Apparatus and method for reducing peak to average power ratio in an orthogonal frequency division multiplexing system

A transmission apparatus for reducing a Peak to Average Power Ratio (PAPR) using a reserved tone set in an Orthogonal Frequency Division Multiplexing (OFDM) communication system, the apparatus comprising:

• a memory for storing the reserved tone set (Si) for OFDM symbols and an impulse waveform based on the reserved tone set;
• a controller for determining a shift value based on a subcarrier spacing interval (x) and a number of spaced symbols (y) of a scattered pilot pattern, determining the reserved tone set (Si) by shifting each of subcarriers (ik) of a predetermined reserved tone set (S0) by the determined shift value, and determining a new impulse waveform generated by rotating a phase of a complex value according to the reserved tone set;
• a tone reservation unit for reserving data, pilots, and the reserved tones in a subcarrier position for every symbol according to a control signal from the controller;
• and
• a gradient algorithm unit for calculating a subtrahend for a PAPR using an updated impulse waveform received from the controller, and adding the calculated subtrahend for the PAPR to an input signal.

A method for reducing a Peak to Average Power Ratio (PAPR) using a reserved tone set in a reception apparatus of an Orthogonal Frequency Division Multiplexing (OFDM) communication system, the method comprising:

• determining a shift value based on a subcarrier spacing interval (x) and a number of spaced symbols (y) of a scattered pilot pattern;
• determining the reserved tone set (Si) for OFDM symbols by shifting each of subcarriers (ik) of a predetermined reserved tone set (S0) by the determined shift value;
• extracting data signals transmitted in tones except for reserved tones in every symbol using the reserved tone set (Si);
• and
• performing a demodulation on the extracted data signals.

A reception apparatus for reducing a Peak to Average Power Ratio (PAPR) using a reserved tone set an Orthogonal Frequency Division Multiplexing (OFDM) communication system, the apparatus comprising:

• a memory for storing the reserved tone set (Si) for OFDM symbols;
• a controller for determining a shift value based on a subcarrier spacing interval (x) and a number of spaced symbols (y) of a scattered pilot pattern, and determining the reserved tone set (Si) by shifting each of subcarriers (ik) of a predetermined reserved tone set (S0) by the determined shift value;
• a data tone signal extractor for extracting data signals transmitted in tones except for reserved tones in every symbol using the reserved tone set (Si) received from the controller;
• and
• a data demodulator for performing demodulation on signals output from the data tone signal extractor.

A method for determining a reserved tone set to be used for reducing a Peak to Average Power Ratio (PAPR) in a transmission apparatus of an Orthogonal Frequency Division Multiplexing (OFDM) communication system, the method comprising:

• determining a shift value based on a subcarrier spacing interval (x), a number of spaced symbols (y) of a scattered pilot pattern, and OFDM symbol indices (I);
• and determining the reserved tone set (Si) for OFDM symbols by shifting each of subcarriers (ik) of a predetermined reserved tone set (So) by the shift value, wherein determining the shift value comprises:
• determining modular arithmetic of each of the OFDM symbol indices (I) with the number of spaced symbols (y);
• and determining the shift value by multiplying the subcarrier spacing interval (x) with a result of the modular arithmetic.

A method for determining a reserved tone set to be used for reducing a Peak to Average Power Ratio (PAPR) in a receiving apparatus of an Orthogonal Frequency Division Multiplexing (OFDM) communication system, the method comprising:

• determining a shift value based on a subcarrier spacing interval (x), a number of spaced symbols (y) of a scattered pilot pattern, and OFDM symbol indices (I);
• and determining the reserved tone set (Si) for OFDM symbols by shifting each of subcarriers (ik) of a predetermined reserved tone set (So) by the shift value, wherein determining the shift value comprises:
• determining modular arithmetic of each of the OFDM symbol indices (I) with the number of spaced symbols (y);
• and determining the shift value by multiplying the subcarrier spacing interval (x) with a result of the modular arithmetic.