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1

City lights revolution : next-gen optical fibre for smart cities

Yaseen Zeyad T., Alghrairi Mokhalad

Opto-Electronics Review

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2024

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Vol. 32, No. 3

art. no. e150610

EN

In the rapidly evolving landscape of smart cities, the integration of advanced technologies is crucial for ensuring safety, optimizing traffic flow, and enhancing the urban living experience. Vehicle-to-vehicle (V2V) communication and visible light communication (VLC) have emerged as promising solutions to address these challenges. This paper explores the integration of V2V communication and VLC at smart pedestrian crosswalks to enhance pedestrian safety and traffic management in smart cities. It explores the impact of neighbouring vehicles on V2V-VLC performance and proposes novel methodologies to assess traffic density effects. Results indicate a significant chance of encountering nearby cars during rush hours, emphasizing the importance of these integrated systems for safety and mobility in urban environments. The outcomes show that the chance of running into extra cars in nearby lanes is independent of the particular lane and increases to 80% through rush hours, but falls to a lower amount than 20% through off-peak and initial morning hours.

2

Performance evaluation of 5G New Radio low-density parity check codes over different scenarios of lognormal fading channel

Ali Mohammed Hussein, Al-Rubaye Ghanim A.

Bulletin of the Polish Academy of Sciences. Technical Sciences

|

2024

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Vol. 72, nr 5

art. no. e150808

EN

Low-density parity check (LDPC) is a channel coding technique widely utilized in the 5G New Radio standard, it is of utmost importance in facilitating proficient and secure communication in noisy environments by effectively minimizing errors during data transmission. It is primarily used in the 5G New Radio (NR) standard for encoding user information on the physical downlink shared channel (PDSCH). The necessity to satisfy the increasing expectations for throughput, latency, and dependability led to the decision to deploy LDPC codes for user data, especially in the enhanced mobile broadband (eMBB) and ultra-reliable and low-latency communications (URLLC) scenarios of 5G networks. The present system proposes the use of NR-LDPC codes to transmit data across a lognormal multipath fading channel model in the presence of AWGN. Wireless communication channels often use a lognormal multipath fading channel model, where the received signal experiences both multipath fading and lognormal shadowing. The research investigates the effectiveness of NR-LDPC coding in improving QAM-OFDM system performance by analyzing two rate-compatible base graphs and comparing their effectiveness with an uncoded system. This analysis is crucial for optimizing communication network design, especially in scenarios where the integrity of data is of utmost importance. We introduce a new method to improve the 5G NR LDPC code capability under lognormal fading conditions. This approach develops a layered min-sum (LMS) algorithm to provide enhanced error-correcting capabilities. The developed and implemented decoding algorithm represents a significant advancement over traditional detection methods. The outcomes of the simulation provide evidence of the effectiveness of the proposed NR-LDPC coding techniques in terms of their error correction and identification capabilities. In addition, the developed LMS decoding algorithm was shown to significantly decrease the BER of the system.

3

Wavelength effect in 100Gbit/s WDM transmission in a telecommunication network

Tebbal El hadj atif, Hasni Abdelhafid

Przegląd Elektrotechniczny

|

2023

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R. 99, nr 3

277--283

EN

These Optical transport networks are today the basic infrastructure of modern communications systems for the transfer of data between nodes. This paper proposes a transparent optical architecture for metropolitan area networks. This multi-service architecture allows supporting both 100Gbit/s WDM-PON transmission system and the wavelength raport to offers a performance suitable for this network architecture. we consider architecture based on the combined use of optical link and increase bit rate with wavelength associate. the simulation of this study was used by optisystem, the system is composed of 100Gbits with 100Km optical fiber length based on the different input design parameters such as input signal power, optical fiber length and attenuation coefficient. The results are discussed in terms of quality factor (Q-factor) and eye diagram.

PL

Te optyczne sieci transportowe są dziś podstawową infrastrukturą nowoczesnych systemów komunikacyjnych do przesyłania danych między węzłami. W artykule zaproponowano przezroczystą architekturę optyczną dla sieci metropolitalnych. Ta wielousługowa architektura pozwala na obsługę zarówno systemu transmisji 100Gbit/s WDM-PON jak i raportu długości fali, oferując wydajność odpowiednią dla tej architektury sieci. rozważamy architekturę opartą na łącznym wykorzystaniu łącza optycznego i zwiększeniu przepływności wraz ze skojarzeniem długości fali. Symulacja tego badania została wykorzystana przez optisystem, system składa się z 100Gbits o długości światłowodu 100Km w oparciu o różne parametry wejściowe projektu, takie jak moc sygnału wejściowego, długość światłowodu i współczynnik tłumienia. Wyniki omówiono pod kątem współczynnika jakości (Q-factor) i wykresu oka.

4

Feasibility study of using various optical filters in conjunction with indoor visible light communication system

Fadhil Hilal A., Alattar Feras Hasson, Fadil Tariq Adnan

Optica Applicata

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2023

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Vol. 53, nr 4

511--522

EN

In modern telecommunication engineering, visible light communication (VLC) is developing a competitive advantage over the traditional RF data communication model since it uses light to transmit data. Optical filters play an important role in optical communication systems to enhance the transmission rate of bit-error rate (BER), especially as a result of noisy environments. We investigate the VLC signal performance induced by four types of filters, including Bessel, Gaussian, rectangular, and trapezoidal filters. The BER is considered an important aspect of improving optical system performance, as it indicates less crosstalk and fewer interferences within the system and is analyzed using eye diagram opening penalties. In our simulation results, the Gaussian filter performs best among these four types of filters. In this paper, a VLC indoor model is developed and simulated using an eye diagram, a bit error rate, and a transmission distance for the proposed model. The results from this study show significant improvements of Gaussian filter over other optical filters for next-generation optical networking systems, the overall BER of a Gaussian filter-based indoor VLC system is less than 9.6×10–15, when the bandwidth of the optical filter is 5 nm at the quality factor of 14 dB.

5

Evaluation of a high-speed hybrid OAM-OFDM-MDM multiplexed coherent FSO system under desert conditions

Sinha Shivaji, Kumar Chakresh

Optica Applicata

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2023

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Vol. 53, nr 3

431--445

EN

To meet the needs of future wireless optical networks, this paper introduces a high-speed, hybrid multiplexed, coherent free-space optical (FSO) communication system that integrates an orbital angular momentum (OAM) multiplexed signal with an orthogonal frequency division multiplexing (OFDM) technique. Two independent QAM polarized beams, each carrying in-phase and quadrature (I/Q) phase 16-QAM-OFDM modulated data, are combined using mode division multiplexing (MDM) to increase the capacity of the proposed system. The reason of choosing OFDM is its capability to support higher data rate, and mitigating intersymbol interference (ISI). The signal is detected using a coherent detection-based digital signal processing (DSP) algorithm at the receiver end. The proposed hybrid FSO system is evaluated in low and heavy dust environments using bit error rate (BER), link distance, optical signal-to-noise ratio (OSNR), and received optical power performance matrices. The simulation results demonstrate the successful transmission of a 120 Gb/s single carrier over the longest link ranges of 1.5 and 0.40 km, respectively, under low and heavy dust weather environments below the signal degradation threshold value (forward error correction (FEC) limit) of BER 2.2 × 10–3 in strong turbulent conditions.

6

Performance of massive MIMO systems under the effect of fading channel

Alzamil Ahmed A.

Przegląd Elektrotechniczny

|

2021

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R. 97, nr 1

53--55

EN

This paper evaluates the performance of an uplink OFDM-based communication system considering multipath propagation environment where a Massive MIMO approach is exploited. In this context, Zero Forcing detector is used and assessed. Numerical analysis of the mathematical model was conducted on MATLAB. The results presented in this paper include Bit Error rate (BER) and the channel capacity of QPSK/OFDM transmission through a fading channel. Performance results verify the positive effect of Massive MIMO even when reduced complexity detection technique is used.

PL

Analizowano właściwości systemu komunikacyjnego bazującego na OFDM. Uwzględniono wielostrumieniowy rozsył z eksploatacja dużego MIMO. Opracowano model matematyczny I przeprowadzono symulację określającą BER I pojemność kanału dla przesyłu QPSK/OFDM.

7

Studying and Modeling the Performance of the TCM-STBC Systems in the Rayleigh Channel

Bendelhoum Mohammed Sofiane, Lahcene Mohamed Rida, Menezla Fayssal, Elarbi Abderraouf

Journal of Telecommunications and Information Technology

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2021

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nr 1

1--7

EN

Multiple-input multiple-output (MIMO) systems will play an important role in future generations of wireless networks. Space-time block code (STBC) and space-time trellis code (STTC) are two techniques that may be used in multi-antenna radio systems. This paper aims, most importantly, to study the performance of STBC systems at different values of such parameters as spectral efficiency, matrix codes and constellations. A performance comparison between STBC and STTC schemes is performed. In order to show the efficiency of the system’s ability to communicate with uncoded and coded transmission structures over AWGN and Rayleigh channels, the trellis-coded modulation (TCM) is introduced. The results obtained show that the proposed TCM-STBC system model, using one and two receiving antennas, improves the performance of Rayleigh channel communication systems at 9.5 dB and 11.5 dB for a BER of 10−5.

8

Analysis of inter-satellite free-space optical link performance considering different system parameters

Kaur Sanmukh

Opto-Electronics Review

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2019

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Vol. 27, No. 1

10--13

EN

The welcome and adaptation of optical wireless technology by the modern era has brought forward the concept of an inter-satellite free-space optical communication system. In the present work, I study the combined effect of selection of different operating wavelengths and detector types along with the pointing errors at the transmitter and receiver side on the performance of an inter-satellite free-space optical link. The link performance has been optimized by measuring and analyzing the bit error rate and quality-factor of received signal under different scenarios. Performance of the inter-satellite link has also been investigated considering different modulation formats and data rates for LEO and MEO distances.

9

Complex Signal Mapping for Improving Spectral Eﬃciency of Li-Fi Systems

Sileh Ibrahim K., Abdulkaﬁ Ayad A., Hussein Mohammed K., Hardan Saad M.

Journal of Telecommunications and Information Technology

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2019

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nr 3

58--62

EN

Light ﬁdelity (Li-Fi) systems based on the orthogonal frequency division multiplexing (OFDM) scheme have gained more attention in the communications circles, as a means to provide high spectral eﬃciency and ensure stricter data rate requirements for visible light communication (VLC) systems. However, common OFDM schemes employ Hermitian symmetry to obtain a real-valued signal which is necessary in intensity modulation and direct detection (IM/DD) optical systems, at the expense of doubling the required bandwidth. In this paper, a novel transmission scheme for an OFDM-based Li-Fi system is proposed to tackle the issue in question. A new approach to complex signal mapping (CSM), based on the pairing function method, has been developed for Li-Fi systems. It does not require Hermitian symmetry and, hence, saves about 50% of the required bandwidth. Unlike existing OFDM-based VLC approaches, the proposed scheme employs CSM to ensure a real and positive signal without Hermitian symmetry in order to fully utilize the bandwidth available to Li-Fi networks. Simulation results show that the proposed scheme signiﬁcantly outperforms other systems in terms of spectral eﬃciency. The CSM-OFDM based Li-Fi system also achieves a good peak-to-average power ratio (PAPR) reduction with acceptable bit-error-rate (BER) performance, compared to conventional approaches.

10

Comparison of Different Wavelength Propagations over Few-Mode Fiber based on Space Division Multiplexing in Conjunction with Electrical Equalization

Al-Dawoodi A., Fareed A., Masuda T., Ghazi A., Fakhrudeen A. M., Aljunid S. A., Idrus S. Z. S., Amphawan A.

International Journal of Electronics and Telecommunications

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2019

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Vol. 65, No. 1

5--10

EN

Nonlinearities in optical fibers deteriorate system performances and become a major performance-limiting issue. This article aims to investigate the compensation of nonlinear distortions in optical communication systems based on different wavelength propagations over few-mode fiber (FMF). The study adopted Space Division Multiplexing (SDM) based on decision feedback equalizer (DFE). Various transmission wavelength of the FMF system is applied to mitigate the attenuation effect on the system. In this paper, different wavelengths (780, 850 and 1550 nm) are used in SDM. Extensive simulation is performed to assess the attenuation and Bit Error Rate (BER) in each case. The results show that the wavelength of 1550 nm produces higher power and less attenuation in the transmission. Furthermore, this wavelength produces the best distance with less BER compared to 780 nm and 850 nm wavelengths. Moreover, the validations show improvement in BER and eye diagram.

11

Analiza skuteczności zakłóceń emisji FH

Jendruszczak Dawid, Bugaj Jarosław

Elektronika : konstrukcje, technologie, zastosowania

|

2019

|

Vol. 60, nr 6

40--45

PL

W artykule została przedstawiona analiza skuteczności zakłócania emisji ze skaczącą częstotliwością (emisji FH – ang. Frequency Hopping). Praca została podzielona na dwie zasadnicze części: symulację procesu zakłócania przy wykorzystaniu programu MATLAB/Simulink oraz praktyczną analizę zakłócania pracy radiostacji rodziny PR4G pracującej w trybie FH. Do analizy skuteczności zakłóceń, miarą jakości transmisji, wykorzystany został współczynnik BER (ang. Bit Error Rate) bitowa stopa błędów.

EN

This paper presents the analysis of the effectiveness of FH (Frequency Hopping) emission jamming. The survey was divided into two main parts: simulation of jamming using the MATLAB/Simulink program and practical jamming of the PR4G family radio working in the FH mode. To analyze the effectiveness of jamming, the measure of transmission quality, in both cases was used the Bit Error Rate (BER).

12

Evaluation of LTE downlink transmission quality in presence of selected disturbances in radio channel

Zankiewicz A., Sadowski M.

Przegląd Elektrotechniczny

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2018

|

R. 94, nr 12

42--45

EN

The goal of this paper is to evaluate quality of the downlink transmission in the LTE system The main parameter of signal transmission correctness is BER value. Transmission reliability depends on many factors – the most significant are type of propagation channel and level of noise or interference from other systems. These factors were taken into consideration for performed simulation experiments in order to determine the transmission reliability indicators like BER and SNIR for selected parameters of radio channel and LTE frame configuration.

PL

Artykuł przedstawia symulacyjną ocenę jakości transmisji łącza “w dół” (downlink) w systemie LTE. Jako parametry jakościowe przyjęte zostały współczynnik BER określający stopę błędów transmisji oraz parametr SNIR (Signal to Noise plus Interference Ratio). Na jakość transmisji ma wpływ bardzo wiele parametrów spośród których w artykule uwzględnione zostały typ kanału propagacyjnego oraz poziom szumu i interferencji od innych systemów.

13

A model of OFDM based maritime VHF communication system for data exchange

Valčić S., Pogány T., Mrak Z.

Polish Maritime Research

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2018

|

nr 2

27--36

EN

In the maritime Very High Frequency (VHF) band, there are no systems for transmitting large amounts of data. Therefore, it is necessary to develop new systems that would modernize the Global Maritime Distress and Safety System (GMDSS), significantly relieve the Automatic Identification System’s (AIS) communication channels, and set guidelines for the development of communication infrastructure of the e-Navigation. In line with this, analytical and simulation models of the maritime VHF data transmission communication system using Orthogonal Frequency Division Multiplexing (OFDM) modulation are worked out in this paper. The achieved data rate, the spectral efficiency and the bit error rate (BER) represent validation parameters on which the results of the analytical and simulation models are evaluated. It is concluded that the application of the digital OFDM modulation in the maritime VHF band may improve the GMDSS system by achieving higher data rates compared to the current terrestrial mandatory systems for data exchange, i.e. Digital Selective Calling (DSC) and AIS.

14

Using Least Mean p-Power Algorithm to Correct Channel Distortion in MC-CDMA Systems

Zidane M., Safi S., Sabri M., Frikel M.

Journal of Telecommunications and Information Technology

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2018

|

nr 3

23--30

EN

This work focuses on adaptive Broadband Radio Access Network (BRAN) channel identiﬁcation and on downlink Multi-Carrier Code Division Multiple Access (MCCDMA) equalization. We use the normalized BRAN C channel model for 4G mobile communications, distinguishing between indoor and outdoor scenarios. On the one hand, BRAN C channel parameters are identiﬁed using the Least Mean p-Power (LMP) algorithm. On the other, we consider these coeﬃcients in the context of adaptive equalization. We provide an overview and a mathematic formulation of MC-CDMA systems. According to these fundamental concepts, the equalizer technique is investigated analytically to compensate for channel distortion in terms of the bit error rate (BER). The numerical simulation results, for various signal-to-noise ratios and diﬀerent p threshold, show that the presented algorithm is able to simulate the BRAN C channel measured with different accuracy levels. Furthermore, as far as the adaptive equalization problem is concerned, the results obtained using the zero-forcing equalizer demonstrate that the algorithm is adequate for some particular cases of threshold p.

15

Suitable Spreading Sequences for Asynchronous MC-CDMA Systems

Addad M., Djebbari A.

Journal of Telecommunications and Information Technology

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2018

|

nr 3

9--13

EN

In order to meet the demand of high data rate transmission with good quality maintained, the multi-carrier code division multiple access (MC-CDMA) technology is considered for the next generation wireless communication systems. However, their high crest factor (CF) is one of the major drawbacks of multi-carrier transmission systems. Thus, CF reduction is one of the most important research areas in MC-CDMA systems. In addition, asynchronous MC-CDMA suﬀers from the eﬀect of multiple access interference (MAI), caused by all users active in the system. Degradation of the system’s bit error rate (BER) caused by MAI must be taken into consideration as well. The aim of this paper is to provide a comparative study on the enhancement of performance of an MC-CDMA system. The spreading sequences used in CDMA play an important role in CF and interference reduction. Hence, spreading sequences should be selected to simultaneously ensure low CF and low BER values. Therefore, the eﬀect that correlation properties of sequences exert on CF values is investigated in this study. Furthermore, a numerical BER evaluation, as a function of the signal-to-noise ratio (SNR) and the number of users, is provided. The results obtained indicate that a trade-oﬀ between the two criteria is necessary to ensure good performance. It was concluded that zero correlation zone (ZCZ) sequences are the most suitable spreading sequences as far as the satisfaction of the above criteria is concerned.

16

10 Gbps optical line using EDFA for long distance lines

Ivaniga P., Ivaniga T.

Przegląd Elektrotechniczny

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2017

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R. 93, nr 3

193--196

EN

The aim of this article is to demonstrate change in the BER (Bit Error Rate) and Q-factor in long distance lines. Nowadays it is not possible to create fully optical communication systems without software tools to simulate real optical networks under the given circumstances. There have been two 10 Gbps optical line topologies created: one without EDFA (Erbium Doped Fibre Amplifier) of up to 115 km and another using EDFA on a long distance line up to 3200 km. The article shows the BER worsening with the distance increasing and also the need for the link amplifier.

PL

Celem niniejszego artykułu jest przedstawienie zmian w BER (Bit Error Rate) oraz współczynnika Q na dużych odległościach. Obecnie nie jest możliwe stworzenie w pełni optycznych systemów komunikacyjnych bez użycia narzędzi programowych do symulacji rzeczywistych sieci optycznych w danych okolicznościach. Utworzono dwie 10 Gbps optyczne topologie liniowe: jedna bez EDFA (Erb z domieszką włókien Amplifier) maksymalnie do 115 km, a druga z użyciem EDFA na duże odległości do 3200 km. W artykule przedstawiono BER pogarszającą się wraz z rosnącą odległością.

17

Hexagonal Photonic Crystal Fiber Behaviour as a Chromatic Dispersion Compensator of a 40 Gbps Link

Betancur-Pérez A. F., Botero-Cadavid J. F., Reyes-Vera E., Gómez-Cardona N.

International Journal of Electronics and Telecommunications

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2017

|

Vol. 63, No. 1

93--98

EN

In this paper, the capabilities of chromatic dispersion compensation of a photonic crystal fiber with a hexagonal distribution of circular air holes was investigated. The vector finite element method with scattering boundary condition was used to analyze a set of configurations of the fiber in which the distance between air holes’ centers was modified. With this method it was possible to obtain the values of chromatic dispersion and confinement factor in the C fiber band. The best suited configurations were tested in a 160 km optical link with a bit rate of 40 Gbps. The performance was evaluated by measuring the bit error rate for a set of 20 channels with channel spacing of 100 GHz. T e simulation results showed that is possible to reach values of hromatic dispersion as low as −850 ps/nm⋅km, confinement losses close to 10⁻³ dB/km and good BER results in the order of 10⁻¹⁷ for a wavelength of 1550 nm.

18

Hardware Implementation of MISO on Orthogonal Frequency Division Multiplexing Platform with the Help of Alamouti Algorithm

Kilaru S.

International Journal of Electronics and Telecommunications

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2017

|

Vol. 63, No. 2

137--143

EN

Many software based OFDM techniques were proposed from last half decade to improve the performance of the system. This paper tried to implement the same with Hardwar implementation. We created Hardware based MISO platform with OFDM. We implemented Alamouti algorithm on this test bed. The test bed is implemented with the help of Field Programmable Gate Array (FPGA). The test bed is functionalized with the help of FPGA through Xilinx based system generator for DSP. In this paper we considered the 2×1 MISO implementation with Alamouti algorithm. The simulation results showed that BER and SNR are considerably high for MISO than SISO. The results also proved that proposed OFDM based Alamouti implementation for MISO is excellent in all performance criterions.

19

Comparative Analysis of Channel Estimation Techniques in SISO, MISO and MIMO Systems

Obinna O., Kennedy O., Osemwegie O., Nsikan N.

International Journal of Electronics and Telecommunications

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2017

|

Vol. 63, No. 3

299--304

EN

The ever-growing need for high data rate, bandwidth efficiency, reliability, less complexity and less power consumption in our communication systems is on the increase. Modern techniques have to be developed and put in place to meet these requirements. Research has shown, that compared to conventional Single Input Single Output (SISO) systems, Multiple-Input Single Output (MISO), and Multiple-Input Multiple-Output (MIMO) can actually increase the data rate of a communication system, without actually requiring more transmit power or bandwidth. This paper aims at the investigation of the existing channel estimation techniques. Based on the pilot arrangement, the block type and comb type are compared, employing the Least Square estimation (L.S) and Minimum Mean Squared Error (MMSE) estimators. Pilots occupy bandwidth, minimizing the number of pilots used to estimate the channel, in order to allow for more bandwidth utilization for data transmission, without compromising the accuracy of the estimates is taken into consideration. Various channel interpolation techniques and pilot-data insertion ratio are investigated, simulated and compared, to determine the best performance technique with less complexity and minimum power consumption. As performance measures, the Mean Squared Error (MSE) and Bit Error Rate (BER) as a function of Signal to Noise power Ratio (SNR) of the different channel estimation techniques are plotted, in order to identify the technique with the most optimal performance. The complexity and energy efficiency of the techniques are also investigated. The system modelling and simulations are carried out using Matlab simulation package. The MIMO gives the optimum performance, followed by the MISO and SISO. This is as a result of the diversity and multiplexing gain experienced in the multiple antenna techniques using the STBC.

20

Algorithm Based New Tone Reservation Method for Mitigating PAPR in OFDM Systems

Saha S., Chakrabarty S., Bhattacharjee S., Sil S.

International Journal of Electronics and Telecommunications

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2017

|

Vol. 63, No. 3

293--298

EN

There are abundant methods to mitigate PAPR in OFDM signals among which algorithm based tone reservation is of great popularity owing to its low complexity as well as decent BER. Here we have put forward a new distinct algorithm based Tone Reservation technique which is not only less complex and calculates its own threshold as well as PRT signal (unlike other algorithms requiring predetermined threshold and PRT) but also aptly modifies the data by bit by bit comparison with a modified copy of itself (algorithm modified) thus scaling the peaks as and providing a decent BER and good PAPR reduction.