Fci, Inc.

Byung Su Kang

Ki Hyun Kim

Beom Jin Kim

A method for reducing a PAPR of an OFDM signal and an OFDM transmitter using the same are disclosed. In an OFDM transmitter, a signal processing circuit for reducing a PAPR of a modulated signal includes: a peak detector configured to detect peaks having sizes above a threshold value from an IQ baseband signal of the modulated signal and to output information on a position, a size and a phase; a memory configured to store a reference peak in time domain; a peak generator configured to generate an inverse peak signal for canceling a part of an amplitude of the IQ baseband signal from the reference peak based on the information on the position, the size and the phase; and a signal processing unit configured to add the inverse peak signal to the IQ baseband signal to constrain the amplitude of the IQ baseband signal.

Method for reducing PAPR of OFDM signal and OFDM transmitter using the same background

Disclosed are a method and apparatus for compressing/decompressing data using floating points. As technology for compressing/decompressing data using floating points for efficient memory management, there are provided a method and apparatus for compressing/decompressing data using floating points, in which a log table is used to compress/decompress data, whereby not only data loss caused by compression/decompression can be minimized, but also degradation of performance can be prevented through a floating point representation even though the same number of bits are used for compression.

Method and apparatus for compressing/decompressing data using floating point

Disclosed is a method for adjusting FFT window of OFDM system. The method is categorized two scenarios when the maximum delay length of the channel is shorter than the guard interval length and when the maximum delay length of the channel is longer than the guard interval length. In respective scenarios, the method comprises steps: Step A, multiplying the guard interval (A1) damaged due to the path fading channel delay by a weighted value (&#x3b1;); Step B, multiplying the guard interval (A2) not damaged due to the path fading channel delay by a weighted value (1-&#x3b1;); and Step C, Adding the guard intervals of Step A and Step B together (A3) to be inputted into FFT; minimizing the inter-symbol interference, the inter-channel interference and the noise.

Method for adjusting FFT window of OFDM system

The present invention provides a demapping device and method. The device includes: an averager receiving a compensation data for determining a degree of the compensation; a demapping function module receiving the compensation data for demapping the compensation data and then outputting a demapped compensation data; a quantizer coupled to the averager and the demapping function module, utilized to quantize the demapped compensation data according to the degree of the compensation and a maximum of quantization; a counter coupled to the quantizer for receiving a quantized data outputted from the quantizer, utilized to count a maximum value and a minimum value within the quantized data and output a counting result, and to simultaneously provide the maximum of quantization for the quantizer; and a compressor coupled to the counter, utilized to compress the counting result to reduce a number of bits.

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Sungnam, South Korea

Byung Su Kang