LMDS系統是使用在20-50GHz Ka Band之雙向細胞通信系統，其提供語音、多媒體及數據傳輸之等服務。但是，在Ka Band的LMDS系統，雨衰及細胞內干擾是影響通訊品質的重要因素。 為了減少LMDS系統中雨衰和細胞內干擾的問題，我們提出基於模糊邏輯相容碼率打孔渦輪碼改進LMDS系統的效能。根據系統的環境，利用模糊邏輯來調整渦輪碼碼率減少冗餘位元和改進頻譜效益。模擬結果顯示在沒有降低BER的狀態，相容碼率打孔渦輪碼在區域多點分配服務系統相較於沒有打孔的渦輪碼擁有較高的效益。 LMDS system is a two-way digital cellular system operating in 20-50 GHz of Ka Band. LMDS offers the services of the audio, video, multimedia and data transmission. However, rain attenuation and inter cell interference (ICI) influence the factor of Quality of Service (QoS) in LMDS system. In order to reduce the impacts of rain fade and of inter cell interference on LMDS systems, we propose Fuzzy logic-based rate compatible punctured turbo codes to improve the performance of LMDS systems. In accordance with the system situation, we use fuzzy logic to adjust the code rate to reduce the redundancy bit and to improve the system efficiency. Simulation results show that the proposed rate compatible punctured Turbo code for LMDS systems compared with unpunctured Turbo code scheme leading an improvement of system efficiency when the BER do not be reduce.
