Abstract: Systems and methods for orthogonal frequency division multiplexing are provided.

Abstract: Systems and methods for orthogonal frequency division multiplexing are provided. In one embodiment, a multi-carrier modem comprises: a receiver configured to receive a waveform comprising a plurality of spectrally overlapping carrier signals from at least two of a plurality of remotes, the carrier signals are modulated using an inverse Fourier transform; a transmitter; a processor coupled to the transmitter, the processor outputs data for transmission to the transmitter, the processor applies an inverse Fourier transform to the data provided to the transmitter; a controller programmed to instruct the transmitter to transmit timing adjustments to the at least two of the plurality of remotes, the timing adjustments instruct the at least two of the plurality of remotes to adjust transmission timing so that transmitted symbols associated with frames of a predetermined multiframe structure are received in sequence from the at least two of the plurality of remotes based on the structure.

Abstract: A head end terminal for a communication system using multicarrier modulation is described. The head end terminal includes a multicarrier modem adapted to receive upstream signals and to demodulate the upstream signals modulated on a plurality of orthogonal carriers in a first frequency bandwidth, the multicarrier modem including a polyphase filter adapted to selectively filter the received upstream signal to provide protection against narrowband ingress for the modulated orthogonal carriers and allow for scalable bandwidth usage in the upstream transmission, and a controller operatively connected to the multicarrier modem for controlling receipt of signals.

Abstract: A method for reducing ingress in orthogonal carriers is described. The method includes receiving a plurality of orthogonal carriers in an upstream frequency bandwidth and polyphase filtering the plurality of orthogonal carriers into a first and second plurality of carrier bands.

Abstract: A method of distributed loop control is described. The method includes receiving at a service unit downstream control and telephony information modulated on orthogonal carriers in a first frequency bandwidth over a distribution network. The method further includes transmitting from the service unit upstream telephony information and control data modulated on orthogonal carriers in a second frequency bandwidth over the distribution network. In addition, the method includes adjusting at least one local transmission characteristic when an adjustment command from a head end terminal is received in the downstream control data. The downstream control data is based on prior upstream transmissions from the service unit.

Abstract: A communication system is described. The communication system includes a distribution network between a head end terminal and at least one remote unit. The head end terminal receives upstream telephony and control data modulated on a plurality of orthogonal carriers in a frequency bandwidth over the distribution network. The head end terminal includes a polyphase filter that filters at least the upstream telephony data to provide ingress protection for the modulated orthogonal carriers. The communication further includes a service unit multicarrier modem associated with the at least one remote unit and operatively connected to the distribution network for modulating at least upstream telephony information on at least one carrier orthogonal at the head end terminal to at least one other carrier in the frequency bandwidth.

Abstract: A method for controlling a plurality of service units in a telecommunications system with a multi-carrier transmission scheme is provided. Specifically, in one embodiment, the method includes broadcasting control signals for the service units over a plurality of control channels distributed in a number of subbands of a frequency bandwidth. The method further includes identifying the service unit to use the control signal with an identifier.

Abstract: A method for controlling a plurality of service units in a telecommunications system with a multi-carrier transmission scheme is provided. Specifically, in one embodiment, the method includes broadcasting control signals for the service units over a plurality of control channels distributed in a number of subbands of a frequency bandwidth. The method further includes identifying the service unit to use the control signal with an identifier.

Abstract: A apparatus for providing a Fast Fourier Transform (FFT) and an inverse FFT is provided. The apparatus comprises a radix-N core. The radix-N core includes at least N multipliers. The radix-N core also includes a twiddle-factor lookup table that stores complex twiddle-factors. The twiddle-factor lookup table is coupled to one input of each of the multipliers. The radix-N core also includes a conversion random access memory (RAM) that stores transform points. The conversion RAM is coupled to another input of each of the multipliers. The radix-N core also includes an array of at least N-times-N adder-subtracter-accumulators.

Abstract: A method of computer data transmission over a telecommunications network having a head end connected to a plurality of service units is provided. The method includes receiving a request for transmitting computer data over the network from a service unit, retrieving provisioning information for the service unit, and selectively assigning one or more data channels based on the provisioning information to transmit the computer data over the network to provide a data path with substantially constant data transfer bandwidth between a head end and the service unit.

Abstract: A multicarrier transmitting modem is described.

Abstract: The communication system includes a hybrid fiber/coax distribution network. A head end provides for downstream transmission of telephony and control data in a first frequency bandwidth over the hybrid fiber/coax distribution network and reception of upstream telephony and control data in a second frequency bandwidth over the hybrid fiber/coax distribution network. The head end includes a head end multicarrier modem for modulating at least downstream telephony information on a plurality of orthogonal carriers in the first frequency bandwidth and demodulating at least upstream telephony information modulated on a plurality of orthogonal carriers in the second frequency bandwidth The head end further includes a controller operatively connected to the head end multicarrier modem for controlling transmission of the downstream telephony information and downstream control data and for controlling receipt of the upstream control data and upstream telephony information.

Abstract: The communication system includes a hybrid fiber/coax distribution network. A head end provides for downs transmission of telephony and control data in a first frequency bandwidth over the hybrid fiber/coax distribution network and reception of upstream telephony and control data in a second frequency bandwidth over the hybrid fiber/coax distribution network. The head end includes a head end multicarrier modem for modulating at least downstream telephony information on a plurality of orthogonal carriers in the first frequency bandwidth and demodulating at least upstream telephony information modulated on a plurality of orthogonal carriers in the second frequency bandwidth. The head end further includes a controller operatively connected to the head end multicarrier modem for controlling transmission of the downstream telephony information and downstream control data and for controlling receipt of the upstream control data and upstream telephony information.

Abstract: A head end terminal for a communication system using multicarrier modulation is described. The head end terminal includes a multicarrier modem adapted to receive upstream signals and to demodulate the upstream signals modulated on a plurality of orthogonal carriers in a first frequency bandwidth, the multicarrier modem including a polyphase filter adapted to selectively filter the received upstream signal to provide protection against narrowband ingress for the modulated orthogonal carriers and allow for scalable bandwidth usage in the upstream transmission, and a controller operatively connected to the multicarrier modem for controlling receipt of signals.

Abstract: A communication system is described. The communication system includes a distribution network and a head end terminal adapted to transmit downstream control data and downstream telephony information in a first frequency bandwidth over the distribution network and adapted to receive upstream telephony information and upstream control data in a second frequency bandwidth over the distribution network. In addition the communication system includes a plurality of service units, each service unit operatively connected to the distribution network for upstream transmission of upstream telephony information and upstream control data in the second frequency bandwidth and for receipt of downstream control data and downstream telephony information in the first frequency bandwidth.

Abstract: The communication system includes a hybrid fiber/coax distribution network. A head end provides for downstream transmission of telephony and control data in a first frequency bandwidth over the hybrid fiber/coax distribution network and reception of upstream telephony and control data in a second frequency bandwidth over the hybrid fiber/coax distribution network. The head end includes a head end multicarrier modem for modulating at least downstream telephony information on a plurality of orthogonal carriers in the first frequency bandwidth and demodulating at least upstream telephony information modulated on a plurality of orthogonal carriers in the second frequency bandwidth. The head end further includes a controller operatively connected to the head end multicarrier modem for controlling transmission of the downstream telephony information and downstream control data and for controlling receipt of the upstream control data and upstream telephony information.

Abstract: A multi-point to point communication system. The system includes a distribution network between a head end terminal and a plurality of remote units, the head end terminal for downstream transmission of downstream control data and downstream telephony information in a first frequency bandwidth over the distribution network and for receipt of upstream telephony information and upstream control data in a second frequency bandwidth over the distribution network. The head end terminal including a head end multicarrier modem means for modulating at least downstream telephony information on a plurality of orthogonal carriers in a plurality of regions of the first frequency bandwidth and for demodulating at least upstream telephony information modulated on a plurality of orthogonal carriers of a plurality of regions in the second frequency bandwidth.

Abstract: The communication system includes a hybrid fiber/coax distribution network. A head end provides for downstream transmission of telephony and control data in a first frequency bandwidth over the hybrid fiber/coax distribution network and reception of upstream telephony and control data in a second frequency bandwidth over the hybrid fiber/coax distribution network. The head end includes a head end multicarrier modem for modulating at least downstream telephony information on a plurality of orthogonal carriers in the first frequency bandwidth and demodulating at least upstream telephony information modulated on a plurality of orthogonal carriers in the second frequency bandwidth. The head end further includes a controller operatively connected to the head end multicarrier modem for controlling transmission of the downstream telephony information and downstream control data and for controlling receipt of the upstream control data and upstream telephony information.

Abstract: A bidirectional multipoint-to-point communications system for sending payload information over a distribution network is provided. The system includes a head-end terminal coupled to the distribution network to a plurality of service units. The head-end terminal includes a head-end controller for sending payload data to and from an external communications network and for producing and processing control messages at the head-end terminal, a head-end multicarrier transmitting modem coupled to the head-end controller for modulating downstream payload information and downstream control messages onto multiple orthogonal carriers spread throughout substantially all of a first frequency band, and a head-end multicarrier receiving modem coupled to the head-end controller for demodulating multiple orthogonal carriers spread throughout substantially all of a second frequency band and carrying upstream payload information and control messages.

Abstract: The present invention provides for a receiver addressable AM compatible digital broadcast system and method. The digital broadcast signal includes a plurality of digitally modulated signals and an analog signal. A transmitter useable within the system includes a data combiner for generating an aggregate digital data signal, and a waveform generator for forming the digital broadcast signal. A receiver useable within the system comprises a waveform detector for separating the signals and a data parser for separating the digitally modulated signals. The present invention further provides for a method of selectively transmitting data via a digital broadcast signal. The method includes forming the digital broadcast signal from an analog signal and a plurality of digitally modulated signals, transmitting and receiving the digital broadcast signal.