Design of a Communication Link to Interconnect Two Locations

UNIVERSITY AFFILIATION
DEPARTMENT OR FACULTY
COURSE ID & COURSE NAME
TITLE: DESIGN OF A COMMUNICATION LINK TO INTERCONNECT TWO
LOCATIONS
STUDENT NAME
STUDENT REGISTRATION NUMBER
DATE OF SUBMISSION
PROFESSOR (SUPERVISOR)
2018

DIGITAL MICROWAVE RADIO SYSTEMS
Introduction
Wireless communication has become a major means of communication since the 20th
century and it uses either the microwave or the radio waves. Terrestrial communication systems
enable wireless communication from one point to another with the transmit and receive signals
propagating in the atmosphere. Another alternative to the terrestrial communication system is the
satellite communication [1]. The choice of terrestrial communication is highly based on the
distance required to propagate a signal and the interferences in between the transceivers. Mobile
communication requires duplex communication for effective communication. most radio
channels are adopted when the communication techniques are half-duplex for instance, radio
broadcasting and the police walkie-talkie phones. All communication systems must contend with
noise or any other form of unwanted interference to guarantee quality of service. In any given
communication systems, there is a transmitter, encoder, and modulator [2]. The radio waves are
created using amplitude modulation whereby a message signal is transmitted by varying the
amplitude of a radio frequency carrier wave of fixed amplitude. During reception, the am
modulated wave is received, it undergoes a diode rectification and the radio frequency is filtered
using the appropriate well-designed filters to obtain the audio frequency signal [3]. For digital
encoding the pulse code modulation is implemented on the carrier wave to transmit the message
signal. The frequency range of a radio communication system lies between 3 to 300 Mhz.
Microwave systems allow for more data transmission based on high frequency where there is an
increased bandwidth and higher speeds. For some systems where the distances are relatively
short, the microwave antenna dimensions are altered to use smaller antennas and when longer
distances are required, larger antennas are used [4]. The small antenna can easily produce more
focused beams which are quite difficult to intercept or alter during transmission because of the
power density.
The case study here seeks to establish a microwave link between the CPA located at 28
Freshwater, PI, Southbank, Melbourne VIC 3006 and the Melbourne Institute of Technology
located on La Trobe St. VIC 3000 Melbourne. Implementing a microwave link between the two
buildings which are 2.6km apart,
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The case study shall use digital microwave systems mainly because system is sufficient for use
in such a long distance. The communication system requires a line of sight to enable propagation
of the microwave signals in a straight line free from any obstructions [5]. The Fresnel zone is
usually an elliptical area that surrounds the line of sight within the transmission and reception
region. the microwave signals are said to spread out into the area once generated by the antenna.
Microwave links are made up of two tower antennae that communicate as long as there is line of
sight the digital transmission technology is used in the design of the microwave links to provide
for a wireless link at a given microwave frequency [6]. The microwave link connects two points
far apart using the microwave communication. The microwave spectrum ranges from 300 MHz
to 300 Ghz. The components of a microwave system are the digital mode, radio frequency unit
and the antenna. The digital modem is a part of the microwave system that modulates the
information signal to an intermediate frequency. The intermediate frequency is fed into the radio
frequency unit and then mounted as close to the antenna as possible. An antenna forms the final
2