Orthogonal Frequency Division Multiplexing (OFDM) is an efficient method of data transmission. It is a base for high speed communication systems. The main drawback of OFDM system is that it suffers from high Peak – to – Average Power Ratio (PAPR). Due to high PAPR there is inefficient use of high power amplifier and this could limit transmission efficiency. OFDM consist of large number of indep...

OFDM is a powerful multicarrier transmission technique used extensively for wireless applications. High PAPR is one of the deleterious problems of OFDM. This paper reviews basic OFDM system and PAPR problem associated with it. Also, the construction of M-QAM particularly 16-QAM sequences using QPSK Golay sequences over 4  is conferred. It is elucidated that a 16-QAM constellation can be writte...

ISSN 2277 5080 | © 2014 Bonfring Abstract--Orthogonal Frequency Division Multiplexing (OFDM) is an inimitable technology in wireless communication. High peak-to-average power ratio (PAPR) is a challenging issue in OFDM system. Large PAPR results in significant distortion in OFDM signal when passed through nonlinear high power amplifier. Selected mapping (SLM) is an efficient technique to reduce...

ABSTARCTDFT spreading is one of the techniques introduced for peak to average power ratio (PAPR) reduction of OFDM systems. In this technique, the input signal with DFT is spreaded such that the PAPR is minimized but this can reduce the PAPR of OFDM signal to the level of single carrier transmission. In this paper, a DFT spreading method is proposed for the PAPR reduction of OFDM systems with s...

Cognitive Radio technology is a promising solution to utilize the licensed frequency band in opportunistically. OFDM is a multicarrier modulation scheme. It provides the number of benefits when it is implemented at the physical layer of the cognitive radio such as ease in spectrum sensing, reducing the Inter Symbol Interference, flexible in adapting to environment conditions, provides interoper...

In this paper a non-linear companding transform is proposed which can effectively reduce the PAPR value in OFDM systems. High value of PAPR has undesirable effects on the performance of wireless communication systems. Various companding schemes are used to reduce the problem of PAPR in orthogonal frequency division multiplexing schemes. High PAPR drives the power amplifiers used at the transmit...

This paper addresses the problem of peak-to-average power ratio (PAPR) in orthogonal frequency division multiplexing (OFDM) systems. It also introduces a new PAPR reduction technique based on adaptive square-rooting (SQRT) companding process. The SQRT process of the proposed technique changes the statistical characteristics of the OFDM output signals from Rayleigh distribution to Gaussian-like ...

In this paper, we propose a peak-to-average power ratio (PAPR) reduction scheme with selective tone reservation. In this scheme, the preset peak reduction tone (PRT) set would be divided into M PRT subsets that can generate M time-domain kernels. The differences of the slopes for the phase responses of the M timedomain kernels would be considered to design the M PRT subsets in reducing the PAPR...