demapper design implemented in SiGe BiCMOS technology, achieving high-speed data processing with energy efficiency suitable for spectrally-efficient communication systems.

Contribution

It introduces a fully MOSFET-based analog 8-PAM demapper design, improving upon previous 4-PAM designs, using open-source IC design tools.

Findings

Energy efficiency of 0.33 pJ/bit at 1 Gbit/s

Design is fully open-source and based on standard IC design tools

Simulated in SiGe BiCMOS technology

Abstract

Spectrally-efficient communication systems rely on the use of multi-level modulation formats. At the receiver side, a demodulator is often used to extract soft information about the transmitted bits. Such a demodulator is typically implemented in the digital domain. However, analog implementations of such demodulators are also possible. In this paper, we design and simulate an analog 8-ary pulse-amplitude modulation (8-PAM) demapper in IHP SG13G2 SiGe BiCMOS technology. We generalize and improve a design available in the literature for 4-PAM. A fully MOSFET-based 8-PAM design is proposed. Our simulations and design are completely based on open-source IC design tools. Our results show an energy efficiency of 0.33 pJ/bit for a data rate of 1Gbit/s.