The Study and Analysis of Effect of MultiAntenna Techniques on LTE network with Different Bandwidth Configurations in the Downlink

Int. J. Advanced Networking and Applications
Volume: 6 Issue: 3 Pages: 2314-2318 (2014) ISSN : 0975-0290
2314
The Study and Analysis of Effect of Multi-
Antenna Techniques on LTE network with
Different Bandwidth Configurations in the
Downlink
Mohana H K
Department of Electronics, Seshadripuram First Grade College, Bangalore University, Bangalore-64
Email: mohana1.amma@gmail.com
Mohankumar N M
Department of Electronic Science, Bangalore University, Bangalore-56
Email: mohan.nm87@gmail.com
Swetha
Department of Electronics, Karnataka State Women’s University, Bijapur-108
Email: shwetha.bengare@gmail.com
Devaraju J T@
Department of Electronic Science, Bangalore University, Bangalore-56
Email: devarajujt@bub.ernet.in
--------------------------------------------------------------------ABSTRACT--------------------------------------------------------------
Long Term Evolution (LTE) system adapts advanced Multiple Input Multiple Output (MIMO) antenna
techniques on both uplink and downlink to achieve high peak data rates and higher system throughput. This
enables LTE to support multimedia applications beyond web browsing and voice, which demands higher
bandwidth configurations. LTE employs Orthogonal Frequency Division Multiple Access (OFDMA) in downlink
to support spectrum flexibility in order to use upto 20MHz system bandwidth to improve the system throughput
and robustness. Therefore the combined study of multi-antenna techniques and spectrum flexibility usage on the
performance of LTE system becomes vital. Hence in this paper, an attempt has been made to evaluate the
performance of different multi-antenna techniques with various system bandwidth configurations from 1.4MHz
to 20MHz using QualNet 5.2 network simulator. The multi-antenna techniques considered for performance
evaluation are Single Input Single Output (SISO), Multiple Input Single Output (MISO) and Multiple Input
Multiple Output (MIMO). The performance metrics such as aggregate bytes received, average throughput,
average delay and average jitter are considered for simulation study.
Keywords - LTE, SISO, MISO, MIMO, OFDMA
-------------------------------------------------------------------------------------------------------------------------------------------------
Date of Submission : October 16, 2014 Date of Acceptance : November 30, 2014
-------------------------------------------------------------------------------------------------------------------------------------------------
1. INTRODUCTION
ong Term Evolution (LTE) is an emerging 4G
broadband wireless communication system developed
to support high peak data rates with quality of services
(QoS), high spectrum efficiency, flexibility of spectrum
usage, increased capacity, multimedia services etc [1, 2].
High peak data rate and higher spectrum efficiency can be
achieved by the integration of MIMO and OFDMA
technology using space time block code (STBC) system
[3, 4]. Hence LTE system employs MIMO antenna
techniques in both uplink and downlink and Orthogonal
Frequency Division Multiple Access (OFDMA) in
downlink. MIMO system is one of the advanced multi-
antenna techniques which carry more than one spatial data
stream over one frequency simultaneously to achieve high
peak data rates suitable for Internet and multimedia
services [5, 6]. The OFDMA is a spectral efficient
multicarrier modulation scheme in which available
@correspondence author: devarajujt@bub.ernet.in
system bandwidth is divided into several parallel closely
spaced orthogonal subcarriers of 15KHz. Using OFDMA,
radio resources are allocated to multiple users based on
frequency (subcarriers) and time (symbols) domain. A unit
of transmission radio resource consisting of 12 subcarriers
in the frequency domain and 1 time slot (0.5ms) in the
time domain to makes a Resource Block (RB) in the LTE
system. Hence a RB occupies 180KHz in the frequency
domain and 0.5 ms in the time domain [1, 7]. This allows
LTE network to dynamically adjust the bandwidth usage
according to the system requirements. The number of RBs
are available for transferring data are depends on the
transmission bandwidth, the available RBs for different
bandwidth configurations is listed in Table 1[1].
Therefore, LTE network deployed with higher bandwidth
configurations provides high peak data rate and higher
system throughput due to the availability of more number
of RBs for transferring data [8]. Also OFDMA assigns
each user to required bandwidth for their transmission and
L

2315
the unassigned subcarriers are off to reduce power
consumption and interference [9]. Further with OFDMA
high spectrum efficiency can be achieved due to multiuser
diversity in a frequency selective channel. Thus the
combination of MIMO and OFDMA scheme can support
multimedia applications such as high definition (HD)
video, video conferencing, video streaming,
teleconferencing, moving pictures, blogging, interactive
gaming, voice over IP (VOIP) etc with reliability in the
LTE system.
Table1: Channel bandwidth with Resource blocks
Channel
bandwidth (MHz)
1.4 3 5 10 15 20
Number of
resource blocks
6 15 25 50 75 100
The rest of this paper is organised as follows. Section 2
discusses SISO, MISO, and MIMO antenna techniques.
Simulation studies are given in section 3 and Section 4
concludes the paper.
2. MULTI-ANTENNA TECHNIQUES
Multi-antenna techniques are employed in LTE systems to
achieve high data rates, spectral efficiency, system
capacity (number of users), and coverage. Multi-antenna
systems can be realized by using multiple antennas at the
transmitter and receivers with an appropriate channel
coding/ decoding scheme. By increasing the number of
transmit and receive antennas it is possible to linearly
increase the throughput of the channel with every pair of
antennas added to the system. Depending on the number
of antennas at transmitter/receivers and coding/decoding
schemes used, MIMO techniques are classified into
several modes such as SISO, SIMO, MISO and MIMO. In
this paper the system performance evolution of SISO,
MISO and MIMO antenna techniques are considered.
Figure 1 gives the system model of MIMO which consists
of nT transmission antennas and nR receive antennas and a
matrix channel which consists of all nTxnR paths between
them [10].
Figure 1. MIMO system model
2.1 SINGLE INPUT SINGLE OUTPUT (SISO):
A SISO system employs single antenna at the transmitter
and receiver side. Due to single transmitter and receiver
antenna it is less complex than MIMO, but reduction in
data speed. The SISO systems are vulnerable to problems
caused by multipath effects. Especially when an
electromagnetic field is met with the obstructions such as
hills, canyons, buildings, and utility wires, the wave fronts
are scattered, and thus they take many paths to reach the
destination. The late arrival of scattered portions of the
signal causes problems such as fading, cliff effect, and
intermittent reception [11].
Figure 2: SISO - Single Input Single Output
2.2 MULTIPLE INPUT SINGLE OUTPUT (MISO):
A MISO system employs two transmitting antenna and
one receiving antennas, it is also termed as transmit
diversity. Transmit diversity techniques are used to reduce
the effect of multipath fading and interference [12]. The
transmit diversity based on Space Frequency Block
Coding (SFBC) scheme which uses two transmit antennas
to improve the signal quality at the receiver. However,
the enhanced performance depends on the channel state
information (CSI) available at the transmitter. The perfect
CSI transmit beam forming for maximizes the signal-to-
noise-ratio at the receiver [11, 13].
Figure 3: MISO- Multiple Input Single Output
2.3 MULTIPLE INPUT MULTIPLE OUTPUT (MIMO):
A MIMO enables multiple antennas at the transmitter and
receiver to support a variety of signal paths to transfer
more data in less time and it significantly increasing the
bandwidth efficiency of the systems. The Open Loop
Spatial Multiplexing (OLSM) is one of the MIMO
techniques used in downlink transmission modes to
support the higher data rate in LTE system. OLSM consist
of two transmit antennas at the eNB and two receive
antennas at the UE (2x2 antenna configuration), sending
either one or two simultaneous data streams from the eNB
to the UE [14]. In a 2x2 antenna configuration, sending
one data stream is known as Rank1 MIMO [14] and
sending two data streams is known as Rank2 MIMO. The
number of independent data streams that can be sent to the
UE is restricted to either one or two data stream, even if
the number of transmit antennas at the eNB is increased to
four. So a 2x2 configuration does not impose any overt
simplification [15].
Figure 4: MIMO- Multiple Input Multiple Output
eNB Tx UE Rx
eNB Tx
UE Rx
eNB Tx
UE Rx

2316
3. SIMULATION STUDIES AND RESULTS
The effect of multi-antenna techniques such as SISO,
MISO and MIMO in the LTE downlink for different
bandwidth configurations is evaluated using QualNet 5.2
simulator by considering an eNB and 20 UEs in a single
cell environment. In this scenario, a downlink CBR
connection of data rate 3.2768Mbps is established between
an eNB and each UEs. Further two-ray path loss model
with constant shadowing of mean 4dB is considered for
the simulation studies and the remaining simulation
parameters considered are listed in Table 2.
Table 2. Simulation Parameters
Property Value
Simulation-Time 30S
Simulation-Area 1.5Km X 1.5Km
Downlink-Channel-Frequency 2.4GHz
Uplink-Channel-Frequency 2.5GHz
Propagation-Model Statistical
Channel-Fading-Model Rayleigh
Propagation-Speed 3.2768 Mbps
MAC-LTE-UE-Scheduler-Type Simple-Scheduler
MAC-LTE-eNB-Scheduler-
Type
Round-Robin
PHY-LTE-Tx-Power 23
Antenna-Model Omni directional
Channel-Bandwidth
1.4, 3, 5, 10, 15
and 20MHz
PHY-LTE-
Num-Tx-
Antennas
SISO 1
MISO 2
MIMO 2
PHY-LTE-
Num-Rx-
Antennas
SISO 1
MISO 1
MIMO 2
Figure 5. Snapshot of the Scenario designed for simulation
study
The snapshot of the scenario designed for the simulation
studies using QualNet 5.2 simulator is shown in Figure 5.
Initially simulation studies are carried out by considering
SISO multi-antenna technique with a system bandwidth of
1.4MHz. The performance metrics such as aggregate bytes
received, average throughput, average delay and average
jitter are evaluated. Simulation studies are repeated for
3MHz, 5MHz, 10MHz, 15MHz and 20MHz system
bandwidth.
Simulation studies are also repeated by considering the
MISO and MIMO multi-antenna techniques.
1.4MHz 3MHz 5MHz 10MHz 15MHz 20MHz
5
10
15
20
25
30
35
40
45
50
55
60
65
AggregateBytesReceived(MB)
Bandwidth
SISO
MISO
MIMO
Figure 6. Aggregate bytes received for different
bandwidth configurations
100
200
300
400
500
600
700
800
900
AverageThroughput(Kbps)
Band Width
SISO
MISO
MIMO
Figure 7. Average throughput for different bandwidth
configurations
Figure 6 and 7 shows aggregate bytes received and
average throughput performance for SISO, MISO and
MIMO multi-antenna techniques for different system
bandwidths from 1.4MHz to 20MHz. It is depicted from
Figure 6 and 7 that the aggregate bytes received and
average throughput increases with increase in bandwidth,
since the increase in system bandwidth increases the
number of RBs and hence more RBs are available for
transferring data [16, 17]. Further, it is observed from
Figure 6 and 7 that MIMO shows better aggregate bytes
received and average throughput performance. Since in

2317
MIMO, multiple transmit and receive antennas create
multiple parallel channels using which multiple data
streams are sent simultaneously [10, 18]. In MISO, data
stream is sent over one channel and its conjugate is sent
over the other which increases transmit diversity rather
than throughput, hence aggregate bytes received and
average throughput is lesser than MIMO [19]. The SISO
shows least aggregate bytes received and average
throughput system performance, since it employs single
antenna for transmission and reception and hence only less
numbers of available RBs are utilized for transferring data.
0.0
0.5
1.0
1.5
2.0
2.5
3.0
AverageDelay(Sec)
Band Width
SISO
MISO
MIMO
Figure 8. Average Delay for different bandwidth
configurations
Figure 8 illustrates the average delay performance for
SISO, MISO and MIMO multi-antenna techniques for
different system bandwidth from 1.4MHz to 20MHz. It is
evident from Figure 8 that for all multi-antenna techniques
average delay decreases for increase in system bandwidth.
Since the increase in system bandwidth increases the
number of RBs and hence more RBs are utilized for
transferring data leading to decrease in average delay [19].
It is also observed from Figure 8 that delay performance
for MIMO is better up to 5MHz as compared to MISO and
SISO. Since in MIMO several data streams are transmitted
by the base station over the same carrier simultaneously
and hence delay occurred is less [20]. The SISO performs
better than MISO and MIMO at higher bandwidth due to
its less complexity [11]. The MISO performs least at
higher system bandwidth configurations due to transmit
diversity [11].
0.005
0.010
0.015
0.020
0.025
0.030
0.035
0.040
0.045
0.050
AverageJitter(Sec)
Bandwidth
SISO
MISO
MIMO
Figure 9. Average Jitter for different bandwidth
configurations
Figure 9 shows the jitter performance for SISO, MISO and
MIMO multi-antenna techniques for different system
bandwidth from 1.4MHz to 20MHz. The average jitter
performance for SISO, MISO and MIMO decreases for
increase in system bandwidth. Since the increase in system
bandwidth increases the numbers of RBs for transferring
data [19]. The average jitter performance is better for
MIMO, Since in MIMO the multiple transmit and receive
antennas create multiple parallel channels using which
multiple data streams are sent simultaneously [10, 18].
4. CONCLUSION
In this paper, the effect of SISO, MISO and MIMO
antenna techniques for different bandwidth configuration
is compared through simulation studies considering
aggregate bytes received, average throughput, average
delay and average jitter as performance metrics. The
simulation results show that the performance of MIMO
scheme is better than SISO and MISO antenna scheme.
ACKNOWLEDGEMENTS
One of the Authors of this paper would like to thank
Director of Studies and Management of Seshadripuram
Educational Trust (SET), Bangalore for their support.
Authors would like to thank UGC for providing Junior
Research Fellowship under ‘At Any One Given Time
Basis Scheme’ to carry out the research work. Authors
would also thank Nihon Communications Bangalore for
their technical support.
REFERENCES
[1] Raad Farhood Chisab, Member IEEE and Prof. (Dr.)
C. K. Shukla “Performance Evaluation of 4G-LTE-
SCFDMA Scheme under SUI and ITU Channel
Models” International Journal of Engineering &
Technology, 14(1)
[2] Jiang Xuehua, Chen Peijiang, “Study and
Implementation of MIMO OFDM In matlab
Simulation” International Conference on Information
Technology and Computer Science, 26th July 2009.
[3] ZHOU Shidong, WANG Jing “Novel Techniques
Improving Downlink Capacity for Cellular Systems
of B3G”, No.90204001, China Future Project
[4] Leila Sahraoui, Djmail Messadeg, Nouredinne
Doghmane “Analyses and Performance of
Techniques PAPR Reduction for STBC MIMO-
OFDM System in (4G) Wireless Communication”
International Journal of Wireless & Mobile Networks
(IJWMN), 5(5), October 2013.
[5] E. Telatar “Capacity of multi-antenna Gaussian
channels” European Transactions on
Telecommunications, 10(6), 1995, 585– 595.
[6] G. Foschini and M. J. Gans “On the limits of wireless
communications in a fading environment when using
multiple antennas Wireless Personal
Communications”, 6(3), 1998, 311–355.

2318
[7] Sonia Rathi, Nisha Malik, Nidhi Chahal, Sukhvinder
Malik “Throughput for TDD and FDD 4 G LTE
Systems” International Journal of Innovative
Technology and Exploring Engineering (IJITEE),
3(12), May 2014.
[8] Alia Asheralieva, Jamil Y. Khan, Kaushik Mahata
“Dynamic Resource Allocation in a LTE/WLAN
Heterogeneous Network” IV international congress
on ultra modern telecommunications and control
systems-2012.
[9] Telesystem Innovations Anritsu discover what is
possible “LTE Resources Guide” and LTE in a
Nutshell: The Physical Layer 2, 2010.
[10] Juho Lee, Jin-Kyu Han and Jianzhong (Charlie)
Zhang, “MIMO Technologies in 3GPP LTE and
LTE-Advanced”, EURASIP Journal on Wireless
Communications and Networking Volume
2009,Article ID 302092.
[11] Akhilesh Kumar, Anil Chaudhary “Channel Capacity
Enhancement of Wireless Communication using
MIMO Technology” International Journal of
Scientific & Technology Research, 1(2), March
2012.
[12] Valentine A. Aalo, Member, “Performance of
Maximal-Ratio Diversity Systems in a Correlated
Nakagami-Fading Environment”, IEEE transactions
on Communications, 43(8), August 1995.
[13] T. R. Ramya and Srikrishna Bhashyam “IEEE
Transactions on Wireless Communications Using
Delayed Feedback for Antenna Selection in MIMO
Systems”, 8(12), December 2009.
[14] J.G. Proakis “Digital Communications” McGraw-
Hill, New York, 2001.
[15] Anup Talukdar, Bishwarup Mondal, Mark Cudak,
Amitava Ghosh, Fan Wang, “Streaming Video
Capacity Comparisons of Multi-Antenna LTE
Systems”, IEEE 71st Vehicular Technology
Conference (VTC 2010-Spring), 2010,
[16] M. Saad ElBamby and Khaled M. F. Elsayed, “A
Transportation Problem based Resource Allocation
Scheme for an LTE-Advanced System with Carrier
Aggregation”, IFIP Wireless Days, 2012, November
2012, 1 – 6.
[17] Juan J. Sánchez, D. Morales-Jiménez, G. Gómez and
J. T. Enbrambasaguas, “Physical Layer Performance
of Long Term Evolution Cellular Technology”, 16th
IST Mobile and Wireless Communications Summit,
July 2007, 1-5.
[18] DavidMartın-Sacristan, Jose F.Monserrat, Jorge
Cabrejas-Penuelas, Daniel Calabuig Salvador
Garrigas and Narcıs Cardona, “On the Way towards
Fourth-Generation Mobile: 3GPP LTE and LTE-
Advanced”, EURASIP Journal on Wireless
Communications and Networking, Volume 2009.
[19] Mohankumar N M, Swetha and Devaraju J T
“performance evaluation of multi-antenna techniques
in Lte” International Journal of Mobile Network
Communications & Telematics (IJMNCT), 2(4),
August 2012.
[20] Rupinder Kaur, Manoj Kumar “An Efficient
Resource Block Allocation in LTE System”
International Journal of Advanced Research in
Computer Science and Software Engineering, 3(10),
October 2013.
Authors Biography
Mohana H. K. received M.Sc degree
from University of Mysore and
working as an Assistant Professor in
the Department of Electronics,
Seshadripuram First Grade College,
Bangalore University. He has 10
years of teaching experiance in
Electronics. Now he is pursuing his Ph.D in the
Department of Electronic Science, Bangalore
University. His interests include LTE and other
Broadband Wireless Access Networks.
MohanKumar N. M. received M.Sc degree from
Bangalore University. Now he is
pursuing his Ph.D in the
Department of Electronic science,
Bangalore University. His interests
include Long Term Evolution
networks and Wireless Sensor
Networks.
Swetha is working as an Assistant
Professor in department of
Electronics, Karnataka State
Women’s University, Bijapur.
Also, she is pursuing her Ph.D in
the Department of Electronic
science, Bangalore University.
Her interests include New Generation Mobile
Networks, Embedded Systems and Broadband
Wireless Access Networks.
Devaraju J. T. is working as an
Professor and chairman at
Department of Electronic Science,
Bangalore University. He has 19
years of teaching and research
experiance in Electronics. He
received his Ph.D degree from
Bangalore University. His research interests include
Embedded Systems, Wireless Networks and
Chalcogenide glasses. He has worked as a member
for several committees. He and his research team are
working on Broadband Wireless Access networks
and Wireless Sensor Networks.

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