  Heavy quark production provides a unique probe of the quark-gluon plasma
transport properties in heavy ion collisions. Experimental observables like the
nuclear modification factor $R_{\rm AA}$ and elliptic anisotropy $v_{2}$ of
heavy flavor mesons are sensitive to the heavy quark diffusion coefficient.
There now exist an extensive set of such measurements, which allow a
data-driven extraction of this coefficient. In this work, we make such an
attempt within our recently developed heavy quark transport modeling framework
(Langevin-transport with Gluon Radiation, LGR). A question of particular
interest is the temperature dependence of the diffusion coefficient, for which
we test a wide range of possibility and draw constraints by comparing relevant
charm meson data with model results. We find that a relatively strong increase
of diffusion coefficient from crossover temperature $T_c$ toward high
temperature is preferred by data. We also make predictions for Bottom meson
observables for further experimental tests.
