Fang Lu

A single-chip universal burst receiver for cable modem/digital cable-TV applications

This paper presents a single-chip cable upstream receiver which demodulates QPSK/16-QAM burst data in a frequency-agile, time-division multiple access (TDMA) scheme. An analog front end (AFE), an all-digital receiver and an FEC decoder are integrated on chip. The AFE performs coarse gain setting and signal quantization on either an IF input or baseband I/Q inputs. The digital QAM receiver contains a quadrature down-mixer, multi-stage decimators, Nyquist filters, carrier/timing acquisition loops, and an adaptive equalizer. The FEC decoder consists of a programmable descrambler and a versatile Reed-Solomon decoder. The chip occupies 4.7/spl times/7.8 mm/sup 2/ die area in a 0.35-/spl mu/m CMOS process, and consumes 1.0 W at 3.3 V in a 100-pin PQFP.

A dual-channel QAM/QPSK receiver IC with integrated cable set-top box functionality

A digital cable-TV receiver IC with a 5 MBaud 64/256-QAM in-band channel and a 1 MBaud QPSK out-of-band channel incorporating on-chip forward error correction, tracking loops and adaptive decision feedback equalizers has been designed. The device further integrates out-of-band message separation and peripheral box control circuitry. The chip interfaces to a MC-68331 microprocessor and uses a mix of semicustom and custom design methodologies to achieve functionality in an 8 mm/spl times/8 mm die area with a 0.5 /spl mu/m CMOS technology, while dissipating 1.8 W at 5 V in a 208-pin PQFP package.