// Helper function to keep code base small
void resamp2_crcf_bench(struct rusage *_start,
struct rusage *_finish,
unsigned long int * _num_iterations,
unsigned int _m,
resamp2_type _type)
{
// scale number of iterations by filter length
// NOTE: n = 4*m+1
// cycles/trial ~ 70.5 + 7.74*_m
*_num_iterations *= 200;
*_num_iterations /= 70.5 + 7.74*_m;
unsigned long int i;
resamp2_crcf q = resamp2_crcf_create(_m,0.0f,60.0f);
float complex x[] = {1.0f, -1.0f};
float complex y[] = {1.0f, -1.0f};
// start trials
getrusage(RUSAGE_SELF, _start);
if (_type == RESAMP2_DECIM) {
// run decimator
for (i=0; i<(*_num_iterations); i++) {
resamp2_crcf_decim_execute(q,x,y);
resamp2_crcf_decim_execute(q,x,y);
resamp2_crcf_decim_execute(q,x,y);
resamp2_crcf_decim_execute(q,x,y);
}
} else {
// run interpolator
for (i=0; i<(*_num_iterations); i++) {
resamp2_crcf_interp_execute(q,x[0],y);
resamp2_crcf_interp_execute(q,x[0],y);
resamp2_crcf_interp_execute(q,x[0],y);
resamp2_crcf_interp_execute(q,x[0],y);
}
}
getrusage(RUSAGE_SELF, _finish);
*_num_iterations *= 4;
resamp2_crcf_destroy(q);
}
int main(int argc, char*argv[])
{
unsigned int m=5; // filter semi-length
float fc=0.037f; // input tone frequency
unsigned int num_samples = 64; // number of output samples
float As=60.0f; // stop-band attenuation [dB]
int dopt;
while ((dopt = getopt(argc,argv,"hn:m:s:")) != EOF) {
switch (dopt) {
case 'h': usage(); return 0;
case 'n': num_samples = atoi(optarg); break;
case 'm': m = atoi(optarg); break;
case 's': As = atof(optarg); break;
default:
exit(1);
}
}
unsigned int i;
// allocate arrays
float complex x[2*num_samples]; // input array
float complex y[ num_samples]; // output array
// generate input
unsigned int w_len = 2*num_samples - 4*m; // window length
float beta = 8.0f; // kaiser window factor
float w_sum = 0.0f; // gain due to window
for (i=0; i<2*num_samples; i++) {
// compute windowing function and keep track of gain
float w = (i < w_len ? kaiser(i,w_len,beta,0) : 0.0f);
w_sum += w;
// compute windowed complex sinusoid
x[i] = w * cexpf(_Complex_I*2*M_PI*fc*i);
}
// create/print the half-band resampler
resamp2_crcf q = resamp2_crcf_create(m,0,As);
resamp2_crcf_print(q);
unsigned int delay = resamp2_crcf_get_delay(q);
// run the resampler
for (i=0; i<num_samples; i++) {
// execute the decimator
resamp2_crcf_decim_execute(q, &x[2*i], &y[i]);
// print results to screen
printf("y(%3u) = %8.4f + j*%8.4f;\n", i+1, crealf(y[i]), cimagf(y[i]));
}
// destroy half-band resampler
resamp2_crcf_destroy(q);
//
// export results
//
FILE*fid = fopen(OUTPUT_FILENAME,"w");
fprintf(fid,"%% %s : auto-generated file\n", OUTPUT_FILENAME);
fprintf(fid,"clear all;\nclose all;\n\n");
fprintf(fid,"h_len=%u;\n", 4*m+1);
fprintf(fid,"num_samples=%u;\n", num_samples);
fprintf(fid,"delay =%u;\n", delay);
fprintf(fid,"w_sum =%12.8f;\n", w_sum);
for (i=0; i<num_samples; i++) {
// save results to output file
fprintf(fid,"x(%3u) = %12.8f + j*%12.8f;\n", 2*i+1, crealf(x[2*i+0]), cimagf(x[2*i+0]));
fprintf(fid,"x(%3u) = %12.8f + j*%12.8f;\n", 2*i+2, crealf(x[2*i+1]), cimagf(x[2*i+1]));
fprintf(fid,"y(%3u) = %12.8f + j*%12.8f;\n", i+1, 0.5f*crealf(y[i ]), 0.5f*cimagf(y[i ]));
}
// plot time series
fprintf(fid,"tx = 0:(2*num_samples-1);\n");
fprintf(fid,"ty = [0:( num_samples-1)]*2 - delay;\n");
fprintf(fid,"figure;\n");
fprintf(fid,"subplot(2,1,1);\n");
fprintf(fid," plot(tx,real(x),'-s','Color',[0.5 0.5 0.5],'MarkerSize',1,...\n");
fprintf(fid," ty,real(y),'-s','Color',[0.5 0.0 0.0],'MarkerSize',1);\n");
fprintf(fid," legend('original','decimated','location','northeast');");
fprintf(fid," axis([-delay 2*num_samples -1.2 1.2]);\n");
fprintf(fid," grid on;\n");
fprintf(fid," xlabel('Normalized Time [t/T_s]');\n");
fprintf(fid," ylabel('real');\n");
fprintf(fid,"subplot(2,1,2);\n");
fprintf(fid," plot(tx,imag(x),'-s','Color',[0.5 0.5 0.5],'MarkerSize',1,...\n");
fprintf(fid," ty,imag(y),'-s','Color',[0.0 0.5 0.0],'MarkerSize',1);\n");
fprintf(fid," legend('original','decimated','location','northeast');");
fprintf(fid," axis([-delay 2*num_samples -1.2 1.2]);\n");
fprintf(fid," grid on;\n");
fprintf(fid," xlabel('Normalized Time [t/T_s]');\n");
fprintf(fid," ylabel('imag');\n");
// plot spectrum
fprintf(fid,"nfft=512;\n");
fprintf(fid,"g = 1/w_sum;\n");
fprintf(fid,"X=20*log10(abs(fftshift(fft( x*g,nfft))));\n");
fprintf(fid,"Y=20*log10(abs(fftshift(fft(2*y*g,nfft))));\n");
fprintf(fid,"f=[0:(nfft-1)]/nfft-0.5;\n");
fprintf(fid,"figure;\n");
fprintf(fid,"plot(f, X,'LineWidth',1, 'Color',[0.5 0.5 0.5],...\n");
fprintf(fid," f/2,Y,'LineWidth',1.5,'Color',[0.1 0.3 0.5]);\n");
fprintf(fid,"grid on;\n");
fprintf(fid,"xlabel('Normalized Frequency [f/F_s]');\n");
fprintf(fid,"ylabel('PSD [dB]');\n");
fprintf(fid,"legend('original','decimated','location','northeast');");
fprintf(fid,"axis([-0.5 0.5 -100 10]);\n");
fclose(fid);
printf("results written to %s\n", OUTPUT_FILENAME);
printf("done.\n");
return 0;
}
//
// AUTOTEST : test half-band filterbank (synthesizer)
//
void autotest_resamp2_synthesis()
{
unsigned int m=5; // filter semi-length (actual length: 4*m+1)
unsigned int n=37; // number of input samples
float As=60.0f; // stop-band attenuation [dB]
float f0 = 0.0739f; // low frequency signal
float f1 = -0.1387f; // high frequency signal (+pi)
float tol = 3e-3f; // error tolerance
unsigned int i;
// allocate memory for data arrays
float complex x0[n+2*m+1]; // input signal (with delay)
float complex x1[n+2*m+1]; // input signal (with delay)
float complex y[2*n]; // synthesized output
// generate the baseband signals
for (i=0; i<n+2*m+1; i++) {
x0[i] = i < 2*n ? cexpf(_Complex_I*f0*i) : 0.0f;
x1[i] = i < 2*n ? cexpf(_Complex_I*f1*i) : 0.0f;
}
// create/print the half-band resampler, with a specified
// stopband attenuation level
resamp2_crcf q = resamp2_crcf_create(m,0,As);
// run synthesis
float complex x_hat[2];
for (i=0; i<n; i++) {
x_hat[0] = x0[i];
x_hat[1] = x1[i];
resamp2_crcf_synthesizer_execute(q, x_hat, &y[2*i]);
}
// clean up allocated objects
resamp2_crcf_destroy(q);
// validate output
for (i=m; i<n-2*m; i++) {
CONTEND_DELTA( crealf(y[i+2*m]), cosf(0.5f*f0*i) + cosf((M_PI+0.5f*f1)*i), tol );
CONTEND_DELTA( cimagf(y[i+2*m]), sinf(0.5f*f0*i) + sinf((M_PI+0.5f*f1)*i), tol );
}
#if 0
// debugging
FILE * fid = fopen("resamp2_test.m", "w");
fprintf(fid,"clear all\n");
fprintf(fid,"close all\n");
for (i=0; i<n+2*m+1; i++) {
fprintf(fid,"x0(%3u) = %12.4e + j*%12.4e;\n", i+1, crealf(x0[i]), cimagf(x0[i]));
fprintf(fid,"x1(%3u) = %12.4e + j*%12.4e;\n", i+1, crealf(x1[i]), cimagf(x1[i]));
}
for (i=0; i<2*n; i++)
fprintf(fid,"y(%3u) = %12.4e + j*%12.4e;\n", i+1, crealf(y[i]), cimagf(y[i]));
// save expected values
for (i=0; i<2*n; i++) {
fprintf(fid,"z(%3u) = %12.4e + j*%12.4e;\n", i+1, cosf(i*0.5f*f0) + cosf(i*(M_PI+0.5f*f1)),
sinf(i*0.5f*f0) + sinf(i*(M_PI+0.5f*f1)));
}
fprintf(fid,"m = %u;\n", m);
fprintf(fid,"figure;\n");
fprintf(fid,"t = 0:(length(y)-1);\n");
fprintf(fid,"plot(t,real(z),t-2*m,real(y));\n");
fclose(fid);
printf("results written to '%s'\n","resamp2_test.m");
#endif
}
//
// AUTOTEST : test half-band filterbank (analyzer)
//
void autotest_resamp2_analysis()
{
unsigned int m=5; // filter semi-length (actual length: 4*m+1)
unsigned int n=37; // number of input samples
float As=60.0f; // stop-band attenuation [dB]
float f0 = 0.0739f; // low frequency signal
float f1 = -0.1387f; // high frequency signal (+pi)
float tol = 1e-3f; // error tolerance
unsigned int i;
// allocate memory for data arrays
float complex x[2*n+2*m+1]; // input signal (with delay)
float complex y0[n]; // low-pass output
float complex y1[n]; // high-pass output
// generate the baseband signal
for (i=0; i<2*n+2*m+1; i++)
x[i] = i < 2*n ? cexpf(_Complex_I*f0*i) + cexpf(_Complex_I*(M_PI+f1)*i) : 0.0f;
// create/print the half-band resampler, with a specified
// stopband attenuation level
resamp2_crcf q = resamp2_crcf_create(m,0,As);
// run half-band decimation
float complex y_hat[2];
for (i=0; i<n; i++) {
resamp2_crcf_analyzer_execute(q, &x[2*i], y_hat);
y0[i] = y_hat[0];
y1[i] = y_hat[1];
}
// clean up allocated objects
resamp2_crcf_destroy(q);
// validate output
for (i=m; i<n-m; i++) {
CONTEND_DELTA( crealf(y0[i+m]), cosf(2*f0*(i+0.5f)), tol );
CONTEND_DELTA( cimagf(y0[i+m]), sinf(2*f0*(i+0.5f)), tol );
CONTEND_DELTA( crealf(y1[i+m]), cosf(2*f1*(i+0.5f)), tol );
CONTEND_DELTA( cimagf(y1[i+m]), sinf(2*f1*(i+0.5f)), tol );
}
#if 0
// debugging
FILE * fid = fopen("resamp2_test.m", "w");
fprintf(fid,"clear all\n");
fprintf(fid,"close all\n");
for (i=0; i<2*n; i++)
fprintf(fid,"x(%3u) = %12.4e + j*%12.4e;\n", i+1, crealf(x[i]), cimagf(x[i]));
for (i=0; i<n; i++) {
fprintf(fid,"y0(%3u) = %12.4e + j*%12.4e;\n", i+1, crealf(y0[i]), cimagf(y0[i]));
fprintf(fid,"y1(%3u) = %12.4e + j*%12.4e;\n", i+1, crealf(y1[i]), cimagf(y1[i]));
}
// save expected values
for (i=0; i<n; i++) {
fprintf(fid,"z0(%3u) = %12.4e + j*%12.4e;\n", i+1, cosf(i*2*f0), sinf(i*2*f0));
fprintf(fid,"z1(%3u) = %12.4e + j*%12.4e;\n", i+1, cosf(i*2*f1), sinf(i*2*f1));
}
fprintf(fid,"m = %u;\n", m);
fprintf(fid,"figure;\n");
fprintf(fid,"t = 0:(length(y0)-1);\n");
//fprintf(fid,"plot(t,real(z0),t-m+0.5,real(y0));\n");
fprintf(fid,"plot(t,real(z1),t-m+0.5,real(y1));\n");
fclose(fid);
printf("results written to '%s'\n","resamp2_test.m");
#endif
}
int main() {
unsigned int m=9; // filter semi-length
unsigned int num_samples=128; // number of input samples
float As=60.0f; // stop-band attenuation [dB]
// derived values
unsigned int h_len = 4*m+1; // half-band filter length
unsigned int N = num_samples + h_len;
// ensure N is even
N += (N%2);
unsigned int n = N/2;
// arrays
float complex x[N]; // input time series
float complex y[n][2]; // output time series (channelized)
float complex z[N]; // output time series
// generate input sequence
unsigned int i;
for (i=0; i<N; i++) {
//x[i] = randnf() * cexpf(_Complex_I*M_PI*randf());
x[i] = cexpf(_Complex_I*2*M_PI*0.072f*i) + 0.6f*cexpf(_Complex_I*2*M_PI*0.37f*i);
//x[i] = cexpf(_Complex_I*2*M_PI*0.072f*i);
//x[i] += 0.6*cexpf(_Complex_I*2*M_PI*0.572f*i);
x[i] *= (i < num_samples) ? hamming(i,num_samples) : 0.0f;
}
// create/print the half-band filter with a specified
// stop-band attenuation
resamp2_crcf q = resamp2_crcf_create(m,0.0f,As);
resamp2_crcf_print(q);
// run the resampler as a two-channel analysis filterbank
for (i=0; i<n; i++)
resamp2_crcf_analyzer_execute(q, &x[2*i], &y[i][0]);
// clear resampler
resamp2_crcf_clear(q);
// run the resampler as a two-channel synthesis filterbank
for (i=0; i<n; i++)
resamp2_crcf_synthesizer_execute(q, &y[i][0], &z[2*i]);
// clean up allocated objects
resamp2_crcf_destroy(q);
//
// export output file
//
FILE*fid = fopen(OUTPUT_FILENAME,"w");
fprintf(fid,"%% %s : auto-generated file\n", OUTPUT_FILENAME);
fprintf(fid,"clear all;\nclose all;\n\n");
fprintf(fid,"m = %u;\n", m);
fprintf(fid,"num_samples = %u;\n", num_samples);
fprintf(fid,"N = %u;\n", N);
// save results to output file
for (i=0; i<n; i++) {
fprintf(fid,"x(%3u) = %12.4e + j*%12.4e;\n", 2*i+1, crealf(x[2*i+0]), cimagf(x[2*i+0]));
fprintf(fid,"x(%3u) = %12.4e + j*%12.4e;\n", 2*i+2, crealf(x[2*i+1]), cimagf(x[2*i+1]));
fprintf(fid,"y0(%3u) = %12.4e + j*%12.4e;\n", i+1, crealf(y[i][0]), cimagf(y[i][0]));
fprintf(fid,"y1(%3u) = %12.4e + j*%12.4e;\n", i+1, crealf(y[i][1]), cimagf(y[i][1]));
fprintf(fid,"z(%3u) = %12.4e + j*%12.4e;\n", 2*i+1, crealf(z[2*i+0]), cimagf(z[2*i+0]));
fprintf(fid,"z(%3u) = %12.4e + j*%12.4e;\n", 2*i+2, crealf(z[2*i+1]), cimagf(z[2*i+1]));
}
fprintf(fid,"tx = 0:(N-1);\n");
fprintf(fid,"ty = tx(1:2:end);\n");
fprintf(fid,"tz = tx - 4*m + 1;\n");
fprintf(fid,"figure;\n");
fprintf(fid,"subplot(2,1,1);\n");
fprintf(fid," plot(tx, real(x), 'LineWidth',1,'Color',[0.50 0.50 0.50],...\n");
fprintf(fid," tz, real(z), 'LineWidth',1,'Color',[0.00 0.25 0.50]);\n");
fprintf(fid," xlabel('time');\n");
fprintf(fid," ylabel('real');\n");
fprintf(fid," legend('original','reconstructed',1);");
fprintf(fid,"subplot(2,1,2);\n");
fprintf(fid," plot(tx, imag(x), 'LineWidth',1,'Color',[0.50 0.50 0.50],...\n");
fprintf(fid," tz, imag(z), 'LineWidth',1,'Color',[0.00 0.50 0.25]);\n");
fprintf(fid," xlabel('time');\n");
fprintf(fid," ylabel('imag');\n");
fprintf(fid," legend('original','reconstructed',1);");
fprintf(fid,"nfft=512;\n");
fprintf(fid,"g = 1 / sqrt( real(x*x') );\n");
fprintf(fid,"X =20*log10(abs(fftshift(fft(x*g, nfft))));\n");
fprintf(fid,"Y0=20*log10(abs(fftshift(fft(y0*g,nfft))));\n");
fprintf(fid,"Y1=20*log10(abs(fftshift(fft(y1*g,nfft))));\n");
fprintf(fid,"Z =20*log10(abs(fftshift(fft(z*g, nfft))));\n");
fprintf(fid,"f=[0:(nfft-1)]/nfft-0.5;\n");
fprintf(fid,"figure;\n");
fprintf(fid,"plot(f,X, 'LineWidth',2,'Color',[0.50 0.50 0.50],...\n");
fprintf(fid," f,Z, 'LineWidth',1,'Color',[0.00 0.25 0.50]);\n");
//fprintf(fid," f,Y0,'LineWidth',1,'Color',[0.00 0.25 0.50],...\n");
//fprintf(fid," f,Y1,'LineWidth',1,'Color',[0.00 0.50 0.25]);\n");
fprintf(fid,"grid on;\n");
fprintf(fid,"xlabel('normalized frequency');\n");
fprintf(fid,"ylabel('PSD [dB]');\n");
fprintf(fid,"legend('original','reconstructed',2);");
fprintf(fid,"axis([-0.5 0.5 -80 20]);\n");
fclose(fid);
printf("results written to %s\n", OUTPUT_FILENAME);
printf("done.\n");
return 0;
}