orthogonal frequency division multiplexing for wireless communications ye li

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... Need for Improvement in Channel Modeling Theory The theory that engineers use to measure and model wireless communications has changed very little over the last 30 years. The main reason for this ... spatial relationships as well. Space -Frequency Transform Map For a static channel, we may extend the time -frequency transform map in Figure 2.9 for the space -frequency relationships shown in Figure ... expanded channel modeling theory. 1.1.1 Higher and Higher Data Rates The capacity for data transmission of current wireless systems is still tiny when compared to wired forms of communications. But wireless...

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... Circuit Design for Wireless Communications 2 Elements of RF Circuit Design 2.1 Introduction The design of RF MEMS circuits for wireless applications is predicated upon the well-established principles ... Design for Wireless Communications 86% 11% 3% 2000 81% 15% 4% 2001 75% 20% 5% 2002 70% 25% 5% 2003 Phone line Power line Wireless Figure 1.4 Distribution of interconnection media usage for home ... (3) the space platform. 4 RF MEMS Circuit Design for Wireless Communications Information  Voice  Broadband data  Messaging  Navigation  DBS  Internet  Video Wireless appliances        ? Power/Bandwidth...

Ngày tải lên: 19/01/2014, 20:20

... scenarios for which reliable communications is desirable. In the literature, channel modeling information can be found for ã wireless (radio) communications [Tur72, Suz77], ã wireline communications ... considering several multiplicities. The trans- mitter multiplexes multiple symbols in parallel, such as code -division multiplexing (CDM) and orthogonal frequency- division multiplexing (OFDM) of ... waveform is the same for each symbol period m. LIST OF FIGURES XVII 6.4 Traveling salesperson problem. 120 6.5 Traveling salesperson tree search. 121 6.6 Traveling salesperson trellis....

Ngày tải lên: 16/03/2014, 22:20

... of ±1 with equal probability, ω=2πf is the carrier frequency, and J = −1 . The Mobile Radio Communications 25 28 TDD-CDMA for Wireless Communications f 0 f 3 f 2 f 1 Frequency Time One bit period One ... station Mobile terminal (TDD) Base station Mobile terminal Common uplink and downlink frequency band Uplink frequency band Downlink frequency band Figure 1.4 TDD and FDD. TEAMFLY ... TDD-CDMA for Wireless Communications Riaz Esmailzadeh Masao Nakagawa Artech House Boston ã London www.artechhouse.com 1.1 Mobile Communications The mobile communications revolution took place for...

Ngày tải lên: 27/05/2014, 04:01

... and per- formance results are also applicable to any radio (sec- ondary user) that is interested in accessing the licensed spectrum as long as it does not compromise the perfor- mance of licensee 3 . As ... above propo sed scheme, henceforth call ed as orthogonal spectrum shar- ing scheme (OSSS), by deriving the closed-form expres- sions for average SNR of the primary system. For comparison, we also ... amplify-and-forward relaying. in Proceedings of IEEE International Symposium on PIMRC, Cannes, France, Sept 2008 36. M Dottling, B Raaf, J Michel, Efficient channel quality feedback schemes for adaptive...

Ngày tải lên: 21/06/2014, 03:20

... Hindawi Publishing Corporation EURASIP Journal on Wireless Communications and Networking Volume 2007, Article ID 24595, 2 pages doi:10.1155/2007/24595 Editorial Space-Time Channel Modeling for Wireless ... 0200, Australia 2 Mobile Communications Department, Eur ´ ecom Institute, 2229 Route des Cr ˆ etes, 06904 Sophia Antipolis, France 3 Wireless Signal Processing Program, National ICT Australia (NICTA), ... configuration for the IEEE 802.11n stan- dard. The measurements are done in line-of-sight and non- line-of-sight-cases. These measurements form the basis of a critical rev iew of the validity of...

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Ngày tải lên: 26/10/2014, 14:30

... frequency domain equalization (SCFDE) over a diffuse optical wireless (DOW) communications. Recently orthogonal frequency division multiplexing (OFDM) has been applied to DOW communications. However, ... for use in indoor wireless data transmission [1, 2]. Diffuse optical wireless (DOW) communications offer a viable alternative to radio frequency (RF) communication for indoor use and other applications ... nonlinearity while in DOW communications, the LED is the nonlinear device that l imits the performance of optical OFDM. The nonlinear characteristic of an LED imposes limitations on the performance of indoor...

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... distributed freely for any purposes (see copyright notice below). For information about publishing your research in EURASIP WCN go to http://jwcn.eurasipjournals.com/authors/instructions/ For information ... acknowledgements and RTS/CTS, the WLAN driver overhead and other limiting effects like MAC firmware performance limitations. Therefore, the measured throughput is expected to be smaller than the ... transmitter module provides functionality for the transmit direction and collision avoidance. The receiver fulfils its natural functionality described earlier. The control component is a broker...

Ngày tải lên: 18/06/2014, 22:20

... hierarchical layers: the upper system layer and the lower wireless link layer. The wireless link layer offers a library of wireless link modules to the system layer; the system layer organizes ... the wireless link layer and link QoS. Fig. 3. State Diagram of the Wireless Link Layer A state diagram of the wireless link layer can be illustrated in Figure 3. The wireless link layer ... the wireless link layer and link QoS. Fig. 3. State Diagram of the Wireless Link Layer A state diagram of the wireless link layer can be illustrated in Figure 3. The wireless link layer...

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