| 摘要: | 在本篇論文中，我們實現了一個數位有限脈衝響應多階多速率之濾波器/降頻器/升頻器模組產生器。使用者能夠藉由此產生器，自動設計出高速低複雜度的數位有限脈衝響應多階多速率濾波器。此產生器利用線性相位濾波器的對稱性架構，並運用多階多速率IFIR濾波器的方法，以達到低複雜度之目的。運用polyphase representation將濾波器分解成多個子濾波器。所產生的濾波器，利用CSD乘法器、transposed direct式架構、和CSA以達到高速的要求。此產生器只需要系統規格為了擁有良好的適應性，輸出的程式碼將以可合成的行為階層硬體描述語言撰寫，讓合成工具軟體能依據使用者所指定的條件選擇最適合的架構。 我們提供了一個用於64-QAM基頻解調器的濾波器設計實例。使用Synopsys的合成工具並採用TSMC 0.25μm製程設計晶片。結果在低複雜度應用方面，減少了1.64倍的面積並節省1.95倍的功率消耗。而對於高速應用方面，此晶片能操作在714 MHz。除此之外，我們以此模組產生器設計一個CDMA規格之多階濾波器(IFIR filters)的例子，與傳統濾波器設計相比較，結果減少了1.72倍的硬體面積，節省13.10倍的功率消耗。並且以相同之規格設計一個多階多速率之降頻器，用運IFIR與polyphase representation之設計技巧，與傳統的降頻器設計相比較，結果減少了3.56倍的硬體面積，節省1.96倍的功率消耗。最後，我們還實現一個窄頻的多階多速率之升頻器，與傳統的升頻器設計相比較，結果減少了3.06倍的硬體面積，節省1.36倍的功率消耗。 In this thesis, a module generator, which can automate the process of designing high-speed low-complexity multirate multistage digital FIR filter / decimator / interpolator, is presented. The generator exploits architectural symmetries in linear phase filters and multistage multirate interpolated FIR filter design methodology for low complexity. In addition, the polyphase representation is used to decompose the filter into subfilters. The resulting filters utilize canonic signed digit (CSD) multipliers, a transposed direct form structure, and carry-save addition for high speed. The input of the generator requires only system-level specifications. In addition, the generator can provide three types of filter structure for different applications. Moreover, the output is a synthesizable Verilog code written in behavioral-level hardware description language (HDL) which allows the synthesis tool to select the appropriate architecture from user’s constraints. Therefore, this tool can eliminate manual calculations, coding, simulation, and verification time of the design cycle. We have designed several filters with TSMC 0.25μm standard cell. A 64-QAM baseband design example shows that the area is reduced about 1.64 times and the power dissipation is saved about 1.95 times for low-complexity applications. Moreover, for high-speed application, the chip can operate at 714MHz. Besides, we design the IFIR filters which specification is the first version of the CDMA cellular, the area is reduced about 1.72 times and the power dissipation is saved about 13.10 times as compared with direct form design. An example of multistage decimator used in CDMA cellular shows that the area is reduced about 3.56 times and the power dissipation is saved about 1.96 times as compared with conventional decimator. Finally, an example of the narrowband multistage interpolator are designed, the area is reduced about 3.06 and the power dissipation is saved about 1.36 times as compared with conventional interpolator. |
