bug fixed

* the big switch statement in lib/adaptive_dfe_impl.cc needs to be improved

examples/.gitignore

@@ -0,0 +1,2 @@
+top_block.py
+*.wav

lib/adaptive_dfe_impl.cc

@@ -159,16 +159,17 @@ adaptive_dfe_impl::general_work(int noutput_items,
   gr_complex const* in = (gr_complex const *)input_items[0];
   gr_complex *out = (gr_complex *)output_items[0];
 
-  int nout = 0;
+  int nout = 0; // counter for produced output items
-  int i = 0;
+  int i    = 0; // counter for consumed input items
   for (; i<ninput_items[0] && nout < noutput_items;) {
     assert(nout < noutput_items);
-
+    switch (_state) {
-    if (_state == WAIT_FOR_PREAMBLE) {
+      case WAIT_FOR_PREAMBLE: {
         insert_sample(in[i++]);
         uint64_t offset = 0;
         float phase_est = 0;
         if (get_correlation_tag(i, offset, phase_est)) {
+          GR_LOG_DEBUG(d_logger, "next state > INITIAL_DOPPLER_ESTIMATE");
           _state = INITIAL_DOPPLER_ESTIMATE;
           _sample_counter = 0;
           _symbol_counter = 0;
@@ -193,9 +194,11 @@ adaptive_dfe_impl::general_work(int noutput_items,
             PyErr_Print();
           }
         }
+        break;
       } // WAIT_FOR_PREAMBLE
 
-    if (_state == INITIAL_DOPPLER_ESTIMATE) {
+      case INITIAL_DOPPLER_ESTIMATE: {
+        _samples.push_back(in[i++]);
         // buffer samples and replay them later once the initial doppler estimate is there
         if (_samples.size() == _sps * _symbols.size()) {
           GILLock gil_lock;
@@ -205,8 +208,9 @@ adaptive_dfe_impl::general_work(int noutput_items,
             if (!update_doppler_information(_physicalLayer.attr("get_doppler")
                                             (complex_vector_to_ndarray(empty_vec),
                                              complex_vector_to_ndarray(_samples)))) {
+              GR_LOG_DEBUG(d_logger, "next state > WAIT_FOR_PREAMBLE");
               _state = WAIT_FOR_PREAMBLE;
-            continue;
+              break;
             }
           } catch (boost::python::error_already_set const&) {
             PyErr_Print();
@@ -229,16 +233,18 @@ adaptive_dfe_impl::general_work(int noutput_items,
               out[nout++] = filter();
           }
           if (_samples.empty()) {
+            GR_LOG_DEBUG(d_logger,"next state > DO_FILTER");
             _state = DO_FILTER;
+            break;
           } else {
+            GR_LOG_DEBUG(d_logger, "next state > INITIAL_DOPPLER_ESTIMATE_CONTINUE");
             _state = INITIAL_DOPPLER_ESTIMATE_CONTINUE;
+            break;
           }
-        continue;
         }
-      _samples.push_back(in[i++]);
       } // INITIAL_DOPPLER_ESTIMATE_CONTINUE
 
-    if (_state == INITIAL_DOPPLER_ESTIMATE_CONTINUE) {
+      case INITIAL_DOPPLER_ESTIMATE_CONTINUE: {
         GR_LOG_DEBUG(d_logger, "INITIAL_DOPPLER_ESTIMATE_CONTINUE");
         while (!_samples.empty() && nout < noutput_items) {
           insert_sample(_samples.back());
@@ -248,23 +254,29 @@ adaptive_dfe_impl::general_work(int noutput_items,
             out[nout++] = filter();
         }
         if (_samples.empty()) {
+          GR_LOG_DEBUG(d_logger, "next state > DO_FILTER");
           _state = DO_FILTER;
         } else {
+          GR_LOG_DEBUG(d_logger, "next state > INITIAL_DOPPLER_ESTIMATE_CONTINUE");
           _state = INITIAL_DOPPLER_ESTIMATE_CONTINUE;
         }
-      continue;
+        break;
       } // INITIAL_DOPPLER_ESTIMATE_CONTINUE
 
-    if (_state == DO_FILTER) {
+      case DO_FILTER: {
         if ((_sample_counter%_sps) == 0) {
           if (_symbol_counter == _symbols.size()) { // frame is ready
             _symbol_counter = 0;
             GILLock gil_lock;
             try {
               // update doppler estimate
-            update_doppler_information(_physicalLayer.attr("get_doppler")
+              if (!update_doppler_information(_physicalLayer.attr("get_doppler")
                                               (complex_vector_to_ndarray(_descrambled_symbols),
-                                        complex_vector_to_ndarray(_samples)));
+                                               complex_vector_to_ndarray(_samples)))) {
+                GR_LOG_DEBUG(d_logger, "next state > WAIT_FOR_PREAMBLE");
+                _state = WAIT_FOR_PREAMBLE;
+                break;
+              }
               // publish soft decisions
               if (!_vec_soft_decisions.empty()) {
                 unsigned int const bits_per_symbol = _constellations[_constellation_index]->bits_per_symbol();
@@ -289,8 +301,6 @@ adaptive_dfe_impl::general_work(int noutput_items,
             _ignore_filter_updates -= 1;
           }
         } // (_sample_counter%_sps) == 0
-
-
         if (_need_samples) {
           _samples.push_back(_hist_samples[_hist_sample_index+_nB+1]);
         }
@@ -302,6 +312,7 @@ adaptive_dfe_impl::general_work(int noutput_items,
         }
         _sample_counter += 1;
       } // DO_FILTER
+    } // switch _state
   } // next input sample
 
   consume(0, i);
@@ -522,7 +533,6 @@ bool adaptive_dfe_impl::update_doppler_information(boost::python::object obj)
   assert(n==2);
   bool  const do_continue = boost::python::extract<bool>(obj[0]);
   if (!do_continue) {
-    _state = WAIT_FOR_PREAMBLE;
     _phase = 0;
     _df    = 0;
     std::fill_n(_hist_samples, 2*(_nB+_nF+1), gr_complex(0));

python/physical_layer/MIL_STD_188_110C.py

@@ -0,0 +1,232 @@
+## -*- python -*-
+
+from __future__ import print_function
+import numpy as np
+
+def n_psk(n,x):
+    return np.complex64(np.exp(2j*np.pi*x/n))
+
+## ---- constellations -----------------------------------------------------------
+CONST_DTYPE=np.dtype([('points',  np.complex64),
+                      ('symbols', np.uint8)])
+BPSK=np.array(zip(np.exp(2j*np.pi*np.arange(2)/2), range(2)), CONST_DTYPE)
+QPSK=np.array(zip(np.exp(2j*np.pi*np.arange(4)/4), [0,1,3,2]), CONST_DTYPE)
+PSK8=np.array(zip(np.exp(2j*np.pi*np.arange(8)/8), [0,1,3,2,7,6,4,5]), CONST_DTYPE)
+QAM16=np.array(
+    zip([+0.866025+0.500000j,  0.500000+0.866025j,  1.000000+0.000000j,  0.258819+0.258819j,
+         -0.500000+0.866025j,  0.000000+1.000000j, -0.866025+0.500000j, -0.258819+0.258819j,
+         +0.500000-0.866025j,  0.000000-1.000000j,  0.866025-0.500000j,  0.258819-0.258819j,
+         -0.866025-0.500000j, -0.500000-0.866025j, -1.000000+0.000000j, -0.258819-0.258819j],
+        range(16)), CONST_DTYPE)
+QAM32=np.array(
+    zip([+0.866380+0.499386j,  0.984849+0.173415j,  0.499386+0.866380j,  0.173415+0.984849j,
+         +0.520246+0.520246j,  0.520246+0.173415j,  0.173415+0.520246j,  0.173415+0.173415j,
+         -0.866380+0.499386j, -0.984849+0.173415j, -0.499386+0.866380j, -0.173415+0.984849j,
+         -0.520246+0.520246j, -0.520246+0.173415j, -0.173415+0.520246j, -0.173415+0.173415j,
+         +0.866380-0.499386j,  0.984849-0.173415j,  0.499386-0.866380j,  0.173415-0.984849j,
+         +0.520246-0.520246j,  0.520246-0.173415j,  0.173415-0.520246j,  0.173415-0.173415j,
+         -0.866380-0.499386j, -0.984849-0.173415j, -0.499386-0.866380j, -0.173415-0.984849j,
+         -0.520246-0.520246j, -0.520246-0.173415j, -0.173415-0.520246j, -0.173415-0.173415j],
+        range(32)), CONST_DTYPE)
+QAM64=np.array(
+    zip([+1.000000+0.000000j,  0.822878+0.568218j,  0.821137+0.152996j,  0.932897+0.360142j,
+         +0.000000-1.000000j,  0.822878-0.568218j,  0.821137-0.152996j,  0.932897-0.360142j,
+         +0.568218+0.822878j,  0.588429+0.588429j,  0.588429+0.117686j,  0.588429+0.353057j,
+         +0.568218-0.822878j,  0.588429-0.588429j,  0.588429-0.117686j,  0.588429-0.353057j,
+         +0.152996+0.821137j,  0.117686+0.588429j,  0.117686+0.117686j,  0.117686+0.353057j,
+         +0.152996-0.821137j,  0.117686-0.588429j,  0.117686-0.117686j,  0.117686-0.353057j,
+         +0.360142+0.932897j,  0.353057+0.588429j,  0.353057+0.117686j,  0.353057+0.353057j,
+         +0.360142-0.932897j,  0.353057-0.588429j,  0.353057-0.117686j,  0.353057-0.353057j,
+         +0.000000+1.000000j, -0.822878+0.568218j, -0.821137+0.152996j, -0.932897+0.360142j,
+         -1.000000+0.000000j, -0.822878-0.568218j, -0.821137-0.152996j, -0.932897-0.360142j,
+         -0.568218+0.822878j, -0.588429+0.588429j, -0.588429+0.117686j, -0.588429+0.353057j,
+         -0.568218-0.822878j, -0.588429-0.588429j, -0.588429-0.117686j, -0.588429-0.353057j,
+         -0.152996+0.821137j, -0.117686+0.588429j, -0.117686+0.117686j, -0.117686+0.353057j,
+         -0.152996-0.821137j, -0.117686-0.588429j, -0.117686-0.117686j, -0.117686-0.353057j,
+         -0.360142+0.932897j, -0.353057+0.588429j, -0.353057+0.117686j, -0.353057+0.353057j,
+         -0.360142-0.932897j, -0.353057-0.588429j, -0.353057-0.117686j, -0.353057-0.353057j],
+        range(64)), CONST_DTYPE)
+
+## ---- constellation indices ---------------------------------------------------
+MODE_BPSK  = 0
+MODE_QPSK  = 1
+MODE_8PSK  = 2
+MODE_16QAM = 3
+MODE_32QAM = 4
+MODE_64QAM = 5
+
+## ---- data scrambler -----------------------------------------------------------
+class ScrambleData(object):
+    """data scrambling sequence generator"""
+    def __init__(self):
+        self.reset()
+
+    def reset(self):
+        self._state = 1
+
+    def next(self, num_bits):
+        r = self._state & ((1<<num_bits)-1)
+        for i in range(num_bits):
+            self._advance()
+        return r
+
+    def _advance(self):
+        lsb = self._state&1
+        self._state = (self._state>>1)&511
+        if lsb:
+            self._state ^= 0x10B
+        return self._state
+
+## ---- preamble definitions  ---------------------------------------------------
+## 184 = 8*23
+PREAMBLE=np.array(
+    [1,5,1,3,6,1,3,1,1,6,3,7,7,3,5,4,3,6,6,4,5,4,0,
+     2,2,2,6,0,7,5,7,4,0,7,5,7,1,6,1,0,5,2,2,6,2,3,
+     6,0,0,5,1,4,2,2,2,3,4,0,6,2,7,4,3,3,7,2,0,2,6,
+     4,4,1,7,6,2,0,6,2,3,6,7,4,3,6,1,3,7,4,6,5,7,2,
+     0,1,1,1,4,4,0,0,5,7,7,4,7,3,5,4,1,6,5,6,6,4,6,
+     3,4,3,0,7,1,3,4,7,0,1,4,3,3,3,5,1,1,1,4,6,1,0,
+     6,0,1,3,1,4,1,7,7,6,3,0,0,7,2,7,2,0,2,6,1,1,1,
+     2,7,7,5,3,3,6,0,5,3,3,1,0,7,1,1,0,3,0,4,0,7,3],
+    dtype=np.uint8)
+
+## 103 = 31 + 1 + 3*13 + 1 + 31
+REINSERTED_PREAMBLE=np.array(
+    [0,0,0,0,0,2,4,6,0,4,0,4,0,6,4,2,0,0,0,0,0,2,4,6,0,4,0,4,0,6,4, ## MP+
+     2,
+     0,4,0,4,0,0,4,4,0,0,0,0,0, # + D0
+     0,4,0,4,0,0,4,4,0,0,0,0,0, # + D1
+     0,4,0,4,0,0,4,4,0,0,0,0,0, # + D2
+     6,
+     4,4,4,4,4,6,0,2,4,0,4,0,4,2,0,6,4,4,4,4,4,6,0,2,4,0,4,0,4,2,0], ## MP-
+    dtype=np.uint8)
+
+## ---- physcal layer class -----------------------------------------------------
+class PhysicalLayer(object):
+    """Physical layer description for MIL-STD-188-110 Appendix D = STANAG 4539"""
+
+    def __init__(self, sps):
+        """intialization"""
+        self._sps = sps
+        self._frame_counter = -1
+        self._constellations = [BPSK, QPSK, PSK8, QAM16, QAM32, QAM64]
+        self._preamble = self.get_preamble()
+        self._scr_data = ScrambleData()
+
+    def get_constellations(self):
+        return self._constellations
+
+    def get_frame(self):
+        """returns a tuple describing the frame:
+        [0] ... known+unknown symbols and scrambling
+        [1] ... modulation type after descrambling
+        [2] ... a boolean indicating whethere or not raw IQ samples needed
+        [3] ... a boolean indicating if the soft decision for the unknown
+                symbols are saved"""
+        print('-------------------- get_frame --------------------',
+              self._frame_counter)
+        ## --- preamble frame ----
+        if self._frame_counter == -1:
+            return [self._preamble,MODE_BPSK,True,False]
+        ## ----- data frame ------
+        if self._frame_counter == 0:
+            self.a = self.make_reinserted_preamble()
+            return [self.a, MODE_QPSK,False,True]
+
+    def get_doppler(self, symbols, iq_samples):
+        """returns a tuple
+        [0] ... quality flag
+        [1] ... doppler estimate (rad/symbol) if available"""
+        print('-------------------- get_doppler --------------------',
+              self._frame_counter,len(symbols),len(iq_samples))
+        #if len(symbols)!=0:
+        #    print('symb=', symbols)
+        success = False
+        doppler = 0
+        if self._frame_counter == -1: ## -- preamble ----
+            success,doppler = self.get_doppler_from_preamble(symbols, iq_samples)
+            if len(symbols) != 0:
+                for s in symbols:
+                    print(s)
+                self._frame_counter = 0
+        else: ## ------------------------ data frame ----
+            if len(symbols) != 0:
+                for s in symbols:
+                    print(s)
+            success = False
+            self._frame_counter = -1
+        return success,doppler
+
+    def get_doppler_from_preamble(self, symbols, iq_samples):
+        """quality check and doppler estimation for preamble"""
+        success = True
+        doppler = 0
+        shift=9
+        if len(iq_samples) != 0:
+            zp   = np.conj(self.get_preamble_z(self._sps)[shift*self._sps:])
+            cc   = np.array([np.sum(iq_samples[i:i+23*self._sps] *
+                                    zp[0:23*self._sps])
+                             for i in range(23*3*self._sps)])
+            acc = np.abs(cc)
+            for i in range(0,len(cc),23*self._sps):
+                print('i=%3d: '%i,end='')
+                for j in range(23*self._sps):
+                    print('%3.0f ' % acc[i+j], end='')
+                print()
+
+            imax = np.argmax(np.abs(cc[0:3*23*self._sps]))
+            print(imax)
+            pks  = np.array([np.sum(iq_samples[(imax+23*i*self._sps):
+                                               (imax+23*i*self._sps+23*self._sps)] *
+                                    zp[(23*i*self._sps):
+                                       (23*i*self._sps+23*self._sps)])
+                             for i in range(1,5)])
+            print('doppler apks', np.abs(pks))
+            print('doppler ppks', np.angle(pks), np.diff(np.unwrap(np.angle(pks)))/23)
+            doppler = np.mean(np.diff(np.unwrap(np.angle(pks))))/23
+            success = True
+            print('success=', success, 'doppler=', doppler)
+        return success,doppler
+
+    def make_reinserted_preamble(self):
+        a=np.zeros(len(REINSERTED_PREAMBLE), dtype=[('symb',     np.complex64),
+                                                    ('scramble', np.complex64)])
+        a['symb']     = n_psk(8, REINSERTED_PREAMBLE)
+        a['scramble'] = n_psk(8, REINSERTED_PREAMBLE)
+        a['symb'][32:32+3*13] = 0 ## D0,D1,D2
+        return a
+
+    @staticmethod
+    def get_preamble():
+        """preamble symbols + scrambler"""
+        a=np.zeros(len(PREAMBLE), dtype=[('symb',     np.complex64),
+                                         ('scramble', np.complex64)])
+        a['symb']     = n_psk(8, PREAMBLE)
+        a['scramble'] = n_psk(8, PREAMBLE)
+        ##a['symb'][-30:] = 0
+        return a
+
+    @staticmethod
+    def get_preamble_z(sps):
+        """preamble symbols for preamble correlation"""
+        a = PhysicalLayer.get_preamble()
+        return np.array([z for z in a['symb'] for i in range(sps)])
+
+if __name__ == '__main__':
+    print(PREAMBLE)
+    z = n_psk(8,PREAMBLE)
+    cc = [np.sum(z[0:23]*np.conj(z[23*i:23*i+23])) for i in range(6)]
+    print(np.abs(cc))
+    print(np.angle(cc)/np.pi*4)
+    print(all(z==PhysicalLayer.get_preamble()['symb']))
+    print(len(PhysicalLayer.get_preamble()['symb']))
+    s = ScrambleData()
+    print([s.next(1) for _ in range(511)])
+    print([s.next(1) for _ in range(511)] ==
+          [s.next(1) for _ in range(511)])
+    print(QAM64)
+    print(QAM32)
+    print(QAM16)
+    print(PSK8)
+    print(QPSK)
+    print(BPSK)