Changeset 8662

Timestamp:

02/05/09 14:54:40 (4 years ago)

Author:

ttsou

Message:

integrated GNU Radio block for clock recovery

Location:

ossiedev/branches/ttsou/dist/components/gmsk_demod

Files:

• config/acx_pthread.m4 (added)
• config/ax_boost_thread.m4 (added)
• configure.ac (modified) (3 diffs)
• gmsk_demod.cpp (modified) (3 diffs)
• gmsk_demod.h (modified) (1 diff)

ossiedev/branches/ttsou/dist/components/gmsk_demod/configure.ac

@@ -20 +20 @@
 
 AX_BOOST_BASE([1.35])
+AX_BOOST_THREAD
 CPPFLAGS="$CPPFLAGS $BOOST_CPPFLAGS"
 CFLAGS="$CFLAGS $BOOST_CPPFLAGS"
@@ -28 +29 @@
 AC_CHECK_HEADERS([standardinterfaces/complexShort.h], [], [AC_MSG_ERROR([cannot find standardInterfaces header files])])
 
+AC_CHECK_LIB([gnuradio-core], [main], [], [AC_MSG_ERROR([cannot find gnuradio library])],[$BOOST_LDFLAGS $BOOST_THREAD_LIB])
+AC_CHECK_HEADERS([gnuradio/gr_count_bits.h], [], [AC_MSG_ERROR([cannot find gnuradio header files])])
+
 AC_LANG_POP
 
@@ -33 +37 @@
 
 PKG_CHECK_MODULES(OSSIE, ossie >= 0.6.0,,exit)
-CXXFLAGS="$CXXFLAGS $OSSIE_CFLAGS"
+CXXFLAGS="$CXXFLAGS $OSSIE_CFLAGS $CPPFLAGS $BOOST_LDFLAGS $BOOST_THREAD_LIB -I/usr/local/include/gnuradio"
 IDL_FLAGS="$OSSIE_CFLAGS"
 AC_SUBST(IDL_FLAGS)

ossiedev/branches/ttsou/dist/components/gmsk_demod/gmsk_demod.cpp

@@ -24 +24 @@
 #include <iostream>
 #include "gmsk_demod.h"
+#include <gr_clock_recovery_mm_ff.h>
 
 gmsk_demod_i::gmsk_demod_i(const char *uuid, omni_condition *condition) : 
@@ -114 +115 @@
     PortTypes::ShortSequence *i_in(NULL), *q_in(NULL);
 
-    std::complex<float> cmplx_prod[i_in_length];
+    std::complex<float> cmplx_prod;;
     std::complex<float> cmplx_cur;
     std::complex<float> cmplx_pre;
-    short demod_out[i_in_length];
-
-    gain = sps * 2 / M_PI;
+
+    unsigned int i_in_len;
+    short i_in_prev = 0;
+    short q_in_prev = 0;
+
+    //
+    // Demod params
+    //
+    unsigned int sps = 4;
+    unsigned int gain = sps * 2 / M_PI;
     float fp_gain = 5000;
-
+    unsigned int pkt_len = 64;
+
+    //
+    // GNU Radio 
+    //
+    gr_vector_int                  ninput_items_required(1);
+    gr_vector_int                  ninput_items(1);
+    gr_vector_const_void_star      input_items;
+    std::vector<bool>              input_done;
+    gr_vector_void_star            output_items;
+    int                            noutput_items;
+
+    float omega;
+    float gain_omega;
+    float mu = 0.5;
+    float gain_mu = 0.175;
+    float omega_relative_limit = 0.005;
+    float freq_err = 0.0;
+
+    omega = sps * (1 + freq_err);
+    gain_omega = 0.25 * gain_mu * gain_mu;
+
+    gr_clock_recovery_mm_ff_sptr gr_clock_recovery =
+        gr_make_clock_recovery_mm_ff(omega, gain_omega, mu, gain_mu);
+
+    gr_clock_recovery->forecast(pkt_len, ninput_items_required);
+
+    //
+    // Processing loop
+    // 
     while (gmsk_demod->processing_active) {
         gmsk_demod->p_in->getData(i_in, q_in);
+        i_in_len = i_in->length();
+        unsigned short demod_out[i_in_len];
 
         //
@@ -129 +168 @@
         //
         cmplx_cur = std::complex<float>((*i_in)[0], (*q_in)[0]);
-        cmplx_pre = std::complex<float>(i_in_save, q_in_save);
-        cmplx_prod[0] = cmplx_cur * conj(cmplx_pre);
-        demod_out[0] = fp_gain * gain * atan( imag(cmplx_prod[0]) / real(cmplx_prod[0]));
-
-        for (unsigned int i=1; i<i_in_length; i++) {
+        cmplx_pre = std::complex<float>(i_in_prev, q_in_prev);
+        cmplx_prod = cmplx_cur * conj(cmplx_pre);
+        demod_out[0] = fp_gain * gain * atan( imag(cmplx_prod) / real(cmplx_prod));
+
+        for (unsigned int i=1; i<i_in_len; i++) {
             cmplx_cur = std::complex<float>((*i_in)[i], (*q_in)[i]);
             cmplx_pre = std::complex<float>((*i_in)[i-1], (*q_in)[i-1]);
-            cmplx_prod[i] = cmplx_cur * conj(cmplx_pre);
-            demod_out[i] = fp_gain * gain * atan( imag(cmplx_prod[i]) / real(cmplx_prod[i]));
+            cmplx_prod = cmplx_cur * conj(cmplx_pre);
+            demod_out[i] = fp_gain * gain * atan( imag(cmplx_prod / real(cmplx_prod)));
         }
 
         //
-        // Floating point hack
-        //
+        // Type conversion
+        //
+        std::vector<const void*> demod_vec(i_in_len);
+        for (unsigned int i=0; i<i_in_len; i++) {
+            demod_vec[i] = (const void*) &demod_out[i];
+        }
 
         //
         // Timing recovery
         //
+        noutput_items = gr_clock_recovery->general_work(pkt_len,
+                                                        ninput_items,
+                                                        demod_vec,
+                                                        output_items);
 
         gmsk_demod->p_in->bufferEmptied();

ossiedev/branches/ttsou/dist/components/gmsk_demod/gmsk_demod.h

@@ -72 +72 @@
 
     // Component specifics
-    unsigned int sps; 
-    short i_in_prev;
-    short q_in_prev;
+    //short i_in_prev;
+    //short q_in_prev;
 };