Constellation Receiver: Difference between revisions

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The phase and frequency synchronization are based on a Costas loop that finds the error of the incoming signal point compared to its nearest constellation point. The frequency and phase of the NCO are updated according to this error.
The phase and frequency synchronization are based on a Costas loop that finds the error of the incoming signal point compared to its nearest constellation point. The frequency and phase of the NCO are updated according to this error.
[[File:Const_rcvr_loop.jpg]]


== Parameters ==
== Parameters ==


'''Constellation''' : constellation of points for generic modulation, see [[Constellation Object]]
; Constellation
: constellation of points for generic modulation, see [[Constellation Object]]


'''Loop BW''' : Loop bandwidth of the Costas Loop.  A good starting point is 2pi/100, or about 0.06.
; Loop BW
: Loop bandwidth of the Costas Loop.  A good starting point is 2pi/100, or about 0.06.


'''Min Freq Deviation''' : minimum normalized frequency value the loop can achieve
; Min Freq Deviation
: minimum normalized frequency value the loop can achieve


'''Max Freq Deviation''' : maximum normalized frequency value the loop can achieve
; Max Freq Deviation
: maximum normalized frequency value the loop can achieve

Latest revision as of 15:56, 4 December 2021

This block makes hard decisions about the received symbols (using a constellation object) and also fine tunes phase synchronization.

The phase and frequency synchronization are based on a Costas loop that finds the error of the incoming signal point compared to its nearest constellation point. The frequency and phase of the NCO are updated according to this error.

Const rcvr loop.jpg

Parameters

Constellation
constellation of points for generic modulation, see Constellation Object
Loop BW
Loop bandwidth of the Costas Loop. A good starting point is 2pi/100, or about 0.06.
Min Freq Deviation
minimum normalized frequency value the loop can achieve
Max Freq Deviation
maximum normalized frequency value the loop can achieve