gps.asv

验证功率倒置算法对gps信号中大功率单频信号的消除

clc
clear
out=CA_gen();          % 伪随机序列产生,n=10
num=1023;
message=randint(1,3);    % 信息序列产生
for i=1:length(message)
    if message(i)==0
        message(i)=-1;
    end
end
sign1=[];
for i=1:length(message)
    sign1((i-1)*num+1:i*num)=out*message(i);   % 信息序列与伪随机序列相乘得到的序列
end

fm=62500;%1023; % 伪随机信号速率 1Hz/s
fd=fm/(2^n-1);      % 信息序列的速率
fc=4*fm;     % 载波频率
fsc=4*fc;    % 载波的采样率

mmm=ones(1,fsc/fm);
for i=1:length(sign1)
    sign4((i-1)*fsc/fm+1:i*fsc/fm)=sign1(i)*mmm;
end
t=0:1/fsc:(length(sign4)-1)/fsc;
%c/a
ca=[];
for i=1:1023
    ca((i-1)*fsc/fm+1:i*fsc/fm)=out(i)*mmm;
end
ca=ca.*exp(-j*2*pi*fc*t(1:16368));

%干扰方位角为n_angle，信号方位角为s_angle=pi/4
%干扰仰角为n0_angle, 信号仰角为s0_angle
n_angle=0;            %干扰信号
n0_angle=pi/4;
s_angle=2*pi/3;         %gps信号1
s0_angle=pi/6;
ss_angle=pi/2;        %gps信号2
ss0_angle=pi/3;

s11=sign4.*exp(-j*2*pi*fc*t);
s11=awgn(s11,-20);
s21=sign4.*exp(-j*2*pi*fc*t);
s21=awgn(s21,-20);
n11=10000*exp(-j*2*pi*fc*t);
gps1=s11+s21+n11;
gps1=gps1/max(abs(gps1));

s12=sign4.*exp(-j*2*pi*fc*t)*exp(-j*pi*cos(s_angle)*cos(s0_angle));
s12=awgn(s12,-20);
s22=sign4.*exp(-j*2*pi*fc*t)*exp(-j*pi*cos(ss_angle)*cos(ss0_angle));
s22=awgn(s22,-20);
n12=10000*exp(-j*2*pi*fc*t)*exp(-j*pi*cos(n_angle)*cos(n0_angle));
gps2=s12+s22+n12;
gps2=gps2/max(abs(gps2));

s13=sign4.*exp(-j*2*pi*fc*t)*exp(-j*pi*cos(2*pi/3-s_angle)*cos(s0_angle));
s13=awgn(s13,-20);
s23=sign4.*exp(-j*2*pi*fc*t)*exp(-j*pi*cos(2*pi/3-ss_angle)*cos(ss0_angle));
s23=awgn(s23,-20);
n13=10000*exp(-j*2*pi*fc*t)*exp(-j*pi*cos(2*pi/3-n_angle)*cos(n0_angle));
gps3=s13+s23+n13;
gps3=gps3/max(abs(gps3));

s14=sign4.*exp(-j*2*pi*fc*t)*exp(j*pi*cos(s_angle-pi/3)*cos(s0_angle));
s14=awgn(s14,-20);
s24=sign4.*exp(-j*2*pi*fc*t)*exp(j*pi*cos(ss_angle-pi/3)*cos(ss0_angle));
s24=awgn(s24,-20);
n14=10000*exp(-j*2*pi*fc*t)*exp(j*pi*cos(n_angle-pi/3)*cos(n0_angle));
gps4=s14+s24+n14;
gps4=gps4/max(abs(gps4));
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y=[];
ww1=[];
w1=1;
w2=0;
w3=0;
w4=0;
c=2^(-4);

for i=1:1:(length(gps1)-1)
    y(i)=gps1(i)*w1-(gps2(i)*conj(w2)+gps3(i)*conj(w3)+gps4(i)*conj(w4));
    w2=w2+gps2(i)*conj(y(i))*c;ww1(i)=w2;
    w3=w3+gps3(i)*conj(y(i))*c;
    w4=w4+gps4(i)*conj(y(i))*c;
end

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