Sorry for the late response.

The dqpsk demodulator which we use is very slow in synchronizing to the symbols of the signal. So it only works with continuous signals like they are used in TMO (particularly downlink) where the BTS broadcasts the signal continuously.

For DMO to work (at least on short tslk-spurts) you would need to implement/use a demodulator that syncs within one tetra burst period.

Hope this helps.

Regards, Harald