/* | | Copyright disclaimer: |   This software was developed at the National Institute of Standards |   and Technology by employees of the Federal Government in the course |   of their official duties. Pursuant to title 17 Section 105 of the |   United States Code this software is not subject to copyright |   protection and is in the public domain. | |   We would appreciate acknowledgement if the software is used. |*//* | Project:	WCDMA simulation environment | Module:      QPSK data modulation and demodulation | Author:      Tommi Makelainen, Nokia/NIST | Date:        January 6, 1999 | | History: |              January 6, 1999 Tommi Makelainen |                      Initial version. | */#include <stdio.h>#include <math.h>#include "config_wcdma.h"/* * Function:    wcdma_dl_qpsk_mod * Desc.:       QPSK downlink data modulation * * Note: *		Incoming data is char vector (one char = one bit). *		Output vectors must be 4 times longer than input vector. */int wcdma_dl_qpsk_mod(	int data[],	/* input data bit vector */        int data_len,	/* length of input data vector, in bytes */        int I_out[],	/* output I parts of complex symbol vector */        int Q_out[],	/* output Q parts of complex symbol vector */        int *out_len)	/* output length of complex symbol vector */{     int I_out_index, Q_out_index, i, j;    I_out_index = 0;    Q_out_index = 0;    for (i=0; i < data_len; i++)    {      /* get I branch, if even turn, otherwise get Q one */      if ( (i % 2) == 0 ) {        I_out[I_out_index] = data[i];        I_out_index++;      } else {        Q_out[Q_out_index] = data[i];        Q_out_index++;      }    }    *out_len = I_out_index;    return(0);}/* * Function:    wcdma_dl_qpsk_demod * Desc.:       QPSK data demodulation * * Note: */int wcdma_dl_qpsk_demod(	int I_in[],	/* IN: input I part of complex symbol vector */        int Q_in[],	/* IN: input Q part of complex symbol vector */        int in_len,	/* IN: length of input symbol vectors */        int out_data[],/* OUT: output symbol vector */        int *out_len)	/* OUT: length of output symbol vector */{     int i, out_index, j, I_index, Q_index;    int antipodal_data, outer_loop_count;    int temp_byte;    I_index = 0;    Q_index = 0;    out_index = 0;        /* Construct one byte per round */    while (I_index < in_len) {       /* Set bits from I branch */      out_data[out_index] = I_in[I_index];      I_index++;      out_index++;      /* Set bits from Q branch */      out_data[out_index] = Q_in[Q_index];      Q_index++;      out_index++;    };    *out_len = out_index;    return(0);}