Recovering symbols from burst transmissions with unknown sample rate

Hello,

As the title says, I'd like to know if it would be possible to recover symbols
from a transmission containing regular bursts separated by noise (TDMA), using
just blocks present in GNU Radio (or some custom algorithm that can be
implemented as a block).

I've tried using the correlation estimator together with the symbol
synchronization block, but the problem I had was that the known
synchronization sequence is placed in the middle of the data burst (as in most
such real life transmissions). This meant that the "time_est" tag will not
jump start the symbol synchronizer in time to recover all symbols of the
burst.

What is even worse is that not all data bursts have an embedded
synchronization sequence, so there is no way to estimate the difference from
expected to actual sample rate until the next sync sequence is transmitted
(every 6 frames).

Is there a way to overcome this apparent limitation of the corr_est + symbol
sync combination?

Thank you,
Adrian