| Optical Code Division Multiple Access(OCDMA)technology possess the characteristics of combating interference, high frequency efficiency, security, and simply network protocol, random access, so it is competitive to apply OCDMA to wireless optical access network. Providing a novel access scheme for solving"last mile"wideband access and global person communications.In wireless optical code multiple access (W-OCDMA)network, Media Access Control(MAC)is a key issue, which determines network performance,bandwidth efficiency,complexity and cost of terminal. Aiming at this issue, on the base of an in-depth study on existing MAC protocols, this thesis exploringly researched on MAC protocols in W-OCDMA access network. The main results are as follows:1. Expatiating on the principle and key technologies of W-OCDMA system. Based on different services in access network, constructed single-length and multi-length OOC. We carried on the simulation to the designed fiber delay line encoder/decoder. The performance of single-length and multi-length OOC W- O C D M A.system were analyzed in detail.2. Several kind of typical MAC protocols in access network were analyzed. Investigating and comparing the characteristics among TDMA,WDMA,CDMA ; Random multiple access protocols such as ALOHA were analyzed; Slotted ALOHA-CDMA multiple access protocol was analyzed too.3. We investigated the topology framework and the MAC protocol in wireless optical CDMA access network.The network throughput for slotted ALOHA- CDMA protocol was derived and analyzed. Aiming at the issue that network has low throughput at high offered payload, this thesis put forward Modified Channel Load Sensing Protocol (MCLSP), the proposed protocol was proved effective in improving network throughput.4. We set up the W-OCDMA system experiment platform, carried through the experiment of W-OCDMA, demonstrated 622Mbps Fast Frequency Hopping (FFH) encoding/decoding experiment with FBG encoder/decoder. The experiment results... |
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