Active Constellation Extension (ACE) is one of techniques introduced for Peak to Average Power Ratio (PAPR) reduction for OFDM systems. In this technique, the constellation points are extended such that the PAPR is minimized but the minimum distance of the constellation points does not decrease. In this paper, an iterative ACE method is extended to spatially encoded OFDM systems. The proposed m...

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...

We investigate the use of single carrier frequency domain equalization (SCFDE) over a diffuse optical wireless (DOW) communications. Recently orthogonal frequency division multiplexing (OFDM) has been applied to DOW communications. However, due to high peak-to-average power ratio (PAPR), the performance of OFDM can severely be affected by the nonlinear characteristics of light emitting diodes (...

In this paper the novel method of “weighted OFDM” is addressed. Different types of weighting factors (including Rectangular, Bartlett, Gaussian, Raised cosine, Half-sin and Shanon) are considered. The impact of weighting of OFDM on the peak-to-average power ratio (PAPR) is investigated by means of simulation and is compared for the above mentioned weighting factors. Results show that by weighti...

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...

-----------------------------------------ABSTRACT------------------------------------------A high speed network 802.11a (OFDM) has emerged as very popular wireless transmission technique in which digital data bits are transmitted at a high speed in a radio environment. But non linear effect (PAPR) is challenge of high speed based communication that has recently drawn much attention. Non linear ...

A Golay Complementary Sequence (CS) has Peak-to-Average-Power-Ratio (PAPR) ≤ 2.0 for its one-dimensional continuous Discrete Fourier Transform (DFT) spectrum. Davis and Jedwab showed that all known length 2m CS, (GDJ CS), originate from certain quadratic cosets of Reed-Muller (1,m). These can be generated using the Rudin-Shapiro construction. This paper shows that GDJ CS have PAPR ≤ 2.0 under a...

–The high peak-to-average-power-ratio (PAPR) of OFDM systems introduces inevitable nonlinear distortion in the transmitter and reduces the performance dramatically. In this paper we propose a novel scheme to reduce the PAPR with an adaptive dynamic range companding (ADRC) technique. Based on the examination of the distribution of OFDM signal amplitude, reduction of the PAPR is achieved by using...

The paper presents Space-Frequency Block Coding (SFBC) as a transmit diversity technique in Single Carrier Frequency Division Multiple Access (SC-FDMA). SC-FDMA is known as a low Peak-to-Average Power Ratio (PAPR) modulation technique. SFBC requires changing the order of the samples in the frequency domain, which results in increase of the PAPR. Because of that, additional clipping and filterin...

Orthogonal Frequency Division Multiplexing (OFDM) is a well-known modulation technique for transmission of large amount of digital data with high data rate in both wired and wireless communication systems. High peak-to-average power ratio (PAPR) is the main problem of OFDM system which can be improved by using single carrier frequency division multiple access (SC-FDMA) technique. The simulation...