GNU Radio 3.7.2 C++ API
A Costas loop carrier recovery module. More...
< costas_loop_cc >
|virtual float||error () const =0|
|static sptr||make (float loop_bw, int order)|
A Costas loop carrier recovery module.
The Costas loop locks to the center frequency of a signal and downconverts it to baseband. The second (order=2) order loop is used for BPSK where the real part of the output signal is the baseband BPSK signal and the imaginary part is the error signal. When order=4, it can be used for quadrature modulations where both I and Q (real and imaginary) are outputted.
More details can be found online:
J. Feigin, "Practical Costas loop design: Designing a simple and inexpensive BPSK Costas loop carrier recovery circuit," RF signal processing, pp. 20-36, 2002.
The Costas loop can have two output streams: stream 1 is the baseband I and Q; stream 2 is the normalized frequency of the loop
|virtual float gr::digital::costas_loop_cc::error||(||)|| const
Returns the current value of the loop error.
Make a Costas loop carrier recovery block.
|loop_bw||internal 2nd order loop bandwidth (~ 2pi/100)|
|order||the loop order, either 2, 4, or 8|