الفهرس 
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Abstract
The high peak to average power ratio (PAPR) is the major drawback in LTE downlink physical layer transmission. It is one of the main reasons for increasing the power consumption. This problem is more effective in uplink transmission due to the limited power of mobile terminal. In this thesis, three techniques (PTS, SLM and ICF) have been applied on the OFDMA and DFT SC-FDMA systems to reduce the PAPR. The PAPR performance has been analyzed with and without pulse-shaping filter,considering two different subcarrier mapping methods (Localized, Interleaved), different modulation scheme (QPSK, 16QAM), and different input block sizes. The BER performance of the systems with two types of power amplifier (SSPA, TWTA) has also been analyzed. In PTS and SLM techniques, different parameters have been used to evaluate the performance. In iterative clipping and filtering (ICF) technique, a optimum clipping ratio (OCR) is selected to reduce the PAPR without degradation in the system performance based on simulation results in MATLAB, considering different channel models (Vehicular A and SUI3) with different modulation scheme. The BER, PAPR, and PSD of DFT SC-LFDMA with ICF has been investigated. The simulation results referred to that the DFT SC-FDMA system has smaller PAPR than OFDMA system by about 3.6 dB, DFT-SC-IFDMA with QPSK gave lower PAPR as compared to DFT-SC-LFDMA systems by approximately 7.56 dB. After applying RC pulse shaping, the PAPR increased but the PAPR of DFT-SC-IFDMA still lower by about 1.63 dB and 0.86 dB for QPSK and 16QAM, respectively. The results also showed