Voice encoders may be further enhanced by encoding digital signals at variable encoding rates 語音編碼器可以通過在可變編碼率編碼數字信號進一步加強。
At the present time , evrc is the best vocoder in the cdma system when take into account both the voice quality and the encode rate 在目前的cdma系統中,綜合語音質量和編碼速率, evrc是最佳的語音編碼器。
The evrc vocoder is varialbe rate , the maximal encode rate is skbps , its voice quality is closed to qcelp - 13k , and has better ability of anti - disturbance Evrc聲碼器是可變速率的,最大編碼速率為8kbps ,在話音質量上接近于qcelp - 13k的語音編碼器,且具有更好的抗干擾能力。
In the proposed method , the controller takes the buffer length as congestion indication , takes sources quality and bandwidth utility as object function so as to learn on line . as the controller outputs , the coding rate for input traffic sources and the corresponding user percentage are used to adjust the cells " arrival rate to the multiplexer buffer . compared with the previous method where cells " arrival rate is tuned only by the encoding rate and the encoding rates for all input traffic sources are regulated in a body , the proposed method guarantee that the quality of cells are optimal while cell loss rate is minimized , which means quality of service is guaranteed 在該方法中,擁塞控制器以緩沖區大小信元作為擁塞指示,以信源質量和帶寬利用率作為目標函數進行在線學習,控制器輸出包括信源編碼率及其對應的用戶數在全部用戶中所占的百分比,即根據信源編碼率及對應的用戶百分數調整信源輸入流,從而克服了以往擁塞控制方法中僅僅調整編碼率帶來的對所有信源進行整體調整的缺陷,使控制系統在信元損失率最小情況下確保信源輸入流質量最高,從而有效地利用了網絡帶寬。
To meet the needs of the third mobile communication system for higher speech quality and greater system capacity , the cdma systems employ variable rate speech coding technologies , which select the encode rate dynamically according to the signal energy and background noise . this method insures the speech quality as well as reduces , the average encode rate , so the system capacity is increased 為了滿足第三代移動通信系統對高質量語音和大容量系統的需要,在cdma系統中普遍采用了變速率語音編碼技術,根據話音的信號能量和背景噪聲動態地決定編碼速率,這種方法既保證了話音的質量,又降低了平均編碼速率,從而增加了系統容量。