Changed frequency estimator to the old one that worked better

2 files changed, 8 insertions, 57 deletions

diff --git a/lib/receiver/receiver_impl.cc b/lib/receiver/receiver_impl.cc
index f55d613..f43f6e0 100644
--- a/lib/receiver/receiver_impl.cc
+++ b/lib/receiver/receiver_impl.cc
@@ -82,10 +82,6 @@ receiver_impl::receiver_impl(int osr, const std::vector<int> &cell_allocation, c
     d_last_time(0.0)
 {
     int i;
-
-    unsigned int alignment = volk_get_alignment();
-    d_freq_estim_vector = (lv_32fc_t*)volk_malloc(sizeof(lv_32fc_t)*160, alignment);
-    d_freq_estim_result = (lv_32fc_t*)volk_malloc(sizeof(lv_32fc_t)*1, alignment);
                                                                       //don't send samples to the receiver until there are at least samples for one
     set_output_multiple(floor((TS_BITS + 2 * GUARD_PERIOD) * d_OSR)); // burst and two gurad periods (one gurard period is an arbitrary overlap)
     gmsk_mapper(SYNC_BITS, N_SYNC_BITS, d_sch_training_seq, gr_complex(0.0, -1.0));
@@ -106,8 +102,6 @@ receiver_impl::receiver_impl(int osr, const std::vector<int> &cell_allocation, c
  */
 receiver_impl::~receiver_impl()
 {
-    volk_free(d_freq_estim_vector);
-    volk_free(d_freq_estim_result);
 }
 
 int
@@ -294,7 +288,7 @@ receiver_impl::work(int noutput_items,
 
                 dummy_burst_start = get_norm_chan_imp_resp(input, &channel_imp_resp[0], &dummy_corr_max, TS_DUMMY);
                 normal_burst_start = get_norm_chan_imp_resp(input, &channel_imp_resp[0], &normal_corr_max, d_bcc);
-                            
+
                 if (normal_corr_max > dummy_corr_max)
                 {
                     d_c0_burst_start = normal_burst_start;
@@ -545,59 +539,20 @@ double receiver_impl::estim_freq_norm(const gr_complex * input, unsigned first_s
 
     unsigned ii;
 
-    gr_complex sum = 0;
+    double sum = 0;
 
-    for (ii = first_sample; ii < last_sample-d_OSR; ii=ii+d_OSR)
+    for (ii = first_sample; ii < last_sample-1; ii++)
     {
-        sum += input[ii+d_OSR] * conj(input[ii]);
+        sum += fast_atan2f(input[ii+1] * conj(input[ii]));
     }
-
-    return fast_atan2f(imag(sum), real(sum))/(2*M_PI);
+    int N = last_sample-1-first_sample;
+    return sum/(2*M_PI)/N * d_OSR;
 }
 
-double receiver_impl::estim_freq_norm2(const gr_complex * input, unsigned first_sample, unsigned last_sample) //another frequency estimator - faster one
-{
-
-    unsigned ii;
-
-    int N = (last_sample-first_sample)/d_OSR;
-    
-    for (unsigned ii = 0; ii < N; ii++)
-    {
-        d_freq_estim_vector[ii] = input[first_sample+ii*d_OSR];
-    }
-
-    volk_32fc_x2_conjugate_dot_prod_32fc(d_freq_estim_result, d_freq_estim_vector+1, d_freq_estim_vector, N-1);
-    
-    return fast_atan2f(imag(d_freq_estim_result[0]), real(d_freq_estim_result[0]))/(2*M_PI);
-}
-
-
 double receiver_impl::compute_freq_offset(const gr_complex * input, unsigned first_sample, unsigned last_sample)
 {
-    float freq_norm = estim_freq_norm2(input, first_sample, last_sample);
-
-//    using namespace std;
-//    clock_t begin = clock();
-//  
-//    for(int ii=0;ii<500;ii++){
-//        float dupa = estim_freq_norm2(input, first_sample, last_sample);
-//    }
-//    clock_t end = clock();
-//    double elapsed_secs = double(end - begin) / CLOCKS_PER_SEC;  
-//    std::cout << "elapsed_secs " << elapsed_secs << std::endl;
-
-//    begin = clock();
-//  
-//    for(int ii=0;ii<500;ii++){
-//        float dupa = estim_freq_norm(input, first_sample, last_sample);
-//    }
-//    end = clock();
-//    elapsed_secs = double(end - begin) / CLOCKS_PER_SEC;  
-//    std::cout << "elapsed_secs_old " << elapsed_secs << std::endl;
-  
+    float freq_norm = estim_freq_norm(input, first_sample, last_sample);
     float freq_offset = (freq_norm - 0.25) * 1625000.0/6.0;
-    
     return freq_offset;
 }
 
diff --git a/lib/receiver/receiver_impl.h b/lib/receiver/receiver_impl.h
index eb406f3..251cf55 100644
--- a/lib/receiver/receiver_impl.h
+++ b/lib/receiver/receiver_impl.h
@@ -37,9 +37,6 @@ namespace gr {
         unsigned int d_c0_burst_start;
         float d_c0_signal_dbm;
         
-        lv_32fc_t* d_freq_estim_vector;//  = (lv_32fc_t*)volk_malloc(sizeof(lv_32fc_t)*160, alignment);
-        lv_32fc_t* d_freq_estim_result;// = (lv_32fc_t*)volk_malloc(sizeof(lv_32fc_t)*1, alignment);
-        
         /**@name Configuration of the receiver */
         //@{
         const int d_OSR; ///< oversampling ratio
@@ -112,8 +109,7 @@ namespace gr {
          */
         double compute_freq_offset(const gr_complex * input, unsigned first_sample, unsigned last_sample);
 
-        double estim_freq_norm(const gr_complex * input, unsigned first_sample, unsigned last_sample); //another frequency estimator
-        double estim_freq_norm2(const gr_complex * input, unsigned first_sample, unsigned last_sample); //another frequency estimator        
+        double estim_freq_norm(const gr_complex * input, unsigned first_sample, unsigned last_sample); //normalized frequency estimator
         /** Computes angle between two complex numbers
          *
          * @param val1 first complex number