New clock offset corrector and clock offset control
diff --git a/lib/receiver/clock_offset_control_impl.cc b/lib/receiver/clock_offset_control_impl.cc
index 43a9b8e..b3a7934 100644
--- a/lib/receiver/clock_offset_control_impl.cc
+++ b/lib/receiver/clock_offset_control_impl.cc
@@ -33,17 +33,17 @@
namespace gsm
{
clock_offset_control::sptr
-clock_offset_control::make(float fc)
+clock_offset_control::make(float fc, float samp_rate)
{
return gnuradio::get_initial_sptr
- (new clock_offset_control_impl(fc));
+ (new clock_offset_control_impl(fc, samp_rate));
}
/*
* The private constructor
*/
-clock_offset_control_impl::clock_offset_control_impl(float fc)
+clock_offset_control_impl::clock_offset_control_impl(float fc, float samp_rate)
: gr::block("clock_offset_control",
gr::io_signature::make(0, 0, 0),
gr::io_signature::make(0, 0, 0))
@@ -51,9 +51,10 @@
{
message_port_register_in(pmt::mp("measurements"));
set_msg_handler(pmt::mp("measurements"), boost::bind(&clock_offset_control_impl::process_measurement, this, _1));
- message_port_register_out(pmt::mp("ppm"));
+ message_port_register_out(pmt::mp("ctrl"));
set_fc(fc);
+ set_samp_rate(samp_rate);
d_alfa = 0.3;
d_ppm_estimate = -1e6;
d_last_ppm_estimate = -1e6;
@@ -77,6 +78,11 @@
d_fc = fc;
}
+void clock_offset_control_impl::set_samp_rate(float samp_rate)
+{
+ d_samp_rate = samp_rate;
+}
+
void clock_offset_control_impl::process_measurement(pmt::pmt_t msg)
{
if(pmt::is_tuple(msg))
@@ -103,66 +109,76 @@
float ppm = -freq_offset/d_fc*1.0e6;
std::string state = pmt::symbol_to_string(pmt::tuple_ref(msg,2));
d_last_state = state;
- if(std::abs(ppm) > 100.0) //safeguard against flawed measurements
+ if(std::abs(ppm) < 100.0) //safeguard against flawed measurements
{
- ppm=0;
- reset();
- }
- if(state == "fcch_search")
- {
- pmt::pmt_t msg_ppm = pmt::from_double(ppm);
- message_port_pub(pmt::intern("ppm"), msg_ppm);
- d_last_fcch_time = d_current_time;
- }
- else
- if (state == "synchronized")
- {
- d_last_fcch_time = d_current_time;
- if(d_first_measurement)
+ if(state == "fcch_search")
{
- d_ppm_estimate = ppm;
- d_first_measurement = false;
- }
- else
+ send_ctrl_messages(ppm);
+ d_last_fcch_time = d_current_time;
+ }
+ else
+ if (state == "synchronized")
{
- d_ppm_estimate = (1-d_alfa)*d_ppm_estimate+d_alfa*ppm;
- }
-
- if(d_counter == 5)
- {
- d_counter = 0;
- if(std::abs(d_last_ppm_estimate-d_ppm_estimate) > 0.1)
+ d_last_fcch_time = d_current_time;
+ if(d_first_measurement)
{
- pmt::pmt_t msg_ppm = pmt::from_double(ppm);
- message_port_pub(pmt::intern("ppm"), msg_ppm);
- d_last_ppm_estimate = d_ppm_estimate;
+ d_ppm_estimate = ppm;
+ d_first_measurement = false;
+ }
+ else
+ {
+ d_ppm_estimate = (1-d_alfa)*d_ppm_estimate+d_alfa*ppm;
+ }
+
+ if(d_counter == 5)
+ {
+ d_counter = 0;
+ if(std::abs(d_last_ppm_estimate-d_ppm_estimate) > 0.1)
+ {
+// pmt::pmt_t msg_ppm = pmt::from_double(ppm);
+// message_port_pub(pmt::intern("ppm"), msg_ppm);
+ send_ctrl_messages(ppm);
+ d_last_ppm_estimate = d_ppm_estimate;
+ }
+ }
+ else
+ {
+ d_counter=d_counter+1;
}
}
else
+ if(state == "sync_loss")
{
- d_counter=d_counter+1;
+ reset();
+// pmt::pmt_t msg_ppm = pmt::from_double(0.0);
+// message_port_pub(pmt::intern("ppm"), msg_ppm);
+ send_ctrl_messages(0);
}
- }
- else
- if(state == "sync_loss")
- {
- reset();
- pmt::pmt_t msg_ppm = pmt::from_double(0.0);
- message_port_pub(pmt::intern("ppm"), msg_ppm);
- }
+ }
}
}
}
+void clock_offset_control_impl::send_ctrl_messages(float ppm)
+{
+// pmt::pmt_t msg_ppm = pmt::from_double(ppm);
+// message_port_pub(pmt::intern("ctrl"), msg_ppm);
+// d_last_fcch_time = d_current_time;
+
+ pmt::pmt_t msg_set_phase_inc = pmt::cons(pmt::intern("set_phase_inc"), pmt::from_double(2*M_PI*d_fc/d_samp_rate*ppm/1.0e6));
+ message_port_pub(pmt::intern("ctrl"), msg_set_phase_inc);
+
+ pmt::pmt_t msg_set_resamp_ratio = pmt::cons(pmt::intern("set_resamp_ratio"), pmt::from_double(1+ppm/1.0e6));
+ message_port_pub(pmt::intern("ctrl"), msg_set_resamp_ratio);
+}
+
void clock_offset_control_impl::timed_reset()
{
reset();
- pmt::pmt_t msg_ppm = pmt::from_double(0.0);
- message_port_pub(pmt::intern("ppm"), msg_ppm);
+ send_ctrl_messages(0);
}
-
void clock_offset_control_impl::reset()
{
d_ppm_estimate = -1e6;
diff --git a/lib/receiver/clock_offset_control_impl.h b/lib/receiver/clock_offset_control_impl.h
index 3c11a6f..cc0ea3d 100644
--- a/lib/receiver/clock_offset_control_impl.h
+++ b/lib/receiver/clock_offset_control_impl.h
@@ -32,9 +32,10 @@
{
private:
float d_fc;
+ float d_samp_rate;
float d_alfa;
float d_ppm_estimate;
- float d_last_ppm_estimate;
+ float d_last_ppm_estimate;
bool d_first_measurement;
int d_counter;
std::string d_last_state;
@@ -43,13 +44,15 @@
bool d_first_time;
void process_measurement(pmt::pmt_t msg);
+ void send_ctrl_messages(float ppm);
void timed_reset();
void reset();
public:
- clock_offset_control_impl(float fc);
+ clock_offset_control_impl(float fc, float samp_rate);
~clock_offset_control_impl();
virtual void set_fc(float fc);
+ virtual void set_samp_rate(float samp_rate);
};
} // namespace gsm
} // namespace gr