The Research Of Algorism For Eliminating The Crosstalk In DWDM

In DWDM optical transport networks, optical crosstalk has great impacts on communication performance, and becomes one of the most important factors when designing optical network, which is also researched by many research institutions. In this thesis, OXC technique is analyzed, and a measure for eliminating intraband crosstalk in OXC is proposed in details. Major subjects in this thesis are discussed as follows:Development of optical networks is presented, and function, application, development trend and key technology in DWDM and OXC are introduced. Crosstalk in DWDM optical transport networks is analyzed, and intraband crosstalk is figure out to be a restrictive factor that affect optical communication, which also become the main point our project focus on. Diverse optical switching matrixes are presented, including Crossbar,Omega,Crossover,Banyan and so on. The features in different switching matrixes are discussed. Matrix theory is analyzed on the example of Crossover. Equivalence of topology in different switching matrixes is derived at last.Crosstalk characteristic in dilated Benes (DB) switching network, principally in a special architecture of modified dilated Benes (MDB) is investigated in this section. Based on the DB, an idea of studying routing through transmission matrix and structure matrix is put forward. Intraband crosstalk can be eliminated through routing optimized with this algorithm, then this algorithm is extended to N×N DB. Intraband crosstalk can be eliminated completely in MDB, and can also be eliminated greatly in DB with this algorithm.On the base of DB switching network, feasibility of reducing the number of ON-OFF switches is investigated in cases of special signal wavelength, such as all the wavelengths of input signals are equal. The software of " 8×8 optical switching analyzer " is developed. The development idea and theory is introduced, and the implementation of control module is present principally, which include two parts: one is communication between PC and optical switching module for transferring the states of optical switch; the other is to detect optical signal and send feedback to PC. Control protocol is put forward in order to assure the communication between PC and control system.An OXC Architectures with wavelength conversion capability is proposed, in which the number of wavelength converters (WCs) is optimized by means of WC sharing. The effectiveness of the number of WCs and the bandwidth of WC for blocking probability is individually investigated through simulation .It is concluded that blocking probability and cost of OXC can be improved by optimizing the number of WCs and the bandwidth of WC.