- 學位論文
具動態調變編碼機制之無線通訊系統設計與分析
Design and Analysis using velocity-specific Modulation and Coding Mechanism in Wireless Communication System
摘要
適應性調變與編碼(Adaptive Modulation and Coding, AMC)，利用通道變動進行系統的調整，以得到好處。行動台在移動狀態時，期間受到各種通道干擾，當接收訊號越來越差時，為了想要維持住行動台之良好的服務品質，基地台可以可調式的改變適合的調變及編碼技術，以維持與行動台傳輸的良好服務品質，以確保資料能正確傳送。 提出新一代無線通訊系統IEEE 802.16m及LTE適用之調變及編碼的結構(Modulation and Coding Scheme, MCS)模組，在不考慮各種重傳(Automatic Repeat Request, ARQ)機制下，由於AMC控制器需根據接收端訊雜比值(Signal-to-noise ratio, SNR)，有效率的控制發射的調變率和編碼比率，所以需發展出一套合理的調變和編碼策略，透過精細的SNR值界定合適調變和編碼。由於行動台不同的移動速度下其效能表現不盡相同，所以其SNR界限值也會有所不同，模擬不同速度之通道狀態下適應性調變和編碼的SNR界限值。 將提出考慮行動台移動速度下之動態適應性調變及編碼技術機制方式，整合入開發出的基地台流量模擬GUI介面軟體，提供基地台在選擇適用調變和編碼方式與行動台溝通時的選擇機制，協助此GUI介面軟體開發完善。
並列摘要
When a user moves during his information transmission the users received signal strength will encounter various kinds of fading and interference effects. In order to maintain a good and acceptable signal quality at the receiver end, the base station and/or the mobile station may use Adaptive Modulation and Coding (AMC) mechanism to adaptively change and select its modulation scheme and coding rate to accommodate the varying communication environment. We propose a new Modulation and Coding Scheme (MCS) for the now being developed future wireless mobile communications, IEEE 802.16m and LTE. Without considering the Automatic Repeat Request (ARQ) mechanism the AMC controller will base on its received Signal-to-noise ratio (SNR) to adjust the transmitter’s modulation scheme and coding rate. From the possible SNR threshold ranges and its statistical characteristics generating from the simulation of the channel responses when the mobile speed changes we develop a reasonable and feasible Modulation and Coding adjustment strategy that varies with the changing of the channel characteristics. Finally we propose a dynamic and adaptive Modulation and Coding mechanism when the mobile speed is taken into consideration in the design of the modulation and coding scheme. We also develop the interface software for the Graphical User Interfaces (GUI) to provide a proper interface in the design of the dynamic and adaptive Modulation and Coding scheme when the base station is communicating with the mobile station.