Orthogonal frequency division multiplexing (OFDM) is an attractive, promising and emerging technique which achieves high data rate in mobile multipath channels. LTE was the first technology to use OFDM. There are many more advantages of OFDM which includes immunity to multipath fading. High Peak to Average Power Ratio(PAPR) is the main disadvantage of OFDM-LTE Networks. This paper describes how...

In this letter, we propose layered asymmetrically clipped optical-orthogonal frequency-division multiplexing (LACO-OFDM) with index modulation (IM), i.e., LACO-OFDM-IM for optical wireless systems. classical LACO-OFDM, the spectral leakage because of out-of-band clipping harmonics increases baseband bandwidth (BB) resulting in lower efficiencies. For LACO-OFDM-IM, use IM and optimize BB by filt...

Being sensitive to synchronization errors, symbol timing is a key factor affecting the performance of orthogonal frequency division multiplexing (OFDM) -based visible light communication (VLC) systems. A novel method based on odd-even symmetry for direct current biased optical OFDM (DCO-OFDM) investigated in this paper. The proposed produces an excellent pulse-like metric, resulting sharper pea...

To improve performance of orthogonal frequency division multiplexing (OFDM) for fading channels, linear dispersion coded OFDM (LDC-OFDM) was recently proposed to increase frequency and time diversity with high bandwith efficiency and performance. The performance of recently proposed LDC-OFDM was investigated through simulations. This paper analyzes the diversity aspects of LDCOFDM system, and s...

OFDM is an efficient modulation technique for wideband digital communication. A major drawback of OFDM modulation is the high Peak-to-Average Power Ratio (PAPR) of the transmitted signal which limits its transmission range of communication. As PAPR increases it reduces the average power which affect on total power consumption of Transmitter. Normally, OFDM is implemented using FFT. In recent ye...

Orthogonal Frequency Division Multiplexing (OFDM) converts a dispersive channel into parallel subchannels and thus facilitates equalization. But when the channel has nulls close to or on the FFT grid, OFDM faces serious symbol recovery problems. As an alternative to various error-control coding techniques that have been proposed to ameliorate the problem, we linearly precode (LP) symbols before...

This paper is concerned with a randomized OFDM (R-OFDM) scheme. The basic principle is to apply a scrambling operation to several OFDM frames. With a proper design strategy, the scrambling operation will not affect intra-cell orthogonality of OFDM (even considering multi-path effect). For signals from different cells, mutually random scramblings are used to reduce their correlation. This allevi...

Orthogonal Frequency Division Multiplexing (OFDM) is a multi-carrier modulation scheme that provides efficient bandwidth utilization and robustness against time dispersive channels. This paper deals with the basic system model for OFDM based systems and with self-interference, or the corruption of desired signal by itself in OFDM systems. A simple transceiver based on OFDM modulation is present...

Orthogonal frequency division multiplexing (OFDM) has great advantages such as high spectrum efficiency and robustness against multipath fading. In order to enhance the advantages, an Hermitesymmetric subcarrier coding for OFDM, which is used for transmission systems like the asymmetric digital subscriber line (ADSL) and multiband OFDM in ultra-wideband (UWB) communications, is very attractive....