第1个回答 2012-05-12
Optical code division multiple access (OCDMA) communications with a strong anti-jamming, privacy, and fully utilize the bandwidth of fibre and advantages of great capacity, random access asynchronously, the current all-optical access technology research [1-3]. In General orthogonal modulation technology, domain/site domain (that is, phase/amplitude modulation) combination of orthogonal modulation format received widespread attention and in-depth study, such as BPSK/OOK[4], DPSK/OOK[5-6],DQPSK/OOK[7], have somebody research IRZ/OOK[8] and FSK/IM[9] orthogonal modulation, but given its obvious technological disadvantages, and not a cause for further concern. This major study of orthogonal modulation combined phase/amplitude modulation, phase modulation format primary investigation DQPSK and study on amplitude modulation format primary PPM. Based on DQPSK/PPM then modulation technology of one-way OCDMA-PON system programme, apart from by with then modulation technology is different from Yu figure 1 by shows programme structure figure in the of DQPSK/OOK combination zhiwai, other part full as, and DQPSK/PPM then modulation technology in fourth chapter in the has do had more of describes, its implementation method and and DQPSK/OOK combination of difference also for has focus description, so in Figure 1 by shows system structure figure Foundation Shang, we just with DQPSK /PPM modulation technology replaces one of DQPSK/OOK modulation technique, to get your WDM/OCDMA-PON system based on orthogonal modulation DQPSK/PPM.本回答被提问者采纳
第2个回答 2012-05-12
Light code division multiple access (OCDMA) communication has the advantages of strong anti-interference, good secrecy, make full use of optical fiber bandwidth, large capacity, random asynchronous access etc, and become the all optical access technology research hot spot [1-3].
Common orthogonal to modulation, the phase domain/picture domain (i.e. phase-modulation/am) of orthogonal modulation format combination to get people's attention and thorough research, such as BPSK/OOK [4], DPSK/OOK [5-6], DQPSK/OOK [7], etc, and some studies the IRZ/OOK [8] and FSK/IM [9] of orthogonal and modulation technology, just as the more obvious technical disadvantage, and Light code division multiple access (OCDMA) communication has strong anti-interference, good secrecy, make full use of optical fiber bandwidth, large capacity, random asynchronous access etc, and become the all optical access technology research hot spot [1-3].
Common orthogonal to modulation, the phase domain/picture domain (i.e. phase-modulation/am) of orthogonal modulation format combination to get people's attention and thorough research, such as BPSK/OOK [4], DPSK/OOK [5-6], DQPSK/OOK [7], etc, and some studies the IRZ/OOK [8] and FSK/IM [9] of orthogonal and modulation technology, just as the more obvious technical disadvantage, and there is none that can cause further attention from people.
This paper mainly studies phase-modulation/an am a quadrature combination, phase modulation format main investigation domain DQPSK and modulation amplitude domain format mainly inspects PPM.
Based on DQPSK/PPM again modulation technology one-way OCDMA system solution-PON, in addition to modulation technology used different from figure 1 scheme of the structure of the DQPSK/OOK outside combination, and the other part just the same, and DQPSK/PPM again modulation technology in chapter 4 has made the detailed introduction, its realization methods and DQPSK/OOK combination of the difference between the key that also, so in figure 1 based on the structure of the system, we need to use DQPSK/PPM again modulation technology replace one of the DQPSK/OOK and modulation technology, you will get DQPSK/PPM based on orthogonal to modulation technology of WDM/OCDMA-PON system diagram.
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