[Commit-gnuradio] r7321 - gnuradio/branches/developers/trondeau/ofdm2/gnuradio-core/src/lib/general

[trondeau]

Author: trondeau
Date: 2008-01-01 18:03:51 -0700 (Tue, 01 Jan 2008)
New Revision: 7321

Modified:
   
gnuradio/branches/developers/trondeau/ofdm2/gnuradio-core/src/lib/general/gr_ofdm_frame_acquisition.cc
Log:
Tightening up loop in correlation to find frequency offset. There should be no 
need to look over the entire range. We could probably do even better by 
remembering the last frequency offset and start there.

Modified: 
gnuradio/branches/developers/trondeau/ofdm2/gnuradio-core/src/lib/general/gr_ofdm_frame_acquisition.cc
===================================================================
--- 
gnuradio/branches/developers/trondeau/ofdm2/gnuradio-core/src/lib/general/gr_ofdm_frame_acquisition.cc
      2008-01-01 23:33:40 UTC (rev 7320)
+++ 
gnuradio/branches/developers/trondeau/ofdm2/gnuradio-core/src/lib/general/gr_ofdm_frame_acquisition.cc
      2008-01-02 01:03:51 UTC (rev 7321)
@@ -115,7 +115,7 @@
 
   int index = 0;
   float max = 0, sum=0;
-  for(i = 0; i < d_fft_length - d_occupied_carriers; i++) {
+  for(i =  zeros_on_left - d_freq_shift_len; i < zeros_on_left + 
d_freq_shift_len; i+=2) {
     sum = 0;
     for(j = 0; j < d_occupied_carriers; j++) {
       sum += (d_known_phase_diff[j] * d_symbol_phase_diff[i+j]);