short_golay.c

short golay code generator short golay code generator short golay code generator short golay code

/******************************************************************************
 *                                                                            *
 *  no prune, d1=1, d2=2 or d1=2, d2=1                                        *
 *        |~~~~~|          |~~~~~|                                            *
 *    ----| D1  |----{+}---| D2  |----{+}----- output                         *
 *     |  |_____|\ /       |_____|\ /                                         *
 *     |          X                X                                          *
 *     |         / \              / \                                         *
 *     ------o-------{+}------o-------{+}--                                   *
 *           W0     -        W1      -                                        *
 *                                                                            *
 *     i=#0: W0= 1, W1= 1                                                     *
 *      =#1: W0= 1, W1=-1                                                     *
 *      =#2: W0=-1, W1= 1                                                     *
 *      =#3: W0=-1, W1=-1                                                     *
 *                                                                            *
 *   w/prune, d1=1, d2=2 or d1=2, d2=1                                        *
 *        |~~~~~|          |~~~~~|                                            *
 *    ----| D1  |----{+}---| D2  |----{+}----- output                         *
 *     |  |_____|\ /     | |_____|\ /                                         *
 *     |          X      |         X                                          *
 *     |         / \     |        / \                                         *
 *     ------o-------    -----o-------{+}--                                   *
 *           W0              W1      -                                        *
 *                                                                            *
 *     i=#0: W0= 1, W1= 1                                                     *
 *      =#1: W0= 1, W1=-1                                                     *
 *      =#2: W0=-1, W1= 1                                                     *
 *      =#3: W0=-1, W1=-1                                                     *
 *                                                                            *
 *                                                                            *
 *                                                                            *
 * Last change:  LU   17 Mar 2001    2:34 pm
 ******************************************************************************/

#include <stdio.h>


typedef short int   INT16;

int main()
{
    INT16       iUp[2];
    INT16       iDn[2];

    INT16       iReS1Out;

    INT16       DELAY0, DELAY1, W0, W1;
    INT16       S_IBUF0[3], S_IBUF1[3], S_PTR[2];
    INT16       i, j, iReIn;

/*  no prune, D1=1, D2=2 */
    DELAY0=1+1; DELAY1=1+2;
    for ( i=0; i<4; i++)
    {
        printf("#%d:  ", i);
        W0 = ( i&2 )? -1: 1;
        W1 = ( i&1 )? -1: 1;
        for ( j=0; j<3; j++)
        {
            S_IBUF0[j] = S_IBUF1[j] = 0;
        }
        S_PTR[0] = S_PTR[1] = 0;
        iReIn = 1;

        for ( j=0; j<4; j++)
        {
            S_IBUF0[S_PTR[0]] = iReIn;
            iUp[0] = S_IBUF0[(S_PTR[0]+DELAY0-1)%DELAY0] + W0 * iReIn;
            iDn[0] = S_IBUF0[(S_PTR[0]+DELAY0-1)%DELAY0] - W0 * iReIn;

            S_IBUF1[S_PTR[1]] = iUp[0];
            iUp[1] = S_IBUF1[(S_PTR[1]+DELAY1-1)%DELAY1] + W1 * iDn[0];
            printf("%3d  ", iUp[1]);

            S_PTR[0] = (S_PTR[0]+DELAY0-1)%DELAY0;
            S_PTR[1] = (S_PTR[1]+DELAY1-1)%DELAY1;
            iReIn = 0;
        }
        printf("\n");
    }

    printf("\n");
/*  no prune, D1=2, D2=1 */
    DELAY0=1+2; DELAY1=1+1;
    for ( i=0; i<4; i++)
    {
        printf("#%d:  ", i);
        W0 = ( i&2 )? -1: 1;
        W1 = ( i&1 )? -1: 1;
        for ( j=0; j<3; j++)
        {
            S_IBUF0[j] = S_IBUF1[j] = 0;
        }
        S_PTR[0] = S_PTR[1] = 0;
        iReIn = 1;

        for ( j=0; j<4; j++)
        {
            S_IBUF0[S_PTR[0]] = iReIn;
            iUp[0] = S_IBUF0[(S_PTR[0]+DELAY0-1)%DELAY0] + W0 * iReIn;
            iDn[0] = S_IBUF0[(S_PTR[0]+DELAY0-1)%DELAY0] - W0 * iReIn;

            S_IBUF1[S_PTR[1]] = iUp[0];
            iUp[1] = S_IBUF1[(S_PTR[1]+DELAY1-1)%DELAY1] + W1 * iDn[0];
            printf("%3d  ", iUp[1]);

            S_PTR[0] = (S_PTR[0]+DELAY0-1)%DELAY0;
            S_PTR[1] = (S_PTR[1]+DELAY1-1)%DELAY1;
            iReIn = 0;
        }
        printf("\n");
    }

    printf("\n");
/*  prune, D1=1, D2=2 */
    DELAY0=1+1; DELAY1=1+2;
    for ( i=0; i<4; i++)
    {
        printf("#%d:  ", i);
        W0 = ( i&2 )? -1: 1;
        W1 = ( i&1 )? -1: 1;
        for ( j=0; j<3; j++)
        {
            S_IBUF0[j] = S_IBUF1[j] = 0;
        }
        S_PTR[0] = S_PTR[1] = 0;
        iReIn = 1;

        for ( j=0; j<4; j++)
        {
            S_IBUF0[S_PTR[0]] = iReIn;
            iUp[0] = S_IBUF0[(S_PTR[0]+DELAY0-1)%DELAY0] + W0 * iReIn;
            iDn[0] = S_IBUF0[(S_PTR[0]+DELAY0-1)%DELAY0] - W0 * iReIn;

            S_IBUF1[S_PTR[1]] = iUp[0];
            iUp[1] = S_IBUF1[(S_PTR[1]+DELAY1-1)%DELAY1] + W1 * iUp[0];
            printf("%3d  ", iUp[1]);

            S_PTR[0] = (S_PTR[0]+DELAY0-1)%DELAY0;
            S_PTR[1] = (S_PTR[1]+DELAY1-1)%DELAY1;
            iReIn = 0;
        }
        printf("\n");
    }

    printf("\n");
/*  prune, D1=2, D2=1 */
    DELAY0=1+2; DELAY1=1+1;
    for ( i=0; i<4; i++)
    {
        printf("#%d:  ", i);
        W0 = ( i&2 )? -1: 1;
        W1 = ( i&1 )? -1: 1;
        for ( j=0; j<3; j++)
        {
            S_IBUF0[j] = S_IBUF1[j] = 0;
        }
        S_PTR[0] = S_PTR[1] = 0;
        iReIn = 1;

        for ( j=0; j<4; j++)
        {
            S_IBUF0[S_PTR[0]] = iReIn;
            iUp[0] = S_IBUF0[(S_PTR[0]+DELAY0-1)%DELAY0] + W0 * iReIn;
            iDn[0] = S_IBUF0[(S_PTR[0]+DELAY0-1)%DELAY0] - W0 * iReIn;

            S_IBUF1[S_PTR[1]] = iUp[0];
            iUp[1] = S_IBUF1[(S_PTR[1]+DELAY1-1)%DELAY1] + W1 * iUp[0];
            printf("%3d  ", iUp[1]);

            S_PTR[0] = (S_PTR[0]+DELAY0-1)%DELAY0;
            S_PTR[1] = (S_PTR[1]+DELAY1-1)%DELAY1;
            iReIn = 0;
        }
        printf("\n");
    }

    return 0;
}