Single-Port DOCSIS® 3.1 Burst Receiver
The BCM31440 is an advanced DOCSIS® 3.1 single-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 A-to-D conversion on RF inputs with a carrier frequency up to 300 MHz. A digital quadrature down-mixer translates the input spectral center to baseband. The BCM31440 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 BCM31440 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 BCM31440 delivers the recovered data streams and accepts receiver control inputs through a receive interface linked to a MAC chip, which can then enable the channel bonding function for DOCSIS 3.1. An on-chip FFT processor can analyze an RF spectrum with a selectable bandwidth and length. The BCM31440 can be configured through the 10 GbE interface
- Supports up to 12 SC-QAM channels — 12 ATDMA or 8 ATDMA + 4 SCDMA per port
- Supports 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 entire 0 to 300 MHz upstream
- Integrated analog-to-digital (A/D) converters support direct digital sampling of entire 0 to 300 MHz reverse path
- Flexible association of A/D and input samples to on-chip FFT engine
- Dynamic channel allocation of carrier frequency, symbol rates, and constellation
- Incorporates LDPC decoder
- Four 10G Ethernet MAC-layer interfaces capable of pt-to-pt connection to the BCM3222