Abstract: Methods for orderwire modulation are provided. In one embodiment, a method for an orthogonal frequency division multiplexing multipoint-to-point communications system comprises: establishing communication between a first remote unit of a plurality of remote units and a host unit, the plurality of remote units communicatively coupled to the host unit in a multipoint-to-point configuration; transmitting non-control data on up to a plurality of tones from the first remote unit using an orthogonal frequency division multiplexing (OFDM) waveform, the up to a plurality of tones modulated with the non-control data using a first modulation scheme; and transmitting control signals on up to a plurality of tones from the first remote unit using an orthogonal frequency division multiplexing (OFDM) waveform, the up to a plurality of tones modulated with the control signals using a second, more robust modulation scheme.

Abstract: Systems for orderwire modulation are provided. In one embodiment, a bidirectional communication system comprises a first remote unit for communicating with a host unit using orthogonal frequency division multiplexing, the host unit communicatively coupled to a plurality of remote units in a multipoint-to-point configuration; wherein the first remote unit is configured to transmit up to a plurality of tones, the up to a plurality of tones modulated with upstream information using orthogonal frequency division multiplexing; and wherein the first remote unit is configured to modulate at least one tone of the up to a plurality of tones with payload data using a first modulation scheme, and modulate at least one tone of the up to a plurality of tones with control data using a second modulation scheme, the second scheme more robust than the first modulation scheme.

Abstract: Systems for control modulation in multipoint-to-point communication using orthogonal frequency division multiplexing (OFDM) are provided. In one embodiment, a system comprises a host; a plurality of remote units using a multiple access scheme to communicate at the same time with the host using OFDM; wherein the host allocates orthogonal tones within the system to the plurality of remote units; wherein the host sends an adjustment signal to at least one of the remote units instructing the at least one remote unit to adjust the timing of transmissions from the remote unit to improve orthogonality of OFDM transmissions received at the host from the plurality of remote units; and wherein control data is sent between the host and at least one remote unit using a more robust modulation scheme than the modulation scheme used to send payload data between the host and the at least one remote unit.

Abstract: A method for an orthogonal frequency division multiplexing multipoint-to-point communications system is provided. The method includes establishing communication between a first remote unit of a plurality of remote units and a host unit, the plurality of remote units communicatively coupled to the host unit in a multipoint-to-point configuration, transmitting up to a plurality of tones from the first remote unit, the up to a plurality of tones modulated with upstream information using orthogonal frequency division multiplexing, and receiving information from the host unit to adjust transmission of the up to a plurality of tones from the first remote unit such that when any tones are transmitted from the first remote unit and at least one other remote unit of the plurality of remote units, all of the tones are substantially orthogonal when received at the host unit.

Abstract: A bi-directional communication system is provided. The system includes a multipoint-to-point host unit and a plurality of remote units communicatively coupled to the multipoint-to-point host unit through an orthogonal frequency division multiplexing waveform. The multipoint-to-point host unit is configured to receive the orthogonal frequency division multiplexing waveform, the orthogonal frequency division multiplexing waveform comprising a plurality of tones transmitted by the plurality of remote units. The multipoint-to-point host unit is configured to adjust transmissions from at least one of the plurality of remote units based on the orthogonal frequency division multiplexing waveform so that the plurality of tones transmitted by the plurality of remote units are substantially orthogonal when received at the multipoint-to-point host unit.

Abstract: Variable error correction for a multipoint-to-point orthogonal frequency division multiplexing (OFDM) system are provided. In one embodiment, a system comprises: a host unit; a plurality of remote units using a multiple access scheme to communicate at the same time with the host unit using OFDM; wherein the host unit allocates orthogonal tones within the system to the plurality of remote units; wherein the host unit sends an adjustment signal to at least one of the remote units instructing the at least one remote unit to adjust the timing of transmissions from the at least one remote unit to improve orthogonality of an OFDM waveform received at the host unit; and wherein at least one of the remote units transmits an upstream OFDM signal to the host unit using variable error correction in which the remote unit applies at least one of a plurality of available levels of error correction.

Abstract: Systems for adaptive modulation in multipoint-to-point communication using orthgonal frequency division multiplexing (OFDM) are provided. In one embodiment, a system comprises: a host unit; and a plurality of remote units using a multiple access scheme to communicate at the same time with the host unit using OFDM; wherein the host unit sends an adjustment signal to at least one of the remote units instructing the at least one remote unit to adjust the timing of transmissions from the remote unit to improve orthogonality of an OFDM waveform received at the host unit; wherein the host unit allocates tones within the OFDM waveform to the plurality of remote units; wherein different modulation schemes are used on different tones within the OFDM waveform; and wherein the host unit allocates tones within the OFDM waveform based on at least one of type of data to be transmitted and error rate requirement.

Abstract: A method for an orthogonal frequency division multiplexing multipoint-to-point communications system is provided. The method includes establishing communication between a first remote unit of a plurality of remote units and a host unit, the plurality of remote units communicatively coupled to the host unit in a multipoint-to-point, multiple access configuration, transmitting up to a plurality of tones from the first remote unit, the up to a plurality of tones modulated with upstream information using orthogonal frequency division multiplexing, and receiving information from the host unit to adjust a carrier power for tones transmitted by the first of remote unit so that the tones are substantially orthogonal when received at the host unit.

Abstract: A bidirectional communication system is provided. The system includes a first remote unit for communicating with a host unit using orthogonal frequency division multiplexing, the host unit communicatively coupled to a plurality of remote units in a multipoint-to-point configuration. The first remote unit is configured to transmit up to a plurality of tones, the up to a plurality of tones modulated with upstream information using orthogonal frequency division multiplexing. The first remote unit is configured to receive information from the host unit to adjust a carrier frequency of tones transmitted by the first remote unit, and is configured to adjust the carrier frequency based on the received information from the host unit.

Abstract: A bidirectional communication system is provided. In one embodiment, a system comprises a plurality of remote units; a multipoint-to-point host unit communicatively coupled with a plurality of remote units in a multi-point to point configuration, the multipoint-to-point host unit including a multi-carrier modem configured to communicate with the plurality of remote units via an orthogonal frequency division multiplexing waveform; wherein the multipoint-to-point host unit is configured to estimate a round trip path delay correction associated with at least one of the plurality of remote units; and wherein the multipoint-to-point host unit is configured to adjust the round trip path delay associated with the at least one of the plurality of remote units.

Abstract: Systems for variable forward error correction in a multipoint to point orthogonal frequency division multiplexing system are provided. In one embodiment, bidirectional communication system comprises: a first remote unit for communicating with a host unit using orthogonal frequency division multiplexing, the host unit communicatively coupled to a plurality of remote units in a multipoint-to-point configuration; wherein the first remote unit is configured to transmit at least one of a plurality of tones, the at least one of a plurality of tones modulated with upstream information using orthogonal frequency division multiplexing; and wherein the first remote unit selects an error correction degree for a first tone of the at least one of a plurality of tones based on error correction information received from the host unit, and encodes upstream information transmitted on the first tone based on the error correction degree.

Abstract: A bidirectional communication system is provided. The system includes a first remote unit for communicating with a host unit using orthogonal frequency division multiplexing, the host unit communicatively coupled to a plurality of remote units in a multipoint-to-point, multiple access configuration. The first remote unit is configured to transmit up to a plurality of tones, the up to a plurality of tones modulated with upstream information using orthogonal frequency division multiplexing. The first remote unit is configured to receive information from the host unit to adjust a carrier power of tones transmitted by the first of remote unit, and to adjust the carrier power based on the received information from the host unit so that the tones are orthogonal when received at the host unit.

Abstract: Systems for use of guard bands in multipoint-to-point orthgonal frequency division multiplexing communication are provided. In one embodiment, an orthogonal frequency division multiplexing (OFDM) system comprises: a host unit; a plurality of remote units using a multiple access scheme to communicate at the same time with the host unit using OFDM; and wherein when at least one tone within the OFDM system carries an upstream alignment signal from at least one remote unit to the host unit to assist in aligning at least one of frequency, timing, and amplitude of transmissions from the at least one remote unit to improve orthogonality of an OFDM waveform received at the host unit, the at least one tone is separated from payload bearing tones within the OFDM system by a guard band of frequency spectrum.

Abstract: Systems and methods for orthogonal frequency division multiplexing multipoint-to-point communications systems are provided. In one embodiment, a method comprises: establishing communication between a first remote unit of a plurality of remote units and a host unit, the plurality of remote units communicatively coupled to the host unit in a multipoint-to-point configuration; receiving an address code assignment from the host unit, the address code to be used in communicating with the host unit, wherein the address code is unique among the plurality of remote units; and transmitting up to a plurality of tones from the first remote unit, the up to a plurality of tones modulated with upstream information using orthogonal frequency division multiplexing.

Abstract: Systems for multipoint-to-point communication using orthgonal frequency division multiplexing and identification codes are provided. In one embodiment, a system comprises: a host unit; and a plurality of remote units using a multiple access scheme to communicate at the same time with the host unit using orthogonal frequency division multiplexing (OFDM); wherein the host unit allocates orthogonal tones within the system to the plurality of remote units; wherein the host unit sends an adjustment signal to at least one of the remote units instructing the at least one remote unit to adjust the timing of transmissions from the remote unit to improve orthogonality of an OFDM waveform received at the host unit, and wherein the host unit associates an address code with each of the plurality of remote units for designating downstream signals to the remote units.

Abstract: A method is provided. The method includes sharing upstream bandwidth capacity among a plurality of remote units in a manner that permits at least two of the remote units to transmit to a host at any one time using the upstream bandwidth capacity, the upstream bandwidth capacity comprising a plurality of orthogonal tones generated using inverse fast Fourier transforms, and causing at least one remote unit to adjust the manner in which symbols are transmitted therefrom on at least one of the plurality of orthogonal tones in order to improve the alignment of symbols received at the host.

Abstract: A bidirectional communication system is provided. In one embodiment, a system comprises a host; and a plurality of remote units, wherein a plurality of tones is shared among the plurality of remote units in order to communicate with the host using orthogonal frequency division multiplexing, wherein the plurality of tones is shared in a manner that permits at least two of the remote units to transmit to the host at any one time using the plurality of tones. The host causes at least one remote unit to adjust a timing of symbols transmitted on at least one of the plurality of orthogonal tones in order to improve an alignment of multiframes received at the host.

Abstract: Methods and systems for adaptive modulation are provided. In one embodiment, a method for a plurality of remote units of an orthogonal frequency division multiplexing multipoint-to-point communications system comprises: establishing communication between a plurality of remote units and a host unit, the plurality of remote units communicatively coupled to the host unit in a multipoint-to-point configuration; transmitting a plurality of tones from the plurality of the remote units such that tones from more than one remote unit are simultaneously received at the host unit, the plurality of tones modulated with upstream information using orthogonal frequency division multiplexing; modulating up to a plurality of tones using a first modulation scheme when transmitting a first type of upstream information; and modulating up to a plurality of tones using a second modulation scheme when transmitting a second type of upstream information.

Abstract: A system is provided. The system includes a host and a plurality of remote units. Upstream bandwidth capacity is shared among a plurality of remote units in a manner that permits at least two of the remote units to transmit to the host at any one time using the upstream bandwidth capacity. The upstream bandwidth capacity includes a plurality of orthogonal tones generated using inverse fast Fourier transforms. The host causes at least one remote unit to adjust the manner in which symbols are transmitted therefrom on at least one of the plurality of orthogonal tones in order to improve the alignment of symbols received at the host.

Abstract: Methods for variable forward error correction in a multi-point to point orthogonal frequency division multiplexing system are provided. In one emboidment, a method for an orthogonal frequency division multiplexing multipoint-to-point communications system comprises: establishing communication between a first remote unit of a plurality of remote units and a host unit, the plurality of remote units communicatively coupled to the host unit in a multipoint-to-point configuration; transmitting up to a plurality of tones from the first remote unit, the up to a plurality of tones modulated with upstream information using orthogonal frequency division multiplexing; and encoding the upstream information based on a degree of error correction selected by the host unit.