Multipoint-to-point communication using orthgonal frequency division multiplexing and identification codes
First Claim
1. A multipoint-to-point, orthogonal frequency division multiplexed (OFDM) communication system comprising:
- a plurality of remote units; and
a host unit that includes a demodulator;
wherein each of the remote units transmits an upstream OFDM signal using multiple access scheme to the host unit demodulator using at least one of a plurality of orthogonal tones within an OFDM waveform, wherein upstream OFDM signals from at least two of the plurality of remote units combine to a unified OFDM waveform at the host unit;
wherein the host unit receives the upstream OFDM signals from a plurality of the remote units, the tones of the upstream signals being substantially orthogonal when received at the host unit;
wherein portions of upstream OFDM signals from at least two of the remote units arrive at the host unit at the same time;
wherein the host unit demodulator demodulates said portions;
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 the unified OFDM waveform received at the host unit;
wherein the host unit incorporates a remote unit identification code within at least one downstream OFDM signal to designate a specific remote unit for which the downstream signal is intended; and
wherein the host unit correlates the identification code with a unique identifier for the specific remote unit.
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Accused Products
Abstract
Systems for multipoint-to-point communication using orthogonal 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.
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Citations
11 Claims
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1. A multipoint-to-point, orthogonal frequency division multiplexed (OFDM) communication system comprising:
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a plurality of remote units; and a host unit that includes a demodulator; wherein each of the remote units transmits an upstream OFDM signal using multiple access scheme to the host unit demodulator using at least one of a plurality of orthogonal tones within an OFDM waveform, wherein upstream OFDM signals from at least two of the plurality of remote units combine to a unified OFDM waveform at the host unit; wherein the host unit receives the upstream OFDM signals from a plurality of the remote units, the tones of the upstream signals being substantially orthogonal when received at the host unit; wherein portions of upstream OFDM signals from at least two of the remote units arrive at the host unit at the same time; wherein the host unit demodulator demodulates said portions; 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 the unified OFDM waveform received at the host unit; wherein the host unit incorporates a remote unit identification code within at least one downstream OFDM signal to designate a specific remote unit for which the downstream signal is intended; and wherein the host unit correlates the identification code with a unique identifier for the specific remote unit. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A system comprising:
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a host unit; 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 upstream OFDM signals from at least two of the plurality of remote units combine to a unified OFDM waveform at the host unit; 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 the unified 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. - View Dependent Claims (9, 10, 11)
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Specification