Progress Calculating Decay Constants with NRQCD and AsqTad Actions

We combine a light AsqTad antiquark with a nonrelativistic heavy quark to compute the decay constants of heavy-light pseudoscalar mesons using the ensemble of 3-flavor gauge field configurations generated by the MILC collaboration. Preliminary results for $f_{B_s}$ and $f_{D_s}$ are given and status of the chiral extrapolation to $f_B$ is reported. We also touch upon results of the perturbative calculation which matches matrix elements in the effective theory to the full theory at 1-loop order.