Hi,
I have a simple QAM16 loopback (Gray code, diff encoding, 4 sps) working as follows:
QAM Mod ---> Throttle ---> QAM Demod
This works fine if I have a constant signal level from the Tx. However, if I add a variable gain between the Tx and Rx and drop the Tx level to zero, then restore the Tx signal after a short time, the demod no longer works. I'm guessing a control loop inside the demod has wandered off during the interval with no signal. Is there any way to re-initialise the demod block to help it find its way again?
The objective is to simulate a 'bursty' link where the Tx is not permanently keyed.
Thanks in advance!
Ernest