The rapid growth in the wireless technology possess the need of high data rate transmission. This can be accomplished by using Orthogonal Frequency Division Multiplexing (OFDM). It is a particular case of multicarrier modulation (MCM), where high rate data stream is transmitted over low rate subcarriers. The system uses a number of carriers to transmit data simultaneously. The disadvantage of t...

In direct-conversion orthogonal frequency division multiplexing (OFDM) receivers, the impact of frequency-dependent I/Q mismatch (IQ-M) with carrier frequency offset (CFO) must be considered. A preamble-assisted estimation is developed to circumvent the frequencydependent IQ-M with CFO. The results of a simulation and an experiment show that the proposed method could provide good estimation eff...

We demonstrate for the first time to the best of our knowledge an analogue orthogonal frequency division multiplexing (OFDM) based electrical code division multiplexing access (ECDMA) passive optical network (PON) for next generation access applications. Advantages of the system include low cost, high capacity, and enhanced spectral efficiency. A proof-of-principle 16 QAM OFDM ECDMA PON downlin...

This letter presents and analyzes orthogonal frequency-division multiplexing (OFDM)-based multi-carrier transmission for cell-free massive multi-input multi-output (CFmMIMO) over frequency-selective fading channels. Frequency-domain conjugate beamforming, pilot assignment, user-specific resource allocation are proposed. The CFmMIMO-OFDM system is scalable to serve a number of users flexible off...

In Multiple Input Multiple Output Orthogonal Frequency Division Multiplexing system using beamforming improve the receive Signal to Noise Ratio. In the transmission signals after beam forming the Peak-to-Average Power Ratio (PAPR) is a major issue in Orthogonal Frequency Division Multiplexing systems, High Peak to Average Power Ratio is complicated to design the power amplifier and also increas...

Increased data rates and reliability are the two key factors required to support emerging multimedia applications and new communications technologies. The two techniques used in high data rate transmission are orthogonal frequency division multiplexing (OFDM) and multiple-input multiple-output (MIMO) scheme. The OFDM is used to mitigate the problem of inter symbol interference (ISI) and provide...

Orthogonal Frequency Division Multiplexing (OFDM) uses as a high speed information transmission technology with excellent anti-interference capabilities. High Peak-to-Average Power Ratio (PAPR) of transmitted signal is one of the major drawbacks in Orthogonal Frequency Division Multiplexing (OFDM) systems. To overcome the drawback of high PAPR of transmitted signal we propose the novel based pa...

Orthogonal frequency division multiplexing (OFDM) is a appealing technique approach for achieving high bit rate data transmission in wireless transmission. It uses available channel more efficiently by placing the subcarriers close enough provided subcarriers are orthogonal to each other. OFDM reduces the inter-symbol interference caused by multipath propagation. OFDM also reduces bit error rat...

The aim of this paper is to survey and compare previous methods for Data-aided timing and frequency synchronization of OFDM System. Synchronization has been one of the crucial research topics in orthogonal frequency division multiplexing (OFDM) system because of its sensitivity to the timing and frequency errors [1]. To guarantee the fast and accurate data transmission, the Inter Symbol Interfe...

In this paper, an approach of time division multiplexing (TDM) for the MIMO-OFDM (orthogonal frequency division multiplexing) transmitter and receiver is studied and evaluated to reduce the power consumption and cost down of the multiple antenna RF chains. With this TDM technique, our proposed MIMO-OFDM communication system can reduce the number of RF chains from N to 1, which significantly red...