The attached narrated power point presentation offers a block level and an elementary level mathematical treatment of optical communication systems employing coherent detection. The material will immensely benefit KTU final year B Tech students who prepare for the subject EC 405, Optical Communications.
Its exploring the technique for spatially successive interference cancellation and superposition of transmission for upcoming radio communication 5G technology.
The attached narrated power point presentation offers a block level and an elementary level mathematical treatment of optical communication systems employing coherent detection. The material will immensely benefit KTU final year B Tech students who prepare for the subject EC 405, Optical Communications.
Its exploring the technique for spatially successive interference cancellation and superposition of transmission for upcoming radio communication 5G technology.
NOTE: The slides contain the visual effects. So for complete information download the presentation and view it in slideshow mode.
Description of Non-orthogonal Multiple access in 5G networks Detailed discussion on downlink NOMA scenario and future challenges and trends.
Wireless communications is a hot topic in technology today, driven by technologies like Wireless Networking, Cellular Telephony, Wireless Connectivity and Satellite Communications among others. Traditionally, wireless and RF communications has been one of the last bastions of analog engineering. With the advent of low cost digital, high speed integrated circuits, this too has become part of the digital domain. Although information transmitted today is largely digital high frequency signals whether digital or analog always behave like analog signals so having fundamental knowledge of this high frequency behavior is key.
NOTE: The slides contain the visual effects. So for complete information download the presentation and view it in slideshow mode.
Description of Non-orthogonal Multiple access in 5G networks Detailed discussion on downlink NOMA scenario and future challenges and trends.
Wireless communications is a hot topic in technology today, driven by technologies like Wireless Networking, Cellular Telephony, Wireless Connectivity and Satellite Communications among others. Traditionally, wireless and RF communications has been one of the last bastions of analog engineering. With the advent of low cost digital, high speed integrated circuits, this too has become part of the digital domain. Although information transmitted today is largely digital high frequency signals whether digital or analog always behave like analog signals so having fundamental knowledge of this high frequency behavior is key.
An Overview : Peak to Average Power Ratio (PAPR) in OFDM system using some ne...Z AL Hashemi
An Overview : Peak to Average Power Ratio (PAPR) in OFDM system using some new PAPR techniques (with matlab code)
By
Zainab Saad Hadi AL-Hashemi
A graduate of University of Baghdad, College of Engineering Electronic & Communications Engineering Department
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
Comparative study of selected subcarrier index modulation OFDM schemesTELKOMNIKA JOURNAL
Orthogonal frequency division multiplexing with subcarrier index modulation (SIM-OFDM) is recently proposed to enhance the performance of traditional OFDM. By incorporating the index modulation in OFDM, the data can be sent on the indices of subcarriers as well as the subcarriers themselves reducing the system complexity. In addition, the Peak to Average Power Ratio (PAPR) and Inter Carrier Interference (ICI) can be reduced by switching on /off some OFDM subcarriers in OOK fashion. In this paper, a comparative study of OFDM with SIM_OFDM and Enhanced SIM_OFDM methods in terms of complexity, spectral efficiency and bit error rate over AWGN channel using two power policies is presented. The simulation results showed that at bit error rate of 10-3, SIM_OFDM and ESIM_OFDM achieved gains in Eb/No of 1.1 dB and 2 dB over 4-QAM OFDM respectively under power reallocation policy. However, the results also showed that traditional OFDM has better spectral efficiency compared to both SIM_OFDM and ESIM_OFDM especially at high M-ary orders.
Design Ofdm System And Remove Nonlinear Distortion In OFDM Signal At Transmit...Rupesh Sharma
although OFDM seems to be a solution to keep up with
the demand of increasing data rates, it has some drawbacks.
Sensitivity to high PAPR is the most significant of these
drawbacks. The main objective of this paper was to investigate
and document the effects of PAPR on the performance of OFDM
based digital communications under different channel conditions.
A step-by-step approach was adopted in order to achieve the
objective of this paper. The first step is to provide a basic
background on the principles of OFDM. The reasons for the
PAPR and a theoretical analysis of these effects on OFDM
systems are documented. The OFDM system has a high peak-toaverage
power ratio (PAPR) that can cause unwanted saturation
in the power amplifiers, leading to in-band distortion and out-ofband
radiation. To be able to observe the system behavior, the
simulation results for different channel models are presented in
graphical form. Next, the simulation results obtained in this work
are compared to the simulation results reported in related studies
Hardware Implementation of OFDM system to reduce PAPR using Selective Level M...IOSR Journals
Abstract : OFDM is a modulation as well as multiplexing technique which is widely used in various high speed mobile and wireless communication systems because of its capacity of ensuring high level robustness against interference. In this paper the design and implementation of OFDM system along with SLM implementation to reduce PAPR[6]is illustrated and a detailed simulation of the OFDM system with 16-QAM. OFDM transceiver is implemented using FPGA Spartan6 kit. The hardware results show a detailed study of RTL schematics and Test Bench. In this paper, the software simulation results show 2dB reduction in the peaks. Keywords - Field Programmable Gate Array, Matlab Simulink, Orthogonal Frequency Division Multiplexing , Peak-to-Average Power Ratio, Selective level Mapping and Xilinx
A SEMI BLIND CHANNEL ESTIMATION METHOD BASED ON HYBRID NEURAL NETWORKS FOR UP...ijwmn
The paper describes how to improve channel estimation in Single Carrier Frequency Division Multiple
Access (SC-FDMA) system, using a Hybrid Artificial Neural Networks (HANN). The 3rd Generation
Partnership Project (3GPP) standards for uplink Long Term Evolution Advanced (LTE-A) uses pilot based
channel estimation technique. This kind of channel estimation method suffers from a considerable loss
ofbitrate due to pilot insertion; all data frame sent contains reference signal. The HANN converts data
aided channel estimator to semi blind channel estimator. To increase convergence speed, HANN uses some
channel propagation Fuzzy Rules to initialize Neural Network parameters before learning instead of a
random initialization, so its learning phase ismore rapidly compared to classic ANN.HANN allows more
bandwidth efficient and less complexity. Simulation results show that HANN has better computational
efficiency than the Minimum Mean Square Error (MMSE) estimator and has faster convergence than
classic Neural Networks estimators.
On Channel Estimation of OFDM-BPSK and -QPSK over Nakagami-m Fading ChannelsCSCJournals
This paper evaluates the performance of OFDM - BPSK & -QPSK based system with and without channel estimation over Nakagami-m fading channels. Nakagami-m variants are generated by decomposition of Nakagami random variable into orthogonal random variables with Gaussian distribution envelopes. Performance of OFDM system in Nakagami channel has been reported here. The results yield the optimum value of m based on BER and SNR. Using this optimum value of m, Channel estimation over flat fading has been reported here. It has been depicted clearly from simulated graphs that channel estimation has further reduced the BER. However, threshold value of m has played a vital role during channel estimation.
A Hybrid VLM Preceded SLM Technique Using Clipping and Filtering Method for P...IJERA Editor
MIMO-OFDM is an attractive interface for the next generation WLANs, WMAN, 4G and 5G mobile cellular
systems. However the performance of the MIMO-OFDM systems is affected by Peak to Average Power Ratio
(PAPR). PAPR is the main disadvantage associated with the MIMO-OFDM systems. So far, many techniques
have been proposed to reduce the value of PAPR but high PAPR for MIMO-OFDM systems is still a demanding
area and a different issue.In this paper, a hybrid VLM precoded SLM scheme using Clipping & Filtering has
been proposed to reduce PAPR in MIMO-OFDM systems. And it has been observed that the proposed scheme
has achieved a significant gain in PAPR reduction without increasing the system complexity and affecting the
error performance of the system.
Analysis of Peak to Average Power Ratio Reduction Techniques in Sfbc Ofdm SystemIOSR Journals
Abstract: Orthogonal Frequency Division Multiplexing (OFDM) has become the most popular modulation echnique for high speed data transmission. But the great disadvantage of the OFDM technique is its high Peak to Average Power Ratio (PAPR). In this paper, the Selected Mapping (SLM) technique and Clipping and Differential Scaling is applied to Space Frequency Block Coded (SFBC) OFDM systems to reduce the PAPR with Alamouti coding scheme. In SLM technique, different representations of OFDM symbols are generated by rotation of the original OFDM frame by different phase sequences, and the signal with minimum PAPR is selected and transmitted. To compensate for the effect of the phase rotation at the receiver, it is necessary to transmit the index of the selected phase sequence as side information (SI). Additionally, a suboptimum detection method that does not need SI is introduced at the receiver side. In Clipping and Differential Scaling technique, the amplitude of complex OFDM signal is clipped and then scaled in such a way so that the PAPR is reduced without causing much degradation in bit error rate (BER). The threshold values for clipping and scaling is determined using Monte Carlo Simulations. Simulation results show that the SLM method and Clipping and Scaling method effectively reduce the PAPR. Keywords: Orthogonal frequency division multiplexing (OFDM), peak to average power ratio (PAPR), selected mapping (SLM), space frequency block coded (SFBC), Side information (SI), high power amplifiers (HPA), complementary cumulative density function (CCDF), inter-symbol interference (ISI).
International Journal of Engineering Research and Applications (IJERA) is a team of researchers not publication services or private publications running the journals for monetary benefits, we are association of scientists and academia who focus only on supporting authors who want to publish their work. The articles published in our journal can be accessed online, all the articles will be archived for real time access.
Our journal system primarily aims to bring out the research talent and the works done by sciaentists, academia, engineers, practitioners, scholars, post graduate students of engineering and science. This journal aims to cover the scientific research in a broader sense and not publishing a niche area of research facilitating researchers from various verticals to publish their papers. It is also aimed to provide a platform for the researchers to publish in a shorter of time, enabling them to continue further All articles published are freely available to scientific researchers in the Government agencies,educators and the general public. We are taking serious efforts to promote our journal across the globe in various ways, we are sure that our journal will act as a scientific platform for all researchers to publish their works online.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
International Journal of Engineering Research and Applications (IJERA) is a team of researchers not publication services or private publications running the journals for monetary benefits, we are association of scientists and academia who focus only on supporting authors who want to publish their work. The articles published in our journal can be accessed online, all the articles will be archived for real time access.
Our journal system primarily aims to bring out the research talent and the works done by sciaentists, academia, engineers, practitioners, scholars, post graduate students of engineering and science. This journal aims to cover the scientific research in a broader sense and not publishing a niche area of research facilitating researchers from various verticals to publish their papers. It is also aimed to provide a platform for the researchers to publish in a shorter of time, enabling them to continue further All articles published are freely available to scientific researchers in the Government agencies,educators and the general public. We are taking serious efforts to promote our journal across the globe in various ways, we are sure that our journal will act as a scientific platform for all researchers to publish their works online.
Performance of Multiple symbol representation with clipping scheme for PAPR r...ijsrd.com
OFDM is one of the multicarrier modulation technique used in various communication systems. The major problem one faces while implementing this system is the high peak to average power .For an efficient OFDM system this PAPR should be low. In this paper a hybrid PAPR (peak to average power ratio) reduction technique for the OFDM (orthogonal frequency division multiplexing) signal which combines a multiple symbol representations method with a signal clipping method is proposed. In multiple symbol representations alternative signaling points are used to represent one symbol and PAPR is further reduced with the clipping scheme. The performance of the hybrid scheme is compared with the partial transmit sequence which is one of the other PAPR reduction scheme. In partial transmit sequence the input data is divided in to disjoint blocks transformed in to time domain sequence and rotated by phase factors. Theoretical analysis and simulation results validate that the proposed scheme has the ability to provide large PAPR reduction, low bit error rate. Performance analysis is also done with the partial transmit sequence scheme.
Overview of the fundamental roles in Hydropower generation and the components involved in wider Electrical Engineering.
This paper presents the design and construction of hydroelectric dams from the hydrologist’s survey of the valley before construction, all aspects and involved disciplines, fluid dynamics, structural engineering, generation and mains frequency regulation to the very transmission of power through the network in the United Kingdom.
Author: Robbie Edward Sayers
Collaborators and co editors: Charlie Sims and Connor Healey.
(C) 2024 Robbie E. Sayers
Sachpazis:Terzaghi Bearing Capacity Estimation in simple terms with Calculati...Dr.Costas Sachpazis
Terzaghi's soil bearing capacity theory, developed by Karl Terzaghi, is a fundamental principle in geotechnical engineering used to determine the bearing capacity of shallow foundations. This theory provides a method to calculate the ultimate bearing capacity of soil, which is the maximum load per unit area that the soil can support without undergoing shear failure. The Calculation HTML Code included.
Welcome to WIPAC Monthly the magazine brought to you by the LinkedIn Group Water Industry Process Automation & Control.
In this month's edition, along with this month's industry news to celebrate the 13 years since the group was created we have articles including
A case study of the used of Advanced Process Control at the Wastewater Treatment works at Lleida in Spain
A look back on an article on smart wastewater networks in order to see how the industry has measured up in the interim around the adoption of Digital Transformation in the Water Industry.
Hierarchical Digital Twin of a Naval Power SystemKerry Sado
A hierarchical digital twin of a Naval DC power system has been developed and experimentally verified. Similar to other state-of-the-art digital twins, this technology creates a digital replica of the physical system executed in real-time or faster, which can modify hardware controls. However, its advantage stems from distributing computational efforts by utilizing a hierarchical structure composed of lower-level digital twin blocks and a higher-level system digital twin. Each digital twin block is associated with a physical subsystem of the hardware and communicates with a singular system digital twin, which creates a system-level response. By extracting information from each level of the hierarchy, power system controls of the hardware were reconfigured autonomously. This hierarchical digital twin development offers several advantages over other digital twins, particularly in the field of naval power systems. The hierarchical structure allows for greater computational efficiency and scalability while the ability to autonomously reconfigure hardware controls offers increased flexibility and responsiveness. The hierarchical decomposition and models utilized were well aligned with the physical twin, as indicated by the maximum deviations between the developed digital twin hierarchy and the hardware.
Cosmetic shop management system project report.pdfKamal Acharya
Buying new cosmetic products is difficult. It can even be scary for those who have sensitive skin and are prone to skin trouble. The information needed to alleviate this problem is on the back of each product, but it's thought to interpret those ingredient lists unless you have a background in chemistry.
Instead of buying and hoping for the best, we can use data science to help us predict which products may be good fits for us. It includes various function programs to do the above mentioned tasks.
Data file handling has been effectively used in the program.
The automated cosmetic shop management system should deal with the automation of general workflow and administration process of the shop. The main processes of the system focus on customer's request where the system is able to search the most appropriate products and deliver it to the customers. It should help the employees to quickly identify the list of cosmetic product that have reached the minimum quantity and also keep a track of expired date for each cosmetic product. It should help the employees to find the rack number in which the product is placed.It is also Faster and more efficient way.
Cosmetic shop management system project report.pdf
SCFDMA
1. 30 | P a g e
SCFDMA PERFORMANCE ANALYSIS FOR PAPR
REDUCTION WITH DIFFERENT SUBCARRIER
MAPPING USING SLM TECHNIQUE AND MODIFIED
SLM TECHNIQUE
Sneha Dubey 1
, Rekha Gupta2
1,2
Department of Electronics and Communication Engineering,
Madhav Institute of Technology and Science, Gwalior, (India)
ABSTRACT
The high PAPR value is a critical issue in OFDM system .The most efficient technique for PAPR reduction is
SCFDMA for uplink transmission in communication system. Firstly in this paper, different subcarrier mapping for
PAPR reduction is discussed and found from study that LFDMA still has high PAPR value than IFDMA and also
found that LFDMA and DFDMA have almost same PAPR value but LFDMA is preferred over DFDMA because the
practical performance of DFDMA is more difficult than LFDMA. In this paper the comparison of different
subcarrier mapping with SLM technique is performed. From simulated result it has been found that, the PAPR
performance of SLM technique for different subcarrier mapping is better than different subcarrier mapping scheme
without SLM technique. In SLM technique also LFDMA and DFDMA have same PAPR performance. In all
simulation QPSK and 16QAM modulations are used. There is also a modified SLM technique in which new phase
sequences are applied. It is found that modified SLM provides improvement in PAPR reduction than conventional
SLM technique with phase sequence (U=8) using QPSK and 16QAM modulation.
Keywords: DFDMA, IFDMA, LFDMA, SLM
I. INTRODUCTION
Two most important data transmission are single carrier and multiple carrier data transmission. Low data rate is the
disadvantage of single carrier data transmission. But high data rate is the advantage of multiple carrier data
transmission. Single carrier frequency division multiple access (SCFDMA) has one most important advantage of low
PAPR compared to OFDMA. But after all advancement, SCFDMA has high PAPR value. So to minimize PAPR value
different PAPR reduction techniques are used. The impact of PAPR reduction depends upon the method for allocating
the subcarriers to every terminal [1]. Three SCFDMA techniques are considered in this work, entitled as localized
FDMA (LFDMA), distributed FDMA (DFDMA) and interleaved FDMA (IFDMA). Localized subcarrier mapping in
2. 31 | P a g e
SCFDMA have higher PAPR value than IFDMA [2]. Localized subcarrier mapping in SCFDMA has almost equal
PAPR value to DFDMA [3].
This high PAPR can be reduced by using different PAPR reduction techniques such as Selective mapping [4], Partial
transmit sequence (PTS) [5], Companding techniques [6], Precoding techniques [7], Clipping techniques [8].
This paper reflects the evaluation of PAPR performance with different subcarrier mapping techniques. In SCFDMA,
Selective mapping techniques is the most important technique for PAPR reduction [9]. This paper also reflects the
selective mapping techniques for PAPR reduction. Then comparison of different subcarrier mapping with SLM
techniques is performed. But there is also a disadvantage of SLM, is that it has high complexity [10]. But for reducing
the complexity of SLM many schemes are proposed [11].
There is also a modified SLM technique in which new phase sequences are applied. It is found that modified SLM
technique provides improvement in PAPR reduction than conventional SLM technique with phase sequence (U=8)
using QPSK and 16QAM modulation.
The rest of the paper is arranged as follows. In section 2, the SCFDMA system model is defined. Section 3 represents
the PAPR of SCFDMA signal. In section 4, SLM technique with different subcarrier mapping is investigated. In
section 5, modified SLM technique is analyzed. In section 6, simulation result is discussed. Finally conclusion is
drawn in section 7.
II. SCFDMA SYSTEM MODEL
SCFDMA is also known as DFT precoded OFDMA. In the transmitter block binary input sequence which is of the
length of M (number of user subcarrier) is modulated by using modulator. In this paper M input sequence is QPSK
and 16QAM modulated.
After modulation, subcarrier mapping is used. In this paper three types of subcarrier mapping is used which are:
IFDMA, LFDMA, DFDMA. After subcarrier mapping length of the data became N (number of system subcarrier)
such that N>M.
2.1. Subcarrier mapping schemes
The performance of SCFDMA framework is chiefly influenced by the kind of subcarrier mapping techniques being
used.
The three sub-carrier mapping techniques that are present for allocating M frequency domain symbols to the sub-
carriers are: Localized (LFDMA), Distributed (DFDMA) and Interleaved (IFDMA) subcarrier mapping.
2.1.1. Interleaved FDMA
Each user has assigned M numbers of subcarrier. Total numbers of subcarriers are denoted by N (where N>M).
When IFDMA allocates DFT outputs with equidistance N/M=S, it is depicted as IFDMA where S is called the
bandwidth spreading factor.
3. 32 | P a g e
Fig.1 Interleaved FDMA
Fig (1) represents the value of M=4 (Number of user subcarrier assigned by each users Ym (0) Ym (1) Ym (2) Ym (3)) is
allocated to N=12 (Number of system subcarrier). So spreading factor is N/M=S which is equal to 3
2.1.2. Distributed FDMA
Each user has assigned M numbers of symbols. Total numbers of subcarriers are denoted by N (Where N>M). The
number of zeros in DFDMA will be N-M. Drawback of DFDMA is that it loses user diversity.
Fig.2 Distributed FDMA
2.1.3. Localized FDMA
Multi user diversity is achieved by using LFDMA in frequency selective channel. Every user transmits data on a set
of adjacent subcarriers. Each users has assigned M numbers of subcarriers are denoted by N. LFDMA distributes
DFT outputs to M successive subcarrier in N subcarriers (where N>M).
Fig.3 Localized FDMA
III. PAPR OF SCFDMA SIGNAL
In SCFDMA, FFT and IFFT both operations are performed. In SCFDMA, We can compose the perplexing vector of
size M as X=[X0, X1, X2…..XM-1] T
. The complex baseband SCFDMA signal with subcarriers can be composed as:
= , n=0, 1……..M-1 (1)
Where j=
The PAPR ratio is defined as the ratio between the maximum power and average power of transmitted signal is
defined as:
4. 33 | P a g e
PAPR= (2)
Is average power of transmitted signal. Degradation of efficiency with high value of PAPR is a major
problem in wireless communication system. PAPR in dB is expressed as:
PAPR (dB)=10log10(PAPR) (3)
IV. SLM TECHNIQUE WITH DIFFERENT SUBCARRIER MAPPING
Fig (4) exhibits the block diagram of the SLM based uplink system. First, data stream is changed from serial to
parallel form which is represented as X=[X0, X1, X2…..XM-1] T
. Each converted data is multiplied by U number of
phase sequences. Each phase sequence has the length sequence of M, B(u)
=[bu,0 ,bu,1 ,……bu,M-1]T
, (u=1,2,…U). So
after multiplying data stream with phase sequences the result will be X (U) = [ ]
Where u=1, 2, 3…U.
Then these blocks of data are DFT precoded which can be written as:
Ym
(u)
= m=0,1….L-1 (4)
The Precoding network P which is characterized as a Precoding Matrix having dimension N × N, can be composed
as:
P= (5)
Where means DFT precoding matrix of mth row and nth column such as, where m and n are
integers from 0 to N-1.
After precoding, subcarrier mapping of precoded signal is performed. Suppose the type of subcarrier mapping is
LFDMA. The subcarrier mapping in the Localized mode can be written as:
(u)
= (6)
Where N is the number of system subcarrier, M is the number of user subcarriers.
After all these processes, mapped data is IFFT precoded. Resultant data is represented by x (1), x (2), x (3)….x (u).
After IFFT operation, PAPR with minimum values are selected.
5. 34 | P a g e
Fig.4 SLM technique in SCFDMA
Dependability of SLM techniques for PAPR reduction is on U, which is the number of phase sequences and also on
selection of output data with the lowest PAPR value.
V. MODIFIED SLM TECHNIQUE
In modified SLM technique, all processes will be same as conventional SLM technique except that we have changed
the phase sequences. Earlier in SLM technique, we have used phase sequences [B (1), B (2)] = [1,-1]. In the modified
SLM technique, we have used phase sequences [B(1),B(2),B(3),B(4)]=[1,-1,j,-j] and then data is converted from serial
to parallel form. By the modified SLM unit, transformed data is processed. Then FFT, subcarrier mapping and IFFT
operations of data is performed. After all these processes, one with lowest PAPR value is selected.
VI. SIMULATION RESULT
For evaluating the PAPR reduction performance, we have carried out wide ranging simulation using MATLAB for
SCFDMA system. SCFDMA system with N=256 subcarriers was used for the simulation with QPSK and 16QAM
modulation. The parameters used for simulation are given below in table:
Table.1. Parameters for simulations
6. 35 | P a g e
In Fig.1.there is a comparison of the results for different subcarrier mapping techniques in SCFDMA. In case of
IFDMA the PAPR have smallest value, whereas PAPR is almost same in case of LFDMA and DFDMA for any
modulation schemes.
1 2 3 4 5 6 7 8 9 10
10
-4
10
-3
10
-2
10
-1
10
0
PAPR of SC-FDMA for 16QAM
PAPR[dB]
PAPR(PAPR>PAPR0)
IFDMA
LFDMA
DFDMA
Fig.1. PAPR of SCFDMA systems using 16QAM modulations Scheme with N=256, M=64
Fig.2, Fig.3 and Fig.4 shows the comparisons of PAPR for the different subcarrier scheme (IFDMA, DFDMA,
LFDMA) with SLM techniques for U=4, 8 and 16 and M=64 and N=256 with 16QAM modulation.
Parameter Value
Modulation QPSK,16QAM
Number of user
subcarriers (M)
64
Number of system
subcarriers (N)
256
Number of iterations 10000
Phase sequences U=4,8,16
Subcarrier mapping IFDMA,LFDMA,DFDMA
7. 36 | P a g e
1 2 3 4 5 6 7 8
10
-4
10
-3
10
-2
10
-1
10
0
PAPR0 [dB]
CCDF(Pr[PAPR>PAPR0])
SLM-DFDMA
SLM-LFDMA
SLM-IFDMA
Fig.2. PAPR of SLM SCFDMA systems using 16 QAM modulation Scheme with N=256, M=64 and
U=4
1 2 3 4 5 6 7
10
-4
10
-3
10
-2
10
-1
10
0
PAPR0 [dB]
CCDF(Pr[PAPR>PAPR0])
SLM-DFDMA
SLM-LFDMA
SLM-IFDMA
Fig.3. PAPR of SLM SCFDMA systems using 16 QAM modulations Scheme with N=256, M=64 and
U=8
8. 37 | P a g e
1.5 2 2.5 3 3.5 4 4.5 5 5.5 6 6.5
10
-4
10
-3
10
-2
10
-1
10
0
PAPR0 [dB]
CCDF(Pr[PAPR>PAPR0])
SLM-DFDMA
SLM-LFDMA
SLM-IFDMA
Fig.4. PAPR of SLM SCFDMA systems using 16QAM modulations Scheme with N=256, M=64 and
U=16.
In Fig.5, we have executed the new phase sequence of modified SLM for U=8 with QPSK modulation. We
compared the result with earlier SLM technique and it is found that modified SLM gives lower PAPR value than
conventional SLM.
Figure 5.CCDF Plot of PAPR for PROPOSED Method using QPSK LFDMA Scheme with N=256,
M=64 and U=8
9. 38 | P a g e
In Fig.6, there is a comparison of Modified SLM, conventional SLM and original SCFDMA for U=8 with 16QAM
modulation. On comparison, it is clear that modified SLM gives lower PAPR value than conventional SLM and
original SCFDMA.
Figure 6.CCDF Plot of PAPR for PROPOSED Method using 16QAM LFDMA Scheme with N=256,
M=64 and U=8
VII. CONCLUSION
In this paper, we have inspected the performance of SCFDMA with SLM techniques. Also we have analyzed the
performance of SCFDMA with modified SLM techniques and compared it with conventional SLM techniques.
Based on all analysis, it is clear that the PAPR for IFDMA is significantly lower than the LFDMA and DFDMA.
PAPR performance of LFDMA and DFDMA is nearly same. We evaluated the performance of the modified SLM
system and concluded that modified SLM gives better PAPR performance than conventional method. Comparing
Fig.5 and Fig.6, it is clear that QPSK modulation gives better performance than 16QAM.
REFERENCES
[1] A. Zolghadrasli and M. H. Ghamat, An Overview of PAPR Reduction Techniques for Multicarrier
Transmission and Propose of New Techniques for PAPR Reduction,Iranian Journal of Electrical and
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[2] Md. Masud Rana, Jinsang Kim and Won-kyung cho, PAPR Reduction Technique for LTE-SCFDMA System
Using Root-Raised Cosine Filter, International Journal of Computer Science and Information
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10. 39 | P a g e
[3] Ferdous Pervej, M.J.I.Sarkar,Tushar Kanti Roy,S.K.Bain,Analysis of PAPR Reduction of DFT-SCFDMA
System using Different Subcarrier Mapping Schemes, 17th
International Conference on Computer and
Information Technology (ICCIT),2014.
[4] Zhongpeng Wang., Reduction PAPR of OFDM Signals by Combining SLM with DCT Transform, Int. J.
Communications, Network and System Sciences, 2010, 3, 888-892.
[5] Nikhil Arora., Prem Singh., Partial Transmit Sequence (PTS)-PAPR Reduction Technique in OFDM Systems
with Reduced Complexity, Conference on Advances in Communication and Control Systems, 2013 (CAC2S
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[6] A.N. Jadhav., M. V. Kutwal., BER and PAPR Reduction Using Companding Algorithms in OFDM”,
International Journal of Application or Innovation in Engineering & Management (IJAIEM), January 2014,
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[7] Jaspreet Virdi., Asst.Professor Surjeet Kumar. PAPR Reduction Based on Precoding Techniques with
Companding in OFDM Systems, International Journal of Scientific & Engineering Research, May-2013,
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