FFT in freq est tested OK

git-svn-id: https://svn.code.sf.net/p/freetel/code@374 01035d8c-6547-0410-b346-abe4f91aad63

diff --git a/codec2-dev/octave/fdmdv.m b/codec2-dev/octave/fdmdv.m
index be274c3dfab628feecfafb7b568c44b107a608fe..7a8f711d39598d92acf8b28c922f483fb3ed6893 100644 (file)
--- a/codec2-dev/octave/fdmdv.m
+++ b/codec2-dev/octave/fdmdv.m
@@ -240,41 +240,6 @@ function rx_filt = rx_filter(rx_baseband, nin)
 endfunction
 
 
-% Estimate frequency offset of FDM signal using BPSK pilot.  This is quite
-% sensitive to pilot tone level wrt other carriers
-
-function [foff s1 s2] = rx_est_freq_offset(rx_fdm, pilot, pilot_prev, nin)
-  global M;
-  global Npilotbaseband;
-  global pilot_baseband1;
-  global pilot_baseband2;
-  global pilot_lpf1;
-  global pilot_lpf2;
-
-  % down convert latest nin samples of pilot by multiplying by
-  % ideal BPSK pilot signal we have generated locally.  This
-  % peak of the resulting signal is sensitive to the time shift between 
-  % the received and local version of the pilot, so we do it twice at
-  % different time shifts and choose the maximum.
- 
-  pilot_baseband1(1:Npilotbaseband-nin) = pilot_baseband1(nin+1:Npilotbaseband);
-  pilot_baseband2(1:Npilotbaseband-nin) = pilot_baseband2(nin+1:Npilotbaseband);
-  for i=1:nin
-    pilot_baseband1(Npilotbaseband-nin+i) = rx_fdm(i) * conj(pilot(i)); 
-    pilot_baseband2(Npilotbaseband-nin+i) = rx_fdm(i) * conj(pilot_prev(i)); 
-  end
-
-  [foff1 max1 pilot_lpf1 s1] = lpf_peak_pick(pilot_baseband1, pilot_lpf1, nin);
-  [foff2 max2 pilot_lpf2 s2] = lpf_peak_pick(pilot_baseband2, pilot_lpf2, nin);
-
-  if max1 > max2
-    foff = foff1;
-  else
-    foff = foff2;
-  end  
-endfunction
-
-
 % LPF and peak pick part of freq est, put in a function as we call it twice
 
 function [foff imax pilot_lpf S] = lpf_peak_pick(pilot_baseband, pilot_lpf, nin)
@@ -299,7 +264,8 @@ function [foff imax pilot_lpf S] = lpf_peak_pick(pilot_baseband, pilot_lpf, nin)
   Mpilot = Fs/(2*200);  % calc decimation rate given new sample rate is twice LPF freq
   h = hanning(Npilotlpf);
   s = pilot_lpf(1:Mpilot:Npilotlpf) .* h(1:Mpilot:Npilotlpf)';
-  S = abs(fft(s, Mpilotfft));
+  s = [s zeros(1,Mpilotfft-Npilotlpf/Mpilot)];
+  S = fft(s, Mpilotfft);
 
   % peak pick and convert to Hz
 
@@ -315,6 +281,41 @@ function [foff imax pilot_lpf S] = lpf_peak_pick(pilot_baseband, pilot_lpf, nin)
 endfunction
 
 
+% Estimate frequency offset of FDM signal using BPSK pilot.  This is quite
+% sensitive to pilot tone level wrt other carriers
+
+function [foff S1 S2] = rx_est_freq_offset(rx_fdm, pilot, pilot_prev, nin)
+  global M;
+  global Npilotbaseband;
+  global pilot_baseband1;
+  global pilot_baseband2;
+  global pilot_lpf1;
+  global pilot_lpf2;
+
+  % down convert latest nin samples of pilot by multiplying by
+  % ideal BPSK pilot signal we have generated locally.  This
+  % peak of the resulting signal is sensitive to the time shift between 
+  % the received and local version of the pilot, so we do it twice at
+  % different time shifts and choose the maximum.
+ 
+  pilot_baseband1(1:Npilotbaseband-nin) = pilot_baseband1(nin+1:Npilotbaseband);
+  pilot_baseband2(1:Npilotbaseband-nin) = pilot_baseband2(nin+1:Npilotbaseband);
+  for i=1:nin
+    pilot_baseband1(Npilotbaseband-nin+i) = rx_fdm(i) * conj(pilot(i)); 
+    pilot_baseband2(Npilotbaseband-nin+i) = rx_fdm(i) * conj(pilot_prev(i)); 
+  end
+
+  [foff1 max1 pilot_lpf1 S1] = lpf_peak_pick(pilot_baseband1, pilot_lpf1, nin);
+  [foff2 max2 pilot_lpf2 S2] = lpf_peak_pick(pilot_baseband2, pilot_lpf2, nin);
+
+  if max1 > max2
+    foff = foff1;
+  else
+    foff = foff2;
+  end  
+endfunction
+
+
 % Estimate optimum timing offset, re-filter receive symbols
 
 function [rx_symbols rx_timing] = rx_est_timing(rx_filt, rx_baseband, nin)

diff --git a/codec2-dev/octave/tfdmdv.m b/codec2-dev/octave/tfdmdv.m
index 020a5840dcadb0f1ddc2cd5745679c2400389643..fd6e9e7581ae0cd02323f38c7a1bff22ca000867 100644 (file)
--- a/codec2-dev/octave/tfdmdv.m
+++ b/codec2-dev/octave/tfdmdv.m
@@ -13,6 +13,8 @@ fdmdv; % load modem code
  
 % Generate reference vectors using Octave implementation of FDMDV modem
 
+global passes;
+global fails;
 passes = fails = 0;
 frames = 25;
 prev_tx_symbols = ones(Nc+1,1);
@@ -27,8 +29,8 @@ pilot_baseband1_log = [];
 pilot_baseband2_log = [];
 pilot_lpf1_log = [];
 pilot_lpf2_log = [];
-s1_log = [];
-s2_log = [];
+S1_log = [];
+S2_log = [];
 
 for f=1:frames
 
@@ -50,14 +52,14 @@ for f=1:frames
 
   [pilot prev_pilot pilot_lut_index prev_pilot_lut_index] = get_pilot(pilot_lut_index, prev_pilot_lut_index, M);
 
-  [foff s1 s2] = rx_est_freq_offset(rx_fdm, pilot, prev_pilot, M);
+  [foff S1 S2] = rx_est_freq_offset(rx_fdm, pilot, prev_pilot, M);
 
   pilot_baseband1_log = [pilot_baseband1_log pilot_baseband1];
   pilot_baseband2_log = [pilot_baseband2_log pilot_baseband2];
   pilot_lpf1_log = [pilot_lpf1_log pilot_lpf1];
   pilot_lpf2_log = [pilot_lpf2_log pilot_lpf2];
-  s1_log  = [s1_log s1];
-  s2_log  = [s2_log s2];
+  S1_log  = [S1_log S1];
+  S2_log  = [S2_log S2];
 
 end
 
@@ -128,69 +130,44 @@ plot_sig_and_error(5, 212, real(pilot_baseband2_log), real(pilot_baseband2_log -
 plot_sig_and_error(6, 211, real(pilot_lpf1_log), real(pilot_lpf1_log - pilot_lpf1_log_c), 'pilot lpf1 real' )
 plot_sig_and_error(6, 212, real(pilot_lpf2_log), real(pilot_lpf2_log - pilot_lpf2_log_c), 'pilot lpf2 real' )
 
-plot_sig_and_error(7, 211, real(s1_log), real(s1_log - s1_log_c), 's1 real' )
-plot_sig_and_error(7, 212, real(s2_log), real(s2_log - s2_log_c), 's2 real' )
+plot_sig_and_error(7, 211, real(S1_log), real(S1_log - S1_log_c), 'S1 real' )
+plot_sig_and_error(7, 212, imag(S1_log), imag(S1_log - S1_log_c), 'S1 imag' )
+
+plot_sig_and_error(8, 211, real(S2_log), real(S2_log - S2_log_c), 'S2 real' )
+plot_sig_and_error(8, 212, imag(S2_log), imag(S2_log - S2_log_c), 'S2 imag' )
 
 % ---------------------------------------------------------------------------------------
 % AUTOMATED CHECKS ------------------------------------------
 % ---------------------------------------------------------------------------------------
 
-if sum(tx_bits_log - tx_bits_log_c) == 0
-  printf("fdmdv_get_test_bits..: OK\n");
-  passes++;
-else;
-  printf("fdmdv_get_test_bits..: FAIL\n");
-  fails++;
-end
- 
-if sum(tx_symbols_log - tx_symbols_log_c) == 0
-  printf("bits_to_dqpsk_symbols: OK\n");
-  passes++;
-else;
-  printf("bits_to_dqpsk_symbols: FAIL\n");
-  fails++;
-end
-
-if sum(tx_baseband_log - tx_baseband_log_c) < 1E-3
-  printf("tx_filter............: OK\n");
-  passes++;
-else;
-  printf("tx_filter............: FAIL\n");
-  fails++;
-end
-
-if sum(tx_fdm_log - tx_fdm_log_c) < 1E-3
-  printf("tx_fdm...............: OK\n");
-  passes++;
-else;
-  printf("tx_fdm...............: FAIL\n");
-  fails++;
-end
+function check(a, b, test_name)
+  global passes;
+  global fails;
 
-if sum(pilot_lut - pilot_lut_c) < 1E-3
-  printf("pilot_lut............: OK\n");
-  passes++;
-else;
-  printf("pilot_lut............: FAIL\n");
-  fails++;
-end
-
-[m n] = size(pilot_baseband1_log);
-if sum(pilot_baseband1_log - pilot_baseband1_log_c)/n < 1E-3
-  printf("pilot_baseband1_log..: OK\n");
-  passes++;
-else;
-  printf("pilot_baseband1_log..: FAIL\n");
-  fails++;
-end
+  [m n] = size(a);
+  printf("%s", test_name);
+  for i=1:(25-length(test_name))
+    printf(".");
+  end
+  printf(": ");  
+
+  if sum(a - b)/n < 1E-3
+    printf("OK\n");
+    passes++;
+  else
+    printf("FAIL\n");
+    fails++;
+  end
+endfunction
 
-[m n] = size(pilot_baseband2_log);
-if sum(pilot_baseband2_log - pilot_baseband2_log_c)/n < 1E-3
-  printf("pilot_baseband2_log..: OK\n");
-  passes++;
-else;
-  printf("pilot_baseband2_log..: FAIL\n");
-  fails++;
-end
+check(tx_bits_log, tx_bits_log_c, 'fdmdv_get_test_bits');
+check(tx_symbols_log,  tx_symbols_log_c, 'bits_to_dqpsk_symbols');
+check(tx_baseband_log, tx_baseband_log_c, 'tx_filter');
+check(tx_fdm_log, tx_fdm_log_c, 'tx_fdm');
+check(pilot_lut, pilot_lut_c, 'pilot_lut');
+check(pilot_baseband1_log, pilot_baseband1_log_c, 'pilot lpf1');
+check(pilot_baseband2_log, pilot_baseband2_log_c, 'pilot lpf2');
+check(S1_log, S1_log_c, 'S1');
+check(S2_log, S2_log_c, 'S2');
 
 printf("\npasses: %d fails: %d\n", passes, fails);

diff --git a/codec2-dev/src/fdmdv.c b/codec2-dev/src/fdmdv.c
index 7f0b9d77c434e9db6094d76cbc09cb1768d20f31..add05ace37894802066b7689d040e6a10566ec87 100644 (file)
--- a/codec2-dev/src/fdmdv.c
+++ b/codec2-dev/src/fdmdv.c
@@ -511,7 +511,7 @@ void generate_pilot_lut(COMP pilot_lut[], COMP *pilot_freq)
 
 \*---------------------------------------------------------------------------*/
 
-void lpf_peak_pick(float *foff, float *max, COMP pilot_baseband[], COMP pilot_lpf[], COMP s[], int nin)
+void lpf_peak_pick(float *foff, float *max, COMP pilot_baseband[], COMP pilot_lpf[], COMP S[], int nin)
 {
     int   i,j,k;
     int   mpilot;
@@ -533,22 +533,20 @@ void lpf_peak_pick(float *foff, float *max, COMP pilot_baseband[], COMP pilot_lp
 
     mpilot = FS/(2*200);  /* calc decimation rate given new sample rate is twice LPF freq */
     for(i=0; i<MPILOTFFT; i++) {
-       s[i].real = 0.0; s[i].imag = 0.0;
+       S[i].real = 0.0; S[i].imag = 0.0;
     }
-
     for(i=0,j=0; i<NPILOTLPF; i+=mpilot,j++) {
-       s[j] = fcmult(hanning[i], pilot_lpf[i]);
-       //s[j] = pilot_lpf[i];
+       S[j] = fcmult(hanning[i], pilot_lpf[i]);
     }
-#ifdef TT
-    fft(&s[0].real, MPILOTFFT, 1);
+
+    fft(&S[0].real, MPILOTFFT, -1);
 
     /* peak pick and convert to Hz */
 
     imax = 0.0;
     ix = 0;
     for(i=0; i<MPILOTFFT; i++) {
-       mag = s[i].real*s[i].real + s[i].imag*s[i].imag;
+       mag = sqrt(S[i].real*S[i].real + S[i].imag*S[i].imag);
        if (mag > imax) {
            imax = mag;
            ix = i;
@@ -561,7 +559,7 @@ void lpf_peak_pick(float *foff, float *max, COMP pilot_baseband[], COMP pilot_lp
     else
        *foff = (ix)*r;
     *max = imax;
-#endif
+
 }
 
 /*---------------------------------------------------------------------------*\
@@ -618,19 +616,13 @@ float rx_est_freq_offset(struct FDMDV *f, float rx_fdm[], int nin)
        f->pilot_baseband2[j] = fcmult(rx_fdm[i], cconj(prev_pilot[i]));
     }
 
-    lpf_peak_pick(&foff1, &max1, f->pilot_baseband1, f->pilot_lpf1, f->s1, nin);
-    lpf_peak_pick(&foff2, &max2, f->pilot_baseband2, f->pilot_lpf2, f->s2, nin);
-    //for(i=0; i<MPILOTFFT; i++) {
-    // printf("%f %f\n", f->s1[i].real, f->s1[i].imag);
-    //}
+    lpf_peak_pick(&foff1, &max1, f->pilot_baseband1, f->pilot_lpf1, f->S1, nin);
+    lpf_peak_pick(&foff2, &max2, f->pilot_baseband2, f->pilot_lpf2, f->S2, nin);
 
-#ifdef T
     if (max1 > max2)
        foff = foff1;
     else
        foff = foff2;
        
     return foff;
-#endif
-    return 0;
 }

diff --git a/codec2-dev/src/fdmdv_internal.h b/codec2-dev/src/fdmdv_internal.h
index 68d334b0db87e1c25d999c36f8753a25f9982b6c..47bee78da65efe6acd995ad72e6dad8ab5b18049 100644 (file)
--- a/codec2-dev/src/fdmdv_internal.h
+++ b/codec2-dev/src/fdmdv_internal.h
@@ -85,8 +85,8 @@ struct FDMDV {
     COMP pilot_baseband2[NPILOTBASEBAND];
     COMP pilot_lpf1[NPILOTLPF];
     COMP pilot_lpf2[NPILOTLPF];
-    COMP s1[MPILOTFFT];
-    COMP s2[MPILOTFFT];
+    COMP S1[MPILOTFFT];
+    COMP S2[MPILOTFFT];
 };
 
 /*---------------------------------------------------------------------------*\
@@ -101,6 +101,6 @@ void fdm_upconvert(COMP tx_fdm[], COMP tx_baseband[NC+1][M], COMP phase_tx[], CO
 void generate_pilot_fdm(COMP *pilot_fdm, int *bit, float *symbol, float *filter_mem, COMP *phase, COMP *freq);
 void generate_pilot_lut(COMP pilot_lut[], COMP *pilot_freq);
 float rx_est_freq_offset(struct FDMDV *f, float rx_fdm[], int nin);
-void lpf_peak_pick(float *foff, float *max, COMP pilot_baseband[], COMP pilot_lpf[], COMP s[], int nin);
+void lpf_peak_pick(float *foff, float *max, COMP pilot_baseband[], COMP pilot_lpf[], COMP S[], int nin);
 
 #endif

diff --git a/codec2-dev/unittest/tfdmdv.c b/codec2-dev/unittest/tfdmdv.c
index f2b3bd63286ae1c83e15d5dad9de244954b3414c..ae11da2d9fbabe8e1c1e3c2b503fd00dc4b5ed52 100644 (file)
--- a/codec2-dev/unittest/tfdmdv.c
+++ b/codec2-dev/unittest/tfdmdv.c
@@ -60,8 +60,8 @@ int main(int argc, char *argv[])
     COMP          pilot_baseband2_log[NPILOTBASEBAND*FRAMES];
     COMP          pilot_lpf1_log[NPILOTLPF*FRAMES];
     COMP          pilot_lpf2_log[NPILOTLPF*FRAMES];
-    COMP          s1_log[32*FRAMES];
-    COMP          s2_log[32*FRAMES];
+    COMP          S1_log[MPILOTFFT*FRAMES];
+    COMP          S2_log[MPILOTFFT*FRAMES];
 
     FILE         *fout;
     int           f,c,i;
@@ -97,8 +97,8 @@ int main(int argc, char *argv[])
        memcpy(&pilot_baseband2_log[f*NPILOTBASEBAND], fdmdv->pilot_baseband2, sizeof(COMP)*NPILOTBASEBAND);
        memcpy(&pilot_lpf1_log[f*NPILOTLPF], fdmdv->pilot_lpf1, sizeof(COMP)*NPILOTLPF);
        memcpy(&pilot_lpf2_log[f*NPILOTLPF], fdmdv->pilot_lpf2, sizeof(COMP)*NPILOTLPF);
-       memcpy(&s1_log[f*32], fdmdv->s1, sizeof(COMP)*32);
-       memcpy(&s2_log[f*32], fdmdv->s2, sizeof(COMP)*32);
+       memcpy(&S1_log[f*MPILOTFFT], fdmdv->S1, sizeof(COMP)*MPILOTFFT);
+       memcpy(&S2_log[f*MPILOTFFT], fdmdv->S2, sizeof(COMP)*MPILOTFFT);
     }
 
     /* dump logs to Octave file for evaluation by tfdmdv.m Octave script */
@@ -115,8 +115,8 @@ int main(int argc, char *argv[])
     octave_save_complex(fout, "pilot_baseband2_log_c", pilot_baseband2_log, 1, NPILOTBASEBAND*FRAMES);  
     octave_save_complex(fout, "pilot_lpf1_log_c", pilot_lpf1_log, 1, NPILOTLPF*FRAMES);  
     octave_save_complex(fout, "pilot_lpf2_log_c", pilot_lpf2_log, 1, NPILOTLPF*FRAMES);  
-    octave_save_complex(fout, "s1_log_c", s1_log, 1, 32*FRAMES);  
-    octave_save_complex(fout, "s2_log_c", s2_log, 1, 32*FRAMES);  
+    octave_save_complex(fout, "S1_log_c", S1_log, 1, MPILOTFFT*FRAMES);  
+    octave_save_complex(fout, "S2_log_c", S2_log, 1, MPILOTFFT*FRAMES);  
     fclose(fout);
 
     codec2_destroy(fdmdv);