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) is considered as a one of the essential components in most of recent telecommunication systems. To maintain a high bit rate and provide a high bandwidth, using the OFDM as a modulation format in RoF system is preferred over other modulation formats. In this paper, up-converting a 20 Gb/s and a 30 Gb/s OFDM signal on a 20-GHz microwave carrier ov...

Orthogonal Frequency Division Multiplexing (OFDM) is a key technique for achieving high data rates and spectral efficiency requirements for wireless communication systems. This paper presents a modeling and simulation of OFDM based on WLAN standard (IEEE 802.11a). Performance of OFDM is evaluated for different modulation schemes such as PSK, QAM, DQPSK, and OQPSK. The performance of OFDM is com...

This work is focused on an efficient model of OFDM transceiver with the help of software-defined radio (SDR) system with reconfigurable architecture for wireless communications. SDR possesses revolutionary developments such as algorithm implementation of digital communication and increased computing capabilities. In the paper, OFDM system design and implementation with novel technology developm...

In this paper, we introduce variable coding rate (VCR) control to OFDM adaptive modulation scheme (OFDM AMS) in order to realize high throughput with relatively simple transceiver configurations in a dynamic parameter controlled-orthogonal frequency and time division multiple access (DPC-OF/TDMA). In the proposed system, multilevel transmit power control (MTPC) is not employed to simplify hardw...

Wavelet Packet Modulation (WPM) is a multicarrier modulation technique like the well established Orthogonal Frequency Division Multiplexing (OFDM). It has several advantages over OFDM, such as flexibility of operation and excellent localization in frequency. The Channel Equalization for WPM is new and an unexplored research area. It is also different from equalization for OFDM because WPM symbo...

The performance of Low-Density Parity-Check (LDPC)-coded Orthogonal Frequency Division Multiplexing (OFDM) is investigated over turbulence channels in underwater wireless optical communications (UWOC). relation between the bit error ratio (BER) and parameters such as scintillation coefficient, signal-to-noise (SNR), length LDPC code, order OFDM quantified by simulation. Results show that while ...

We propose and experimentally demonstrate a scheme to improve the energy efficiency of wavelength division multiplexing - orthogonal frequency division multiplexing - passive optical networks (WDM-OFDM-PONs). By using an N × M opto-mechanic switch in optical line terminal (OLT), an OFDM modulation module is shared by several channels to deliver data to multiple users with low traffic demands du...

In this paper, α-OFDM, a generalization of the OFDM modulation, is proposed. This new modulation enhances the outage capacity performance of bursty communications. The α-OFDM scheme is easily implementable as it only requires an additional time symbol rotation after the IDFT stage and a subsequent phase rotation of the cyclic prefix. The physical effect of the induced rotation is to slide the D...

The time domain synchronous orthogonal frequency division multiplex (TDS-OFDM) modulation scheme has recently been proposed in a new digital television (DTV) system. The European DTV standard DVB-T, on the other hand, uses the cyclic prefix (CP) OFDM modulation. In this paper, TDS-OFDM and CP-OFDM for nonergodic broadcast inter-symbol-interference channels are compared from an information theor...