multiple access techniques for wireless communication rappaport ppt

Ngày tải lên: 11/07/2014, 21:20

Ngày tải lên: 22/06/2014, 19:20

... interests include multiple access techniques, estimation theory, multi-user detection and channel modeling. “I am extremely grateful to my parents for the sacrifices they have made and for imparting ... of wireless telecommunications, a number of trends are gaining widespread popularity. Among these is the explosion of interest in multi-carrier communications, and its application to wireless multiple- access. ... mobiles from TDMA (time division multiple access) to DS-CDMA (direct sequence code division multiple access) to MC-CDMA to OFDM, while maintaining a common hardware platform. In this chapter, we demonstrate...

Ngày tải lên: 02/03/2013, 16:59

... 44 2.5.3 Wireless Local Area Network (WLAN) Standards 46 2.6 Summary 48 3 Multiple Access in Cellular Communication Systems 49 3.1 Multiple Access and the OSI Layers 49 3.2 Basic Multiple Access ... Protocol for Hybrid CDMA/TDMA 12 1.4.1 Why Combine CDMA and PRMA? 12 1.4.2 Hybrid CDMA/TDMA Multiple Access Schemes 14 1.4.3 Literature on Multiple Access Protocols for Packet CDMA 15 1.4.4 Access ... individual portions of its resources to support multiple communications, basic multiple access techniques (such as frequency-, time-, or code-division multiple access, with FDMA, TDMA, and CDMA as their...

Ngày tải lên: 02/03/2013, 16:59

... p erform flavor stabilit y studies. At the present time, the two most common procedures reported in the literature for the isolation of the aromatics are headspace methods and extraction. The former ... transferred. Consequently, for very low levels of analyte concentration in the original sample material, static headspace techniques may lack the sensitivity required for the determination. Elevating ... reasons for this include simplicity of operation, no need for complex apparatus, reproducibility, rapidity, and the range of samples that can be handled. Steam distillation works best for compounds...

Ngày tải lên: 17/02/2014, 10:20

Ngày tải lên: 29/03/2014, 20:20

... circuits. Fundamentals of microfabrication techniques employed for making AlN CMR are briefly introduced. Different methods for arraying these devices and form either electrically or mechanically ... increasing recent interest in wireless applications [41–43] has generated new efforts to miniaturize and integrate the off-chip passives needed for filtering and frequency generation in communication circuits. ... therefore enabling multiple frequencies of vibration on the same silicon chip and greatly reducing manufacturing tolerances to film thicknesses. In general, the equivalent circuit representation for...

Ngày tải lên: 30/03/2014, 07:20

... algorithm for highly uniform cluster formation,” in European Workshop on Wireless SensorNetworks (EWSN 2004), Jan. 2004. [30] S. Soro and W. B. Heinzelman, “Cluster head election techniques for coverage ... detected events in the lowest and highest sensing ranges for the case of 25% of message loss is 35% for FEDand 42% for [27]. The results for the case of 15% of message loss also support the idea. ... International Journal of Wireless & Mobile Networks (IJWMN) Vol. 3, No. 6, December 2011 40 events. The results show thatFED performs better in all the sensing ranges. For instance, FED detects...

Ngày tải lên: 30/03/2014, 16:20

... concept holds true for single channel. For multiple channel case, it is easy to iterate for C wmn in a WMN. If each channel has the same characteristics, then it is sim- ply c ì C wmn for c subchannels. ... D-cluster formation in wireless ad hoc networks, in Proceedings of the IEEE International Conference on Computer Communications,32–41 (2000) 27. S Banerjee, S Khuller, A clustering scheme for hierarchical ... doi:10.1007/978-3-540-71805-5_18 34. IEEE 802.16 - Standard for local and metropolitan area networks, Part 16: Air Interface for Broadband Wireless Access Systems (2004) 35. H-Y Wei, S Ganguly, R Izmailov,...

Ngày tải lên: 20/06/2014, 22:20

... the dynamics of wireless communications, the frequent failures of sensor nodes and the variety of the applications for wireless sensor networks. Some testbeds or test platforms for wireless sensor ... disturb the wireless communications of the wireless sensor network at all. Therefore HINT has no size effects on the spontaneous network behavior and it is a nonintrusive testbed for wireless sensor ... networks must be consumed for the purpose of collecting test data. Obviously, the test platforms of the latter category do not disturb the wireless communications of wireless sensor networks at...

Ngày tải lên: 21/06/2014, 17:20

... TIME-HOPPING MULTIPLE ACCESS PPM OR PAM UWB SYSTEM With more than one user active in the system, multiaccess interference (MAI) is a major factor limiting performance and capacity, particularly for a ... theorem. This allows the capacity analysis given in Section 3 for a single user to be extended to a multiple- access system. 4.1. Multiple- access interference model Asgivenin(4), the received signal ... Journal on Wireless Communications and Networking Volume 2008, Article ID 273018, 9 pages doi:10.1155/2008/273018 Research Article Capacity of Time-Hopping PPM and PAM UWB Multiple Access Communications...

Ngày tải lên: 21/06/2014, 22:20

... standard for Information Technology—Telecommunications and information exchange between systems—Local and metropolitan area networks— Specific requirements, Part 15.4 Wireless Medium Access Control ... link. Therefore, 6 EURASIP Journal on Wireless Communications and Networking 0 1 2 3 4 5 6 7 8 9 10 Hops R = 6 R = 8 R = 12 ALG1 ALG2 ALG3 Figure 6:Averagenumberofhopstogetoneproxyforascenario with ... outperforms both Noureddine Mehallegue et al. 9 Table 1: Comparison of ALG1, ALG2, and ALG3. ALG1 ALG2 ALG3 Resolve the path key establishment problem for WSNs Suitable for sparse WSNs Suitable for...

Ngày tải lên: 21/06/2014, 22:20

... considered for such systems [15]. These works show performance improvement over the conventional single- input single-output (SISO) UWB systems for commonly adopted modulation and multiple- access techniques, ... transmitted power is E. For simplicity, the random time-hopping (T H) codes for multiple access are omitted ([13]). A class of unitary space-time signals is proposed in [16] for flat-fading channels ... and A. R. Calderbank, “Space-time codes for high data rate wireless communication: performance criterion and code construction,” IEEE Transactions on Infor- mation Theory, vol. 44, no. 2, pp....

Ngày tải lên: 21/06/2014, 22:20

... and M. B. Pursley, “Error probabilities for slow-frequency-hopped spread-spectrum multiple- access communications over fading channels,” IEEE Transactions on Communications, vol. 30, no. 5, part ... Einarsson, “Coding for a multiple- access frequency- hopping system,” IEEE Transactions on Communications, vol. 32, no. 5, pp. 589–597, 1984. [4] A. W. Lam and D. V. Sarwate, Multiple- user interference in ... that the optimal hop for the coded FHSS system over Rayleigh fading channel is m = 32, for all the number of users. In Figure 10, the same information shown in Figure 9 is shown for Rician fading channel...

Ngày tải lên: 21/06/2014, 23:20

... 4 EURASIP Journal on Wireless Communications and Networking Table 1: Notation. h() Use for the one-way hash function of key generation a j , a j−1 Two parameters for generation of key pre-deployed ... Corporation EURASIP Journal on Wireless Communications and Networking Volume 2008, Article ID 691571, 10 pages doi:10.1155/2008/691571 Research Article Dynamic Session-Key Generation for Wireless Sensor Networks Chin-Ling ... 2008 Recommended by Jong Hyuk Park Recently, wireless sensor networks have been used extensively in different domains. For example, if the wireless sensor node of a wireless sensor network is distributed...

Ngày tải lên: 21/06/2014, 23:20

... protocol that mitigates congestion while providing general event information, per-node event information, and prioritized event information for multiple events. Moreover, MCCP associates a schedule-based ... general event region information, per-node event information, or multiple events information, and so forth. Consider a WSN working inside a mine for the purpose of environmental monitoring and control. ... Fapojuwo Wireless sensor networks are application-dependent networks. An application may require general event region information, per- node event region information, or prioritized event information...

Ngày tải lên: 21/06/2014, 23:20

... transmitted off-line 50 times (for statistical purposes) over the IEEE 802.11 PHY layer for a wide range of fixed C/N power levels. For each sequence, for each GOP, and for each C/N, the average received ... known link adaptation techniques such as ARF, for a given received signal level trace. Validations of our approach will be performed using a real-time experimental platform. ACKNOWLEDGMENTS This ... “Cross-layer wireless multimedia transmission: challenges, principles, and new paradigms,” IEEE Wireless Communications,vol.12,no.4,pp. 50–58, 2005. [5] “IEEE Standard 802.11b—part 11: wireless LAN...

Ngày tải lên: 22/06/2014, 01:20

... window or kernelwhichwouldperformwellforallsignals.Akernel might perform very well for a certain class of signals but is not optimal for other types of signals. For optimal TFR, the selection ... representation for the ASK signal will also be represented based on the same binary sequence of “1101,” for simplicity, and the modulation parameters defined in Section 2. For this signal, f k = f 0 for ... kernel parameters that can give the optimal performance for every performance measure used in this paper, simultaneously. Thus, we can conclude that for the best TFR, the lag-window width and the...

Ngày tải lên: 22/06/2014, 01:20

Ngày tải lên: 22/06/2014, 19:20

Ngày tải lên: 22/06/2014, 19:20