Merge branch 'full-grid-search-standalone' of https://github.com/joebre/gnss-sdr into joebre-full-grid-search-standalone

docs/CHANGELOG.md

@@ -62,6 +62,15 @@ All notable changes to GNSS-SDR will be documented in this file.
 
 ### Improvements in Availability:
 
+- Added `Acquisition_XX.full_grid_search` (default: `false`) for acquisition
+  implementations using the CPU PCPS block. When enabled, each search stage
+  accumulates all `max_dwells` non-coherent integrations before accepting or
+  rejecting the strongest peak. This also applies to both stages of
+  `make_two_steps` and to the reduced grid used by `enable_doppler_narrowing`.
+  The default preserves early acceptance; `max_dwells=1` is unchanged.
+  `bit_transition_flag=true` takes precedence and still uses a single
+  double-length dwell. Waiting for all dwells increases acquisition latency.
+  Contributed by @joebre.
 - Improved TOW rollover handling in Telemetry Decoder blocks.
 - Galileo F/NAV and I/NAV ephemerides are now retained independently instead of
   overwriting each other when they have the same PRN. PVT automatically uses the

src/algorithms/acquisition/gnuradio_blocks/pcps_acquisition.cc

@@ -819,19 +819,47 @@ void pcps_acquisition::acquisition_core(uint64_t sample_count)
 
     if (!d_acq_parameters.bit_transition_flag)
         {
-            if (result.test_statistics > get_threshold())
+            if (d_acq_parameters.full_grid_search)
                 {
-                    handle_threshold_reached(result);
+                    // Search the entire acquisition grid (accumulate through the full max_dwells)
+                    // before deciding accept/reject, instead of exiting as soon as any single dwell's
+                    // (possibly still noisy, partially non-coherently accumulated) grid crosses
+                    // threshold -- a later dwell's fuller integration can reveal a different, genuinely
+                    // stronger peak elsewhere in the same grid that an early exit never gets the chance
+                    // to compare against.
+                    if (d_num_noncoherent_integrations_counter == d_acq_parameters.max_dwells)
+                        {
+                            if (result.test_statistics > get_threshold())
+                                {
+                                    handle_threshold_reached(result);
+                                }
+                            else
+                                {
+                                    handle_integration_done(result);
+                                }
+                        }
+                    else
+                        {
+                            d_buffer_sample_count = 0;
+                            d_state = 1;
+                        }
                 }
             else
                 {
-                    d_buffer_sample_count = 0;
-                    d_state = 1;
-                }
+                    if (result.test_statistics > get_threshold())
+                        {
+                            handle_threshold_reached(result);
+                        }
+                    else
+                        {
+                            d_buffer_sample_count = 0;
+                            d_state = 1;
+                        }
 
-            if (d_num_noncoherent_integrations_counter == d_acq_parameters.max_dwells)
-                {
-                    handle_integration_done(result);
+                    if (d_num_noncoherent_integrations_counter == d_acq_parameters.max_dwells)
+                        {
+                            handle_integration_done(result);
+                        }
                 }
         }
     else

src/algorithms/acquisition/libs/acq_conf.cc

@@ -83,6 +83,7 @@ void Acq_Conf::SetFromConfiguration(const ConfigurationInterface *configuration,
     make_2_steps = configuration->property(role + ".make_two_steps", make_2_steps);
     blocking_on_standby = configuration->property(role + ".blocking_on_standby", blocking_on_standby);
     enable_doppler_narrowing = configuration->property(role + ".enable_doppler_narrowing", enable_doppler_narrowing);
+    full_grid_search = configuration->property(role + ".full_grid_search", full_grid_search);
 
     if (pfa <= 0.0)
         {

src/algorithms/acquisition/libs/acq_conf.h

@@ -92,6 +92,14 @@ public:
     // flag has no effect and the full configured Doppler grid is always searched.
     bool enable_doppler_narrowing{false};
 
+    // Accumulate through the full max_dwells before deciding accept/reject, instead
+    // of exiting as soon as any single dwell's (possibly still noisy, partially
+    // accumulated) grid crosses threshold -- a later dwell's fuller integration can
+    // reveal a different, genuinely stronger peak elsewhere in the grid that an early
+    // exit never gets the chance to compare against. Opt-in: off by default, enable
+    // per-implementation in the .conf (e.g. Acquisition_1B.full_grid_search = true).
+    bool full_grid_search{false};
+
     // Specific to some implementations
     bool acquire_pilot{false};
     bool acquire_iq{false};