Apparatus and method for reducing PAPR in an OFDM mobile communication system
AssigneeSamsung Electronics Co., Ltd.
InventorsKi-Ho Jung, Heung-Gyoon Ryu, In-Bae Kim, Byoung-il Jin
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Abstract
Disclosed is an apparatus and method for reducing a peak-to-average power ratio (PAPR) due to multiple subcarriers in an OFDM (Orthogonal Frequency Division Multiplexing) mobile communication system. In the OFDM mobile communication system, a transmitter pre-emphasizes an output signal of an IFFT (Inverse Fast Fourier Transform) block, and a receiver de-emphasizes a received signal before FFT (Fast Fourier Transform), thereby efficiently reducing PAPR due to multiple subcarriers.
Claims12
A method for controlling a value of symbols in order to reduce a peak-to-average power ratio (PAPR) in a transmitter for a mobile communication system for generating OFDM (Orthogonal Frequency Division Multiplexing) modulation symbols by performing IFFT (Inverse Fast Fourier Transform) on input data, the method comprising the steps of:
- pre-emphasizing a symbol value S(n) with different transfer characteristics according to whether the symbol value S(n) is smaller than a prescribed reference value k1 or not;
- and
- converting a digital value Spre of the pre-emphasized symbol value into an analog signal and amplifying the analog signal at a prescribed gain.
An apparatus for controlling a value of symbols in order to reduce a peak-to-average power ratio (PAPR) in a transmitter for a mobile communication system for generating OFDM (Orthogonal Frequency Division Multiplexing) modulation symbols by performing IFFT (Inverse Fast Fourier Transform) on input data, the apparatus comprising:
- a pre-emphasis block for pre-emphasizing a symbol value S(n) with different transfer characteristics according to whether the symbol value S(n) is smaller than a prescribed reference value k1 or not;
- a digital-to-analog converter for converting a digital symbol value Spre output from the pre-emphasis block into an analog signal;
- and
- a high-power amplifier for amplifying the analog signal from the digital-to-analog converter at a prescribed gain.
A method for receiving by a receiver modulation symbols transmitted from a transmitter through IFFT (Inverse Fast Fourier Transform)-based OFDM (Orthogonal Frequency Division Multiplexing) in a mobile communication system, the method comprising the steps of:
- low-noise-amplifying the modulation symbols and converting the amplified modulation symbols into digital symbol values;
- de-emphasizing the symbol values Spre(n) with different transfer characteristics according to whether the symbol values Spre are smaller than a prescribed reference value k2 or not;
- and
- performing FFT (Fast Fourier Transform) on the pre-emphasized symbol values S(n).
An apparatus for receiving modulation symbols transmitted from a transmitter through IFFT (Inverse Fast Fourier Transform)-based OFDM (Orthogonal Frequency Division Multiplexing) in a receiver for a mobile communication system, the apparatus comprising:
- a low-noise amplifier for low-noise-amplifying the modulation symbols;
- an analog-to-digital converter for converting the amplified modulation symbols into digital symbol values;
- a de-emphasis block for de-emphasizing the symbol values Spre(n) with different transfer characteristics according to whether the symbol values Spre are smaller than a prescribed reference value k2 or not;
- and
- an FFT (Fast Fourier Transform) block for performing FFT on the pre-emphasized symbol values S(n).
Dependencies are inferred from the claim text.