Peak to average power ratio in WLAN-OFDM system

Orthogonal frequency division multiplexing (OFDM) is one of the multicarrier modulation techniques that can reduce the ISI and delay spread of signal. This technique also allows subchannel to overlap. The orthogonality of the subchannels reduce the bandwidth (BW) and increase the spectral efficiency of system. Due to the numerous advantages of this system, it has been successfully applied in wide variety of digital communications over the past several years and has been adapted to the wireless LAN standards. However, the power amplifier of OFDM system dynamic range is typically two or four times larger than a single carrier system. The increments of the dynamic range will lead to the increasing in cost, power consumption of transmitter amplifier and also lead to high peak to average power ratio (PAPR). This is the major drawback of this system. This paper analyzes the behavior of PAPR in the WLAN-OFDM system. The model was designed based on the WLAN 802.11a standard. The simulation and analysis are based on two perspectives; combination bit (codeword) and code length effect on the PAPR.