Indoor wireless links have intrinsic characteristics that affect the
system performance, such as the multipath effect that causes signal
fading, and interference effect from adjacent cells that degrades the bit
error rate. From the physical layer perspective, one solution to combat
these impairments is the use of directional antennas rather than the traditional
omnidirectional ones [1]. They have the ability to confine the
power in certain directions instead of scattering the power everywhere.
As a result of less power loss toward unwanted directions, the multipath
and interference effects are reduced. Directional antennas can be
single or dual/multi-beam. Dual/multi-beam antennas are antennas that
have more than one directive beam from a single aperture. These antennas
are useful for indoor wireless systems which require coverage
of multiple areas [2], as they reduce the required number of antennas
and are found to improve the link quality [3], resulting in easier network
deployment.