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.