Generalized Discrete Fourier Transform Based Minimization of PAPR on OFDM Systems

Download or read book Generalized Discrete Fourier Transform Based Minimization of PAPR on OFDM Systems written by Ahmed Mohamed Elshirkasi and published by . This book was released on 2015 with total page 164 pages. Available in PDF, EPUB and Kindle. Book excerpt: Future applications of communication systems require more data rate and mobility. Orthogonal frequency division multiplexing (OFDM) is one of the candidate techniques to achieve these requirements. However, OFDM implementation suffers from high peak to average power ratio (PAPR) of the transmitted signal. In this research, a nonlinear phase from the generalised discrete Fourier transform (GDFT) theory has been used to improve the PAPR reduction using partial transmit sequence (PTS) technique; one of the techniques used to reduced high PAPR in OFDM systems. This is done by multiplying the input OFDM block by M nonlinear phase vectors generated according to GDFT theory, then the optimal nonlinear phase vector is selected based on the autocorrelation properties of the multiplication result between the OFDM input block and each nonlinear phase vector. Results are given in terms of number of side information bits (m) used to represent the nonlinear phase. When m is 2, the performance of modified PTS of one sub-block gives as much PAPR reduction as the original PTS with two sub-blocks. When m is 4, the performance of modified PTS gives as much PAPR reduction as the original PTS with four subblocks. Additional PAPR reduction of about 0.5dB is achieved when m is raised to 6. Moreover, simulation showed that the distribution of the parameter bi which used to generate the nonlinear phase of GDFT, follows a uniform distribution and the bit error rate (BER) of the proposed system is sensitive to errors in the side information bits of the nonlinear phase, hence, requiting extra protection.