scholarly journals Analisis Pengaruh Reduksi Peak to Average Power Ratio (PAPR) dengan Teknik Selected Mapping (SLM) Terhadap Efisiensi Spektrum pada Sistem OFDM

Jurnal INFORM ◽  
2019 ◽  
Vol 4 (2) ◽  
Author(s):  
Walid Maulana Hadiansyah ◽  
Masfiyatul Hikmiyah ◽  
Yoedy Moegiharto ◽  
Ida Anisah
Keyword(s):  
Orthogonal Frequency Division Multiplexing ◽  
Wireless Local Area Network ◽  
Local Area Network ◽  
Average Power ◽  
Local Area ◽  
Area Network ◽  
Power Ratio ◽  
Digital Subscriber Line ◽  
Asymmetric Digital Subscriber Line ◽  
High Power Amplifier

Teknologi Orthogonal Frequency Division Multiplexing (OFDM) telah banyak diimplementasikan dalam komunikasi digital berkecepatan tinggi seperti Wireless Local Area Network (WLAN), Digital Audio Broadcasting (DAB), Digital Video Broadcasting (DVB), dan Asymmetric Digital Subscriber Line (ADSL). Salah satu kelemahan dari sistem OFDM adalah tingginya nilai Peak to Average Power Ratio (PAPR) yang menyebabkan terjadinya distorsi non linier pada High Power Amplifier (HPA). Akibatnya, terjadi penurunan efisiensi spektrum. Teknik reduksi PAPR yang digunakan pada karya tulis ini adalah teknik Selected Mapping (SLM) dan SLM Riemann. Hasil simulasi digambarkan dengan kurva Cumulative Complementary Distribution Function (CCDF) dan kurva efisiensi spektrum. Parameter yang digunakan yaitu jumlah subblok dan jumlah subcarrier. Pada penelitian ini, teknik SLM menghasilkan nilai PAPR sebesar 8.912 dB sedangkan teknik SLM Riemann menghasilkan nilai PAPR sebesar 9.099 dB. Sehingga teknik SLM dapat mereduksi nilai PAPR lebih baik dibandingkan dengan teknik SLM Riemann. Perbedaan jumlah subblok juga mempengaruhi kinerja teknik reduksi, teknik SLM dengan subblok 8 menghasilkan kinerja 0.5 dB lebih baik dibandingkan subblok 4. Sehingga kinerja akan semakin baik apabila jumlah subblok yang digunakan semakin banyak. Kemudian semakin banyak jumlah subcarrier maka nilai PAPR yang dihasilkan akan semakin besar. Selanjutnya, efisiensi spektrum meningkat seiring bertambahnya daya transmit. Teknik reduksi SLM dan SLM Riemann mampu meningkatkan daya transmit yang juga menyebabkan meningkatnya efisiensi spektrum. Penggunaan jumlah subblok yang lebih banyak akan meningkatkan efisiensi spektrum. Teknik SLM dengan subblok 4 menghasilkan efisiensi spektrum sebesar 0.425 bit/s/Hz dan subblok 8 menghasilkan efisiensi spektrum sebesar 0.444 bit/s/Hz. Teknik reduksi SLM memberikan hasil efisiensi spektrum yang lebih baik dari teknik reduksi SLM Riemann.

A Hybrid Method to Reduce PAPR of OFDM to Support 5G Technology

2021 ◽  
pp. 241-257
Author(s):  
Bhavana D. ◽  
Adada Neelothpala ◽  
Pamidimukkala Kalpana
Keyword(s):  
Power Efficiency ◽  
Orthogonal Frequency Division Multiplexing ◽  
Average Power ◽  
Multimedia Data ◽  
High Peak ◽  
Modulation Scheme ◽  
Power Ratio ◽  
Digital Subscriber Line ◽  
Asymmetric Digital Subscriber Line ◽  
High Power Amplifier

The orthogonal frequency division multiplexing (OFDM) is a multicarrier modulation scheme used for the transfer of multimedia data. Well-known systems like ADSL (asymmetric digital subscriber line) internet, wireless local area networks (LANs), long-term evolution (LTE), and 5G technologies use OFDM. The major limitation of OFDM is the high peak-to-average power ratio (PAPR). High PAPR lowers the power efficiency, thus impeding the implementation of OFDM. The PAPR problem is more significant in an uplink. A high peak-to-average power ratio (PAPR) occurs due to large envelope fluctuations in OFDM signal and requires a highly linear high-power amplifier (HPA). Power amplifiers with a large linear range are expensive, bulky, and difficult to manufacture. In order to reduce the PAPR, a hybrid technique is proposed in this chapter with repeated clipping and filtering (RCF) and precoding techniques. The proposed method is improving the PAPR as well as BER. Five types of pre-coding techniques are used and then compared with each other.

RF CMOS power amplifier using a split inter-stage inductor for IEEE 802.11n applications

2016 ◽  
Vol 9 (4) ◽  
pp. 719-727 ◽  
Author(s):  
Minoh Son ◽  
Jinho Yoo ◽  
Inseong Kang ◽  
Changhyun Lee ◽  
Jihoon Kim ◽  
...  
Keyword(s):  
Power Amplifier ◽  
Wireless Local Area Network ◽  
Local Area Network ◽  
Average Power ◽  
Local Area ◽  
Area Network ◽  
Chip Area ◽  
Layout Technique ◽  
Stage Matching ◽  
Parasitic Components

In this study, we design a differential CMOS power amplifier using a 180-nm SOI RFCMOS process for 802.11n (64-QAM, 20 MHz bandwidth, 9.6 dB peak to average power ratio (PAPR)) applications. To minimize the chip area and mismatch in differential signals, we propose a layout method with an inter-stage matching network using a split inductor. By virtue of the symmetrical layout of the proposed split inductor, the mismatch in the differential signals is minimized, while the interconnection lines between the driver and power stages are shortened to minimize the overall chip area and the loss induced by the resistive parasitic components. The designed power amplifier is measured using a wireless local area network (WLAN) 802.11n signal to verify the feasibility of the proposed layout technique. The power amplifier achieved 20.34 dBm output power, while the measured EVM for the 802.11n applications is satisfied. From the measured results, we successfully prove the feasibility of the proposed power amplifier.

scholarly journals Analysis of a framework implementation of the transceiver performances for integrating optical technologies and wireless LAN based on OFDM-RoF

2020 ◽  
Vol 10 (4) ◽  
pp. 4252
Author(s):  
Adnan Hussein Ali ◽  
Alaa Desher Farhood ◽  
Maham Kamil Naji
Keyword(s):  
Optical Fibers ◽  
Wireless Lan ◽  
Orthogonal Frequency Division Multiplexing ◽  
Wireless Local Area Network ◽  
Local Area Network ◽  
Systems Design ◽  
Local Area ◽  
Area Network ◽  
Optical Wireless ◽  
Communication Tool

The greatest advantages of optical fibers are the possibility of extending data rate transmission and propagation distances. Being a multi-carrier technique, the orthogonal frequency division multiplexing (OFDM) can be applicable in hybrid optical-wireless systems design owing to its best spectral efficiency for the interferences of radio frequency (RF) and minor multi-path distortion. An optical OFDM-RoF-based wireless local area network (W-LAN) system has been studied and evaluated in this work. The outline for integrating an optical technology and wireless in a single system was provided with the existence of OFDM-RoF technology and the microstrip patch antenna; these were applied in the Optisystem communication tool. The design of the proposed OFDM-RoF system is aimed at supporting mm-wave services and multi-standard operations. The proposed system can operate on different RF bands using different modulation schemes like 4,16 and 64QAM, that may be associated to OFDM and multidata rates up to 5 Gbps. The results demonstrate the robustness of the integrated optical wireless link in propagating OFDM-RoF-based WLAN signals across optical fibers.

Link-Level Simulator for Wireless local Area Network

2018 ◽  
Vol 6 (7) ◽  
pp. 314
Author(s):  
Chaithra. H. U ◽  
Vani H.R
Keyword(s):  
Wireless Local Area Network ◽  
Local Area Network ◽  
Local Area Networks ◽  
Local Area ◽  
Long Term Evolution ◽  
Wireless Local Area Networks ◽  
Area Network ◽  
Network Simulator ◽  
Term Evolution

Now a days in Wireless Local Area Networks (WLANs) used in different fields because its well-suited simulator and higher flexibility. The concept of WLAN  with  advanced 5th Generation technologies, related to a Internet-of-Thing (IOT). In this project, representing the Network Simulator (NS-2) used linked-level simulators for Wireless Local Area Networks and still utilized IEEE 802.11g/n/ac with advanced IEEE 802.11ah/af technology. Realization of the whole Wireless Local Area Networking linked-level simulators inspired by the recognized Vienna Long Term Evolution- simulators. As a outcome, this is achieved to link together that simulator to detailed performances of Wireless Local Area Networking with Long Term Evolution, operated in the similar RF bands. From the advanced 5th Generation support cellular networking, such explore is main because different coexistences scenario can arise linking wireless communicating system to the ISM and UHF bands.

PERANCANGAN ANTENA MIKROSTRIPRECTANGULAR

Jurnal Teknik ◽  
2018 ◽  
Vol 7 (1) ◽  
Author(s):  
Heru Abrianto
Keyword(s):  
Dielectric Constant ◽  
Patch Antenna ◽  
Wireless Lan ◽  
Microstrip Antenna ◽  
Wireless Local Area Network ◽  
Local Area Network ◽  
Local Area ◽  
Area Network ◽  
Dual Polarization ◽  
Feeding Technique

Microstrip antenna which designed with dual feeding at 2.4 GHz and 5.8 GHz can meet WLAN (Wireless Local Area Network) application.Antenna fabrication use PCB FR4 double layer with thickness 1.6 mm and dielectric constant value 4.4. The length of patch antenna according to calculation 28.63 mm, but to get needed parameter length of patch should be optimized to 53 mm. After examination, this antenna has VSWR 1.212 at 2.42 GHz and 1.502 at 5.8 GHz, RL -13.94 dB at 2.42 GHz and -20.357 dB at 5.8 GHz, gain of antenna 6.16 dB at 2.42 GHz and 6.91 dB at 5.8 GHz, the radiation pattern is bidirectional. Keywords : microstrip antenna, wireless LAN, dual polarization, single feeding technique

IEEE 802.11 Tutorial

2018 ◽  
Author(s):  
Kiramat
Keyword(s):  
Access Control ◽  
Ieee 802.11 ◽  
Wireless Local Area Network ◽  
Local Area Network ◽  
Local Area ◽  
Physical Layer ◽  
Media Access Control ◽  
Area Network ◽  
Media Access ◽  
Computer Communications

IEEE 802.11 is a set of media access control (MAC) and physical layer (PHY) specifications for implementing wireless local area network (WLAN) computer communications. Maintained by the Institute of Electrical and Electronics Engineers (IEEE) LAN/MAN Standards Committee (IEEE 802). This document highlights the main features of IEEE 802.11n variant such as MIMO, frame aggregation and beamforming along with the problems in this variant and their solutions

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