扩频通信技术

主程序
clc;clear all;close all
T=1;Rb=20;fs=1e5;t=1/fs:1/fs:T;
Tr=fs/Rb;n=64;N=Rb*T;Rbc=Rb*10;
Trc=fs/Rbc;a=randint(1,N);
cd=randint(1,10*N);
a(find(a==0))=-1;
cd(find(cd==0))=-1;
for i=1:N
st((i-1)*Tr+1:i*Tr)=a(i);
end
for i=1:10*N
ct((i-1)*Trc+1:i*Trc)=cd(i);
end
kst=st.*ct;
plot(kst);
c_2=kst(Trc/2:Trc:end);
c_2(find(c_2==-1))=0;
c_4=c_2(1:2:end)*2+c_2(2:2:end);
for i=1:length(c_4)
s_4((i-1)*2*Trc+1:i*2*Trc)=c_4(i);
end
qsig=QPSKmod(s_4,t,2000);
a0=QPSKdemod(qsig,t,2000,Trc);
for i=1:length(a0)
s_40((i-1)*2*Trc+1:i*2*Trc)=a0(i);
end
for i=1:length(a0)
c2(2*(i-1)+1):2*i)=dectobin(a0(i),2);
end
c2(find(c2==0))=-1;
c0=c2.*cd;
for i=1:length(c0)
sct((i-1)*Trc+1:i*Trc)=c0(i);
end
subplot(2,1,1)
stem(st(Tr/2:Tr:end))
subplot(2,1,2)
stem(sct(Tr/2:Tr:end))
错误：
??? Error: File: dectobin.m Line: 1 Column: 24
Unbalanced or misused parentheses or brackets.
Error in ==> DCkuopin at 30
c2(2*(i-1)+1:2*i)=dectobin(a0(i),2);
function函数
function c2=dectobin(a0(i),2)
c2=zeros(1,n);
a0(i)=y0;
if y0=0
n=ceil(log2(y0));
a0(i)=y0;
for j=1:n1
c2(n+1-j)=mod(a0(i),2);
a0(i)=floor(a0(i)/2);
end
end
错误：
??? Error: File: dectobin.m Line: 1 Column: 24
Unbalanced or misused parentheses or brackets.
function a0=QPSKdemod(qsig,t,fc,Trc)
sig=qsig.*exp(-2*j*pi*fc*t);
phi0=angle(sig);
phi0(find(phi0<0))=phi0(find(phi0<0))+2*pi;
phi=phi0(Trc:2*Trc:end);
a0(find(phi<pi/2))=0;
a0(find(phi>=pi/2&phi<pi))=1;
a0(find(phi>=pi&phi<3*pi/2))=2;
a0(find(phi>=3*pi/2))=3;
错误：
??? Input argument "qsig" is undefined.
Error in ==> QPSKdemod at 2
sig=qsig.*exp(-2*j*pi*fc*t);
function qsig=QPSKmod(s_4,t,fc)
fc=2000;t=2
kst=2*pi/4;
for i=1:length(kst)
qsig=cos(2*pi*fc*t+s_4*kst+pi/4);
qsig=hilbert(qsig);
end
错误：
??? Input argument "s_4" is undefined.
Error in ==> QPSKmod at 5
qsig=cos(2*pi*fc*t+s_4*kst+pi/4);
有哪个高手能帮忙解决下问题，，改来改去搞不定。。I