International Journal of Engineering Trends and Technology (IJETT) – Volume 33 Number 1- March 2016
4G Communication Resource Analysis with
Adaptive Physical Layer Technique
Mubinul Haque1, Dr. Md. Abu Bakar Siddiqui2
Dept. of Electrical and Electronic Engineering
American International University –Bangladesh (AIUB), Dhaka, Bangladesh
Abstract- For telecommunication services the
dramatic shift in the market has been made in
beginning of 21st century. In present days,
communication network is the key challenges to
integrate numerous services, convey the additional
data as expeditiously as doable through limited
bandwidth and providing high information data rates.
For 4G communication systems 3GPP introduced two
features. Higher Order Modulation and Multiple
Input Multiple Output (MIMO) in OFDM system but
one limiting issue in implementing high-speed
wireless systems is the impairment associated with
analog processing due to component imperfections.
Numerous works have discussed in LTE performance;
however, most have been restricted to limited
scenarios. For LTE MIMO-OFDM system is sensitive
to frequency errors, causing inter carrier interference
(ICI) among subcarriers and phase noise. This
analysis Investigate to the maximum data throughput
under different conditions and scenarios which will
provide in depth performance study in LTE physical
layer’s characteristics under 3GPP standard in
release 10. As performance metrics date throughput,
Bit Error Rate (BER) are evaluated in terms of Signal
to Noise ratio (SNR) for 2 completely different MultiInput Multi-Output (MIMO) schemes, Which is
outlined in LTE standard under different combination
of digital modulation schemes.
System for Mobile (GSM) and IS-95. The emergence
of 3G systems came to the scene when IMT-2000
(International Mobile for Telecommunications-2000)
[3] was developed in mid-1980 at ITU (International
Telecommunication Union). Within the year 2002
outstanding systems were developed beneath IMT2000, WCDMA/UMTS (Wideband CDMA/Universal
Mobile Telecommunication System) and CDMA2000 [4]. each of the higher than have evolved in to
questionable “3.5G”.At present, the Third Generation
Partnership Project long term Evolution (3GPP LTE)
is taken into account because the path to the next
generation of cellular system [5].
II. SYSTEM DESCRIPTION AND MODELING
MIMO-OFDM is being considered the most
promising multiplexing techniques to support the 4G
communication system because of its bandwidth
efficiency performance. The effects of Inter Symbol
interference (ISI) is very less than the system compare
to the other multiplexing techniques. But
Unfortunately OFDM is very sensitive to the
synchronization errors such as Carrier frequency
offset (CFO), phase noise.
A. MIMO-OFDM System Model
Keywords—LTE, Data Throughput, PHY, phase
noise, MIMO-OFDM, Code word Bit Error Rate
(CBER).
I.
INTRODUCTION
Mobile
wireless
communication
provides
evolutionary methods for individuals to communicate,
because it blends communication with quality. In a
very short span of time outstanding achievements and
advancements have already been recorded within the
story of wireless communications. The Evolution of
wireless communication has already began its fourth
Generation, [1].1G, The first generation of mobile
wireless communication used analog communication
techniques, that were designed primarily on
modulation (FM) and frequency division multiple
access (FDMA) [2]. Electronic communication
techniques emerged from (2G) that were designed on
time division multiple access (TDMA); the foremost
wide accepted systems of 2nd generation were Global
ISSN: 2231-5381
Fig. 1 OFDM System Model (Reciver Section)
In fig. 1, Consider the mth symbol of an N- sub
carrier OFDM system in presence of normalized CFO
(ε), phase noise φm(n) and timing jitter (ξ).
B. Carreir Frequency Offset
For carrier frequency offset the absolute value of is
fε, an integer multiple or a fraction of Δf. Now if the
sub carrier spacing Δf normalized by fε then it
normalized CFO. The channel is expressed as δ is an
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International Journal of Engineering Trends and Technology (IJETT) – Volume 33 Number 1- March 2016
integer and |є|=<0.5 If the Carrier frequency offset
occurs then the symbol transmitted on a certain sub
carrier k, will shift to another sub carrier ks = k+δ.
C. Phase Noise
Phase noise φm (n) can be generated at both
transmitter and receiver side. It can be modeled as
The transfer function of the Rayleigh fading
H m (k ) is the transfer function of the Rayleigh fading
channel at the frequency of the kth carrier and
wm (n) is the complex envelope of the AWGN with
zero mean and variance ζ2. Assuming
small so,
m
(n) is very
n
m
n
m 1
N 1
u m N
i
(1)
m N Ng
Ng
i
Ng n
u i
cm
m N
u i And
m
n
1 j
m
n
u Tm i
i 0
Where S (k), Θ (k) and W (k) are the DFT responses
of sm (n), m ( n) and wm (n) respectively.
(2)
Ng 1
j
(8)
n
i 0
m N Ng
e
Ng
Ng
Ng 1
E. Downlink OFDM Parameters
i 0
(3)
Respectively. For cyclic prefix Ng is the length and u
(i) denotes Gaussian random variables having zero
mean and variance of ζu2. There is another noise that
is introduced by the channel. It is Additive White
Gaussian Noise (AWGN). This noise added to the
message signal and its PDF follows Gaussian‟s
distribution function.
The basic technology of LTE is Orthogonal Frequency
Division Multiplexing (OFDM), which is used in the
downlink transmission scheme because of its multicarrier modulation. This provides a large system
bandwidth into multiple narrowband sub-carriers and
occurs each sub-carrier nearly flat fading. Cyclicprefix mitigates inter symbol interference in a time
dispersive channel. For OFDM system it has several
basic parameter such as the sub-carrier spacing Δf, the
number of the FFT size (N ), subcarriers ( N sc ), and
D. Calculation of SNR and BER
the cyclic prefix length ( N cp ). As shown in Table. 1,
In fig 1 the transmitted OFDM signal for the mth
symbol is given by the N point complex modulation
sequence
15 kHz used for sub-carrier spacing and the latter
three parameters are decided by the system bandwidth
(BW). It has some other parameter such as, the
sampling frequency s f and the number of OFDM
symbols in a slot ( N symb ) [6].
Where cm and Tm are defined by
N 1
xm n
j
Xm k e
2
nk
N
k 0
TABLE I
(4)
Downlink OFDM parameters [6]
BW(MH
z)
Where n is ranges from 0 to N+Ng-1 After passing
through a Rayleigh fading channel and LO, the
received signal impaired by AWGN and PN can be
modeled asN 1
ym n
X m k Hm k e
j
2
n k
N
ej
m
n
wm n
k 0
(5)
1.4
3
ym n
sm n e
m
n
wm n
15
20
N sc
72
180
300
600
900
1200
N
128
256
512
1024
1536
2048
fs
1.92
3.84
7.68
15.36
23.04
30.72
7/6 (normal/extended CP)
N symb
N cp
(6)
10
15 KHz
f
Where
j
5
9
18
36
72
108
144
32
64
128
256
384
512
(7)
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International Journal of Engineering Trends and Technology (IJETT) – Volume 33 Number 1- March 2016
F. MIMO Receiver
For Channel estimation, least-squares estimation has
used averaging over a sub frame for noise reduction
to the reference signals and the data element of the
subcarriers liner interpolation is using.
TABLE II
Simulation parameters
Parameter
Value
Channel Bandwidth
Duplex Mode
Channel Type
FEC Coding
Modulation
5 MHz
FDD
EPA 5MHz
Turbo Coding 1/3
QPSK, 16-QAM, 64QAM
15 KHz
0.75
4X4 and 3X6 MIMO
Subcarrier Spacing
Code Rate
Antenna Diversity
III.
SIMULATION AND RESULT ANALYSIS
Fig. 2 Performance of QAM using AWGN and Rayleigh
channel for 4x4 MIMO.
The above figure depicts BER for 16-QAM, 64-QAM
modulation scheme with OFDM in AWGN and
Rayleigh channels without diversity. For the chosen
setup parameters, it evaluates the performance of 16QAM OFDM using AWGN is better than Rayleigh
channel because AWGN channel has a simpler model
without experiencing any fading.
The performance of LTE physical layer was analyzed
and evaluated at different noise levels. Various BER
vs SNR, data throughput vs SNR plots are presented
for different essential modulation. For MIMO-OFDM
fading channel Performance analysis results are
provided based on FDD operation. Our results are
based on MATLAB simulations for which the relevant
parameters are summarized in Table 2. For better
understanding of the LTE performance, results are
classified as two main categories: 5 MHz of system
bandwidth utilizing 4x4 MIMO, and 5 MHz of system
bandwidth utilizing 3x6 MIMO in downlink.
A. Analysis of Different Modulation with Fading
Chanel in LTE system
In this simulation part a number of simulation
scenarios have been conducted to investigate the
impact of higher order modulation along with the
effects of using MIMO techniques in AWGN and
Rayleigh Channels. BER is evaluated as a function of
SNR in all simulation Scenarios. The following
scenarios are investigated:
Performance of QPSK and M-QAM Using
AWGN and Rayleigh channel for 4x4
MIMO Techniques.
Performance of QPSK and M-QAM Using
AWGN Rayleigh and channel for 3x6
MIMO Techniques.
ISSN: 2231-5381
Fig. 3 Performance of QPSK and QAM using AWGN and
Rayleigh channel for 3x6 MIMO
Above figure indicates that the bit error rate of QPSK
is smaller as compared to 16 or 64 QAM. In the above
figure, LTE operates in Multi Path Rayleigh fading
channel along with different MIMO Configurations,
changing the antenna pattern in both side respect to
transmitter and receiver antennas when using M-QAM
–OFDM system. It can be seen from the above figure,
as the numbers of antennas are increased on the
transmitter side or the receiver side, the bit error rate
becomes lower. Initially, Fig.2 and fig.3 analyzed with
two code word for codebook index 1 as Specification
of 3GPP release which are QPSK, M-QAM. The two
MIMO techniques (4X4 and 3X6) are applied. It has
seen that the lower modulation scheme gives better
performance with less SNR. Furthermore, the perfect
selection of the Adaptive modulation (AMC) mode
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International Journal of Engineering Trends and Technology (IJETT) – Volume 33 Number 1- March 2016
has made in such a way that guarantees a BER below
a given target BER. In 64-QAM modulation,
relatively high SNR was observed for the good BER
performance. In fact, in 3x6 MIMO configuration
system the BER of 10^-3 was achieved with 28 dB,
however the same value of BER is with only 24 dB in
the 4x4 diversity scheme. So it has proven that 4 dB
SNR gain is clearly increasing in 3x6 diversity
scheme. This has happened due to the fact of
enhancing complexities for higher order modulation
schemes. Moreover, the Euclidean distances between
the symbols decrease for higher order QAM, hence
higher order QAM which leads to increase BER even
for the little occurrence of noise. OFDM and MIMO
are implemented where we utilized the Transmit
Diversity (TD) for the LTE transmission.
configuration is shown in Fig.4. It can observed that
as the SNR increase the data throughput increase and
it reaches its maximum at almost 24 dB SNR as in
BER and 30 Mbps capacity can be achieved in the
PDSCH channel. For achieving maximum capacity
high order modulation high SNR required. The data
throughput of 3x6 MIMO configurations is shown in
Fig.5 and it shows for maximum data throughput of
74 Mbps can be achieved at SNR 28 dB when the
eNB uses the bandwidth of 5 MHz for transferring
data to the UE in the PDSCH channel by using 0.75
code rate with 64-QAM.
C. Performance Analysis of Data Throughput Vs
SNR
A. Performance Analysis
Transmission System
Fig. 4 4X4 MIMO Downlink Throughput in 5 MHz bandwidth.
IV. ANALYSIS OF NOISE IN DIFFERENT MIMO
SYSTEM
for
3x6,
4x4,
2x2
Fig 6 Analysis of the SNR Vs BER for 3x6, 4x4, and 2x2
transmission
Fig 7 Analysis of the SNR Vs BER graph for different value of
Fig. 5 3X6 MIMO Downlink Throughput in 5 MHz bandwidth.
Fig 4 and fig 5 shows data throughput vs SNR in
fixed 5 MHz channel bandwidth for downlink system
with two MIMO system.Fig.4 and fig. 5 for FDD
operation based on mentioned parameters in
Table.2.The data throughput of 4x4 MIMO
ISSN: 2231-5381
noises (Tx=3; Rx=6)
Fig 6 is for BER vs SNR graph for 3 different MIMO
system configuration and analysis that which
configuration gives batter performance for phase
noise.it has been seen that 3x6 antenna system gives
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International Journal of Engineering Trends and Technology (IJETT) – Volume 33 Number 1- March 2016
better performance so using that configuration phase
noise has been varied with different variances of
phase noise value which has been seen in fig 7.
C. Analysis for SNR Vs BER for 4x8, 3x6, 4x4, 2x2
Transmission
Fig. 10 Analysis of the receiver sensitivity graphs are plotted
for different value of noises
Fig 10 shows that Receiver sensitivity graph that
shows if number of transmission antenna increasing
then signal to noise ratio is decreasing.
Fig 8 Analysis of the SNR Vs BER for 4x8,3x6, 4x4, and 2x2
transmission
Fig:8 is for 4x8 with other three different MIMO
antenna system which represents BER vs SNR and
phase noise analyzed for 4x8 system with different
phase values And it has been seen that 4x8 gives less
performance then 3x6 antenna. In 3x6 antenna
configuration we can archived 7 dB SNR gain where
4x8 system 9 dB, means 2 dB SNR increased. Other
antenna system.
V. DISCUSSIONS AND CONCLUSIONS
In this thesis paper I have been analyzing the
performance of LTE (Release 10). The analysis has
targeted on the most feature involved in the
downlink, just like the user multiplexing, adaptive
modulation and support for multiple antennas through
MIMO system. The present results in this paper show
that, 3x6 MIMO-OFDM system for LTE can achieve
74 Mbps of downlink data throughput for PDSCH
and 10-3 BER when using 64-QAM and phase noise
also analyzed with that configuration.it has clearly
shows that for LTE downlink system, if 3x6 MIMO
antenna configuration will be used then 74 Mbps data
capacity can achievable with lower phase noise.
ACKNOWLEDGMENT
I would like to express my special thanks to my
supervisor Dr. Md. Abu Bakar Siddiqui, Assistant
Professor, Faculty of Engineering, AIUB for giving us
enormous support, motivation and invaluable advises
regarding this thesis.
Fig. 9 Analysis of the SNR Vs BER graph for different value of
noises (Tx=4; Rx=8)
Fig 9 for different value of noises. We can observed
that , for 4x8 antenna configuration system the SNR
level vary from 5.5 to 9 dB . Which is some grater
then 3x6 system.
REFERENCES
[1]
[2]
ISSN: 2231-5381
Diva, J. Sengupta, K. Amit and Y. Liu. (2010) “Evolution of
Mobile Wireless Communication Networks: 1G to 4G”.
International Journal of Electronics and Communication
Technology (IJECT) Vol. 1 Issue 1.p.68-72.
H.G. Myung (2007) “Single Carrier Orthogonal Multiple
Access Technique for Broad-band Wireless Communication”
.PhD Dissertation, Polytechnic University, January 2000.
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International Journal of Engineering Trends and Technology (IJETT) – Volume 33 Number 1- March 2016
[3]
[4]
[5]
[6]
J.Berkmann(2008) On 3G LTE Terminal Implementation –
Standard, Algorithms, Complexities and Challenges. IWCMC
2008 Mobile Computing Symposium, 2008.
ETSI TS 136 211 V10.0.0 (2011-01) LTE; Technical
Specification. Evolved Universal Terrestrial Radio Access
(E-UTRA); Physical channels and modulation (3GPP TS
36.211 version 10.0.0 Release 10).
I. Toufik, M. Baker, S. Sesia (2011) „LTE The UMTS Long
Term Evolution From Theory To Practice‟. Second Edition
Wiley Publication 2011.
3GPP Technical Specification Group Radio Access Network;
“Evolved Universal Terrestrial Radio Access (EUTRA);User
Equipment (UE) radio access capabilities (Release10)”,
3GPP TS36.306 v10.0.0 (2010-12).
University (AIUB). He joined AIUB in May 2013.
He completed his M.Sc in 1987 from Technical
University, Sofia, Bulgaria. He also obtained PhD
from the same university in 1991 on
Telecommunication area. During his PhD study, he
made invention on line coding (Balanced 3B2T).
Before his joining to AIUB, he held various technical
positions
in
telecommunications
corporate
organizations in Bangladesh. His research interest
includes 4G mobile communication, digital
broadcasting system and VLSI circuit design.
Mubinul Haque has completed his
Bachelor of Science in Electrical
and Electronics Engineering (EEE)
from
American
International
University-Bangladesh (AIUB) in
2013.After the completion of his
BSc program currently he is doing
Master of Science in Electrical and Electronics
Engineering (M.Sc in EEE) in American International
University-Bangladesh (AIUB). His current research
interests include Networking,Wireless Comunication,
Microwave system,. He is also an Assosiate Member
of The Institution of Engineers Bangladesg (IEB).
Dr. Md. Abu Bakar Siddiqui has
been serving as an assistant
professor in the Department of
Electrical
and
Electronic
Engineering
at
American
International
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