Báo cáo hóa học: "Location based spectrum sensing evaluation in cognitive radio networks" pptx

... component of the emerging cognitive radio networks. In this article, we study the spectrum sensing problem jointly taking the fad- ing and the location of SUs into account. We obtain the overall average ... Consequently, the spectrum sensing with jointly taking the fading and location of SUs into account is more suitable for the small scale network. Concluding remarks Spectrum...

Ngày tải lên: 21/06/2014, 00:20

... in Chinacom 2010. Author details 1 Department of Electronic Engineering, Tsinghua University, Beijing, 100084 P. R. China 2 School of Aerospace, Tsinghua University, Beijing, 100084 P. R. China Received: ... (selection indication) is included in the head of each relay-packet. Matching the instantaneous code grap h, the destination will generate an ad aptive decoder to perform message-pass...

Ngày tải lên: 20/06/2014, 22:20

... preemptive mechanism in joint leasing and sensing -based CRNs. Keywords: cognitive radio networks, joint leasing and sensing, non-preemptive mechanism, QoS tradeoff 1. Introduction Cognitive radio (CR) ... sensing -based access model , leasing -based access model, and joint leasing and sensing -based access model. In sensing -based CRNs [2-5], SUs acquire the informa...

Ngày tải lên: 20/06/2014, 22:20

... Trans Inform Theory, 51 , 3037–3063 (2005) 20. VA Bohara, SH Ting, Preliminary measurement results for cognitive spectrum sharing based on cooperative relaying. in Proceedings of International International ... Jafar, I Maric, S Srinivasa, Breaking spectrum gridlock with cognitive radios: an information theoretic perspective. in Proceedings of IEEE. 97, 894–914 (2009) 13. Y Han,...

Ngày tải lên: 21/06/2014, 03:20

... performance costs in terms of processing and networking overhead for the in- creased security that it offers. In this paper, we examined the certification process for clustering routing protocols in ad hoc ... message also contains tables carrying infor- mation about the neighboring nodes and adjacent clusters. These HELLO messages are useful for maintaining up-to- date two-hop topology...

Ngày tải lên: 23/06/2014, 00:20

... studied, both in point-to-point and relay communication systems. Typical combining schemes include maximal ratio combining (MRC), equal gain combining (EGC), and selection combining (SC). Since SC ... for coherent communica tions. Since obtaining the channel state information (CSI) in coherent commu- nications might be unrealistic in fast fading environment and in multiple-relay ne tw...

Ngày tải lên: 20/06/2014, 22:20

... policy follows waterfilling on channel SNR, that is, P  i increases with increasing ζ i ;andforζ i >ζ (o) i , the power allocation is according to inversion in the channel SNR, that is, increasing ζ i decreases ... work may also include the power consumed in the sensing, preparing the observation for transmission and in the receiving processes. Appendices A. Proof of Reconstruction...

Ngày tải lên: 21/06/2014, 17:20

... distributions for the desired link and interfering link, such as the Rayleigh for the channel envelope of the desired link, and Rician for the interfering link, or vice versa. Using (3)and(5), the SIR ... computational complexity involved in solving multiple integrals in SIR computation. But, a major shortcoming of these and other similar papers [7] is that, only the small-scale fading or...

Ngày tải lên: 21/06/2014, 22:20

... number of node-disjoint path between S and T. As a limit of node-disjoint multipath routing, the above relationship shows the intrinsic constraint of minimizing r and maximizing a at the same time. ... canceling flow- generating cycles can be interpreted as rerouting flow from its current paths to the highest-gain paths. An efficient algorithm for computing a most improving augmenting path based...

Ngày tải lên: 21/06/2014, 23:20

... satisfying a minimum rate constraint for each user. The problem was formulated as an integer programming problem and a continuous-relaxation- based suboptimal solution method was studied. In [4], ... planning for cellular networks with cooperative relays [1], considering the randomness of channel gains between three types of links formed in cooperative relaying as shown in Figure 1....

Ngày tải lên: 22/06/2014, 00:20