Systems and method for orthogonal frequency divisional multiplexing
First Claim
1. A remote communication device using minimum allocations in a multipoint-to-point communication system, the device comprising:
- at least one symbol mapper that maps data into symbols using quadrature amplitude modulation (QAM) symbol mapping and phase-shift keying (PSK) symbol mapping;
a Fast Fourier Transform (FFT) engine that receives a frame of parallel data based on symbol data generated by the symbol mapper, the Fast Fourier Transform (FFT) engine generating a frame of time domain in-phase and quadrature phase data from the symbol data generated by the symbol mapper;
at least one converter generating an analog signal based on the stream of time domain in-phase and quadrature phase data;
a radio frequency transmitter for transmitting a radio frequency signal based on the analog signal;
wherein the radio frequency signal comprises a plurality of orthogonal frequency division multiplexing (OFDM) sub-carriers transmitted by the transmitter, the plurality of OFDM sub-carriers synchronized in time and frequency to combine with OFDM sub-carriers transmitted by at least one other transmitter to form a composite OFDM waveform at a host unit;
wherein the minimum bandwidth allocation received by the remote communication device from the host unit for upstream payload comprises at least two OFDM sub-carriers within the composite OFDM waveform available for transmitting the radio frequency signal.
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Accused Products
Abstract
Systems and methods for orthogonal frequency division multiplexing are provided. In one embodiment, a multi-carrier modem comprising: a receiver configured to de-modulate symbols from at least one of a plurality of spectrally overlapping carrier signals; a transmitter configured to modulate symbols onto at least one of a plurality of the spectrally overlapping carrier signals; a processor coupled to the transmitter, wherein the processor outputs data for transmission by the transmitter, wherein the processor applies an inverse Fourier transform to the data transmitted by the transmitter; and a controller programmed to multiplex both payload data and control data onto a first carrier of the spectrally overlapping carrier signals.
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Citations
9 Claims
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1. A remote communication device using minimum allocations in a multipoint-to-point communication system, the device comprising:
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at least one symbol mapper that maps data into symbols using quadrature amplitude modulation (QAM) symbol mapping and phase-shift keying (PSK) symbol mapping; a Fast Fourier Transform (FFT) engine that receives a frame of parallel data based on symbol data generated by the symbol mapper, the Fast Fourier Transform (FFT) engine generating a frame of time domain in-phase and quadrature phase data from the symbol data generated by the symbol mapper; at least one converter generating an analog signal based on the stream of time domain in-phase and quadrature phase data; a radio frequency transmitter for transmitting a radio frequency signal based on the analog signal; wherein the radio frequency signal comprises a plurality of orthogonal frequency division multiplexing (OFDM) sub-carriers transmitted by the transmitter, the plurality of OFDM sub-carriers synchronized in time and frequency to combine with OFDM sub-carriers transmitted by at least one other transmitter to form a composite OFDM waveform at a host unit; wherein the minimum bandwidth allocation received by the remote communication device from the host unit for upstream payload comprises at least two OFDM sub-carriers within the composite OFDM waveform available for transmitting the radio frequency signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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Specification