This thesis introduces the elementary concept, evolutive history, working flow and operational principle of secondary surveillance radar and the systemic principle of monopulse secondary surveillance radar . then recommend the structrue and elements of actel ’ fpga and the development and design of fpga based on vhdl . the new responder can detect the video pulse signal upon 100mv and deal with 40 real planes in real time . it also can identify the responding signal of mode a / c and mode 6 and can be swithed freely from one mode to another according to the mode information and transmit the report table of corresponding mode 本論文介紹二次雷達(dá)的基本概念、發(fā)展歷史、工作流程、運(yùn)作機(jī)理以及單脈沖二次雷達(dá)的系統(tǒng)原理。重點(diǎn)介紹了actel公司fpga的結(jié)構(gòu)、原理以及fpga的vhdl實(shí)現(xiàn)。本文介紹的mssr應(yīng)答信號(hào)處理器,可以檢測大于100mv的視頻信號(hào),實(shí)時(shí)處理40個(gè)真實(shí)目標(biāo),并且支持模式ac和模式6應(yīng)答信號(hào),處理過程中可以根據(jù)模式指示信號(hào)在兩種模式下任意切換,送出相應(yīng)模式的報(bào)表。
The new algorithm has three characters : first is that the new algorithm is on the basis of super frame which include 3 continuous simple frames in melp algorithm, the algorithm deal with parameters of a super frame by the mode of the super frame . secondly, two algorithms are introduced for improving vector quantization quality of line spectral frequency ( lsf ) parameter . one is swithed-adaptive inter-frame vector prediction ( sivp ), which can get rid of the correlation between neighboring frames effectively, the other is joint codebook optimization for multi stage vector quantization ( jco-msvq ), which can improve performance of codebook 第二是在制作線譜對參數(shù)(lsf)矢量量化碼本時(shí),引入了目前提高lsf碼本性能的兩個(gè)方法:在利用重點(diǎn)幀對非重點(diǎn)幀作預(yù)測時(shí),借鑒自適應(yīng)幀間矢量量化(sivp)去除相關(guān)性算法的優(yōu)點(diǎn),提出了以固定矩陣去除相關(guān)性的方法,有效的控制了預(yù)測后殘差的動(dòng)態(tài)范圍,提高了對殘差矢量量化的精度;采用聯(lián)合碼本優(yōu)化多級(jí)矢量量化算法(jco-msvq),改良多級(jí)矢量量化碼本的性能。