ms_sfun_turbointerleaver.m

用matlab的Simulink对cdma2000中信道编码进行仿真 主要是turbo码部分。可能要用matlab7。0打开。

function[sys,x0,str,ts]=MS_SFUN_TurboInterleaver(t,x,u,flag,interleaver_size)
switch flag,
    case 0,
        [sys,x0,str,ts]=mdlInitializeSizes(interleaver_size);
    case 2,
        sys=mdlUpdate(t,x,u,interleaver_size);
    case 3,
        sys=mdlOutputs(t,x,u,interleaver_size);
    case{1,4,9}
        sys=[];
    otherwise
        error(['Unhandled flag=',num2str(flag)]);
end


function [sys,x0,str,ts]=mdlInitializeSizes(interleaver_size)
sizes=simsizes;
sizes.NumContStates=0;
sizes.NumDiscStates=1;
sizes.NumOutputs=-1;
sizes.NumInputs=-1;
sizes.DirFeedthrough=1;
sizes.NumSampleTimes=1;
sys=simsizes(sizes);

n=mdlInterleaverInit(interleaver_size);
x0=n;

str=[];

ts=[-1,0];

function sys=mdlUpdate(t,x,u,interleaver_size)
n=mdlInterleaverInit(interleaver_size);
sys=n;


function sys=mdlOutputs(t,x,u,interleaver_size)
n=x(1);
A=zeros(1,interleaver_size);
counter=0;
for index=0:interleaver_size-1
    label=1;
    while label==1
        msb=bitshift(bitand(counter,(2^n-1)*32),-5);
        lsb=bitand(counter,31);
        a=mod(msb+1,2^n);
        b=0;
        for k=1:5
            if bitget(lsb,k)==1
                b=bitset(b,6-k);
            end
        end
        c=mdlLookupTable(lsb,n);
        d=mod(a*c,2^n);
        e=b*2^n+d;
        counter=mod(counter+1,2^(n+5));
        if e<interleaver_size
            label=0;
        end
    end
    A(index+1)=u(e+1);
end
sys=A;



function n=mdlInterleaverInit(interleaver_size)
switch interleaver_size
    case{378,570,762,1146,1530,2298,3066,4602,6138,9210,12282,20730}
        n=ceil(log2(interleaver_size/32));
    otherwise
        error('Error:Invalid Interleaver Size in MS_SFUN_TurboInterleaver');
end


function index=mdlLookupTable(lsb,n)
LookupTable=[5 27 3 15 3 13 1;15 3 27 127 1 335 349;5 1 15 89 5 87 303;15 15 13 1 83 15 721;
    1 13 29 31 19 15 973;9 17 5 15 179 1 703;9 23 1 61 19 333 761;15 13 31 47 99 11 327;
    13 9 3 127 23 13 453;15 3 9 17 1 1 95;7 15 15 119 3 121 241;11 3 31 15 13 155 187;
    15 13 17 57 13 1 497;3 1 5 123 3 175 909;15 13 39 95 17 421 769;5 29 1 5 1 5 349;
    13 21 19 85 63 509 71;15 19 27 17 131 215 557;9 1 15 55 17 47 197;3 3 13 57 131 425 499;
    1 29 45 15 211 295 409;3 17 5 41 173 229 259;15 25 33 93 231 427 335;1 29 15 87 171 83 253;
    13 9 13 63 23 409 677;1 13 9 15 147 387 717;9 23 15 13 243 193 313;15 13 31 15 213 57 757;
    11 13 17 81 189 501 189;3 1 5 57 51 313 15;15 13 15 31 15 489 75;5 13 33 69 67 391 163];
index=LookupTable(lsb+1,n-3);