978-1-5386-2833-1/17/$31.00 ©2017 IEEE
Digital Beamforming of Smart Antenna in
Millimeterwave Communication
Rahmad Hidayat
Dept. of Electrical Engineering
Sekolah Tinggi Teknologi Mandala
Bandung 40286
rhidayat4000@gmail.com
Rushendra, Ellisa Agustina
Faculty of Computer Science & Engineering
Mercubuana University
Jakarta 11650
rushendra.rustam@gmail.com, ellisa.agustina@gmail.com
Abstract—In this paper, a digital beamforming technique is
studied which its transmitter model is designed for a 16-element
linear phased array to a 256-element (16x16) rectangular phased
array. First, its directivity is calculated. Base on the result, beam
pattern characteristics are analyzed. Furthermore, the
interference potential is compared by means the beamforming
demo of millimeter waves against the microwave band used now.
The simulation results demonstrate that the beam squint effect is
relatively better at a higher frequency of millimeter wave band;
the addition of directivity is in line to the increasing of the
amount of the antenna array elements. Although, the potential of
destructive interference is increasingly in the millimeters wave
bands.
Keywords—digital beamforming, beam squint, millimeter wave,
directivity, beam pattern, smart antenna
I. INTRODUCTION
Nowadays, the increasingly diverse and expanding use of
wireless and mobile service needs pushes smart antenna
solutions for better transmission quality provision. Basically,
mobile antenna design is valid for both base station and
mobile terminal and antennas using the same principles and
techniques can also be used for 4
th
generation (LTE) and 5
th
generation (5G).[1][2] Simultaneous optimization of antenna
patterns (called beam) and massive MIMO (multiple input
multiple output) precoding can be made possible through the
beam-tilt feature of an active antenna system electronically.
This process is known as beamforming. In general, it is being
proposed at a beamforming design to optimize gain and
allocation of antenna power in order to obtain the maximum
weighted sum rate in multi-user active. [3] In this paper, two
digital beamforming transmitter design simulation will be
presented. which two spatial filters of the phased array
antenna will be applied to result in beam pattern on the
simulations by the perfect beam pattern considered by array
processing premise.
II. DIGITAL BEAMFORMING
In a digital beamforming process, the use of multiple
antennas on the sending side to form a total antenna radiation
pattern will maximize a gain of the total antenna in direction
of the mobile terminal. Increasing the received signal power
can be obtained through this beamforming proportional to the
number of sending antennas of at least eight elements. The
implementation of the beam is then performed by applying
different complex-value gains to different elements of the
antenna array. Then by applying a different phase shift to the
existing signal on different antennas, it can be done steering to
the total beam generated.[4] A sensor array arrangement can
be made in any form with the coordinates p = (px, py, pz)
representing it. The signal acknowledged by each sensor will
be the similar origin of the signal if a plane wave signal f (t, p)
is incoming at a finicky position in space, and the point of
each sensor in space is dissimilar.[5]
(1)
B(k) is the price of the beam pattern at a fastidious location in
space with a complex weight w*n and v(k) as the array
manifold vector; N is the quantity of the array elements; where
k represents the wave number. If θ represent the angle of
arrival as well as Ø for the angle of incoming wave azimuth,
the next modify of variables can be prepared to illustrate B(k)
in terms of the angle of occurrence :
(2)
With the beamforming of the directional signal of
transmitting or receive antenna array can be controlled to
produce the radiation pattern by adding the signal phase in the
desired direction and by poses the nulling pattern for the
undesirable direction, where the received signal optimization
is done by phase adjustment and amplitude. The vector