PAPR reduction using tent map for multiple data rate OFDMA system

Orthogonal Frequency Division Multiple Access (OFDMA) is a multiple access technique that can accommodate many users with widely varying applications, data rates and Quality of Service requirements, with increased spectral efficiency. Peak to Average Power Ratio (PAPR) reduction for OFDMA is motivated by a desire to increase the mean transmit power and to improve the power amplifier efficiency. This paper presents use of chaotic sequences generated using tent map for multiple data rate spreading and PAPR reduction in OFDMA system. Increase in PAPR due to variable spreading could be reduced by spreading using chaotic sequences. Chaotic sequences gave constant PAPR values for different combinations of data rates. It was also noted that the sequences could be chosen irrespective of the data rates used. Bit error rate was found to be comparable with that for Orthogonal Variable Spreading Factor codes.