Peak to average Power Ratio (PAPR) is the major drawback of orthogonal Frequency Division Multiplexing (OFDM) systems. Since OFDM is the indispensable technology for 4G wireless schemes, great attention is given to PAPR reduction. Some of the techniques classified under signal distortion and signal scrambling already existing to meet the needs, but their effectiveness is still a question for re...

Multiple-input multiple-output orthogonal frequency division multiplexing systems (MIMO-OFDM) has became a promising candidate for high performance 4G broadband wireless communications. However, like OFDM, one main disadvantage of MIMO-OFDM is that the signals transmitted on different antennas may exhibit a prohibitively large peakto-average power ratio (PAPR). In this paper, the influence of g...

A peak to average power ratio (PAPR) reduction method is proposed that exploits the precoding or beamforming mode in WiMAX. The method is applicable to any OFDM/A systems that implements beamforming using dedicated pilots which use the same beamforming antenna weights for both pilots and data. Beamforming performance depends on the relative phase shift between antennas, but is unaffected by a p...

To benefit the advantages both from the Multiple Input Multiple Output (MIMO) and Orthogonal Frequency Division Multiplexing (OFDM) techniques, we propose a spacetime block coded (STBC) scheme with the Partition Dummy Sequence Insertion (PDSI) method (STBC-PDSI) to reduce the high peak-to-average power ratio (PAPR) problem from the summation of OFDM subcarriers of the MIMO-OFDM system. The high...

In wireless communication systems, the design and analysis of an orthogonal frequency division multiplexing (OFDM) system is highly affected by the nonlinear effects of high power amplifier (HPA). The nonlinear effects of HPA reducing the OFDM system performance. OFDM signalling exhibits high peak-to-average power ratio (PAPR) which results in large sensitivity to nonlinear distortion created b...

A major drawback of orthogonal frequency-division multiplexing (OFDM) signals is their high peak-to-average power ratio (PAPR), which causes serious degradation in performance when a nonlinear power amplifier (PA) is used. Companding transform is a well-known method to reduce PAPR without restrictions on system parameters such as number of subcarriers, frame format and constellation type. Recen...

In this paper, an efficient method for minimizing the high Peak to Average Power Ratio (PAPR), based on Clipping and Differential Scaling, in Orthogonal Frequency Division Multiplexing (OFDM) systems is proposed. In this technique, the amplitude of complex OFDM signal is clipped and then scaled in such a way so that the PAPR is reduced without causing much degradation in Bit Error Rate (BER). C...

In several wireless communication systems and standards, Orthogonal Frequency Division Multiplexing (OFDM) is used widely due to its high spectral efficiency, high data rate, multipath delay spread tolerance, power efficiency, robustness to multipath fading channels and immunity to the frequency selective fading channels. However, the main challenge for OFDM system implementation is high PAPR, ...

High Peak to Average Power Ratio (PAPR) of the transmitted signal is a serious problem in multicarrier modulation systems. In this paper a new technique for reduction in PAPR of the Multicarrier Code Division Multiple Access (MC CDMA) signals based on combining the Discrete Transform either Discrete Cosine Transform (DCT) or multi-resolution Discrete Wavelet Transform (DWT) with companding is p...

Partial Transmit Sequences (PTS) is an efficient scheme for Peak-to-Average Power Ratio (PAPR) reduction in Orthogonal Frequency Division Multiplexing (OFDM) system. It does not bring any signal distortion. However, its remarkable drawback is the high computational complexity. In order to reduce the computational complexity, currently many PTS methods have been proposed but with the cost of the...