遥测遥控实验报告.docVIP

遥测遥控实验报告4 遥测遥控技术 实验四 学院 电子工程 学生姓名：严丰 班级学号：2902107014 指导老师：李 晋 一、实验名称：GPS信号跟踪原理与仿真 二、实验程序： 主程序： function [diata_dll,diata_fll]=tracksignal(iniphcode,inifd,iniph,snr,Code_Method_flag,Carrier_Method_flag,codew,codeb,carrierw,carrierfllb,carrierpllb) svnum = 10; %卫星号 iniphcode = 500; %生成信号源的码相位 inifd = 3000; %生成信号源的载波多普勒频率 iniph = 5; %生成信号源的载波初相位 snr = 0; %生成信号源的信噪比 global time_unit; % 数据跳变时间单位 global time; % 数据发送时间 global time_cyc;% 一个完整扩频码周期 global fs; % 采样率 global nn; % 一个完整扩频周期采样点数 global kk; % 数据总采样点 global F_if; % 载波中频 global CA_freq; % PN码速率 global tc; global CA ; % 扩频码基玛 global F_Carrier; % L1波段载波频率 %%%%%%%%%%%%%%%%%%%%%%%%参数设置%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% time = 100*(10^(-3)); time_unit = 20*(10^(-3)); time_cyc = 1*(10^(-3)); fs = 5*(10^6); nn = time_cyc*fs; kk = (time/time_cyc)*nn; F_if = 1.25*(10^6); F_Carrier = 1575.42*(10^6); CA_freq = 1.023*(10^6); %%%%%%%%%%%生成C/A以供使用%%%%%%%%%% PN = codegen(svnum); CA = []; k = 5; for n = 1:length(PN) CA((1+k*(n-1)):k*n) = PN(n)*ones(1,k); end tc = 1/(k*CA_freq); loop_time = time/time_cyc; %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%生成信号源 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %Signal_Source是生成的信号源, buffer_bit_data是随机生成的数据位，用于与最后解调的数据进行比对 [Signal_Source,Phase_signal,buffer_bit_data]=CreateSource(iniphcode,inifd,iniph,snr); %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%捕获%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% [fd_ac,f_ac_code] = acqu(Signal_Source); %%%%%%%%%%%%%%%%%%%%%%%%%%%%定义跟踪中用到的参数%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% IPSum_old = 0.01; QPSum_old = 0.01; %%%%%%%%%%码跟踪环滤波器参数设置%%%%%%%%%%%%%% Code_Method_flag=2; %码跟踪环鉴相法选择标志 diffoffside = 0.5; %码鉴相时，正负偏移半个码片 k0 =10^(-6); %码跟踪环鉴相器增益 k1=10^(-3); %码跟踪环NCO增益 %k1 = 50/k0; %码跟踪环NCO增益 codew = 20 %自然圆频率 codeb = 2 %阻尼系数