Apparatus and method for FT pre-coding of data to reduce PAPR in a multi-carrier wireless network
First Claim
1. For use in a wireless network, a subscriber station capable of communicating with the wireless network according to a multi-carrier protocol, the subscriber station comprising:
- a size M Fourier Transform (FT) block capable of receiving input symbols and generating therefrom M FT pre-coded outputs, the input symbols comprising data signals and pilot signals; and
a size N inverse Fourier Transform (IFT) block capable of receiving N inputs, the N inputs including the M FT pre-coded outputs from the size M FT block, and generating therefrom N outputs to be transmitted to a base station of the wireless network, wherein the size M FT block and the size N IFT block are one of;
1) a Fast Fourier Transform (FFT) block and an inverse Fast Fourier Transform (IFFT) block; and
2) a Discrete Fourier Transform (DFT) block and an inverse Discrete Fourier Transform (IDFT) block,wherein the data signals and pilot signals are mapped to alternating subcarriers and the size N IFT block receives signaling and control information on at least some of the N inputs other than the M FT pre-coded outputs.
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Accused Products
Abstract
A subscriber station for use in a wireless network capable of communicating according to a multi-carrier protocol, such as OFDM or OFDMA. The subscriber station comprises a size M Fourier Transform (FFT or DFT) block for receiving input symbols and generating M FT pre-coded outputs and a size N inverse Fourier Transform (IFFT or IDFT) block capable of receiving N inputs, where the N inputs include the M FT pre-coded outputs from the size M FT block. The size N IFT block generates N outputs to be transmitted to a base station of the wireless network. The input symbols comprise user data traffic to be transmitted to the base station. The size N IFT block also receives signaling and control information on at least some of N-M inputs. The FT pre-coding generates a time-domain signal that has a relatively lower peak-to-average power ratio (PAPR).
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Citations
47 Claims
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1. For use in a wireless network, a subscriber station capable of communicating with the wireless network according to a multi-carrier protocol, the subscriber station comprising:
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a size M Fourier Transform (FT) block capable of receiving input symbols and generating therefrom M FT pre-coded outputs, the input symbols comprising data signals and pilot signals; and a size N inverse Fourier Transform (IFT) block capable of receiving N inputs, the N inputs including the M FT pre-coded outputs from the size M FT block, and generating therefrom N outputs to be transmitted to a base station of the wireless network, wherein the size M FT block and the size N IFT block are one of;
1) a Fast Fourier Transform (FFT) block and an inverse Fast Fourier Transform (IFFT) block; and
2) a Discrete Fourier Transform (DFT) block and an inverse Discrete Fourier Transform (IDFT) block,wherein the data signals and pilot signals are mapped to alternating subcarriers and the size N IFT block receives signaling and control information on at least some of the N inputs other than the M FT pre-coded outputs. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. For use in a subscriber station capable of communicating with a wireless network according to a multi-carrier protocol, a method for reducing the peak-to-average power ration (PAPR) of a radio frequency signal transmitted by the subscriber station to a base station of the wireless network, the method comprisingthe steps of:
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receiving input symbols to be transmitted to the base station, the input symbols comprising data signals and pilot signals; performing a size M Fourier Transform (FT) operation on the received input symbols to thereby generate M FT pre-coded outputs; and performing a size N inverse Fourier Transform (IFT) operation on N inputs, the N inputs including the M FT pre-coded outputs, to thereby generate N outputs to be transmitted to the base station, wherein the size M FT operation and the size N IFT operation are one of;
1) a Fast Fourier Transform (FFT) operation and an inverse Fast Fourier Transform (IFFT) operation; and
2) a Discrete Fourier Transform (DFT) operation and an inverse Discrete Fourier Transform (IDFT) operation mapping the data signals and pilot signals to alternating subcarriers, wherein the size N IFT operation receives signaling and control information on at least some of the N inputs other than the M FT pre-coded outputs. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17, 18)
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19. A base station for use in a wireless network capable of communicating with subscriber stations according to a multi-carrier protocol, the base station comprising:
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down-conversion circuitry capable of receiving incoming radio frequency signals from the subscriber stations and generating therefrom a baseband signal; a size N Fourier Transform (FT) block capable of receiving the baseband signal on N inputs and performing an FT operation to generate N outputs; a size M Inverse Fourier Transform (IFT) block capable of receiving M of the N outputs of the size N FT block and performing a size M IFT operation on the M outputs to generate a plurality of data symbols transmitted by a first one of the subscriber stations, wherein the size N FT block and the size M IFT block are one of
1) a Fast Fourier Transform (FFT) block and an inverse Fast Fourier Transform (IFFT) block; and
2) a Discrete Fourier Transform (DFT) block and an inverse Discrete Fourier Transform (IDFT) block; anda frequency-domain equalizer capable of receiving a pilot signal transmitted by the first subscriber station and using the pilot signal to perform frequency-domain equalization on the M outputs of the size N FT block prior to the size M IFT operation of the size M IFT block wherein the size N FT block generates on at least some of the N outputs signaling and control information transmitted by the first subscriber station. - View Dependent Claims (20, 21)
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22. A method for use in base station of a wireless network capable of communicating with subscriber stations according to a multi-carrier protocol, the method comprisingthe steps of:
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receiving incoming radio frequency (RF) signals from the subscriber stations; down-converting the incoming RF signals to generate a baseband signal; performing a size N Fourier Transform (FT) operation on the baseband signal to generate N outputs; performing a size M Inverse Fourier Transform (IFT) operation on M of the N outputs of the size N FT operation to generate a plurality of data symbols transmitted by a first one of the subscriber stations, wherein the size N FT operation and the size M IFT operation are one of;
1) a Fast Fourier Transform (FFT) operation and an inverse Fast Fourier Transform (LEFT) operation; and
2) a Discrete Fourier Transform (DFT) operation and an inverse Discrete Fourier Transform (IDFT) operation; andusing a pilot signal transmitted by the first subscriber station to perform frequency-domain equalization on the M outputs of the size N FT operation prior to the size M IFT operation, wherein the size N FT operation generates on at least some of the N outputs signaling and control information transmitted by the first subscriber station. - View Dependent Claims (23, 24)
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25. A wireless network comprising a plurality of base stations capable of communicating with subscriber stations according to a multi-carrier protocol, each of the base stations comprising:
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down-conversion circuitry capable of receiving incoming radio frequency signals from the subscriber stations and generating therefrom a baseband signal; a size N Fourier Transform (FT) block capable of receiving the baseband signal on N inputs and performing an IFT operation to generate N outputs; a size M Inverse Fourier Transform (IFT) block capable of receiving M of the N outputs of the size N FT block and performing a size M IFT operation on the M outputs to generate a plurality of data symbols transmitted by a first one of the subscriber stations, wherein the size N FT block and the size M IFT block are one of;
1) a Fast Fourier Transform (FFT) block and an inverse Fast Fourier Transform (IFFT) block; and
2) a Discrete Fourier Transform (DFT) block and an inverse Discrete Fourier Transform (IDFT) block; anda frequency-domain equalizer capable of receiving a pilot signal transmitted by the first subscriber station and using the pilot signal to perform frequency-domain equalization on the M outputs of the size N FT block prior to the size M IFT operation of the size M IFT block wherein the size N FT block generates on at least some of the N outputs signaling and control information transmitted by the first subscriber station. - View Dependent Claims (26, 27)
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28. A data transmission method in a communication system, the method comprising:
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modulating data information to generate non-FT pre-coded modulation data symbols; modulating control information to generate non-FT pre-coded modulation control symbols; Fourier Transform (FT) pre-coding the non-FT pre-coded modulation data symbols to generate FT pre-coded symbols; mapping the FT pre-coded symbols to a first set of subcarriers; mapping the non-FT pre-coded modulation control symbols to a second set of subcarriers; performing an inverse Fourier Transform (IFT) operation on at least one of (i) the FT pre-coded symbols based on the first set of subcarriers and (ii) the non-FT pre-coded modulation control symbols based on the second set of subcarriers to generate an output signal; and transmitting the output signal. - View Dependent Claims (29, 30, 31, 32)
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33. A method for receiving data in a communication system, the method comprising:
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receiving a transmitted signal; performing a Fourier Transform (FT) operation on the received signal to generate N outputs, wherein a first subset of the N outputs comprises FT pre-coded modulated data symbols and a second subset of the N outputs comprises non-FT pre-coded modulated control symbols; demapping the first subset of outputs; performing Inverse Fourier Transform (IFT) operation on the demapped outputs to recover modulated data symbols; and demodulating the modulated data symbols. - View Dependent Claims (34, 35, 36, 37)
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38. An apparatus for data transmission in a communication system, the apparatus comprising:
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a modulation block configured to modulate data information to generate non-FT pre-coded modulation data symbols and control information to generate non-FT pre-coded modulation control symbols; a Fourier Transform (FT) block configured to FT pre-code the non-FT pre-coded modulation data symbols to generate FT pre-coded symbols; a subcarrier mapping block configured to map the FT pre-coded symbols to a first set of subcarriers and the non-FT pre-coded modulation control symbols to a second set of subcarriers; and an inverse FT (IFT) block configured to perform an IFT operation on at least one of (i) the FT pre-coded symbols based on the first set of subcarriers and (ii) the non-FT pre-coded modulation control symbols based on the second set of subcarriers to generate an output signal, wherein the apparatus is configured to transmit the output signal. - View Dependent Claims (39, 40, 41, 42)
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43. An apparatus for receiving data in a communication system, the apparatus comprising:
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a Fourier Transform (FT) block configured to perform an FT operation on a received signal to generate N outputs, wherein a first subset of the N outputs comprises FT pre-coded modulated data symbols and a second subset of the N outputs comprises non-FT pre-coded modulated control symbols; an inverse FT (IFT) block configured to perform IFT operations on M inputs, wherein M is less than N; a subcarrier demapping block configured to receive the first subset of the N outputs from the FT block and to demap the first subset of outputs to the inputs of the IFT block, wherein the IFT block is further configured to perform an IFT operation on the inputs to recover modulated data symbols; and a demodulation block configured to demodulate the modulated data symbols. - View Dependent Claims (44, 45, 46, 47)
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Specification