HW #1 (due Sept 10) 3.3, 3.4, 3.7, 3.8, 3.10, 3.14, 3.18, 3.19, 3.20
(Your life will be easier if you use the matlab files which you 
can find on the CD. Otherwise, you'll do a lot of typing. Make sure to
stick them in the matlab path.)

HW #2 (due Sept 17)  4.2, 4.7, 4.9, 4.10, 4.17, 4.18, 4.19

HW #3 (due Sept 24) 5.6, 5.7, 5.9, 5.10, 5.12 

HW #4 (due Oct 1) 6.1, 6.6, 6.8, 6.9, 6.16, 6.17

HW #5 (due Oct 8) 6.19, 6.22, 7.4, 7.10, 7.11, 7.19

HW #6 (due Oct 15) 7.20, 7.21, 7.24, 8.1, 8.3, 8.7, 8.10, 8.12


Unfortunately, the code for naivecode.m was left off the
CD - here it is....

%naivecode.m:  Try a naive encoding scheme

mesLen=1000; %message length
bits=(sign(rand(1,mesLen)-.5)+1)/2; %binary message to send
%index into constl = 1+ bits(i) + 2*bits(i+1)
constl=[-3 1 -1 3];
k=1;
pam4mes=zeros(1,length(bits)/2);
for i=1:2:length(bits)
  pam4mes(k)=constl(1+bits(i)+2*bits(i+1)); %switch to a PAM4 constellation
  k=k+1;
end

v=.5; %noise variance

%pass the signal through a noisy channel
noisyPam=sqrt(v)*randn(1,length(pam4mes))+pam4mes;

%quantize the received signal
recSig=quantalph(noisyPam,[-3,-1,1,3]);

k=1;
recBits=zeros(1,2*length(recSig));
%decode the signal using the naive code
for i=1:length(recSig)
  if recSig(i)==3
    recBits(k)=1;
    recBits(k+1)=1;
  elseif recSig(i)==1
    recBits(k)=1;
    recBits(k+1)=0;
  elseif recSig(i)==-1
    recBits(k)=0;
    recBits(k+1)=1;
  elseif recSig(i)==-3
    recBits(k)=0;
    recBits(k+1)=0;
  end
  k=k+2;
end

%calculate the percentage error
percErrs=sum((recBits~=bits))/length(recBits)