Rate and Power Adaptation in OFDM With Quantized Feedback
White Papers In the first type, rate and power allocation algorithm is performed at the transmitter to maximize throughput using quantized Channel-to-Noise Ratio (CNR) feedback from the receiver. In the second type, power allocation is implicit such that the...
[April 11, 2007, 1:01]
Smartacking: Improving TCP Performance From the Receiving End
White Papers This paper presents smartacking, a technique that improves performance of Transmission Control Protocol (TCP) via adaptive generation of acknowledgments (ACKs) at the receiver. When the bottleneck link is underutilized, the receiver transmits an...
[December 20, 2007, 0:01]
Low Complexity OFDM Detector for Underwater Acoustic Channels
White Papers The receiver performs MMSE combining of signals received across an array, using adaptive channel estimation. An adaptive algorithm is proposed for OFDM signal detection on Doppler-distorted, time-varying multipath channels.
[April 11, 2007, 1:01]
Interference Avoidance Dynamic Adaptive OFDM Using a Reconfigurable Radio Platform
White Papers The main focus of this work is the creation of a receiver-centric improved OFDM wireless transmission system that has reduced Bit Error Rate (BER) and increased channel capacity usage in interference-prone wireless bands.
[April 11, 2007, 1:01]
Software Radio Architecture with Smart Antennas: A Tutorial on Algorithms and Complexity
White Papers The analytical and numerical results show that adaptive beam forming at the receiver reduces the probability of blocking and forced termination of the calls and increases the total carried traffic in the system.
[November 9, 2003, 23:49]
Joint Compensation of Transmitter and Receiver Impairments in OFDM Systems
White Papers The algorithms include post-FFT least-squares and adaptive equalization, as well as a pre-distortion scheme at the transmitter and a pre-FFT correction at the receiver. Such imbalances are caused by the analog processing of the Radio Frequency (RF...
[April 11, 2007, 1:01]
MIMO Techniques for Mobile WiMAX Systems
White Papers It turns out that implementing a 2x2 spatial multiplexing MIMO receiver is a considerable challenge with a present state of technology. SEQUANS Communications has devised and patented a receiver algorithm and architecture, which substantially...
[April 23, 2009, 1:24]
A Simple and Effective Cross Layer Networking System for Mobile Ad Hoc Networks
White Papers In particular, the size of a digital constellation can be varied dynamically based on the channel condition estimated at the receiver which can be relayed to the transmitter via the control packets. The channel reservation control packets employed...
[August 13, 2007, 8:09]
The Case for Heterogeneous Wireless MACs
White Papers Different from existing network protocol design, the method results in dynamic, context-aware, heterogeneous MAC protocols that are usually applied on a per sender-receiver pair basis, for the same function of wireless medium access control.
[June 16, 2006, 0:00]
On MIMO Signal Processing for Adaptive W-CDMA and OFDM Wireless Transceivers
White Papers Simulation study compares cases with one and two transmit/receive antennas and shows that BER of W-CDMA system consistently improves by exploiting multi-path diversity through additional antenna at the receiver, while additional transmit antenna...
[July 21, 2005, 6:00]
A Symbol Estimation Scheme for Alamouti Coded OFDM Systems
White Papers In Alamouti coded OFDM systems, the simple decoding at the receiver relies on the assumption that the subchannels are flat fading, decoupled, and quasi-static so that each subchannel does not change over an Alamouti codeword period (two...
[April 11, 2007, 1:01]
Broadband MIMO-OFDM Wireless Communications
White Papers OFDM may be combined with antenna arrays at the transmitter and receiver to increase the diversity gain and/or to enhance the system capacity on time-variant and frequency-selective channels, resulting in a multiple-input multiple-output (MIMO...
[November 2, 2004, 2:00]
Pilot-Tone Based ZP-OFDM Demodulation for an Underwater Acoustic Channel
White Papers Multicarrier modulation in the form of Orthogonal Frequency Division Multiplexing (OFDM), on the other hand, converts a frequency selective channel into a set of parallel frequency-flat subchannels, thus greatly simplifying receiver equalization.
[April 11, 2007, 1:01]
Waiting for the wireless Internet
News G networks will also benefit from smart antenna technology, which can steer the radio signal in the direction of the receiver in the terminal from the base station. Other enablers include adaptive processing and smart antennas, both of which will...
[July 7, 2000, 13:54]
Spatial Multiplexing for Outdoor MIMO-OFDM Systems With Limited Feedback Constraint
White Papers For outdoor environments with a limited angular spread at the base station, the proposed technique is able to separate the users' streams through a joint spatial processing at both the transmitter and the receiver requiring only a limited feedback...
[April 11, 2007, 1:01]
On the Design of Robust Multiband OFDM Ultra-Wideband Receivers
White Papers This paper analyzes the effects of NarrowBand Interferences (NBI) on the performance of a Multi-Band Orthogonal Frequency Division Multiplexing (MB-OFDM) Ultra-WideBand (UWB) receiver and proposes efficient schemes for signal reception and...
[April 13, 2007, 1:01]
Adaptive MIMO OFDM Receivers: Implementation Impairments and Complexity Issues
White Papers However, the commercial deployment of MIMO OFDM systems faces some challenges, including those arising from front-end analog implementation impairments and complex receiver structures. MIMO OFDM communications is a promising choice for future high...
[March 29, 2005, 3:00]
