function R_PN_out=R_Long_PN(Start_state2)

%This is the Long PN sequence Generator at the Receiver
%It produces a total of 24576 PN chip for processing every 20 ms data frame

%The PN Long Code generating polynomial is
%G(x)=x^42+x^35+x^33+x^31+x^27+x^26+x^25+x^22+x^21+x^19+x^18+x^17+x^16+x^10+ x^7+x^6+ x^5+x^3+x^2+x^1+1

gshift2 =Start_state2;
R_PN_out1=zeros([1,24576]);

% The output from the Long Code Generator is 1.2288Mcps
% Therefore for every 20ms data frame,the LFSR(Linear Feedback Shift Register)iterates
% 24576 times(1.2288Mcps/50)
for i=1:24576
% obtain PN chip from output of shift register
R_PN_out1(i)=gshift2(42);
% we set the initial feedback value to be x^1
gfeed2=gshift2(1);
gfeed2=mod((gfeed2+gshift2(42)+gshift2(35)+gshift2(33)+gshift2(31)+gshift2(27)+gshift2(26)+gshift2(25)+gshift2(22)+gshift2(21)+gshift2(19)+gshift2(18)+gshift2(17)+gshift2(16)+gshift2(10)+gshift2(7)+gshift2(6)+gshift2(5)+gshift2(3)+gshift2(2)+gshift2(1)),2);
% the state of the current stage shift register is replaced by the state of the previous
% stage shift register 2 to 42
gshift2(2:42)=gshift2(1:41);
% the first stage shift register receives the feedback value
gshift2(1)=gfeed2;
end
R_PN_out=R_PN_out1;