Local Area Network Applications Research Articles

Reference-Modulated PI-DCSK: A New Efficient Chaotic Permutation Index Modulation Scheme

In this paper, we propose a reference-modulated permutation index differential chaos shift keying (RM-PI-DCSK) over multipath fading channels. Due to quasi-orthogonal property between different permutated chaotic signals, the proposed scheme can remarkably suppress the inter-sequence interference to recover the desired information. Moreover, the proposed RM-PI-DCSK has one more modulation bit in the reference segment than the conventional permutation index differential chaos shift keying (PI-DCSK). Both the reference signal in the first time-slot and a permuted replica of the reference in the second time-slot are modulated for efficient transmission. The theoretical bit-error-rate (BER) performance and the highly consistent simulation results demonstrate that the proposed RM-PI-DCSK can achieve a performance gain 3 dB over the conventional PI-DCSK at a BER of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$10^{-4}$</tex-math></inline-formula> , and this gain becomes larger in a high-delay-spread channel. In particular, the performance superiority of the RM-PI-DCSK is further demonstrated in a typical ultra-wideband (UWB) channel with narrow-band interference. Therefore, this proposed scheme can be deemed as an efficient transmission alternative for chaotic-based wireless communications, such as in wireless local area network (WLAN) applications and indoor applications of the transmitted-reference UWB.

An FPGA-Assisted Intelligent QoS Management System for Local Area Networks

This article presents a novel intelligent quality of service (QoS) management system for local area networks (LANs). The QoS management is based on service quality prediction, which is carried out by general regression neural network algorithm with a profile containing the past records of the services. A novel fast computation scheme is proposed to reduce the search space for finding the optimal bandwidth allocation without degrading the performance of the QoS management. To further reduce the computation time, a hardware implementation of the proposed algorithm based on field-programmable gate array (FPGA) is also presented. The FPGA architecture is served as an accelerator to a system on a chip in a real LAN for performance evaluation. The experiment results reveal that the proposed algorithm provides reliable QoS management for LAN applications with low computational overhead and accurate network resource allocation.

Low Profile Monopole Meander Line Antenna for WLAN Applications.

An antenna assumes a significant role in expanding the levels of communication to meet the demands of contemporary technologically based industry and private data services. In this paper, a printed compact meander line patch antenna array for wireless local-area network (WLAN) applications in the frequency span of 2.3685–2.4643 GHz is presented. The impedance matching of the antenna is generated by applying a partial rectangular-shaped ground plane backside of the meander line antenna. The proposed antenna evolved on the Rogers RT5880 substrate with a dielectric permittivity of 2.2, and the height of the substrate was 1.575 mm to accomplish the lowest possible return loss. The proposed antenna was developed to achieve particular outcomes, for example, voltage standing wave ratio (VSWR) 1.32, reflection coefficient 20 dB with a bandwidth of 94.2 MHz, a gain of 2.8 dBi, and an efficacy measurement of 97%. This antenna is appropriate for WLAN applications that utilize a 2.4 GHz resonance frequency. The overall dimensions of the antenna are 15 mm × 90.86 mm.

Frequency reconfigurable circular microstrip patch antenna with slots for cognitive radio

In this paper, a novel multi-frequency microstrip antenna with complementary ring slot resonator (CRSR) structure that satisfies Bluetooth, worldwide interoperability for microwave access (WiMAX), and wireless local area network (WLAN) applications is proposed. The conventional antenna consists of a circular microstrip patch at a resonance frequency band of 2.5 GHz. By loading two CRSR at the radiating element, three operating frequency bands 2.5 GHz, 3.6 GHz, and 5.2 GHz are achieved. The operational bands covered by the antenna are Bluetooth 2.5 GHz, WiMAX 3.6 GHz, and WLAN 5.2 GHz. The insertion of CRSR to patch antenna has made it possible to compact and simple design, and miniaturized antenna for cognitive radio. Moreover, the directivity of the proposed antenna is adequate with acceptable radiation properties and perfectly matches with the simulated and measured results.

Ultra-Compact Slitted Flower-Shaped Dual-Band Monopole Antenna for Modern Portable Devices

A meanderingly slitted bio-inspired (MSB)-shaped antenna is presented in this work. The footprint of the proposed MSB antenna is 12 × 10 mm2 0.12 × 0.10 λ g 2 at 2.1 G H z . The MSB antenna proposed in this operates at 2.1 GHz and 5.2 GHz frequencies with a bandwidth of 70 MHz and 570 MHz and a radiation efficiency of 52.5% and 96%, respectively, which is suitable for UMTS, radio navigation, Long Term Evolution (LTE), and 5 GHz Wireless Local Area Network (WLAN) applications. The proposed MSB antenna demonstrates a peak gain of 2.9 dBi at 5.2 GHz and an omnidirectional radiation pattern at both E-plane and H-plane in both operating bands. The fabrication and measurement of the proposed antenna prototype are presented. The parametric study of the proposed structure is performed and presented. Therefore, the proposed antenna is a promising candidate for modern portable devices.

Design of Decimation Filters for Wireless Local Area Network Applications

Multirate signal processing is critical to realizing the digital frequency converter in WLAN technologies. In this paper, we focus on designing and analyzing the different structures of decimators that support WLAN-b applications to reduce the frequency by 12 for an IEEE. The structure modeling of the decimator used Simulink. Implementing a single-stage decimator required a higher-order filter, extra storage space, and a long simulation time. Results showed that the necessary storage elements for 2-stage design are 55% and for 3-stage design is 65% of single stage. For 133 MHz WLAN-b application, a two-stage decimator is proved to be efficient.

A compact four-band high-isolation quad-port MIMO antenna for 5G and WLAN applications

A miniaturized quad-port multiple-input-multiple-output (MIMO) antenna, generating four-band and high port isolation properties, is developed for 5G and wireless local area network (WLAN) applications. The realized MIMO antenna consists of four elements. Each element combines multiple L-shaped and rectangular branches with concave grounds, so that good impedance matching in four frequency bands is reached. The four elements are orthogonally placed to reduce current coupling. Moreover, four pairs of rotationally symmetrical strip lines are added to further improve the isolation between the units at low frequency. The antenna has been optimized to achieve a compact size of 39 mm × 39 mm × 1.6 mm, covering three 5G bands (2.6/3.5/4.8 GHz) and the 5.8 GHz WLAN band. In addition, inter-port isolation is better than 21.5 dB. Furthermore, the measured envelop correlation coefficient is smaller than 0.012 in the desired bands. Measurements also show that the radiation patterns and gains of the fabricated antenna agree well with the simulated ones. The diversity gain is as good as 9.94 dB. Moreover, the channel capacity loss is satisfactory, being below 0.4 bits/s/Hz. Satisfactory efficiency and diversity performance are realized. These facts indicate that the antenna system is a promising candidate for MIMO usage on 5G and WLAN devices.

A New Compact Dual-Polarized MIMO Antenna Using Slot and Parasitic Element Decoupling for 5G and WLAN Applications

This paper presents a compact dual-polarized multiple-input multiple-output (MIMO) antenna for fifth generation (5G) and wireless local area network (WLAN) applications. At first, a compact two-element dual-polarized MIMO antenna designed to operate at 3.5 GHz was developed. After that, some modifications were performed in the initial configuration, and a compact two-element dual-polarized MIMO was designed to operate at 3.5 and 5.35 GHz. A simple decoupling technique using parasitic element and slot was used to enhance the isolation between the radiating elements and to achieve an isolation above 18 dB over the band ranging from 3.4 to 3.6 GHz for the first antenna, and to achieve isolations above 19.8 dB over the first band ranging from 3.4 to 3.6 GHz and above 16.75 dB over the second band ranging from 5.15 to 5.85 GHz for the second antenna. Simulations were performed in the Ansoft HFSS software for numerical characterization and the prototype was fabricated with FR-4 dielectric and measured, presenting a good agreement between simulated and measured results. Furthermore, the envelope correlation coefficient (ECC) and the diversity gain (DG) were analyzed and present good results.

Characteristic mode analysis of two port semi‐circular arc‐shaped multiple‐input‐multiple‐output antenna with high isolation for 5G sub‐6 GHz and wireless local area network applications

SummaryThe work presents the design of a novel semi‐circular arc‐shaped two‐element multiple‐input‐multiple‐output (MIMO) antenna with improved isolation. The antenna is obtained by cutting and subtracting a circular disk from another circular disk, forming the shape of a semi‐circular arc. The antenna is replicated to form a two element MIMO antenna system on a FR4 substrate of size 36 × 26 mm2 with edge‐to‐edge separation of 12.4 mm. The developed MIMO antenna resonates in the frequency range 3.26 to 6.97 GHz giving a maximum element‐to‐element isolation around 26 dB in the operating bandwidth. Also, the antenna gives a maximum radiation efficiency of 98% with a peak gain of 5.3 dBi in the operating band. The proposed compact MMO antenna covers wide variety of wireless applications like 5G sub‐6 GHz and wireless local area network (WLAN) applications, which includes n77/n78/n79, WiFi‐5, V2X/DSRC, WiFi‐6, and INSAT‐C bands. Characteristic mode analysis (CMA) is performed in characterizing the performance of the antenna over the specified operating bands by studying and analyzing the parameters like modal significance (MS), characteristic angle (CA), modal current, and modal patterns. The obtained MIMO parameters like envelope correlation coefficient (ECC), diversity gain (DG), mean effective gain (MEG), and total active reflection coefficient (TARC) reveal that the proposed antenna is a suitable choice in MIMO environment.

A multimode substrate integrated waveguide based s elf‐hexplexing antenna for mobile terminal applications

A low-profile self-hexplexing antenna based on the multimode substrate integrated waveguide (SIW) cavity is presented for mobile terminal applications. It has three feeding ports, each of which can generate two resonant modes. Taking the advantage of the truncated SIW resonant cavity, the footprint of the antenna remains compact in the multiple functional mode scenario. The proposed antenna operates at six different modes, namely TM10 mode at 3.55 GHz, TM01 mode at 4.85 GHz, TE110 mode at 2.45 GHz, TE220 mode at 5.6 GHz, TE110 mode at 3.4 GHz and TE120 mode at 5.35 GHz. Good agreement is achieved between the simulated and measured antenna performance. The excitation and field distribution of each mode is analyzed. Keeping the structure miniaturized, the proposed antenna realizes hex-band characteristics without excessive feeding ports. It can be used for Microwave Access (WIMAX), the 5th Generation Mobile Communication Technology (5G) and Wireless Local Area Network (WLAN) applications, which is suitable for mobile handheld multiband terminals.

Highly efficient microstrip patch antenna for wireless gigabit alliance applications

A &lt;span&gt;wireless gigabit alliance (WiGig) is widely known for higher bandwidth which operates at 60GHz unlicensed spectrum for super-fast data speed over short distances for millimeter-wave band application. This study offers an efficient, compact microstrip patch antenna for WiGig with a lesser return loss -50.45 dB (60 GHz). The gain and directivity of the proposed antenna are 13.01 dB and 13.42 dBi. It provides higher efficiency of around 91%. The proposed antenna also covers another mm-wave band that is at 95 GHz. The U.S. military uses electromagnetic radiation of 95 GHz as a non-lethal weapon. So, the anticipated antenna can be used for a miniaturized active denial system. The proposed antenna has a good gain, directivity, and efficiency for the multigigabits/s data rate. The aforesaid properties imply that it can be used for wireless personal area networks (WPAN) and wireless local area network (WLAN) and fifth-generation (5G) applications too.&lt;/span&gt;

A Compact Dual-Band Bandpass Filter Using Coupled Microstrip Lines

In this paper, a new compact dual-band bandpass filter (DB-BPF) is proposed using parallel coupled lines. The design method is based on introducing transmission zeros (TZs) in the frequency response of a single-wideband filter. In the proposed structure, three coupled lines and a multi-mode resonator are used to realize the wide bandpass filter. Meanwhile, two coupled lines that are connected at the end and loaded by an open-circuit stub are employed to make a new notch filter. The proposed DB-BPF is designed and fabricated on Rogers RO3210 substrate for Wireless Local Area Networks (WLANs) applications. The simulation results show good agreement with measurements. The measured results exhibit two passbands centered at 2.4 and 5.2 GHz, having an insertion loss of less than 0.1 dB and 0.9 dB, respectively. Low insertion loss, compact size, and high attenuation between two passbands are the main advantages of the proposed DB-BPF.

Multiband Planar Antenna for Long Term Evaluation and Wireless Local Area Network Applications

In this paper, a planar antenna for Long Term Evolution (LTE) bands and Wireless Local Area Network (WLAN) is proposed. The antenna is based on a coupled-fed monopole with a distributed inductor and a direct-fed monopole. These three components form two bands of operations namely a low operating band from 0.59 to 0.635 GHz and a high operating band from 1.67 to 2.80 GHz. The two operating bands satisfy the WMTS 610, UMTS 1700, GSM 1800, LTE 1900, LTE 2100, WLAN 2400, LTE 2600 and WLAN 3600 applications. The proposed antenna having dimensions 75 × 10 × 0.8 mm3 is suitable for the top edge of a mobile handset and a copper plate of 75 × 100 mm2 (5 inches screen plate), is used as the ground plane system.

A MIMO Antenna with High Gain and Enhanced Isolation for WLAN Applications

In this paper, a novel two-port dual-band multiple-input-multiple-output (MIMO) antenna with enhanced isolation and high gain is presented. The presented antenna is composed of a symmetrical ground element and two identical antenna radiating elements. At the bottom of the substrate, the ground part is applied to strengthen the isolation performance of the designed MIMO antenna. The measured −10 dB bandwidth according to the input reflection coefficient S11 are 650 MHz (2.25–2.9 GHz) and 980 MHz (5.05–6.03 GHz), which are in strong agreement with the 2.4 GHz frequency band (2.4–2.4835 GHz) and the 5 GHz frequency band (5.15–5.85 GHz) of wireless local area network (WLAN) applications. The measured S21 at both the lower and the higher frequency operation bands are less than −19.3 dB. In the operating frequency bands, the measured gain is from 1.5 dBi to 3.8 dBi. The measured results show that the presented MIMO antenna is a good candidate for WLAN applications.

Investigation on Performance of Microstrip Patch Antenna for a Practical Wireless Local Area Network (WLAN) Application

Abstract: The performance of a microstrip patch antenna for a practical wireless local area network application is investigated in this research. This design is built around the transmission line concept. The antenna design substrate is FR4 (lossy) with a dielectric constant (Er) of 4.3 dielectric material, and the ground and patch materials are copper (annealed). The substrate is 71.62mm in width and 55.47mm in length. The height of the dielectric material is 1.6mm, which is the normal size for FR4 material. The conducting patch element has a width of 35.81mm and a length of 27.73mm for a resonance frequency of 2.573 GHz. A simulation with CST studio suite was used to optimise the antenna design. Keywords: Microstrio patch antenna, CST suite, WLAN application, Transmission line, Antenna design

Designed Circularly Polarized Two-Port Microstrip MIMO Antenna for WLAN Applications

The proposed work describes a corner square-cut square-patch multiple-input multiple-output (MIMO) antenna with reduced mutual coupling for circular polarization (CP). A two-port MIMO-CP antenna was designed and operated at 5.6 GHz for wireless local area network (WLAN) applications. The dimensions of the MIMO-CP antenna were 22.5×50mm2(0.43λ0×0.933λ0) and the FR4 substrate height was 1.6 mm. Between the two-elements, the edge-to-edge distance was 12.2 mm (0.227 λ0), where λ0 was the free space wavelength at 5.6 GHz. A slot was created in the middle of the ground in the proposed MIMO antenna to reduce mutual coupling and improve CP. The ground slot improves impedance matching and provides a better S-parameter and axial ratio (AR), according to the antenna results. According to the simulated results, the proposed antenna bandwidth of 5.23–6.42 GHz (21.4%) for S11 were &lt;−10 dB, isolation was −37 dB with a peak gain of 6 dB and AR ≤3 dB from 5.37 to 5.72 GHz (6.25%). The proposed antennas are simple to fabricate, have low profiles, are inexpensive, have good isolation, and are CP. The diversity gain (DG) and envelop correlation coefficient (ECC) results are better in the simulated frequency band. A MIMO-CP antenna geometry prototype is built and measured for comparison, yielding good results when compared to the simulated and measured results. The MIMO-CP antenna, as designed, is suitable for WLAN applications.

Dual-Band Circularly Polarized Omni-Directional Biconical Antenna With Double-Circular Parallelepiped Elements for WLAN Applications

This research proposes a novel dual-band (2.45/5.80 GHz) omnidirectional circularly polarized (CP) biconical antenna with double-circular parasitic parallelepiped elements for wireless local area network (WLAN) applications. The proposed dual-band CP antenna scheme consisted of a biconical radiating structure surrounded by inner- and outer-circular parallelepiped elements that convert linearly polarized electric fields into CP fields. Simulations were performed to optimize the antenna parameters, and an antenna prototype was fabricated and experiments were conducted. The measured impedance bandwidths (IBWs) were 44.4% (1.84 – 2.89 GHz) and 4.56% (5.73 – 5.99 GHz) for the lower- (2.4 GHz) and upper-frequency (5.80 GHz) bands, respectively. The corresponding 3-dB axial ratio bandwidths (ARBWs) were 11.22% (2.27 – 2.54 GHz) and 10.49% (5.6 – 6.2 GHz). The radiation patterns of the dual-band antenna scheme were omnidirectional left-hand circular polarization, with the measured antenna gains of 3.2 dBic and 8.5 dBic at 2.45 and 5.80 GHz, respectively. The simulated and measured results were reasonably agreeable. Despite the narrow IBW and ARBW for the upper-frequency band, the bandwidths adequately covered the target upper frequency band, rendering the proposed CP omnidirectional biconical antenna scheme operationally suitable for WLAN applications. Furthermore, the novelty of this research lies in the use of a biconical radiating structure augmented with double-circular parasitic parallelepiped elements to realize circular polarization for dual-band WLAN applications.

Four Elements Reconfigurable MIMO Antenna for Dual Band Applications

Four-element reconfigurable multiple-input-multiple-output (MIMO) antennas for dual band applications are proposed. The frequency reconfigurability of the proposed antennas is achieved by incorporation of three PIN diodes within the single element. The antenna covers multiple switchable operating bands for Worldwide Interoperability for Microwave Access (Wi-MAX)/Wireless Local Area Network (WLAN) applications (3.4-3.6GHz, 3.8-3.86GHz, 5.18-5.27GHz, 5.35-5.5GHz and 5.67-5.8GHz). The proposed MIMO antenna consists of 2x2 elements on a single FR4 substrate.The combinations of MIMO and reconfigurable antenna provide improved performance in terms of envelope correlation coefficient (ECC) and channel capacity loss (CCL) in multiple-frequency bands. The MIMO antenna system performance including the isolation, ECC, CCL, and the diversity gain (DG) are simulated and measured. High isolation (≥ 25dB) is achieved between reconfigurable MIMO antenna ports without any internal and external decoupling network. The proposed antenna has sufficient performance that makes it suitable for indoor access points (IAPs).

A CPW-Fed Circular SRR-Inspired Flexible Antenna Using Polydimethylsiloxane (PDMS) Substrate for WLAN and WBAN Applications

This article presents a <inline-formula> <tex-math notation="LaTeX">$50\times40$ </tex-math></inline-formula> mm² coplanar waveguide (CPW)-fed triple-band flexible antenna operating at 5, 5.8, and 6.6 GHz for wireless local area network (WLAN) and wireless body area network (WBAN) applications. In the proposed design, polydimethylsiloxane (PDMS) is used as a substrate with a dielectric constant <inline-formula> <tex-math notation="LaTeX">$\varepsilon _{r}$ </tex-math></inline-formula> of 2.65 and a loss tangent tan<inline-formula> <tex-math notation="LaTeX">$\delta _{\varepsilon r}$ </tex-math></inline-formula> of 0.02. In addition to the rectangular slot on the ground, the presented antenna has a single circular split-ring resonator (SRR) structure on the same side of the patch. This provides the required frequency notched characteristics for the targeted frequency bands, compactness, minimize losses, and backward radiation when used in close proximity to the human body. The proposed flexible antenna provides stable results in terms of performance parameters and specific absorption rate (SAR). We have also investigated the antenna under different operating conditions of moisture and bending. There exists a strong correlation between the simulation and measured findings.

Asymmetric microstrip fed meander line slot antenna for 5.6 GHz applications

This paper presents the design of a meander line slot antenna. The designed antenna operates at the frequency range of 5.45 GHz to 5.7 GHz covering wireless local area network applications. The proposed antenna comprises a circular patch design with a meander slot embedded within the patch. Besides to meander line slot structure, asymmetric microstrip feed is provided to the antenna. To achieve better antenna performance, parametric studies are carried out. The antenna's total size is 15 × 14 × 1.57 mm3. For the designed antenna, the −10 dB impedance bandwidth is 4.48 %, the gain is 1.3 dBi with a radiation efficiency of 84.43 %. The current distribution and radiation pattern of the proposed meander slot antenna have been observed and simulated.