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Orthogonal Frequency Division Multiplexing Based on Offset QAM
White Papers One of the factors determining the performance of wireless Orthogonal Frequency Division Multiplexing (OFDM) systems is time-frequency localization of the transmitter and receiver pulse shaping filters.
[March 28, 2005, 0:00]
Design and Simulation of Orthogonal Frequency Division Multiplexing (OFDM) Signaling
White Papers A MATLAB program has been written to investigate Orthogonal Frequency Division Multiplexing (OFDM) communication systems. This program is valuable for future researchers simulating systems that are too theoretically complex to analyze.
[January 8, 2008, 1:26]
Optical CDMA With Optical Orthogonal Code
White Papers This paper examines optical CDMA communication techniques with optical orthogonal codes. Simulations that show the desired properties of theses codes and their use in optical CDMA are reported in the paper.
[October 13, 2005, 3:00]
On Orthogonal Reduction to Hessenberg Form With Small Bandwidth
White Papers One of the most useful types of such reduction is the orthogonal reduction to (upper) Hessenberg form. This paper studies necessary and sufficient conditions on A so that the orthogonal Hessenberg reduction yields a Hessenberg matrix with small...
[July 11, 2008, 1:02]
Characterizing Achievable Rates in Multi-Hop Wireless Mesh Networks With Orthogonal Channels
White Papers This paper considers the problem of determining the achievable rates in multi-hop wireless mesh networks with orthogonal channels. The authors classify wireless networks with orthogonal channels into two types, half duplex and full duplex, and...
[December 13, 2006, 0:00]
Orthogonal Frequency Division Multiplexing for Wireless Communications
White Papers Orthogonal frequency division multiplexing (OFDM) is a promising technique for high-data-rate wireless communications because it can combat inter-symbol interference (ISI) caused by the dispersive fading of wireless channels.
[July 21, 2005, 6:00]
Orthogonal Frequency Division Multiplexing (OFDM)
White Papers OFDM is a promising candidate for achieving high data rate transmission in mobile environment. The application of OFDM to high data rate mobile communication system is being investigated by many researchers.
[March 30, 2005, 3:00]
Diversity Reception for OFDM Systems Using Antenna Arrays
White Papers Orthogonal Frequency Division Multiplexing (OFDM) is a multicarrier modulation scheme that achieves high spectral efficiency by using minimally densely spaced orthogonal subcarriers without increasing the transmitter and receiver complexities.
[April 11, 2007, 1:01]
OFDM Based WLAN Systems
White Papers Orthogonal Frequency Division Multiplexing (OFDM) is a special form of multi-carrier transmission where all the subcarriers are orthogonal to each other. OFDM promises a higher user data rate and great resilience to severe signal fading effects of...
[April 18, 2007, 1:00]
ICI Cancellation Based Channel Estimation for OFDM Systems
White Papers Orthogonal Frequency Division Multiplexing OFDM), which is a multicarrier modulation scheme, splits high data rate information symbols into lower rate parallel data streams and transmits this parallel information on different orthogonal carriers.
[April 11, 2008, 7:13]
Pilot-to-Data Power Ratio for Maximizing the Capacity of MIMO-OFDM
White Papers Orthogonal frequency division multiplexing (OFDM) can be used with a multiple-input multiple-output (MIMO) system to improve communication quality and capacity. This paper analyzes the effects of pilot-symbol-aided channel estimation on the lower...
[March 30, 2005, 3:00]
IEEE 802.16 Medium Access Control and Service Provisioning
White Papers This paper describes the IEEE 802.16 Orthogonal Frequency Division Multiplexing (OFDM) and the 802.16 Orthogonal Frequency Division Multiple Access (OFDMA), Medium Access Control (MAC) protocols, both of which are key elements of the Worldwide...
[September 11, 2009, 3:32]
Exploiting Time Diversity to Improve Block Spread OFDM
White Papers A method used to implement mutually orthogonal signals is called Orthogonal Frequency Division Multiplexing (OFDM) and this is done by setting up multiple carriers at a suitable frequency separation and modulating each symbol stream separately.
[April 11, 2007, 1:01]
Mobile WiMAX Performance Improvement Using a Novel Algorithm With a New Form of Adaptive Modulation
White Papers Mobile WiMAX is based on orthogonal frequency division multiplexing/ orthogonal frequency division multiplexing Access (OFDM/OFDMA) technology. Worldwide Interoperability for Microwave Access (WiMAX) is an emerging broadband wireless technology...
[April 23, 2009, 1:24]
Two-Stage Variable Clustering for Large Data Sets
White Papers The procedure uses oblique principal components analysis and binary iterative splits for variable clustering, and it provides non-orthogonal principal components. Even if this procedure sacrifices the orthogonal property among principal components...
[May 31, 2008, 1:01]
4G gets more serious
News Variable Spreading Factor Orthogonal Frequency and Code Division Multiplexing (VSF-OFCDM) provides the downlink from the network, and Variable Spreading Factor Code Division Multiple Access (VSF-CDMA) is used for the uplink.
[June 11, 2004, 17:55]
Linear Algebra Quick Study Guide - FREE chapters on Linear Equations, Determinant, more in the trial
Downloads Matrices Matrix addition Matrix multiplication Basis transformation matrix Characteristic polynomial, Characteristic Equation Trace Eigenvalue, eigenvector and eigenspace Cayley-Hamilton theorem Spread of a matrix Symbolic Computation of Matrix...
[May 11, 2007, 8:00]
Using Constellation Shaping to Reduce the Peak and Average Power of OFDM Signals
White Papers This paper suggests applying constellation shaping to reduce the peak and average power of Orthogonal Frequency Division Multiplexing (OFDM) signals using Quadrature Amplitude Modulation (QAM) in all subcarriers without clipping or reducing the...
[April 11, 2007, 1:01]
Adaptive OFDM Techniques With One-Bit-Per-Subcarrier Channel-State Feedback
White Papers In the Orthogonal Frequency-Division Multiplexing (OFDM) scheme, some subcarriers may be subject to a deep fading. Adaptive techniques can be applied to mitigate this effect if the Channel-State Information (CSI) is available at the transmitter.
[April 11, 2007, 1:01]
An Efficient Implementation of NC-OFDM Transceivers for Cognitive Radios
White Papers This paper presents an efficient implementation of a Non-Contiguous Orthogonal Frequency Division Multiplexing (NC- OFDM) transceiver for cognitive radio systems. NC-OFDM is designed to transmit information in the presence of incumbent users...
[April 11, 2007, 1:01]
