gen_trellis.m

cpm调制解调实现,关联长度为3

function [state_from_input, state_from, to_state_output, to_state, phase_state] = gen_trellis(m, h, L)
p = 2/h;
to_state = zeros(p,m,m,m,L);
to_state_output = zeros(p,m,m,m);
state_from = zeros(p,m,m,m,L);
state_from_input = zeros(p,m,m,m);

phase_state = (1 : p);

for phk = 1:p
	for ak2 = 1:m
		for ak1 = 1:m
			for ak = 1:m
				phk_new = mod( phk-1 + 2*(ak2-1)-(m-1),p)+1; 
				to_state(phk,ak2,ak1,ak,:) = [phk_new,ak1,ak];
				to_state_output(phk,ak2,ak1,ak) = ak - 1;
			end;
		end;
	end;
end;

for a = 1:p
for b = 1:m
for c = 1:m
		d = 1;
		for i = 1:p
		for j = 1:m
		for k = 1:m
		for l = 1:m
			if(reshape(to_state(i,j,k,l,:),1,3) == [a,b,c])
				state_from(a,b,c,d,:) = [i,j,k];
				state_from_input(a,b,c,d) = l;				
				d = d + 1;
			end;
		end;end;end;end;
end;end;end;
			

%p = 2/h;
%state_num = p * m^(L-1);
%input_sym_num = m;
%
%to_state = zeros(state_num, input_sym_num);    
%to_state_output = zeros(state_num, input_sym_num);
%phase_state = zeros(state_num, input_sym_num);
%state_from = zeros(state_num, input_sym_num);               % State transition matrix
%state_from_input = zeros(state_num, input_sym_num);         % State transition matrix corresponding input
%
%
%for i = 1:state_num
%    for ak = 1:m
%        phk = fix((i-1)/(m^2)) + 1;
%        ak1 = fix( mod(i-1,m^2)/m ) + 1;
%        ak2 = fix( mod(mod(i-1,m^2),m)) + 1;
%        phk_new = mod( phk-1 + 2*(ak2-1)-(m-1),p)+1; 
%        to_state(i,ak) = (phk_new-1)*m^2 + (ak-1)*m + ak1;
%        to_state_output(i,ak) = ak - 1;
%    end;
%end;
%
%phase_state = (0 : p - 1);
%
%for k = 1 : state_num
%    l = 1;
%    for i = 1 : state_num
%        for j = 1 : input_sym_num
%            if to_state(i, j) == k
%                state_from(k, l) = i;
%                state_from_input(k, l) = j - 1;
%                l = l + 1;
%            end
%        end
%    end
%end