  This paper proposes a new sparse array geometry for 2-D (azimuth and
elevation) DOA (direction-of-arrival) estimation. The proposed array geometry
is V-shaped sparse array and it is composed of two linear portions which are
crossing each other. The degrees of freedom of the sparse array is enhanced by
sparse sampling property. In this respect, V-shaped coprime (VCA) and V-shaped
nested array (VNA) structures are developed. VCA can resolve both azimuth and
elevation angles up to MN sources with 2M + N -1 sensors in each portion and
the total number of sensors is 4M+2N-3. VNA can resolve O(N^2) sources with 2N
sensors. Instead of 2-D grid search, the proposed method computes 1-D search
for azimuth and elevation angle estimation in a computational efficient way. In
order to solve the pairing problem in 2-D scenario, the cross-covariance matrix
of two portion is utilized and 2-D paired DOA estimation is performed. The
performance of the proposed method is evaluated with numerical simulations and
it is shown that the proposed array geometries VCA and VNA can provide much
less sensors as compared to the conventional coprime planar arrays.
