Cognitive radio is an intelligent communication system which focus on dynamic spectrum usage rather than fixed spectrum assignment. Cooperative spectrum sensing is a technique for detecting the primary user accurately based on information collected from various secondary users. Energy detection technique for spectrum sensing method is employed to determine the occupancy of the frequency spectru...

Spatial channel networks (SCNs) and related key technologies have been proposed to increase the capacity flexibility of optical networks. We define network resource allocation problem in a static SCN as routing, modulation format (MF), spatial lane, spectrum block assignment (RMSSA) try solve it. In this paper, we derive relationship between traffic bit rate, transmission distance channels, MFs...

The excitation spectrum of the photosynthetic reaction center (PSRC) of Rhodopseudomonas (Rps.) Viridis is assigned by using the SAC(symmetry adapted cluster)-CI(configuration interaction) method. All the chromophores included in the PSRC, bacteriochlorophyll b dimer (special pair, P), bacteriochlorophyll b in Land M-branches (BL and BM), bacteriopheophytin b in Land M-branches (HL and HM), men...

Dynamic flexible grid optical networks have gained much attention because of the advantages of high spectrum efficiency and flexibility, while the performance analysis will be more complex compared with fixed grid optical networks. An analytical Markov model is first presented in the paper, which can exactly describe the stochastic characteristics of the spectrum allocation in flexible grid opt...