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Diversity Analysis for Frequency-Selective MIMO-OFDM Systems With General Spatial and Temporal Correlation Model
White Papers An upper bound on the maximum achievable diversity order for frequency-selective MIMO-OFDM systems with general temporal and spatial correlation is derived. For the space-frequency coded MIMO-OFDM system, it is shown that any space-frequency code...
[August 14, 2009, 4:49]
diversity and decentralization
Talkback Furthermore, I sincerely believe that diversity and decentralization is the key to keep the whole secure, highly available and inviting to innovative new solutions to thus forever thrive markets and businesses.
[May 12, 2007, 23:43]
Diversity
Downloads Diversity is a new tool for entering and inspecting ecological data, and for measuring the diversity of ecological communities. Diversity makes it quick to enter your data and to see the composition of your samples.
[July 3, 2009, 16:11]
Diversity, Interference Cancellation and Spatial Multiplexing in MIMO Mobile WiMAX Systems
White Papers This paper first discusses the tradeoffs between diversity, interference cancellation and spatial multiplexing in MIMO systems, and it compare Optimum Combining (OC), Maximum-Ratio Combining (MRC) and interference cancellation for different...
[April 23, 2009, 1:24]
Diversity Reception for OFDM Systems Using Antenna Arrays
White Papers This provides space diversity in multipath channels, making it possible to realize high transmission rates envisioned for the next generation wireless communications. Orthogonal Frequency Division Multiplexing (OFDM) is a multicarrier modulation...
[April 11, 2007, 1:01]
Exploiting Time Diversity to Improve Block Spread OFDM
White Papers This paper presents a new method to improve on block spread OFDM by exploiting time diversity to ensure that the blocks are independent and uncorrelated. Simulation results have shown significant improvement over conventional OFDM and Block Spread...
[April 11, 2007, 1:01]
Cooperative Diversity in Wireless Networks: A Geometry-Inclusive Analysis
White Papers Cooperation between physically separated wireless nodes can achieve the high Signal-to-Noise Ratio (SNR) diversity gains characteristic of multi-antenna arrays. Cooperation further yields SNR gains in addition to diversity gains.
[December 7, 2006, 0:00]
Joint Scale-Lag Diversity in Mobile Wideband Systems
White Papers This paper considers the effect of mobility on a wideband Direct Sequence Spread Spectrum (DSSS) communication system, and study a scale-lag Rake receiver capable of leveraging the diversity that results from mobility.
[August 10, 2007, 11:26]
On Achieving Software Diversity for Improved Network Security Using Distributed Coloring Algorithms
White Papers It is widely believed that diversity in operating systems, software packages, and hardware platforms will decrease the virulence of worms and the effectiveness of repeated applications of single attacks.
[September 20, 2008, 0:00]
WiMAX Relay Networks: Opportunistic Scheduling to Exploit Multiuser Diversity and Frequency Selectivity
White Papers The paper solves the problem of MAC scheduling in such networks so as to serve the mobiles in a fair manner while exploiting the multiuser diversity, as well as the frequency selectivity of the wireless channel.
[April 15, 2009, 1:22]
Temporal Diversity Assisted Blind Channel Estimation for Downlink Long-Code CDMA Systems
White Papers However, after introducing temporal diversity in the transmitted chip sequence for all users, subspace technique can be applied to estimate channel. Experimental comparison with the previously proposed spatial diversity method shows superior...
[November 8, 2006, 0:00]
On Cyclic Delay Diversity in OFDM Based Transmission Schemes
White Papers Cyclic Delay Diversity (CDD) is a simple approach to introduce spatial diversity to an Orthogonal Frequency Division Multiplexing (OFDM) based transmission scheme that itself has no built-in diversity.
[March 25, 2008, 7:41]
Optimizing Voice-Over-IP Speech Quality Using Path Diversity
White Papers Then, it identifies the limitations of the VoIP application for this scheme and proposes improvement using path diversity approach that can be implemented via a Service Overlay Network (SON). In last few years, Voice over Internet Protocol (VoIP...
[May 23, 2007, 1:00]
Multimedia Communication Over OFDM Mobile Wireless Networks: A Cross-Layer Diversity Approach
White Papers Diversity can be used to combat multipath fading and improve the performance of mobile wireless multimedia communication systems. In this work, by considering transmission of an embedded bitstream over a slow varying Rayleigh faded environment, the...
[April 11, 2007, 1:01]
Scale-Lag Diversity Reception in Mobile Wideband Channels
White Papers This paper considers the effect of mobility on a wideband Direct Sequence Spread Spectrum (DSSS) communication system, and study a scale-lag Rake receiver capable of leveraging the diversity that results from mobility.
[August 10, 2007, 11:27]
Campaign calls for diversity in engineering
Blog Ergo, the Royal Society of Engineering has launched its Diversity in Engineering Campaign, fronted by none other than the recently-honoured Professor, Dame etc Wendy Hall of the University of Southampton.
[January 15, 2009, 14:02]
Transmit Diversity Vs Beamforming for Multi-User OFDM Systems
White Papers This paper compares Pre-IDFT downlink beamforming with Space-Time Block coded and Space-Frequency block coded transmit diversity schemes for 4×1 downlink multi-user OFDM (OFDM-TDMA and OFDMA) systems.
[April 18, 2007, 1:00]
BER Performance of OFDM System in Frequency-Selective Rician Fading With Diversity Reception
White Papers In addition, the error probability is determined with the use of diversity reception. This paper theoretically studies the Bit Error Rate (BER) performance of OFDM systems with MDPSK modulation for subchannels in frequency-selective flat Rician...
[April 18, 2007, 1:00]
A Low Complexity Antenna Diversity Receiver for OFDM Based Systems
White Papers A low complexity antenna diversity architecture with a new combining technique suitable for Orthogonal Frequency Division (OFDM) based systems is introduced in this paper. For a two branch antenna diversity, this structure requires only one FFT at...
[April 14, 2007, 1:01]
A Reduced Complexity Channel Estimation for OFDM Systems With Precoding and Transmit Diversity in Mobile Wireless Channels
White Papers A precoding approach for reduced complexity channel estimation for OFDM systems with transmit diversity is presented. Two different OFDM schemes that employ the precoding are investigated: the first one is based on space-time coding, the second is...
[April 13, 2007, 1:01]
