A 10 Mbit/s Upstream Cable Modem with Automatic EqualizationPatrick Schaumont Radim Cmar Serge Vernalde Marc Engels

Abstract

A fully digital QAM16 burst receiver ASIC is presented. The BO4 receiver demodulates at 10 Mbit/s and uses an advanced signal processing architecture that performs perburst automatic equalization. It is a critical building block in a broadband access system for HFC networks. The chip was designed using a C++ based flow and is implemented as a 80 Kgate 0.7u CMOS standard cell design. 1 Introduction The widespread use of Internet is opening a pathway to emerging multimedia consumer networks and applications. These require a broadband data communications link to be established in the access network that connects the consumer to a core service network. The hybrid fiber-coax (HFC) access network that is currently in use for cable TV, is considered as an attractive candidate [4]. We have developed a chip that is embedded in an HFC head-end and that demodulates data transmitted from the consumer set-top. This chip is a fully digital burst receiver, characterized as shown in table 1. The chip..