?%數字下變頻全過程仿真程序?窄帶信號

clear?all;
close?all;
clc;

%?fid_narrow_i?=?fopen（‘E:\ise_project\ddc_top_v2?_2channel\Modelsim_code\data_out_narrow_i.txt‘）;
%?data_narrow_i?=?fscanf（fid_narrow_i‘%d‘）;
%?for?i?=?1:439
%?????if?data_narrow_i（i）?>?2^15
%?????????data_narrow_i（i）?=?data_narrow_i（i）?-?2^16;
%?????end
%??????
%?end
%?fclose（fid_narrow_i）;
%?fid_narrow_q?=?fopen（‘E:\ise_project\ddc_top_v2?_2channel\Modelsim_code\data_out_narrow_q.txt‘）;
%?data_narrow_q?=?fscanf（fid_narrow_q‘%d‘）;
%?for?i?=?1:439
%?????if?data_narrow_q（i）?>?2^15
%?????????data_narrow_q（i）?=?data_narrow_q（i）?-2^16;
%?????end
%?end
%?fclose（fid_narrow_q）;
%?
%?fid_narrow_data_in0?=?fopen（‘E:\ise_project\ddc_top_v2?_2channel\Modelsim_code\narrow_data_in0.txt‘）;
%?fid_narrow_data_in1?=?fopen（‘E:\ise_project\ddc_top_v2?_2channel\Modelsim_code\narrow_data_in1.txt‘）;
%?narrow_data_in0?=?fscanf（fid_narrow_data_in0‘%d‘）;
%?narrow_data_in1?=?fscanf（fid_narrow_data_in1‘%d‘）;
%?for?i?=?1:22000
%?????if?narrow_data_in0（i）?>?2^11
%?????????narrow_data_in0（i）?=?narrow_data_in0（i）?-?2^12;
%?????end
%?????if?narrow_data_in1（i）?>?2^11
%?????????narrow_data_in1（i）?=?narrow_data_in1（i）?-?2^12;
%?????end
%?end
%?num?=?2*length（narrow_data_in0）;
%?for?i?=?1?:?num
%?????if（mod（i2））
%?????????narrow_data_in（i）?=?narrow_data_in1（fix（i/2）+1）;
%?????else
%?????????narrow_data_in（i）?=?narrow_data_in0（i/2）;
%?????end
%?end

fid_wide_i?=?fopen（‘data_out_wide_i.txt‘）;
data_wide_i?=?fscanf（fid_wide_i‘%d‘）;
for?i?=?1:1199
????if?data_wide_i（i）?>?2^15
????????data_wide_i（i）?=?data_wide_i（i）?-?2^16;
????end
end
fid_wide_q?=?fopen（‘data_out_wide_q.txt‘）;
data_wide_q?=?fscanf（fid_wide_q‘%d‘）;
for?i?=?1:1199
????if?data_wide_q（i）?>?2^15
????????data_wide_q（i）?=?data_wide_q（i）?-2^16;
????end
end
fid_wide_data_in0?=?fopen（‘wide_data_in0.txt‘）;
fid_wide_data_in1?=?fopen（‘wide_data_in1.txt‘）;
wide_data_in0?=?fscanf（fid_wide_data_in0‘%d‘）;
wide_data_in1?=?fscanf（fid_wide_data_in1‘%d‘）;
for?i?=?1:60000
????if?wide_data_in0（i）?>?2^11
????????wide_data_in0（i）?=?wide_data_in0（i）?-?2^12;
????end
????if?wide_data_in1（i）?>?2^11
????????wide_data_in1（i）?=?wide_data_in1（i）?-?2^12;
????end
end
num?=?2*length（wide_data_in1）;
for?i?=?1?:?num
????if（mod（i2））
????????wide_data_in（i）?=?wide_data_in1（fix（i/2）+1）;
????else
????????wide_data_in（i）?=?wide_data_in0（i/2）;
????end
end

j=sqrt（-1）;

fsamp=200e6;????%采樣頻率
f0=250e6;???????????%中頻
Ts=1/fsamp;
fc=2e6;????????????%混頻解調信號
band=2e6;?????????%帶寬
%?Tp=220e-6;??????????%脈沖寬度
Tp=600e-6;??????????%脈沖寬度
%??Tp=50e-6;??????????%脈沖寬度
N=Tp*fsamp;
n=0:N-1;
u=band/Tp;??????%u為帶寬除以時寬

%CIC濾波器參數
%???mfilt.cicdecim或者fdesign.decimator
M=25;???%抽取倍數
%?DELAY=1;
%?wp=1;???%通帶衰減
%?ws=90;??%阻帶衰減

t=-Tp/2:Tp/N:Tp/2-Tp/N;

figure_i=1;
%信號源?2Mhz帶寬?中頻250MHZ線性調頻波
%?xs=cos（2*pi*（f0*t+0.5*u*t.^2））;????????%信號表達式
%?%?xs=exp（j*2*pi*（f0*t+0.5*u*t.^2））;%.*（abs（t）<=Tp/2）;
%?xs=awgn（xs30）;
%?xs1?=?rea

?屬性????????????大小?????日期????時間???名稱
-----------?---------??----------?-----??----
?????目錄???????????0??2015-04-20?21:58??radar_ddc\
?????文件????????8393??2015-02-05?18:08??radar_ddc\data_out_wide_i.txt
?????文件????????8393??2015-02-05?18:08??radar_ddc\data_out_wide_q.txt
?????文件????????9454??2015-04-20?16:44??radar_ddc\ddc_2m.asv
?????文件????????9454??2015-04-20?16:51??radar_ddc\ddc_2m.m
?????文件??????360000??2015-02-05?18:08??radar_ddc\wide_data_in0.txt
?????文件??????360000??2015-02-05?18:08??radar_ddc\wide_data_in1.txt