gen2trellis.m

摘要或目录空时网格码实现的完整程序 摘要或目录空时网格码实现的完整程序

function [trellis1,trellis2,statego]=gen2trellis(g1,g2,M)

% function to change generator code to trellis
% trellis1 = trellis antenna 1
% trellis2 = trellis antenna 2
% statego  = state moving

v1 = length(g1)-1;
v2 = length(g2)-1;
v = v1+v2;       
jumlahstate = 2^v;
m =log2 (M);
state = 0:jumlahstate-1;
for a=1:jumlahstate
    for b=1:4
        input = [getbits(state (1,a),jumlahstate/2),getbits(state(1,b),2)];
        
        % serial to paralel
        n_kol = length (input)/2;
        for index=0:n_kol-1
            c(:,index+1) = input(1,(m * index)+1:m*(index+1));
        end
        temp = zeros (m,v);
        
        for k=0:n_kol-1 % time
            % initialzation
            for in=0:v-2
                temp(:,v-in)=temp(:,v-in-1);
            end
            temp(:,1)=c(:,k+1);
            
            % symbol = g*c
            for l=1:m
                for j=0:v1
                    stemp1(l,j+1)= g1(l,j+1)*temp(1,j+1);
                end
                for j=0:v2
                    stemp2(l,j+1)= g2(l,j+1)*temp(2,j+1);
                end
                shat(l,k+1) = sum(sum(stemp1)) + sum(sum(stemp2));
                stemp1=[];stemp2=[];
            end
            temp;
        end
        s = mod(shat,M);
        trellis1(a,b) = s(1,n_kol);
        trellis2(a,b) = s(2,n_kol);
        statego(a,b) = bit2num(input(1,(length(input)-v2):length(input)));
    end
end