Dual-Port DOCSIS® 3.1 Burst Receiver
The BCM31442 is an advanced DOCSIS® 3.1 dual-port cable network burst receiver that accepts upstream burst data in a frequency-agile time division multiple access (TDMA), synchronous code division multiple access (S‑CDMA), or orthogonal frequency division multiple access (OFDMA) scheme. The chip integrates an analog front end (AFE), QAM (up to 4096 order)/OFDMA demodulators, FEC decoders, and a MAC/PHY interface.
The AFE performs analog-to-digital (A/D) conversion on RF inputs with a carrier frequency of up to 300 MHz. A digital quadrature down-mixer translates the input spectral center to baseband. The BCM31442 features a ranging processor that estimates the received timing and amplitude of the ranging sequence, plus an adaptive equalizer that characterizes the RF channel response and/or removes intersymbol interference (ISI) caused by microreflections.
The BCM31442 ingress-canceling processor suppresses ingress/narrowband interference in TDMA/SCDMA channels. The FEC decoder performs deinterleaving, descrambling, and RS/LDPC decoding with flexible parameters.
The BCM31442 delivers the recovered data streams and accepts receiver control inputs through a receive interface linked to a MAC chip, which can then enable channel bonding function for DOCSIS 3.1. An on-chip FFT processor can analyze an RF spectrum with a selectable bandwidth and length. The BCM31442 can be configured through the 10GbE interface.
- Up to 12 SC-QAM channels: 12 ATDMA or 8 ATDMA + 4 SCDMA per port
- Up to 2x 96 MHz OFDMA operation per port
- Integrated ingress canceler enables operation in impaired RF channels
- Integrated FFT enables advanced spectrum management of the entire 0 to 300 MHz upstream
- Integrated A/D converters support direct digital sampling of the entire 0 to 300 MHz reverse path
- Flexible association of A/D and input samples to the on-chip FFT engine
- Dynamic channel allocation of carrier frequency, symbol rates, and constellation
- Integrated LDPC decoder
- Four 10G Ethernet MAC-layer interfaces capable of point-to-point connection to the BCM3222 DOCSIS 3.1 CCAP Upstream Media Access Control chip