From 807cbc31a2f9cd2f43954d03e574fffb64bdf4c8 Mon Sep 17 00:00:00 2001
From: Roman Zeyde <roman.zeyde@gmail.com>
Date: Thu, 8 Jan 2015 09:22:19 +0200
Subject: [PATCH] recv: split sampler update

---
 amodem/recv.py | 31 +++++++++++++++++--------------
 1 file changed, 17 insertions(+), 14 deletions(-)

diff --git a/amodem/recv.py b/amodem/recv.py
index ac36957..5269968 100644
--- a/amodem/recv.py
+++ b/amodem/recv.py
@@ -26,7 +26,7 @@ class Receiver(object):
         self.omegas = 2 * np.pi * self.frequencies / config.Fs
         self.Nsym = config.Nsym
         self.Tsym = config.Tsym
-        self.iters_per_report = config.baud  # report once per second
+        self.iters_per_update = config.baud  # update sampler once per second
         self.modem_bitrate = config.modem_bps
         self.equalizer = equalizer.Equalizer(config)
         self.carrier_index = config.carrier_index
@@ -138,20 +138,23 @@ class Receiver(object):
                 self.stats['rx_bits'] = self.stats['rx_bits'] + len(bits)
                 yield bits
 
-            if i % self.iters_per_report == 0:
-                err = np.array([e for v in errors.values() for e in v])
-                err = np.mean(np.angle(err))/(2*np.pi) if len(err) else 0
-                errors.clear()
+            if i % self.iters_per_update == 0:
+                self._update_sampler(i, errors, sampler)
 
-                duration = time.time() - self.stats['rx_start']
-                sampler.freq -= 0.01 * err * self.Tsym
-                sampler.offset -= err
-                log.debug(
-                    'Got  %8.1f kB, realtime: %6.2f%%, drift: %+5.2f ppm',
-                    self.stats['rx_bits'] / 8e3,
-                    duration * 100.0 / (i*self.Tsym),
-                    (1.0 - sampler.freq) * 1e6
-                )
+    def _update_sampler(self, iter_index, errors, sampler):
+        err = np.array([e for v in errors.values() for e in v])
+        err = np.mean(np.angle(err))/(2*np.pi) if len(err) else 0
+        errors.clear()
+
+        duration = time.time() - self.stats['rx_start']
+        sampler.freq -= 0.01 * err * self.Tsym
+        sampler.offset -= err
+        log.debug(
+            'Got  %8.1f kB, realtime: %6.2f%%, drift: %+5.2f ppm',
+            self.stats['rx_bits'] / 8e3,
+            duration * 100.0 / (iter_index * self.Tsym),
+            (1.0 - sampler.freq) * 1e6
+        )
 
     def start(self, signal, gain=1.0):
         sampler = sampling.Sampler(signal, sampling.Interpolator())