[Commit-gnuradio] r5724 - gnuradio/branches/features/ofdm/sync/gnuradio-core/src/lib/general

[trondeau]

Author: trondeau
Date: 2007-06-06 19:43:02 -0600 (Wed, 06 Jun 2007)
New Revision: 5724

Modified:
   
gnuradio/branches/features/ofdm/sync/gnuradio-core/src/lib/general/gr_ofdm_qam_mapper.cc
   
gnuradio/branches/features/ofdm/sync/gnuradio-core/src/lib/general/gr_ofdm_qam_mapper.h
Log:
quick hack to get QAM16 to work

Modified: 
gnuradio/branches/features/ofdm/sync/gnuradio-core/src/lib/general/gr_ofdm_qam_mapper.cc
===================================================================
--- 
gnuradio/branches/features/ofdm/sync/gnuradio-core/src/lib/general/gr_ofdm_qam_mapper.cc
    2007-06-06 23:09:49 UTC (rev 5723)
+++ 
gnuradio/branches/features/ofdm/sync/gnuradio-core/src/lib/general/gr_ofdm_qam_mapper.cc
    2007-06-07 01:43:02 UTC (rev 5724)
@@ -72,24 +72,30 @@
   
   if(!ok)
     throw std::invalid_argument("Order M must be [2, 4, 16, 64, 256]");  
+
+  make_constellation();
 }
 
 gr_ofdm_qam_mapper::~gr_ofdm_qam_mapper(void)
 {
 }
 
-void gr_ofdm_qam_mapper::make_constellation(int m)
+void gr_ofdm_qam_mapper::make_constellation()
 {
   int i = 0, j = 0, ii = 0, jj = 0;
   // number of bits/symbol (log2(M))
-  int k = (int)(log10(m) / log10(2.0));
+  int k = (int)(log10(d_mod_order) / log10(2.0));
 
   int a, b;
   float re, im;
   float coeff = 1;
   std::vector<int> bits_i, bits_q;
 
-  for(i=0; i < m; i++) {
+  int rr = 0;
+  int ss = 0;
+  int ll = bits_i.size();
+
+  for(i=0; i < d_mod_order; i++) {
     a = (i & (0x01 << (k-1))) >> (k-1);
     b = (i & (0x01 << (k-2))) >> (k-2);
     for(j=2; j < k; j+=2) {
@@ -97,38 +103,57 @@
       bits_q.push_back( (i & (0x01 << (k-(j+1)-1))) >> (k-(j+1)-1));
     }
     
-    int ss = 0;
-    int ll = bits_i.size();
-    for(ii = 0; i < ll; i++) {
-      int rr = 0;
+    ss = 0;
+    ll = bits_i.size();
+    for(ii = 0; ii < ll; ii++) {
+      rr = 0;
       for(jj = 0; jj < (ll-ii); jj++) {
        rr = abs(bits_i[jj] - rr);
-       ss += rr * pow(2.0, ii+1);
       }
-      re = (2.0*a-1.0)*(ss+1.0);
-      
-      ss = 0;
-      ll = bits_q.size();
-      for(ii = 0; ii < ll; ii++) {
-       rr = 0;
-       for(jj = 0; jj < (ll-ii); jj++) {
-         rr = abs(bits_q[jj] - rr);
-       }
-       ss += rr*pow(2.0, ii+1.0);
+      ss += rr * pow(2.0, ii+1.0);
+    }
+    re = (2.0*a-1.0)*(ss+1.0);
+    
+    ss = 0;
+    ll = bits_q.size();
+    for(ii = 0; ii < ll; ii++) {
+      rr = 0;
+      for(jj = 0; jj < (ll-ii); jj++) {
+       rr = abs(bits_q[jj] - rr);
       }
-      im = (2.0*b-1.0)*(ss+1.0);
+      ss += rr*pow(2.0, ii+1.0);
+    }
+    im = (2.0*b-1.0)*(ss+1.0);
       
-      a = std::max(re, im);
-      if(a > coeff) {
-       coeff = a;
-      }
-      d_constellation_map.push_back(gr_complex(re, im));
+    a = std::max(re, im);
+    if(a > coeff) {
+      coeff = a;
     }
-    
-    for(i = 0; i < d_constellation_map.size(); i++) {
-      d_constellation_map[i] /= coeff;
-    }
+    d_constellation_map.push_back(gr_complex(re, im));
   }
+  
+  d_constellation_map[0] = gr_complex(-3, -3);
+  d_constellation_map[1] = gr_complex(-3, -1);
+  d_constellation_map[2] = gr_complex(-3, 1);
+  d_constellation_map[3] = gr_complex(-3, 3);
+  d_constellation_map[4] = gr_complex(-1, -3);
+  d_constellation_map[5] = gr_complex(-1, -1);
+  d_constellation_map[6] = gr_complex(-1, 1);
+  d_constellation_map[7] = gr_complex(-1, 3);
+  d_constellation_map[8] = gr_complex(1, -3);
+  d_constellation_map[9] = gr_complex(1, -1);
+  d_constellation_map[10] = gr_complex(1, 1);
+  d_constellation_map[11] = gr_complex(1, 3);
+  d_constellation_map[12] = gr_complex(3, -3);
+  d_constellation_map[13] = gr_complex(3, -1);
+  d_constellation_map[14] = gr_complex(3, 1);
+  d_constellation_map[15] = gr_complex(3, 3);
+
+  coeff = sqrt(31.0)/2.0;
+  for(i = 0; i < d_constellation_map.size(); i++) {
+    d_constellation_map[i] /= coeff;
+    printf("const[%d]: %f + j%f\n", i, d_constellation_map[i].real(), 
d_constellation_map[i].imag());
+  }
 }
 
 static float
@@ -186,7 +211,15 @@
     unsigned char bit1 = (d_msg->msg()[d_msg_offset] >> (d_bit_offset)) & 0x01;
     d_bit_offset++;
     
-    out[i + zeros_on_left] = gr_complex(-1+2*(bit0), -1+2*(bit1) );
+    unsigned char bit2 = (d_msg->msg()[d_msg_offset] >> (d_bit_offset)) & 0x01;
+    d_bit_offset++;
+    
+    unsigned char bit3 = (d_msg->msg()[d_msg_offset] >> (d_bit_offset)) & 0x01;
+    d_bit_offset++;
+
+    unsigned char bit = (bit0 << 3) | (bit1 << 2) | (bit2 << 1) | (bit3 << 0);
+    
+    out[i + zeros_on_left] = d_constellation_map[bit];
     i++;
     if(d_bit_offset == 8) {
       d_bit_offset = 0;
@@ -197,7 +230,7 @@
   // Ran out of data to put in symbol
   if (d_msg_offset == d_msg->length()) {
     while(i < d_occupied_carriers) {   // finish filling out the symbol
-      out[i + zeros_on_left] = gr_complex(randombit(),0);
+      out[i + zeros_on_left] = d_constellation_map[rand() & 0x0F];
       i++;
     }
 

Modified: 
gnuradio/branches/features/ofdm/sync/gnuradio-core/src/lib/general/gr_ofdm_qam_mapper.h
===================================================================
--- 
gnuradio/branches/features/ofdm/sync/gnuradio-core/src/lib/general/gr_ofdm_qam_mapper.h
     2007-06-06 23:09:49 UTC (rev 5723)
+++ 
gnuradio/branches/features/ofdm/sync/gnuradio-core/src/lib/general/gr_ofdm_qam_mapper.h
     2007-06-07 01:43:02 UTC (rev 5724)
@@ -67,7 +67,7 @@
   int                     d_mod_order;
   std::vector<gr_complex> d_constellation_map;
 
-  void make_constellation(int m);
+  void make_constellation();
 
  public:
   ~gr_ofdm_qam_mapper(void);