DOD-DOA Estimation using MIMO Antenna Arrays with Manifold Extenders

With increasing demands on capacity and height-ened user density, it is imperative to propose approaches that exploit and utilise all possible degrees of freedom (DoF) of a MIMO system. This directly translates to increased channel estimation accuracy. With this motivation, in this paper, a novel MIMO antenna array system with a receiver of
$N$
antennas that includes a joint estimation of Direction-of-Arrival (DOA) and Direction-of-Departure (DOD) of the desired user in the presence of other multiple access users, is presented. This is achieved by using the concept of the “Manifold Extender” which increases the dimensionality of the observation space of the received vector-signals, and thus increases the DoF from
$N$
to
$NN_{\text{ext}}$
where
$N_{\text{ext}}$
is the extended dimension. The performance of the receiver is evaluated against the existing spatial-only and virtual receivers by computer simulation studies.