Preamble design for LS channel estimation in OFDM/OQAM cooperative systems is investigated in this paper. A simple but important setup is considered, consisting of a pair of single-antenna terminals (source and destination) assisted in their communication by an AF relay and following a well-established two-phase transmission protocol. The so-called sparse preamble case (i.e., pilot tones surrou...

Constant-power adaptive transmission technique adopting UL-coded spectrally-precoded orthogonal frequencydivision multiplexing (SP-OFDM) signals with one tap zeroforcing equalization is studied on the flat fading channel. By jointly adapting the precoding order for spectral precoder and the component modulation for OFDM, constant-power ULcoded adaptive SP-OFDM is shown to outperform conventiona...

With its robustness against multipath fading, orthogonal frequency division multiplexing (OFDM) has become the modulation of choice for many modern wireless standards. However, OFDM is very sensitive to offsets in frequency and time. This makes synchronization an essential part of an OFDM system. This paper aims to motivate and analyze past work on OFDM synchronization techniques.

The popular modulation scheme which offers reliable high bit rate wireless system with reasonable complexity is Orthogonal Frequency Division Multiplexing (OFDM). OFDM is preferred in most high bandwidth efficient transmission systems because it effectively resists Intersymbol Interference (ISI) and is robust towards multipath fading. One of the main factor affecting the performance of an OFDM ...

We propose a four-dimensional (4D) coded multiband-OFDM scheme suitable for beyond 1.4 Tb/s serial optical transport. The proposed scheme organizes the N-dimensional (ND) signal constellation points in the form of signal matrix; employs 2D-inverse FFT and 2D-FFT to perform modulation and demodulation, respectively; and exploits both orthogonal polarizations. This scheme can fully exploit advant...

The Orthogonal Frequency Division Multiplexing (OFDM) has widely been used in broadband wireless communication due to its ability to efficiently utilize the spectrum with multicarrier communication. In this paper BER expression for π/4 DQPSK modulation has been derived from FrFT based OFDM system in the presence of carrier frequency offset (CFO) under frequency selective Rayleigh fading channel...

Orthogonal Frequency Division Multiplexing (OFDM) is a promising technique used in the wireless broadband communication systems these days. It is a form of multi-carrier modulation technique. High spectral efficiency, robustness to channel fading, immunity to impulse interference, uniform average spectral density, capacity to handle very strong echoes and very less nonlinear distortion are the ...

A MIMO-OFDM wireless communication system is a combination of MIMO and OFDM Technology. The combination of MIMO and OFDM produces a powerful technique for providing high data rates over frequency-selective fading channels. MIMO-OFDM system has been currently recognized as one of the most competitive technology for 4G mobile wireless systems. MIMO-OFDM system can compensate for the lacks of MIMO...

Orthogonal frequency division Multiplexing (OFDM) is one of the most popular multicarrier or multiplexing modulation techniques in high speed wireless communication. The main principle of OFDM system is to transmit multiple numbers of signals simultaneously over a single transmission path. OFDM convert high data rate stream in to smaller data rate stream. Due to this high data rate and ability ...

Analysis of Coded OFDM System over Frequency-Selective Fading Channels. (August 2003) Jun Zheng, B.S., Tsinghua University, P.R. China Chair of Advisory Committee: Dr. Scott L. Miller This thesis considers the analysis of system performance and resource allocation for a coded OFDM system over frequency selective fading channels. Due to the inseparable role taken by channel coding in a coded OFD...