PAPR Analysis of Class-III IN OFDM Signal Sequences

PAPR:

The transmit signals in an orthogonal frequency-division multiplexing (OFDM) system can have high peak values in the time domain since many subcarrier components are added via an inverse fast Fourier transformation (IFFT) operation. As a result, OFDM systems are known to have a high peak-to-average power ratio (PAPR) when compared to single-carrier systems. In fact, the high PAPR is one of the most detrimental aspects in an OFDM system as it decreases the signal-to-quantization noise ratio (SQNR) of the analog-digital convertor (ADC) and digital-analog convertor (DAC) while degrading the efficiency of the power amplifier in the transmitter.

 

Fig:OFDM

ORTHOGONAL frequency division multiplexing (OFDM) is a popular multicarrier modulation technique. Because of the orthogonality of its subcarriers, a receiver can recover the transmitted data without interference. Due to its robustness  against multipath fading, OFDM has been adopted as a standard technique for various wireless communication systems

When OFDM signals with high PAPR pass through nonlinear high power amplifier, they experience
in-band distortion and out-of-band radiation. Thus, in order to reduce PAPR, many schemes have been proposed such as selected mapping (SLM), partial transmit sequence  and tone reservation.Because of large computational complexity, the conventional SLM scheme in has been modified to many low complexity SLM schemes

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PAPR Analysis of Class-III IN OFDM Signal Sequences