/* Function "encodeQPSK"
** Description: encode message using QPSDK pi/4 modulation
**
** INPUT :
** message the input message
** size the imput message size
** OUTPUT:
** signal the modulation signal
**
*/
extern void encodeQPSK(short message[], double signal[], int size)
{
double Ik[HALF_BUFF_SIZE], Qk[HALF_BUFF_SIZE];
double Isam[SAMPLE_RANGE], Qsam[SAMPLE_RANGE];
int i, j, halfsize, Sample_Range;
double oldI, oldQ, newI, newQ;
int replicate_carrier;
short tbc1, tbc2;
short NORMALIZATION = 10;
halfsize = size >> 1;
Sample_Range = NUM_SAMPLES * halfsize;
// Remap to {-1, 1}
for(i = 0; i < size; ++i)
message[i] = (message[i] << 1) - 1;
oldI = 1;
oldQ = 0;
// Returns the phase shifts for pi/4 DQPSK from the input binary data stream
for(i = 0; i < halfsize; ++i)
{
tbc1 = message[i * 2];
tbc2 = message[i * 2 + 1];
newI = ( oldI * tbc1 - oldQ * tbc2) * multFact;
newQ = ( oldQ * tbc1 + oldI * tbc2) * multFact;
oldI = newI;
oldQ = newQ;
Ik[i] = newI;
Qk[i] = newQ;
}
j = 0;
for(i = 0; i < Sample_Range; ++i)
if( i % NUM_SAMPLES == 0 )
{
Isam[i] = Ik[j];
Qsam[i] = Qk[j];
j = j + 1;
}
else
Isam[i] = Qsam[i] = 0;
fir_filter( Isam, Sample_Range );
fir_filter( Qsam, Sample_Range );
// Upmix with carrier
for(j = 0; j < Sample_Range; ++j)
{
replicate_carrier = j % CARRIER_SIZE;
signal[j] = ( Isam[j] * Icarrier[replicate_carrier] + Qsam[j] * Qcarrier[replicate_carrier] ) * NORMALIZATION;
}
}
int main (){
double y[N];
double b[MAX_TAP] = {
3.558363, -0.542859, -0.928322, -0.993428, 4.643953, -5.909149, 1.722120, -1.854375,
-1.967672, -2.170269, 0.673272, 0.182548, -4.812593, 0.818270, 0.889598, 0.322937,
-0.430576, -4.259421, -0.983597, 4.285341, -2.333795, 1.856496, -4.711222, -0.517585,
-8.376492, -1.440117, -6.255069, -0.000203, 0.881922, 6.955272, -0.209273, 5.219892 };
double x[N] = {
0.286381, 0.310398, 0.732308, 0.301956, 0.053523, 0.431617, 0.999498, 0.801469,
0.639967, 0.293192, 0.404720, 0.823173, 0.695269, 0.744480, 0.676903, 0.968651,
0.524716, 0.843609, 0.562026, 0.297492, 0.384924, 0.379665, 0.087916, 0.535140,
0.224908, 0.136965, 0.186164, 0.811894, 0.010466, 0.754323, 0.227373, 0.296848,
0.064720, 0.959681, 0.598804, 0.118243, 0.391298, 0.598302, 0.919712, 0.031265,
0.891494, 0.324432, 0.854438, 0.586763, 0.068912, 0.531341, 0.555414, 0.593628,
0.374950, 0.117441, 0.891120, 0.759874, 0.497106, 0.979036, 0.295014, 0.722014,
0.116001, 0.481178, 0.533908, 0.126467, 0.235500, 0.761281, 0.423315, 0.300220 };
int i;
fir_filter(y,b,x,N,TAP);
printf("Result data:\n");
for(i=0; i < N; i++) // unroll this for (64 times) !!
printf("%f %f\n", (double)i, y[i]);
printf("end\n");
return 0;
}
int main(){
float input_data;
int32 output_data;
//Configure hardware
codec_init();
fir_init(banda1,banda2,banda3,banda4,banda5);
while(1){
//Processing data
if(DSK6713_DIP_get(3)==0){
//Initialize processing
leds_output(LED_STATE_ACTIVE);
while(DSK6713_DIP_get(3)==0){
input_data = codec_read();
output_data = fir_filter(input_data);
codec_write(output_data);
}
}
//Waiting
else{
leds_output(LED_STATE_WATING);
}
}
}
/**
* Resample
*
* @note When downsampling, the input count must be divisible by rate ratio
*
* @param rs Resampler
* @param outv Output samples
* @param outc Output sample count (in/out)
* @param inv Input samples
* @param inc Input sample count
*
* @return 0 if success, otherwise error code
*/
int auresamp(struct auresamp *rs, int16_t *outv, size_t *outc,
const int16_t *inv, size_t inc)
{
size_t incc, outcc;
if (!rs || !rs->resample || !outv || !outc || !inv)
return EINVAL;
incc = inc / rs->ich;
if (rs->up) {
outcc = incc * rs->ratio;
if (*outc < outcc * rs->och)
return ENOMEM;
rs->resample(outv, inv, inc, rs->ratio);
*outc = outcc * rs->och;
fir_filter(&rs->fir, outv, outv, *outc, rs->och,
rs->tapv, rs->tapc);
}
else {
outcc = incc / rs->ratio;
if (*outc < outcc * rs->och || *outc < inc)
return ENOMEM;
fir_filter(&rs->fir, outv, inv, inc, rs->ich,
rs->tapv, rs->tapc);
rs->resample(outv, outv, inc, rs->ratio);
*outc = outcc * rs->och;
}
return 0;
}
int main()
{
double x;
struct FirStruct fs;
int i;
init_fir(&fs, 100.0 * 30.0 * 60.0);
for (i = 0; i < 1000000; i++) {
x = sin(2.0 * M_PI * (double) i / 4000) + sin(2.0 * M_PI * (double) i / 8000);
printf("%g %g\n", x, fir_filter(x, &fs));
}
return (0);
}
/* Function "decodeQPSK"
** Description: decode signal using QPSDK pi/4 modulation
**
** INPUT :
** signal the modulation signal (Received)
** size signal size
** OUTPUT:
** message the transmitted message
**
*/
extern void decodeQPSK(double signal[], short message[], int size)
{
int i, j, replicate_carrier;
double Irec[SAMPLE_RANGE], Qrec[SAMPLE_RANGE];
double Ik[HALF_BUFF_SIZE], Qk[HALF_BUFF_SIZE];
FILE *file;
for(j = 0; j < size; ++j)
{
replicate_carrier = j % CARRIER_SIZE;
Irec[j] = signal[j] * Icarrier[replicate_carrier];
Qrec[j] = signal[j] * Qcarrier[replicate_carrier];
}
fir_filter(Irec, size);
fir_filter(Qrec, size);
file = fopen("plot.txt", "w");
i = 0;
for(j = NUM_TAPS; j < size; j +=NUM_SAMPLES )
{
Ik[i] = Irec[j];
Qk[i] = Qrec[j];
fprintf(file, "%g %g\n", Ik[i], Qk[i]);
++i;
}
fclose(file);
// Loop through and decode the phases
for(j = 1; j < HALF_BUFF_SIZE; ++j)
{
message[(j << 1) - 2] = (Qk[j] * Qk[j-1] + Ik[j] * Ik[j-1]) > 0;
message[(j << 1) - 1] = (Ik[j-1] * Qk[j] - Ik[j] * Qk[j-1]) > 0;
}
}
