| Summary: | 碩士 === 國立中央大學 === 通訊工程研究所碩士在職專班 === 96 === In every microwave transmission technology, LMDS can be said and receive the note purpose most. LMDS system is a two-way digital cellular system operating at 20-50 GHz. It offers the multiple services of the audio, video, multimedia and data transmission and can meet all kinds of
users'' demands. However, it is to influence the important factor in LMDS system which is rain attenuation and inter-cell interference (ICI).
Therefore, LMDS is affected the interference problem by rain attenuation and inter-cell interference (ICI). Avoiding the band-width unnecessary waste, we proposed new idea that is the fuzzy-based rate compatible LDPC code for LMDS system. It utilized fuzzy control and according to the LMDS system channel quality to determine the code ate. We simulated the LMDS system interference factors such as rain attenuation, Cross-Polarization Discrimination (XPD) and beam-width. Those factors will be influence the LMDS system performance.
The fuzzy membership function and fuzzy rule was defined by LMDS simulation results. And we implement the LDPC code of error correction coding to increasing the system performance and reduce the redundancy bit. Base on LMDS system does not loss Bit-Error-Rate and got the good spectrum efficiency.
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