Orthogonal frequency division multiplexing (OFDM) is a multi-carrier transmission technique, which divides the available spectrum into many subcarriers, each one being modulated by a low data rate stream[1]. Compare with the traditional ways, the OFDM system has the features of resisting frequency selective fading and high frequency-band utility ratio and so on. OFDM has been successfully appli...

Orthogonal Frequency Division Multiplexing (OFDM) being a multi-carrier transmission, is one of the most superior technologies in wireless communication. In this paper, a brief overview of an OFDM system is explained. High Peak-to-Average Power Ratio (PAPR) is the major issue associated with an OFDM system, so a novel Partial Transmit Sequence (PTS) technique is proposed for PAPR reduction. The...

In this contribution, a direct comparison of the Offset-QAM-OFDM (OQAM-OFDM) and the Cyclic Prefix OFDM (CP-OFDM) scheme is given for an 802.11a based system. Therefore, the chosen algorithms and choices of design are described and evaluated as a whole system in terms of bit and frame error rate (BER/FER) performance as well as spectral efficiency and complexity in the presence of multipath pro...

I. INTRODUCTION Orthogonal frequency-division multiplexing (OFDM) [1] is one of the promising techniques for very high-speed data transmissions in a severe frequency-selective fading channel [2]. However, since OFDM uses a numerous number of narrowband orthogonal subcarriers to transmit data in parallel, the problem of high peak-to-average power ratio (PAPR) arise. To alleviate the PAPR problem...

Additive mapping scheme represents alternative signals of selected mapping (SLM) by linear combination of signals in time domain for peak to average power ratio (PAPR) reduction in orthogonal frequency division multiplexing (OFDM) system. It can reduce the computational complexity considerably without sacrificing PAPR reduction performances especially for the OFDM system with quadrature amplitu...

In this modern wireless technology Multicarrier communication is one of the more suitable and reliable communication technique. Orthogonal Frequency Division Multiplexing (OFDM) is used as modulation technique in multicarrier communication. The present paper gives an overview of OFDM and the various Channel Estimation techniques used in OFDM. The results implemented in MATLAB gives the performa...

Unique word OFDM is a novel technique for constructing OFDM symbols, that has many advantages over cyclic prefix OFDM. In this paper we investigate two different approaches for the generation of an OFDM symbol containing a unique word in its time domain representation. The two-step and the direct approach seem very similar at first sight, but actually produce completely different OFDM symbols. ...

In wireless communications systems, Orthogonal Frequency Division Multiplexing (OFDM) and Multiple Input Multiple Output (MIMO) are used to improve spectral efficiency and spatial diversity. Beamforming is used to improve bandwidth utilization. It increases the network range in wireless systems. The main challenge of OFDM system is Carrier frequency offset (CFO). The project focuses on CFO esti...

ABSTRACT Standard OFDM systems are associated with a rectangular grid in the time-frequency plane. However such a setup is in general not optimal for pulse shaping OFDM systems for doubly dispersive channels. We introduce lattice-OFDM systems (LOFDM), which are OFDM systems constructed with respect to general lattices in the time-frequency plane. We show how to design optimal pulse shapes for L...

This paper provide MMSE Channel estimation For MIMO-OFDM Using Spatial and Temporal Correlations. Generally there are a lot of methods for channel estimation of OFDM as well as MIMO OFDM. In this paper I first described about the latest MIMO OFDM channel estimation which is super resolution approach that explores spatial and temporal correlation of MIMO-OFDM. I then implemented it using MMSE ch...