Abstract: 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.

Abstract: A receiver receives payload data from a downstream signal, and includes a filter to receive the downstream signal, and including signalling data identifying downstream resources for the payload data, and an analog to digital converter to receive the downstream signal from the filter and to convert it into a sampled digital form. A demodulator demodulates the digital form of the downstream signal to recover the payload data and the signalling data. The signalling data includes a mode switch signal to indicate an active mode or a sleep mode for the receiver. A controller detects the mode switch signal to control the analog to digital converter to switch sampling rates in response thereto, and to control the filter to switch frequency bands. The frequency bands perform anti-alias filtering for respective sampling rates.

Abstract: A transmitting apparatus for transmitting signals in a multi carrier system on the basis of a frame structure, each frame including at least two signalling patterns adjacent to each other in the frequency direction and at least two data patterns, the transmitting apparatus including signalling mapping means to map signalling data on frequency carriers of each of the at least two signalling patterns in a frame, each signalling pattern having the same length, data mapping means to map data on frequency carriers of the at least two data patterns in a frame, transforming means to transform the signalling patterns and the data patterns from the frequency domain into the time domain in order to generate a time domain transmission signal, and transmitting means to transmit the transmission signal. A corresponding transmitting method and a frame pattern for a multi carrier system are also provided.

Abstract: A receiver receives payload data from a downstream signal, and includes a filter to receive the downstream signal, and including signalling data identifying downstream resources for the payload data, and an analogue to digital converter to receive the downstream signal from the filter and to convert it into a sampled digital form. A demodulator demodulates the digital form of the downstream signal to recover the payload data and the signalling data. The signalling data includes a mode switch signal to indicate an active mode or a sleep mode for the receiver. A controller detects the mode switch signal to control the analogue to digital converter to switch sampling rates in response thereto, and to control the filter to switch frequency bands. The frequency bands perform anti-alias filtering for respective sampling rates.

Abstract: 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.

Abstract: A receiver receives data from a sequence of OFDM symbols transmitted via a channel, each OFDM symbol comprising a plurality of data bearing sub-carriers and a plurality of pilot bearing sub-carriers. The receiver includes a channel estimator for estimating the channel and an equalizer for reducing the effects of the channel so that the data can be recovered from the received OFDM symbols. The channel estimator includes a notch processor which is arranged in operation to detect a notch in a received OFDM symbol, the notch providing a plurality of the sub-carriers of the received OFDM symbol within a frequency range which were not transmitted by the transmitter, to determine one or more missing pilot sub-carriers which would have been transmitted within the notch sub-carriers of OFDM symbols according to a pilot sub-carrier pattern, and to generate one or more replacement pilot data symbol for a missing pilot data sub-carrier.

Abstract: A receiver receives data from a sequence of OFDM symbols transmitted via a channel, each OFDM symbol comprising a plurality of data bearing sub-carriers and a plurality of pilot bearing sub-carriers. The receiver includes a channel estimator for estimating the channel and an equaliser for reducing the effects of the channel so that the data can be recovered from the received OFDM symbols. The channel estimator includes a notch processor which is arranged in operation to detect a notch in a received OFDM symbol, the notch providing a plurality of the sub-carriers of the received OFDM symbol within a frequency range which were not transmitted by the transmitter, to determine one or more missing pilot sub-carriers which would have been transmitted within the notch sub-carriers of OFDM symbols according to a pilot sub-carrier pattern, and to generate one or more replacement pilot data symbol for a missing pilot data sub-carrier.

Abstract: A transmitting apparatus for transmitting signals in a multi carrier system on the basis of a frame structure, each frame including at least two signalling patterns adjacent to each other in the frequency direction and at least two data patterns, the transmitting apparatus including signalling mapping means to map signalling data on frequency carriers of each of the at least two signalling patterns in a frame, each signalling pattern having the same length, data mapping means to map data on frequency carriers of the at least two data patterns in a frame, transforming means to transform the signalling patterns and the data patterns from the frequency domain into the time domain in order to generate a time domain transmission signal, and transmitting means to transmit the transmission signal. A corresponding transmitting method and a frame pattern for a multi carrier system are also provided.

Abstract: A transmitting apparatus for transmitting signals in a multi carrier system on the basis of a frame structure, each frame including at least two signalling patterns adjacent to each other in the frequency direction and at least two data patterns, the transmitting apparatus including signalling mapping means to map signalling data on frequency carriers of each of the at least two signalling patterns in a frame, each signalling pattern having the same length, data mapping means to map data on frequency carriers of the at least two data patterns in a frame, transforming means to transform the signalling patterns and the data patterns from the frequency domain into the time domain in order to generate a time domain transmission signal, and transmitting means to transmit the transmission signal. A corresponding transmitting method and a frame pattern for a multi carrier system are also provided.

Abstract: A transmitting apparatus for transmitting signals in a multi carrier system on the basis of a frame structure, each frame including at least two signalling patterns adjacent to each other in the frequency direction and at least two data patterns, the transmitting apparatus including signalling mapping means to map signalling data on frequency carriers of each of the at least two signalling patterns in a frame, each signalling pattern having the same length, data mapping means to map data on frequency carriers of the at least two data patterns in a frame, transforming means to transform the signalling patterns and the data patterns from the frequency domain into the time domain in order to generate a time domain transmission signal, and transmitting means to transmit the transmission signal. A corresponding transmitting method and a frame pattern for a multi carrier system are also provided.

Abstract: A housing for a microwave circuit is formed from a base made of metal matrix composite material and walls made of sheet metal. The base and the walls are joined together by diffusion soldering. Some holes to receive feedthroughs are formed at the junction of the base and a wall.