Orthogonal frequency division multiplexing is a multi-carrier inflection method employed in wireless communication. OFDM has attained a remarkable center of attention for its forcefulness with elementary equalization in the existence of rigorous multipath strait circumstances, forceful in opposition to Inter symbol Interference (ISI), multipath fading, and high spectral efficiency. Despite of i...

High peak to average power ratio of the transmit signal is a major drawback of OFDM systems. After defining the PAPR and analyzing its statistical properties, some of the most representative PAPRreduction techniques available in the literature are reviewed in detail. Several methods have been proposed to reduce the peak power of OFDM signals. In this paper the effectiveness of some recently pro...

There are various issues related to OFDM such as dispersion (ICI), external interference (crosstalk) and nonlinearities (PAPR). OFDM suffers from a high Peak to Average Power Ratio (PAPR), caused by the addition of a large number of independently modulated sub-carriers in parallel at the transmitter. When subject to a non-linear power amplifier, these signals may undergo significant spectral di...

Orthogonal frequency Division multiplexing (OFDM) is the most familiar word in telecommunication and wireless communication systems as it provides enhanced spectral efficiency than Frequency division multiplexing (FDM).Although it is sustaining an orthogonal relation betweencarriers but high peak to average power ratio (PAPR) is one of the main disadvantages of OFDM system.Various PAPR reductio...

In this letter , super-orthogonal space-time trellis codes (SOSTTC) are extended for quadrature amplitude modulation (QAM) constellations. A systematic set-partitioning method for QAM constellations is given. Furthermore, trellis shaping based on set partitioning is incorporated in SOSTTC with QAM symbols to achieve extra shaping gain. Peak constraints can be used to limit the constellation exp...

Orthogonal frequency division multiplexing (OFDM) is a peculiar case of multicarrier transmission technique for high speed data transmission over multipath fading channels. The high Peak to Average Power Ratio (PAPR) is one of the most detrimental aspects in the OFDM system, as it degrades the efficiency of the power amplifier in the transmitter. Discrete Cosine Transform-II (DCT-II) is a less ...

Several properties of OFDM has made it an essential modulation scheme for high speed transmission links. But one major drawback ofOFDM is its large Peak-toaverage power ratio. Here we have reviewed some of the PAPR reduction techniques and compared the performance of clipping and filtering,partial transmit sequence and selected mapping methods for QAM modulated OFDM. We have also shown analytic...

This paper presents a new technique to reduce the peak-to-average power ratio (PAPR) in OFDM system by insertion of extra semi-dummy sequence in frequency domain. The extra sequence is generated via Fourier transform of a number of the data modulated symbols. The proposed technique provides instant frequency domain process for the PAPR problem solution. For the 16PSK-OFDM system using 512 subca...

Multicarrier transmission system such as Orthogonal Frequency Division Multiplexing (OFDM) is a promising technique for high bit rate transmission in wireless communication systems. OFDM is a spectrally efficient modulation technique that can achieve high speed data transmission over multipath fading channels without the need for powerful equalization techniques. A major drawback of OFDM is the...

Orthogonal Frequency division is an emerging modulation technique that provides high spectral efficiency and bandwidth. It has a drawback of high Peak to Average Power Ratio. In this paper we discuss a new clipping and filtering approach which is based on cancellation of clipping noise to overcome the drawback of PAPR in OFDM. This method requires only single iteration to resolve the problem of...