  We study the ground state phase diagram of a two dimensional mixed-spin
system of coupled alternating spin-1 and $1/2$ chains with a stripe supersolid
phase. Utilizing different analytical and numerical approaches such as mean
field approximation, cluster mean field theory and linear spin wave theory, we
demonstrate that our system displays a rich ground state phase diagram
including novel stripe supersolid, solids with different fillings and
super-counterfluid phases, in addition to a stripe solid with half filling,
superfluid and Mott insulating phases. In order to find a minimal mixed-spin
model for stripe supersolidity, in the second part of the paper we consider two
kinds of mixed-spin system of coupled alternating spin-1 and $1/2$ chains with
(i) anisotropic nearest neighbor interactions, (ii) anisotropic hoppings and
study their ground state phase diagrams. We demonstrate that, for the systems
with uniform hoppings, the repulsive intra-chains interactions are necessary
for stripe supersolidity. In this case the minimal two dimensional mixed-spin
model is a system of spin-1 and spin-1/2 XXZ chains, interacting via a XY
Hamiltonian. In the case of anisotropic hoppings, a system of coupled Ising
chains is the minimal model.
