-Multi-carrier modulation has been used in many wired and wireless communications. It was used in many military high frequency radios, audio-video broad casting and DSL. Multi-carrier modulation can be digitally implemented using Orthogonal Frequency Division Multiplexing (OFDM).Inter symbol Interference can be completely avoided in OFDM by inserting cyclic prefixes. In OFDM wide band channel b...

The use of multiple antenna’s at both transmitter and receiver to form multiple input and multiple output(MIMO) channels currently hold the potential to drastically improve the spectrum efficiency and capacity of future wireless communication system. For broadband systems ,OFDM turns a frequency selective channel into a set of parallel flat channels which reduces the receiver complexity. Design...

Channel prediction is an appealing technique to mitigate the performance degradation due to the inevitable feedback delay of the channel state information (CSI) in modern wireless systems. In the existing method, the 2-step algorithm fixes the prediction order, which first exploits temporal correlation temporal correlation and then follows spatial correlation. Our proposed method is selected fl...

Mobile WiMAX (Worldwide Interoperability for Microwave Access) or 802.16e standard was ratified by the IEEE in late 2005 as a potential to emerge as a real viable competitor to existing 3G technologies. Mobile WiMAX uses an OFDMATM technology called 1K-FFT. Orthogonal Frequency-Division Multiple Access (OFDMA) is a multi-user version of the popular Orthogonal frequency-division multiplexing (OF...

This paper investigates the Multi-bandOFDM (MB-OFDM) based Ultra-Wideband for working group on short-range high data-rate Ultra-wide-Band (UWB) communications. An overview of the MB-OFDM PHYlayer architecture with its various parameters is presented and the optimal choice of critical parameters is discussed. Next, we derive the theoretical un coded bit error rate (BER) of MB-OFDM over the fadin...

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...

A resource Allocation Problem for spectrum sharing in wireless communication system. Using multiinput multi-output orthogonal frequency division multiple ( MIMO-OFDM) is a very promising technology for enhancing the flexibility and efficiency of cellular and future communication systems. A joint optimization problem for resource allocation is solved by a combine scheme of multiple-input multipl...

Orthogonal frequency division multiplex/offset QAM (OFDM/OQAM) and N-continuous OFDM are both improved multi-carrier modulation (MCM) techniques for the transmission of signals over multipath fading channels. In this paper, we aim to compare these two techniques with respect to out-of-band radiation, bit error ratio (BER) and calculation complexity. Analysis and simulation results show that, co...