Changeset 5463

Timestamp:

10/20/07 21:33:18 (6 years ago)

Author:

jgaeddert

Message:

fixing loop filter coefficients to work with matched filter delay

Location:

experimental/components/SymbolSyncPoly/branches/SymbolSyncPoly-metadata/src

Files:

• FrameSynchronizer.cpp (modified) (1 diff)
• FrameSynchronizerDSP.cpp (modified) (10 diffs)
• FrameSynchronizerDSP.h (modified) (2 diffs)

experimental/components/SymbolSyncPoly/branches/SymbolSyncPoly-metadata/src/FrameSynchronizer.cpp

@@ -304 +304 @@
             I_in, Q_in, N_in, num_read,
             I_out, Q_out, buf_len, num_written);
+        //printf("fs cv = %f\n", cv/(2*PI));
 
         DEBUG(7, FrameSynchronizer, "Emptying port buffer...")

experimental/components/SymbolSyncPoly/branches/SymbolSyncPoly-metadata/src/FrameSynchronizerDSP.cpp

@@ -51 +51 @@
     q_hat_cl = 0.0f;
     q_prime_cl = 0.0f;
-    UpdateCostasLoopFilterCoefficients(0.001f);
+    UpdateCostasLoopFilterCoefficients(0.02f);
 
 #ifdef FS_LOGGING
@@ -79 +79 @@
     unsigned int &num_written)
 {
-    unsigned int i;
+    alpha_s = 0.027f;
+    beta_s = 1.02f;
+
+    int i(0);
     short I, Q;
     num_read = 0;
@@ -85 +88 @@
     //printf("nco CV = %f\n", cv/(2*PI));
 
-    for (i=0; i<input_length; i++) {
+    while ( i < (signed int) input_length ) {
         v++;
 
@@ -92 +95 @@
         //I = I_in[i];
         //Q = Q_in[i];
+        i++;
 
         // push samples into buffer
@@ -100 +104 @@
         
         // compute costas loop phase error on matched-filter outputs
-        //pd2_cl = GenerateCostasLoopPhaseError(mf_i, mf_q);
-        pd2_cl = GenerateCostasLoopPhaseError(I, Q);
+        ///\todo matched filter output won't work because of delay
+        //pd2_cl = GenerateCostasLoopPhaseError(I, Q);
+        pd2_cl = GenerateCostasLoopPhaseError(mf_i, mf_q);
         pd2_cl /= Ac;
         
@@ -109 +114 @@
         // update nco
         UpdateNCO();
+            //I_out[num_written] = mf_i;
+            //Q_out[num_written] = mf_q;
+            //num_written++;
 
         // decimate
@@ -117 +125 @@
             Q_out[num_written] = mf_q;
             num_written++;
+            //printf("I = %d, Q = %d\n", mf_i, mf_q);
 
             // generate timing error
@@ -133 +142 @@
                 break;
             case SKIP:
-                i++;
+                v--;
+                //printf("skip\n");
                 lc = SHIFT;
                 break;
             case STUFF:
-                i--;
+                v++;
+                //printf("stuff\n");
                 lc = SHIFT;
                 break;
@@ -150 +161 @@
                 r_frame_sync = abs(r);
                 std::cout << "PN FRAME SYNC CODE FOUND!!!" << std::endl;
+                std::cout << "  r = " << r_frame_sync << std::endl;
 
                 // check for phase inversion; if so inject pi radians into NCO
@@ -175 +187 @@
     
     num_read = input_length;
+    return false;
+}
+
+// Find frame header
+bool FrameSynchronizerDSP::ExtractFrameHeader(
+    short * I_in,
+    short * Q_in,
+    unsigned int input_length,
+    unsigned int &num_read,
+    short * I_out,
+    short * Q_out,
+    unsigned int output_length,
+    unsigned int &num_written)
+{
+    unsigned int i;
+    short I, Q;
+    num_read = 0;
+    num_written = 0;
     return false;
 }

experimental/components/SymbolSyncPoly/branches/SymbolSyncPoly-metadata/src/FrameSynchronizerDSP.h

@@ -68 +68 @@
         short * I_in,
         short * Q_in,
-        unsigned int N_in,
-        unsigned int &num_read);
+        unsigned int input_length,
+        unsigned int &num_read,
+        short * I_out,
+        short * Q_out,
+        unsigned int output_length,
+        unsigned int &num_written);
 
     /// \brief Decodes the frame header information
@@ -139 +143 @@
         alpha_cl = 2*XI*beta_cl;
 
-        //beta_cl /= Ac;
-        //alpha_cl /= Ac;
+        printf("\n\nbeta_cl = %f\n\n\n", beta_cl);
+        printf("\n\nalpha_cl = %f\n\n\n", alpha_cl);
 
+        ///\todo this is necessary because of the delay introduced by the filter
+        beta_cl /= 30.0f;
     };