Receiver and method of receiving and transmitter and method of transmitting for OFDM symbols

摘要

A receiver receives payload data transmitted on a downstream using Orthogonal Frequency Division Multiplexed (OFDM) symbols via a cable network. The receiver includes circuitry configured to receive a downstream signal representing the payload data modulated onto one or more OFDM symbols, and to demodulate the OFDM symbols of each frame to detect and to recover the payload data using the physical layer signalling data. One or more of the frames of the received signal includes a preamble of the frame providing the physical layer signalling data, and in a separate media access control (MAC) signal within the frame, upstream messages relating to the transmission of data from the receiver to the transmitter. Accordingly, an arrangement is provided for a cable network communications system in which a capacity for upstream signalling messages for communicating on the downstream can be adapted to a requirement of receivers connected to the network.

主权项

1. A communications apparatus for receiving payload data transmitted on a downstream using Orthogonal Frequency Division Multiplexed (OFDM) symbols via a cable network, the communications apparatus comprising:
a receiver comprising a receiver filter, an analogue to digital converter, and a Fast Fourier Transformer, the receiver being configured to receive a downstream signal representing the payload data modulated onto one or more OFDM symbols, the downstream signal comprising
one or more data profiles transmitted in scheduling intervals, each of the one or more data profiles providing the payload data according to a different receiver profile and being carried by different downstream communications resources of the OFDM symbols within the scheduling intervals, andphysical layer signalling data identifying the downstream communications resources of the data profiles in each of the scheduling intervals; and a demodulator configured to demodulate the OFDM symbols of one of the data profiles to detect and to recover the payload data using the physical layer signalling data, wherein the physical layer signalling data is received as a preamble of one of the scheduling intervals, wherein the receiver and the demodulator are further configured to receive one or more of the scheduling intervals, which include in separate communications resources of the downstream signal a media access control (MAC) signal representing upstream messages relating to the transmission of data from the receiver to a transmitter.