spread symbol
RSS spread symbolICI Mitigation for Pilot-Aided OFDM Mobile Systems
White Paper As delay spread increases, symbol duration should also increase in order to maintain a near-constant channel in every frequency subband. Therefore, to have an acceptable reception quality for the applications that experience high delay and Doppler... [16 May 2008]
Exploiting Multipath Induced Diversity in OFDM Systems
White Paper It is primarily used in high bit rate systems to mitigate inter-symbol interference (ISI) caused due to de- lay spread. While the ISI caused by delay spread is an annoyance factor, it also provides path diversity advantage if the path gains fade... [03 Apr 2008]
A RAKE Receiver With ICI/ISI Equalizer for CCK Wireless LAN Modem
White Paper As the delay spread is larger, Inter-Symbol Interference (ISI) and Inter-Chip Interference (ICI) generated due to multipath environments are increased. This paper proposes a new type of RAKE receiver for complementary code keying (CCK) codes, which... [05 Dec 2007]
Timing Synchronization in High Mobility OFDM Systems
White Paper The performance of OFDM systems, however, is sensitive to the performance of the timing synchronizer and channel estimator (in this paper, timing synchronization refers to the correct detection of the start of an OFDM symbol). [02 Aug 2007]
Don't Dither About Your Data, Let SAS/GRAPH Trending Box Plots Drive Decision Making
White Paper Multiple SYMBOL, AXES, and PLOT statements, as well as the OVERLAY, statement are employed to enhance the graphic by including dithered data points on the boxplots. Box and Whisker plots (box plots) are excellent tools for communicating point... [27 Apr 2007]
Channel Modeling and Associated Inter-Carrier Interference Equalization for OFDM Systems With High Doppler Spread
White Paper On the other hand it shows that, considering a whole CP-OFDM symbol, this leads to a duality between equalization of the delay spread of a time-varying channel in time domain, and the equalization of the Doppler spread of a frequency selective... [18 Apr 2007]
New Estimation and Equalization Approach for OFDM Under Doppler-Spread Channel
White Paper Then, ICI is canceled by multiplying the inverse matrix of the estimated channel matrix to the received OFDM symbol vector. In OFDM transmission, a loss of subcarrier orthogonality due to Doppler-spread of the channel leads to Inter-Carrier... [18 Apr 2007]
Preemptive Response to West Nile Virus in New York City
White Paper System hardware consists of Symbol PPT 2846 Pocket PC handheld data terminals with built in 802.11b networking. With the growing threat to the community from the spread of West Nile Virus, the City of New York was acutely aware of the need for... [16 Apr 2007]
Chirped-OFDM for Transmissions Over Time-Varying Channels With Linear Delay/Doppler Spreading
White Paper This paper shows that the optimal digital communication strategy for transmissions over time-varying channels with spread function maximally concentrated along a line of the delay-Doppler domain consists in multiplexing the input symbol block with... [14 Apr 2007]
Blind Channel Estimation for OFDM Systems Based on Non-Redundant Linear Precoding
White Paper It is composed of unitary sub-matrices, which spread each symbol onto multiple sub-carriers, thus enabling robustness to subcarrier nulls. This paper considers a novel approach that can be applied on a single transmit/receive antenna OFDM system... [13 Apr 2007]
Bandwidth Efficient Channel Estimation Using Super-Imposed Pilots in OFDM Systems
White Paper The pilot symbols are added linearly to the modulated data symbol at a fraction of the total transmit power, making the method spectrally efficient. This paper observes that the performance of the receiver is independent of the channel's Doppler... [13 Apr 2007]
Asymptotic Performance of Transmit Diversity Via OFDM for Multipath Channels
White Paper Here it shows that when the Alamouti code is placed within an OFDM structure, using adjacent frequency bands rather than consecutive symbol intervals, it can asymptotically achieve the same performance in multipath fading as the Alamouti code in... [13 Apr 2007]
Increasing Time Domain Diversity in OFDM Systems
White Paper However, extensive delay and Doppler spread may cause non-negligible Inter-Symbol Interference (ISI) and/or Inter-Carrier Interference (ICI) in OFDM systems. Delay- and Doppler spread of multipath fading channels have already been identified as... [11 Apr 2007]
ICI Reduction Method for OFDM Systems
White Paper However, the longer symbol duration increases the Inter-Carrier-Interference (ICI) caused by Doppler spread in time variant channels. Orthogonal Frequency Division Multiplexing (OFDM) has an increased symbol duration which makes it robust against... [11 Apr 2007]
Symbol Timing for Multiple Antenna OFDM Systems
White Paper Accurate symbol timing in Multiple-Input Multiple-Output (MIMO) OFDM systems allows for Guard-Intervals (GIs), which are short compared to the channel's rms delay spread. These short GIs improve the effective throughput of these kinds of systems. [11 Apr 2007]
