gen_trellis.asv

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;
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_new,ak1,ak2] = dec_state(i);
        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