Báo cáo hóa học: " Research Article Channel Sensing without Quiet Period for Cognitive Radio Systems: A Pilot Cancellation Approach" ppt

... source and/or channel coding block. Thus, the channel measurement reporting for channel adaptation mechanism (e.g., the power control and the adaptive modulation and coding) is usually carried ... out frame-by-frame basis. If the channel condition changes largely during a frame, the channel estimation is likely to be inaccurate, and the system performance can be severely degrade...

Ngày tải lên: 21/06/2014, 05:20

... it shall compute a backoff delay based on a random number of backoff period and performs CCA (clear channel assessment) before accessing to the channel. If the channel is busy, both NB and BE are ... 136–139, Lausanne, Switzerland, July 2009. [27] A. Mehta, G. Bhatti, Z. Sahinoglu, R. Viswanathan, and J. Zhang, “Performance analysis of beacon-enabled IEEE 802.15.4 MAC for emergenc...

Ngày tải lên: 21/06/2014, 05:20

... optical recording system for simulation. An 8-state transition diagram, as depicted in Figure 7 (a) , can describe the EPRII optical channel. During simulation, a Gaussian optical recording channel ... [2–9], whichcanbetreatedasa(0,k) modulation code, has recently been studied for partial response channels. The TMTR code matched to the partial response channel can delete some domin...

Ngày tải lên: 21/06/2014, 08:20

... physical and MAC overheads are fixed for each frame and the transmission rate variation has no impact on these overheads. The VoIP frame payload which is small has little impact on the total transmission ... used for performance analysis in WLANs. In particular, time is slotted and each state represents a station or AC in a particular time period. At each state, a transition is trig...

Ngày tải lên: 21/06/2014, 11:20

... Germany, 2009. [5] X. Kang, Y C. Liang, A. Nallanathan, H. K. Garg, and R. Zhang, “Optimal power allocation for fading channels in cognitive radio networks: ergodic capacity and outage capacity,” ... much larger than π NSA , especially when the channel s state switches slowly (namely, μ and λ are small), and is always larger than π PA , especially when the channel s state switches fa...

Ngày tải lên: 21/06/2014, 11:20

... − 1 π  H  a, b  , 2.24 for all a, b > 0witha /  b. 2 Journal of Inequalities and Applications Let C a, b a 2 b 2 / a b ,A a, b a b/2,G a, b √ ab,andH a, b2ab/ a b be the contraharmonic, ... Inequalities and Applications, vol. 2006, Article ID 46782, 25 pages, 2006. 21 T. Hara, M. Uchiyama, and S E. Ta kahasi, “ A refinement of various mean inequalities,” Journa...

Ngày tải lên: 21/06/2014, 05:20

... transmission gap, termed Rate-Based. The Rate-based is more suitable for delivering real-time trafficbecauseit can provide a more smooth transmission rate and it has no need to wait for an ACK message from ... results are shown in Figure 7(b) for an arrival rate between 0.08 (flows/sec) and 0.1 (flows/sec). The reason is the same as varying the CBR arrival rate case that a ects frame var...

Ngày tải lên: 21/06/2014, 05:20

... the CIMA reaction,” Transactions of the American Mathematical Society, vol. 357, no. 10, pp. 3953–3969, 2005. 29 P. Pang and M. Wang, “Qualitative analysis of a ratio-dependent predator-prey ... Venturino, Spatiotemporal Patterns in Ecology and Epidemiology, Chapman and Hall/CRC Press, Boca Raton, Fla, USA, 2008. 2 R. S. Cantrell and C. Cosner, Spatial Ecology via Reaction-Diffusion Equa...

Ngày tải lên: 21/06/2014, 05:20

... fractional delay is necessary for precise time alignment of the two bands. A good fit for this purpose is a standard all- pass interpolated fractional delay line. However, in contrast to usual applications ... where a specific fractional delay time at DC is required, we need to match a particular fractional delay at an arbitrary frequency. The equation specifying the group-delay of...

Ngày tải lên: 21/06/2014, 05:20

... the arbitrary measure and Markov measure on the generalized Bethe tree. As corollaries, a class of Shannon-McMillan theorems for arbitrary random fields and the Markov chains field on the generalized ... pages doi:10.1155/2011/470910 Research Article Some Shannon-McMillan Approximation Theorems for Markov Chain Field on the Generalized Bethe Tree Kangkang Wang 1 and Decai Zong 2 1 Sch...

Ngày tải lên: 21/06/2014, 05:20