Abstract: An apparatus for a transmit end in a wireless communication system is provided. The apparatus includes at least one scrambler configured to scramble a transmission bit stream, wherein the at least one scrambler comprises, a first circulation unit configured to output, during one cycle, at least one bit for scrambling odd-numbered bits of the transmission bit stream and at least one bit for scrambling even-numbered bits of the transmission bit stream, a second circulation unit configured to output, during one cycle, at least one bit for scrambling odd-numbered bits of the transmission bit stream and at least one bit for scrambling even-numbered bits of the transmission bit stream, and operators configured to generate a scrambled bit stream, wherein each of the operators generates a scrambled bit using an input bit, an output bit from the first circulation unit and an output bit from the second circulation unit.

Abstract: An apparatus for a transmit end in a wireless communication system is provided. The apparatus includes at least one scrambler configured to scramble a transmission bit stream, wherein the at least one scrambler comprises, a first circulation unit configured to output, during one cycle, at least one bit for scrambling odd-numbered bits of the transmission bit stream and at least one bit for scrambling even-numbered bits of the transmission bit stream, a second circulation unit configured to output, during one cycle, at least one bit for scrambling odd-numbered bits of the transmission bit stream and at least one bit for scrambling even-numbered bits of the transmission bit stream, and operators configured to generate a scrambled bit stream, wherein each of the operators generates a scrambled bit using an input bit, an output bit from the first circulation unit and an output bit from the second circulation unit.

Abstract: An apparatus and method for scrambling in a wireless communication system are provided. The apparatus includes a selector, a plurality of scramblers, and a plurality of modulators. The selector selects a scrambling scheme to be applied to a transmission bit stream according to a modulation scheme to be applied to the transmission bit stream. The plurality of scramblers scramble the transmission bit stream according to a scrambling scheme corresponding to each of a plurality of modulation schemes. The plurality of modulators modulate the scrambled transmission bit stream according to the plurality of modulation schemes.

Abstract: A method and apparatus for reducing a Peak to Average Power Ratio (PAPR) using peak windowing is provided. In the apparatus, an absolute value calculator calculates an absolute value of an input signal, a subtractor subtracts a predetermined clipping threshold level from the absolute value, a smoothing unit performs smoothing on the subtracted signal according to a predetermined smoothing scheme and outputs a first smoothed signal, an adder adds the first smoothed signal to the clipping threshold level, an inverse calculator outputs a second smoothed signal by multiplying the clipping threshold level by an inverse of the added signal, and a multiplier outputs a final PAPR-reduced signal by multiplying the input signal by the second smoothed signal.

Abstract: A method and apparatus for transmitting a signal whereby it is determined if a Bandwidth Expansion Factor (BEF) Q is an integer, the BEF being determined as N/M according to a number N of subcarriers of a system band and a number M of subcarriers of an allocated band, an input signal to be transmitted Q times in a time domain when the Q is an integer is expanded, a Single Carrier Frequency Division Multiplexing Access (SC-FDMA) signal is generated, and the SC-FDMA signal is transmitted.

Abstract: A method and an apparatus for reducing Digital-to-Analog Conversion (DAC) bits at a transmitter of a Frequency Division Multiple Access (FDMA) system reduces a number of the bits for conversion so as to save power and reduce the cost of operation. The method can include generating a digital signal gain control value and an analog signal gain control value using subcarrier allocation information, a required Signal to Noise Ratio (SNR), and a Peak to Average Power Ratio (PAPR); controlling a gain of a signal input to a digital-to-analog converter using the digital signal gain control value; converting a digital signal of the controlled gain to an analog signal using the digital-to-analog converter; and restoring an original signal by controlling a gain of a signal output from the digital-to-analog converter using the analog signal gain control value.

Abstract: A method and apparatus for reducing a Peak to Average Power Ratio (PAPR) using peak windowing is provided. In the apparatus, an absolute value calculator calculates an absolute value of an input signal, a subtractor subtracts a predetermined clipping threshold level from the absolute value, a smoothing unit performs smoothing on the subtracted signal according to a predetermined smoothing scheme and outputs a first smoothed signal, an adder adds the first smoothed signal to the clipping threshold level, an inverse calculator outputs a second smoothed signal by multiplying the clipping threshold level by an inverse of the added signal, and a multiplier outputs a final PAPR-reduced signal by multiplying the input signal by the second smoothed signal.

Abstract: An apparatus and method for scrambling in a wireless communication system are provided. The apparatus includes a selector, a plurality of scramblers, and a plurality of modulators. The selector selects a scrambling scheme to be applied to a transmission bit stream according to a modulation scheme to be applied to the transmission bit stream. The plurality of scramblers scramble the transmission bit stream according to a scrambling scheme corresponding to each of a plurality of modulation schemes. The plurality of modulators modulate the scrambled transmission bit stream according to the plurality of modulation schemes.

Abstract: A method and apparatus for transmitting a signal in a Single Carrier-Frequency Division Multiplexing Access (SC-FDMA) communication system are provided. The method includes determining if a Bandwidth Expansion Factor (BEF) Q is an integer, the BEF being determined as N/M according to a number N of subcarriers of a system band and a number M of subcarriers of an allocated band, expanding an input signal to be transmitted Q times in a time domain when the Q is an integer, generating an SC-FDMA signal, and transmitting the SC-FDMA signal.

Abstract: A method and an apparatus for reducing Digital-to-Analog Conversion (DAC) bits at a transmitter of a Frequency Division Multiple Access (FDMA) system reduces a number of the bits for conversion so as to save power and reduce the cost of operation. The method can include generating a digital signal gain control value and an analog signal gain control value using subcarrier allocation information, a required Signal to Noise Ratio (SNR), and a Peak to Average Power Ratio (PAPR); controlling a gain of a signal input to a digital-to-analog converter using the digital signal gain control value; converting a digital signal of the controlled gain to an analog signal using the digital-to-analog converter; and restoring an original signal by controlling a gain of a signal output from the digital-to-analog converter using the analog signal gain control value.

Abstract: A method and apparatus for block interleaving that eliminates the step of intermediary buffering. The method includes: (a) calculating a memory address at which first output data, of which number is equal to the number of rows of a first encoder is stored, (b) storing the first output data at the calculated memory address of a circular buffer, (c) storing second output data at an address which is incremented by a specific constant value from the calculated memory address of the circular buffer, and (d) storing (n+1)th output data at an address which is incremented by n from the calculated memory address of the circular buffer.