Research of WLAN Adaptive Modulation Technology Based on OFDM Subcarrier Amplitude Frequency Characteristics

2014 ◽  
Vol 513-517 ◽  
pp. 1187-1191
Author(s):  
Zeng You Sun ◽  
Xiao Fan Sun ◽  
Xia Ling
Keyword(s):  
High Speed ◽  
Wireless Local Area Network ◽  
Local Area Network ◽  
Adaptive Modulation ◽  
Local Area ◽  
Spectrum Efficiency ◽  
Modulation Method ◽  
System Throughput ◽  
Area Network ◽  
Modulation Mode

Expound the existing modulation mode of the present wireless local area network. Directing at the problem that when single modulation method conveys data with high speed in the frequency selective fading channel, the system throughput will be declined and the efficiency of the spectrum will be lowered . Put forward the scheme that the OFDM sub-carrier will use different modulation modes after dynamic groups by amplitude frequency response. Simulation results show that the scheme will lower the complexity of the system achievement, and can get a higher spectrum efficiency.

scholarly journals Highest Cost First-Based QoS Mapping Scheme for Fiber Wireless Architecture

Photonics ◽  
2020 ◽  
Vol 7 (4) ◽  
pp. 114
Author(s):  
Khalid.H. Mohammadani ◽  
Rizwan Aslam Butt ◽  
Kamran Ali Memon ◽  
Fayaz Hassan ◽  
Abdul Majeed ◽  
...  
Keyword(s):  
High Speed ◽  
Wireless Local Area Network ◽  
Local Area Network ◽  
Optical Network ◽  
Access Network ◽  
Local Area ◽  
Passive Optical Network ◽  
Area Network ◽  
Broadband Wireless ◽  
Dynamic Bandwidth Assignment

The combination of a high-speed wireless network with passive optical network technologies has led to the evolution of a modern integrated fiber wireless (FiWi) access network. Compared to broadband wireless networks, the FiWi network offers higher bandwidth with improved reliability and reduced maintenance costs due to the passive nature of passive optical network (PON). Since the quality of service (QoS) is a baseline to deploy high-speed FiWi broadband access networks, therefore, it is essential to analyze and reduce the typical problems (e.g., bandwidth and delay) in the high-speed next-generation networks (NGANs). This study investigates the performance of a fiber wireless architecture where a 10-Gigabit-capable passive optical network (XGPON) and fifth generation of wireless local area network (WLAN) (i.e., IEEE 802.11ac) are integrated. Both technologies take benefits from each other and have pros and cons concerning the QoS demands of subscribers. The proposed work offers a very flexible QoS scheme for the different types of services of 5G WLAN and XGPON with the help of the highest cost first (HCF) algorithm, which leads to reduced upstream delays for delay-sensitive applications. The simulation results show that the HCF algorithm boosts the performance of the dynamic bandwidth assignment (DBA) scheme and results in up to 96.1%, 90.8%, and 55.5% reduced upstream (US) delays for video: VI(T2), background: BK(T3), and best effort: BE(T4) traffic in enhanced-distributed-channel-access (EDCA) mode. Compared to earlier work, the HCF and immediate allocation with the colorless grant (IACG) DBA combination results in the reduction of up to 54.8% and 53.4% mean US delays. This happens because of 50% to 65% better bandwidth assignment by the IACG DBA process due to efficient mapping by the HCF algorithm.

scholarly journals Experimental Results of Network-Assisted Interference Suppression Scheme Using Adaptive Beam-Tilt Switching

2017 ◽  
Vol 2017 ◽  
pp. 1-10
Author(s):  
Tomoki Murakami ◽  
Riichi Kudo ◽  
Koichi Ishihara ◽  
Masato Mizoguchi ◽  
Naoki Honma
Keyword(s):  
Wireless Local Area Network ◽  
Local Area Network ◽  
Interference Suppression ◽  
Multiple Input Multiple Output ◽  
Local Area ◽  
Experimental Results ◽  
System Throughput ◽  
Area Network ◽  
Network Systems ◽  
Transmit Power

This paper introduces a network-assisted interference suppression scheme using beam-tilt switching per frame for wireless local area network systems and its effectiveness in an actual indoor environment. In the proposed scheme, two access points simultaneously transmit to their own desired station by adjusting angle of beam-tilt including transmit power assisted from network server for the improvement of system throughput. In the conventional researches, it is widely known that beam-tilt is effective for ICI suppression in the outdoor scenario. However, the indoor effectiveness of beam-tilt for ICI suppression has not yet been indicated from the experimental evaluation. Thus, this paper indicates the effectiveness of the proposed scheme by analyzing multiple-input multiple-output channel matrices from experimental measurements in an office environment. The experimental results clearly show that the proposed scheme offers higher system throughput than the conventional scheme using just transmit power control.

scholarly journals New Vertical Handover Method to Optimize Utilization of Wireless Local Area Network in High-Speed Environment

PLoS ONE ◽  
2016 ◽  
Vol 11 (11) ◽  
pp. e0165888 ◽  
Author(s):  
Hoe Tung Yew ◽  
Eko Supriyanto ◽  
Muhammad Haikal Satria ◽  
Yuan Wen Hau
Keyword(s):  
High Speed ◽  
Wireless Local Area Network ◽  
Local Area Network ◽  
Local Area ◽  
Vertical Handover ◽  
Area Network

An Effective Adaptive Autocorrelation-Based Neighboring Matching Location-Aware Computing in WLANs

2011 ◽  
Vol 204-210 ◽  
pp. 2011-2014
Author(s):  
Yu Bin Xu ◽  
Mu Zhou ◽  
Lin Ma
Keyword(s):  
High Speed ◽  
Wireless Local Area Network ◽  
Nearest Neighbor ◽  
Local Area Network ◽  
Local Area ◽  
Measured Signal ◽  
Area Network ◽  
K Nearest Neighbor ◽  
Context Aware Computing ◽  
High Efficient

The recent advances of ubiquitous wireless infrastructures and requirements for high speed context-aware computing have created the opportunities to supply the high efficient location based service (LBS) in indoor wireless local area network (WLAN) environment. Because of the serious multi-path effect, unpredictable co-channel interference and inherent equipment noise, the measured signal strengths vary a lot in the real-world indoor environment. And this strength variation will also result in the performance deterioration of radio map-based neighboring matching algorithm. In response to this compelling problem, we propose the adoption of adaptive autocorrelation-based signal preprocessing method as a specific solution by effectively eliminating the singular strength from the original fingerprint set. Finally, the feasibility and effectiveness of autocorrelation-based preprocessing are also verified by decreasing about 33.4% and 32.9% of errors in k nearest neighbor (KNN) and weighted KNN (WKNN).

scholarly journals A Wider Impedance Bandwidth Dual Filter Symmetrical MIMO Antenna for High-Speed Wideband Wireless Applications

Symmetry ◽  
2021 ◽  
Vol 14 (1) ◽  
pp. 29
Author(s):  
Manish Sharma ◽  
Prem Chand Vashist ◽  
Ibrahim Alsukayti ◽  
Nitin Goyal ◽  
Divya Anand ◽  
...  
Keyword(s):  
High Speed ◽  
Wireless Local Area Network ◽  
Local Area Network ◽  
Local Area ◽  
Impedance Bandwidth ◽  
Area Network ◽  
Rectangular Slot ◽  
Mimo Antenna ◽  
Wireless Applications ◽  
Radiating Element

This research article reports a compact fractal 4 × 4 UWB extended bandwidth MIMO antenna with physical dimensions of 44 × 44 mm2 for high-speed wireless applications. The reported antenna comprises four fractal radiating elements that are symmetrical and placed orthogonal to each other with a respective rectangular ground printed on the opposite plane. A higher isolation is achieved between the radiating elements by the placement of a fractal patch orthogonally and no separate decoupling structure is required. The antenna offers a −10 dB transmission capacity of 2.84–15.88 GHz. The fractal radiating element, which is embedded by an inverted T-type stub placed within a rectangular slot and an etched rotated C-type slot, provides band-stop filters for WiMAX (Worldwide inter-operability for Microwave Access) and WLAN (wireless local area network)-interfering bands. The key parameters of diversity performance are compared by simulation and measurement (fabricated prototype) of ECC (envelope correlation coefficient), DG (directive gain), TARC (total active reflection coefficient) and CCL (channel capacity loss). The antenna offers an omnidirectional radiation pattern with an average gain of 3.52 dBi.

scholarly journals WLAN Security: Threats And Countermeasures

2018 ◽  
Vol 2 (4) ◽  
pp. 232 ◽  
Author(s):  
Suroto Suroto
Keyword(s):  
High Speed ◽  
Wireless Local Area Network ◽  
Local Area Network ◽  
Small And Medium Enterprises ◽  
Cost Effective ◽  
Local Area ◽  
General Purpose ◽  
Security Requirements ◽  
Area Network ◽  
Medium Enterprises

A wireless local area Network (WLAN) is being widely recognized as a viable cost effective general purpose solution in providing high speed real time access to information. With a WLAN, users can gain access to shared information without being bound to fixed plug-in-point. WLAN transmit and receive data over the air and thus collectively combine data connectivity with ease of mobility. WLAN provides wireless access to multi location enterprises, small and medium enterprises. It can replace wired LAN or simply be used as extension of wired infrastructure. Besides all these advantages WLAN are also facing major problems of security.So security is the aspect where most of the researchers are working. Following are the major objective of our study : i) To study the various Vulnerabilities and attacks on WLAN and their solutions. ii) To study the some of the exiting security methods used for securing WLAN and explore the possibility of improvements in the same. Our conclusion that WLAN security is not easy, and it is constantly changing. They expose the network to a new group of hackers. All businesses need to determine their security requirements based on the application using the WLAN. Goal so that a WLAN is as protected as Wired LAN.

OPNET Network Simulations Based on the Performance of WLAN IEEE802.11

2013 ◽  
Vol 385-386 ◽  
pp. 1651-1654
Author(s):  
Tian Yi
Keyword(s):  
Ieee 802.11 ◽  
Wireless Local Area Network ◽  
Local Area Network ◽  
Reference Value ◽  
Local Area ◽  
System Throughput ◽  
Media Access Control ◽  
Area Network ◽  
Distributed Coordination ◽  
Media Access

This paper mainly focus on the modeling and simulating of WLAN (the wireless local area network) IEEE802.11. Based on the current research of IEEE 802.11 protocol and the most powerful network simulation tool OPNET, the paper introduces various behavior of WLAN and standards for WLAN. Research on CSMA / CA(Carrier Sense Multiple Access / Collision Avoidance) and a simulation study of optimization algorithm to the binary backoff time are conducted, DCF(Distributed Coordination Function)-based access solutions are analyze. The simulation of MAC(media access control) and PHY(Physical Layer）functional design and algorithm theory have been carried out. It can be seen from the simulation result that the theory of optimal design reduces network latency and packet loss rate, and improve the system throughput, which has an important reference value for the future deployment of WLAN IEEE 802.11 standards.

scholarly journals Compact and Broadband Microstrip Antennas for Next Generation High-Speed Wireless Communication Using HIPERLAN/2

2007 ◽  
Vol 2007 ◽  
pp. 1-4 ◽  
Author(s):  
Jibendu Sekhar Roy ◽  
Milind Thomas
Keyword(s):  
Wireless Communication ◽  
High Speed ◽  
Wireless Local Area Network ◽  
Local Area Network ◽  
Local Area ◽  
Microstrip Antennas ◽  
Area Network ◽  
Next Generation ◽  
Rectangular Slot ◽  
Measurement Results

The investigations on rectangular-slot-loaded and V-slot-loaded proximity-coupled microstrip antennas are reported. The performances of two antennas are investigated for the application in wireless local area network 2 (HIPERLAN/2) using IE3D software and the computed results are verified by measurement. Results show that the antennas have wide bandwidth and moderate gain and may be used as small, compact antennas for HIPERLAN/2 communication.

scholarly journals Coexistence issues for a 2.4 GHz wireless audio streaming in presence of bluetooth paging and WLAN

2015 ◽  
Vol 13 ◽  
pp. 181-188
Author(s):  
F. Pfeiffer ◽  
M. Rashwan ◽  
E. Biebl ◽  
B. Napholz
Keyword(s):  
Ieee 802.11 ◽  
High Speed ◽  
Wireless Local Area Network ◽  
Local Area Network ◽  
Electronic Devices ◽  
Local Area ◽  
Area Network ◽  
Digital Audio ◽  
Coexistence Issues ◽  
The Impact

Abstract. Nowadays, customers expect to integrate their mobile electronic devices (smartphones and laptops) in a vehicle to form a wireless network. Typically, IEEE 802.11 is used to provide a high-speed wireless local area network (WLAN) and Bluetooth is used for cable replacement applications in a wireless personal area network (PAN). In addition, Daimler uses KLEER as third wireless technology in the unlicensed (UL) 2.4 GHz-ISM-band to transmit full CD-quality digital audio. As Bluetooth, IEEE 802.11 and KLEER are operating in the same frequency band, it has to be ensured that all three technologies can be used simultaneously without interference. In this paper, we focus on the impact of Bluetooth and IEEE 802.11 as interferer in presence of a KLEER audio transmission.

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