WiMAX System Research Articles

A compact dual band hexagon rectangular shaped monopole antenna for WIMAX and WLAN applications

This paper presents a compact dual-band hexagon-rectangular shaped monopole antenna for WiMAX and WLAN applications. The miniaturized size of the antenna being 29 × 38 × 0.8 mm3. The proposed antenna operates efficiently within two distinct frequency ranges: 2.7 GHz to 3.2 GHz and 4.0 GHz to 5.1 GHz, addressing the needs of both WiMAX and WLAN systems. The antenna achieves bandwidths of 16.67% and 25.58% for the respective frequency bands, ensuring reliable performance and wide coverage for high-speed wireless communication. The antenna design attains its nature and application as a result of the center hexagonal shaped cavity which creates the required dual bands.

A Survey on Physical Layer Performance of MIMO-WiMAX

The IEEE 802.16 WiMAX standard for BWA (Broadband Wireless Access) was designed to offer end users high transmission data rates across wider regions.Wireless communication requires MIMO systems because they enable data to be sent and received through multiple antennas. This study examines how the MIMO-WiMAX physical layer performs while using different modulation techniques and channel coding approaches the BER performance of WiMAX systems, the Alamouti Space Time Block Code method for MIMO is being investigated.

Reducing Bit Error Rate in WiMAX using Spread Spectrum Techniques in Comparison with OFDM based Modulations

This research investigated the Bit Error Rate (BER) performance of the WiMAX(Worldwide Interoperability for Microwave Access), a wireless system which uses IEEE 802.16 standard. For the implementation of OFDM model and analyzing the performance of WiMAX system using the Bit Error Rate (BER) and Signal to Noise Ratio (SNR) MATLAB software tool is used. We have used different adaptive modulation techniques such as QPSK, 16-QAM and 64-QAM and spread spectrum techniques such as FHSS (Frequency Hopping Spread Spectrum) and DSSS (Direct Sequence Spread Spectrum). In the current research the Bit Error Rate is improved by using spreading signals. Spread spectrum enables a signal to be transmitted across a frequency band that is much wider than the minimum bandwidth required by the information signal. The simulation results of this research show that FHSS and DSSS have given low BER at low SNR as compared to other modulation techniques.

Design and Modelling of a Compact Triband Passband Filter for GPS, WiMAX, and Satellite Applications with Multiple Transmission Zero’s

Designing microwave filters with high selectivity and sharp roll-off between the stop and pass bands can be challenging due to the complex nature of the R.F. signals and the requirements for achieving high performance in a limited physical space. To achieve a high selectivity and sharp roll-off rate, this paper presents a compact filter with a triple passband response. The two different passbands at 1.57 GHz and 3.5 GHz are achieved using a step impedance resonator (SIR) with metallic slots perturbation added to the lower corner of the high impedance section of the SIRs, which helps to enhance the filter’s selectivity and size reduction greatly. The embedded L-shaped structure originates a third passband at 4.23 GHz, resulting in a triband response with eight transmission zeros below and above the passbands at 1.22/1.42/1.98/3.18/3.82/3.98/4.38/4.53 GHz, respectively. The prototype has low signal attenuation of <1.2 dB and high signal reflection of >25 dB for the three passbands. The fractional bandwidths achieved are 2.54%, 4.2%, and 1.65% at 1.57/3.57/4.23 GHz, respectively, with rejection levels in the stopband greater than 15 dB. Lastly, the structure is fabricated on RO-4350B PCB and observed good matching between experimental and measured results. This demonstrates that the prototype can be successfully implemented in real-world applications such as GPS, WiMAX, and Satellite systems. The area occupied by the filter on a substrate or in a circuit is 0.31 λg × 0.24 λg, where λg is the guided wavelength of the material calculated at the lowest frequency.

Minaret Shape Micro-Strip Patch Antenna with Partial Ground Plane for Lower 5G and Wi-Max Applications

Antennas are a difficult component to design, yet they play critical functions in wireless transmission systems. To construct the required antenna, the antenna designer must overcome enormous challenges in getting all of the antenna's optimal qualities. Antenna designers must consider antenna factors like bandwidth, return loss, VSWR, gain, directivity, efficiency, and so on, for specific applications. So keep all parameter values as optimal as possible; sometimes you may need to adjust the design of the antenna from its standard shape. The present investigation describes the development of a partial ground-plane micro-strip patch antenna in the shape of a minaret for use in lower 5G and Wi-MAX networks. A microstrip patch antenna with a minaret-shaped radiating element and a partial ground plane is suggested. The suggested antenna is simple because it does not include any unwanted components on the patch, yet the significant gain is maintained by optimizing the ground plane's dimensions and position. The proposed antenna is constructed using a Rogers RT5880 (lossy) substrate, the line feeding method, and 0.035 mm thick (annealed) copper for the patch and ground components. CST Studio Suite 2018 is used for layout and modelling. The antenna is 28 x 16 x 0.79 mm3 and offers a maximum gain of 2.321 dB and a maximum directivity of 2.529 dBi. The recommended antenna has a frequency range of 3.3721 GHz to 4.2382 GHz, making it usable for both low-band 5G and Wi-MAX systems.

A tri-band flexible antenna based on tri-band AMC reflector for gain enhancement and SAR reduction

A tri-band wearable antenna fed by coplanar waveguide (CWP) with an artificial magnetic conductor (AMC) reflector is presented in this paper. The radiation patch consists of three open inverted triangles for multiband, and the ground is defected for better impedance matching The AMC unit is composed of three concentric nested regular octagonal rings. And to improve the performance of gain, the unit achieves three reflection zero phases at 1.8, 2.45 and 3.5 GHz corresponding to the three bands of the antenna. The proposed antenna based on AMC has been fabricated and measured. The working frequency bands are 1.34–1.67 GHz, 2.33–2.47 GHz and 3.55–3.7 GHz. The measured gain has increased by 3.4, 1.8, 4 dBi at 1.8, 2.45 and 3.5 GHz, respectively. The scenario that the antenna is placed on the human arm is also considered and experimented for wearable applications. The results are in good agreement with the simulation data and verify that the antenna has good robustness. When the antenna is conformal with the human tissue, the specific absorption rate (SAR) is calculated and reduced by about 99.8% after adding AMC reflector. Hence the proposed antenna has excellent wearable safety and is compatible with LTE 1800, WLAN, WiMAX communication systems.

New Preamble Sequence for WiMAX System with Improved Synchronization Accuracy

Worldwide Interoperability for Microwave Access (WiMAX) trusts Multiple Input Multiple Output-Orthogonal Frequency Division Multiplexing (MIMO-OFDM) combination for the deployment of physical layer functions and for connecting the medium access control to the wireless media. Even though Orthogonal Frequency Division Multiplexing (OFDM) facilitates reliable digital broadband transmission in the fading wireless channels, the presence of synchronization errors in the form of Carrier Frequency Offset (CFO) and Time Offset (TO) adversely affect the performance of OFDM based physical layers. The objective of this work is to improve the accuracy of the frequency and the time offset estimation in the WiMAX physical layer. A method to enhance the synchronization accuracy by fine-tuning the merit factor of the preamble sequence is suggested in this paper. Also, a new preamble with improved synchronization accuracy is proposed for the WiMAX system. The performance of the proposed preamble is evaluated in a Rayleigh fading channel and the results of simulations show that the Mean Square Error (MSE) in offset estimation is significantly reduced and it outperforms the standard WiMAX preamble.

Investigations on Complementary Split Ring Resonator (CSRR) array integrated printed conformal band pass filters for modern wireless communication applications

This paper presents the performance analysis of two different conformal band pass filters (BPFs) loaded with an array of circular complementary split ring resonators (CSRRs). Type-1 bandpass filter has been designed by integrating a 9 × 9 array of circular complementary split ring resonator on the bottom layer of the filter. Similarly, Type-2 bandpass filter has been constructed by loading an array of 5 × 5 split ring resonator on the patch layer of the filter. A comparative study between Type-1 and Type-2 bandpass filters are also evaluated that shows dual pass bands for Type-1 filter and triple pass bands for the Type-2 bandpass filter. Furthermore, the conformality of both bandpass filters are judged through bending deformation analysis with various bending positions at 15°, 30°, 45°, 60° and 90°. During the bending performance analysis, the suggested BPFs retains the dual and triple pass band characteristics without any major deviations in its characteristic's parameters. Various performance parameters like return loss, insertion loss, group delay, bandwidth, and quality factor are measured. Detailed analysis of E and H field distributions and surface current distributions are also presented. The Type-2 bandpass filter shows better performance in terms of filter properties compared to Type-1 band pass filter. Hence, the prototype of Type-2 filter with an area of 30 × 30 mm2 is fabricated and measured. The validated results are agreed with the simulated results which confirms the applicability of the proposed filter for several modern wireless communication applications such as Wi-Max and personal communication systems (PCS) applications.

A miniaturized tri-band antenna loaded with d-shaped meta-structures

This paper presents a miniaturised tri-band antenna for WLAN, airport surveillance radar/aviation services, and Wi-MAX systems. The proposed radiator consists of an inset-fed rectangular-shaped radiator and a ground, which is loaded with two different sized 1 × 2 arrays of d-shaped meta-structure (DS-MS). The loading of the ground surface with DS-MSs changes the surface current circulation, lowering the operating frequency and generating additional operating bands. The effective material attributes of the DS-MR are computed to check it’s metamaterial behaviour over stop bands. The developed antenna is unilayer and operates in three bands with centre frequencies of 2.44 GHz, 2.82 GHz, and 3.52 GHz. The total volume of the proposed tri-band radiator is 35 × 25 × 1.6 mm3.

A compact dual-band antenna with an elliptical-shaped meta-resonator array

A planar miniaturised dual-band patch antenna for WLAN and Wi-MAX systems is investigated in this paper. The prospective design is made of an inset-fed square patch radiator and a defected ground plane, which is loaded with a 2 × 2 array of elliptical-shaped-meta-resonator (ES-MR). The loading of ES-MR results in size miniaturisation and dual-band operation. The medium parameters of the ES-MR are calculated to evaluate its metamaterial behaviour, and the antenna operates at 2.46 GHz and 3.50 GHz. The overall footprint of the developed dual-band radiator is 30 × 35 × 1.60 mm3.

Theoretical Analysis of Adaptive Algorithm Modulation Scheme in 3D OFDM WiMAX System

The growth of wireless networking has contributed to the need for high-speed services and multimedia applications anywhere and at any time. OFDM WiMAX technology is now considered one of the most popular technologies capable of delivering faster implementation and lower cost than standard wired options for Broadband Wireless Connectivity in metropolitan areas. This paper proposes appropriate adaptive modulation to be used in wireless networks based on SISO and MIMO OFDM WiMAX, which allows the performance of the network to be improved in the case of non-line-of-sight communications that are typical in urban environments. The effects of several paths, signal attenuation, Doppler shift, and different mobility speeds on the performance of the system were investigated. Mathematical models analysis of adaptive modulation in SISO and MIMO systems is treated by using BER, SNR and noise components. Simulation results show that the adaptive algorithm would improve throughput. It can also be concluded that when processing signals in a receiving system under conditions of multi-path signal propagation, the use of adaptive algorithms has a positive effect on noise immunity.
 HIGHLIGHTS
 
 With the growing evolution of wireless communication technologies, there is still a need for higher data rates, increased system capacity, and improved service quality
 3D OFDM-MIMO WiMAX technology is now regarded as one of the most common solutions for Broadband Wireless Connectivity in Urban Areas, capable of offering faster implementation and lower costs than standard wired options
 Effective adaptive algorithm processing in 3D wireless networks based on SISO-OFDM and MIMO-OFDM WiMAX was proposed, enabling network performance to be enhanced in the case of non-LOS wireless communications, which are standard in urban conditions. On the performance of the system, signal attenuation, the effects of several paths, different mobility speeds and Doppler shift were studied
 The adaptive algorithm significantly reduces the probability of error and increases the throughput. It can be concluded that the use of adaptive spatio-temporal algorithms has a positive effect on noise immunity when processing signals in the receiving system under conditions of multipath signal propagation
 
 GRAPHICAL ABSTRACT

A novel binary branch bionic antenna for communication and navigation

In this article, a novel printed multiband monopole antenna is presented for communication and navigation. The antenna adopts multi-branched structure simulating antlers to achieve multiband characteristics. The electromagnetic simulation software HFSS is used to model and analyze the designed antenna. The length and width of each antler branch and the shape and size of the grounding plate are optimized. A prototype antenna is fabricated on the FR4 substrate with the thickness of 1.6 mm. Experimental results have validated the design procedure of the antenna with a volume of 40 mm × 50 mm × 1.6 mm3 and indicated the realization of the requirements for communication and navigation. The test working frequency bands are 1.60–2.78 GHz, 3.34–3.93 GHz, and 4.83–5.54 GHz. It can be applied to GSM1800, 4G LTE33-41, Bluetooth, WLAN, WiMAX, and satellite navigation systems.

A Miniaturized Planar Monopole Antenna Based on a Coupling Structure for Compact Mobile Internet of Things (IoT) and Electric Vehicles (EVs) Device Applications in 5G, LTE, WLAN, WiMAX, Sirius/XM Radio, V2X, and DSRC Wireless Systems

A miniaturized internal antenna with monopole structure is constituted, including three radiating strips of a compact prototype and a back-coupling pad to improve the impedance matching, which achieves a wide bandwidth of 2.972 GHz between the operating frequencies of 2315–5285 MHz, and is introduced and researched. There is an urgent need for a complete frequency-continuous and large bandwidth design in the current wireless communication design to achieve a multimode, multifrequency, physical phenomenon design with large bandwidth and continuous operating frequency. The recommended antenna provides a broadband operation in an electric vehicles (EVs) and Internet of Things (IoT) devices application embedded in the wireless communication standard for 5G, LTE, V2X, WLAN, WiMAX, Sirius/XM Radio, V2X, and DSRC to support the multiband application. This design is embedded side edge of overall placement in the device and is integrated applicable to the trend of heterogeneous wireless multiple access networks in electric vehicle and Internet of Things system devices, which covered the 5G with supporting the band of n7/n38/n40/n53/n77/n78/n79/n90, the 4G with supporting the band of 7/38/40/41/42/43/48/67, the V2X and DSRC for the operating frequencies between 2500 and 5000 MHz, the Sirius/XM Radio for the operating frequencies of 2320–2345 MHz, the ISM band of WiFi and BT covering the band of 2450–2483.5 and 5150–5350 MHz, and the WiMAX also supporting the band of 2300–2690 and 3400–3690 MHz. Moreover, the compact antenna manufactured an FR4 material with the antenna area of 5 × 10 × 0.8 mm3 and the ground area of 33.5 × 10 × 0.8 mm3. The proposed design better benefits a narrow space on the PCB with a low profile and is easy to make with a circuit board design.

WI-MAX NETWORK SIMULATION FOR SALAHADDIN UNIVERSITY NEW CAMPUS

Wireless Networks became very important in this latest decade and especially Wi-Max system because of high bit rate, handover flexibility and longer distance of mobility. Signal strength and coverage is one of the challenges for this systems which leads to affect directly on Quality of Service (QoS), this paper is an attempt to design and study of Wi-Max network for a certain coverage area, testing the coverage of the signal for the area that can hold the sufficient amount of data with less latency has been studied depending upon the Wi-Max advanced specification and data stream behavior benefit’s, some Wi-Max parameters like coverage, quality of service, data rate are optimized, the study and design has been done using OPNET modeler used in the a simulation of the certain coverage area, in this paper the new campus of university of Salahaddin has been used on supposed area of about 4 X4 km. The results show a perfect bit rate as a bit stream for the global characteristics in which is sufficient to the students and teachers of the university in addition of providing the mobility by high performance. It is needed to design a wireless computer network to Salahaddin University to improve mobility and to let the teachers and students to stay connected at any time in any university location Especially with the nowadays learning techniques and requirements which needs both teacher and students to be online with each other especially like E-learning and online remount learning especially with the COVID-19 university campus blocking. Therefore, it is needed to cover overall area of the university campus and with additional coverage that exceed the university boundaries to improve the reliability of the hall network and to insure the required coverage area. To do that is very efficient to design an advanced computer network like Wi-Max with the most powerful and advanced hardware capabilities to full-fit the teachers and students requirement of fast net browsing and download in addition in e-learning bases it is very regular to use video conferencing or video streaming which normally needs a very fast network data transfer

Miniaturized flexible metamaterial antenna of circularly polarized high gain‐bandwidth product for radio frequency energy harvesting

SummaryA discussion of using an ultrawide band (UWB) Hilbert‐shaped metamaterial (MTM) antenna structure for RF energy harvesting is exemplified in this article to conduct the use of organic substrates. Therefore, the proposed design is structured as a low profile rectangular MTM array in the context of wearable systems. The antenna is mounted on a prepared indium‐nickel oxide‐based polymerized Palm fiber (INP) substrate and backed with a ground plane of square electromagnetic band gap (EBG) defects. Fifteen samples of INP substrate are prepared for this study. Thus, the prepared INP substrates characterizations are tested using a T‐resonator transmission line technique printed on an FR4 substrate. In this technique, the measured scattering parameters are interpreted from two resonators with two different characteristics impedance to be employed for retrieving the relative permittivity (εr) and permeability (μr). This process is included to ensure the prepared substrate properties controllability for microwave devices manufacturing. After that, the proposed antenna is manufactured from silver nanoparticle (SNP) printout. The performance of the proposed antenna is tested numerically and experimentally. It is found that the proposed antenna shows an UWB response to start from 3 and up to 10 GHz that suits different applications including IoT, 5G, and WiMAX system networks. The measured gain spectrum shows four peaks at 3.5, 4.2, 5.4, and 6 GHz with gain values of 1.1, 2, 3.4, and 3.9 dBi, respectively. Finally, the conversion efficiency of RF harvesting is measured experimentally for the antenna in case of flat profile and bended structure at the frequency bands of interest to reveal insignificant changes.

The Impact of Length of Frame on The Performance of Video Application in WiMAX System

The IEEE 802.16e standard includes several features that aid data capacity. When dealing with real-time applications such as video conference services, however, it quickly depletes its resources. The quality of the video, on the other hand, is a crucial factor for the user. There is a tradeoff between the video quality and the resources available. In this paper the influence of frame length on video applications was investigated by examining the effect of four frame lengths (5, 10, 15, and 20 mSec) on the Packet Delay Variation, End-to-end packet delay, traffic sent and received with modulation type 64QAM and high quality of video conference application are used. The optimal frame length was found to be 10 milliseconds, with the Packet Delay Variation being the smallest, the Packet End-to-End Delay being the shortest, and the number of received packets being equal to the number of sent packets.

Tri-Band, Stable and Compact Patch Frequency Selective Surface Optimized via Hybrid Bioinspired Computing for Applications at 2.4, 3.5 and 5.8 GHz

This work addresses the synthesis of a multi-band frequency selective surface (FSS) through bioinspired computing and a general regression neural network (GRNN). This hybrid computational method, which utilizes the multi-objective cuckoo search algorithm combined to a GRNN, determine the best physical dimensions of the FSS in order to achieve a multi-band filtering at the 2.4, 3.5 and 5.8 GHz spectrums. Therefore, the results are to be applied to aid the propagation of Wi-Fi, WLAN, WiMAX and future sub-6 GHz 5G systems. The resonant frequencies were measured and a -10 dB cutoff value has been considered for the transmission coefficient. The triple rectangular loop conductor geometry of the device is printed upon a glass epoxy (FR-4) substrate. Measurements were made for different wave incidence angles, from 0° up to 45°, to demonstrate how signal incidence would affect the device’s functioning. The agreement between simulated and measured data display satisfactory results.

New printed slot antennas with etched SIR components in the ground plane

In this study, two new printed slot antennas have been simulated and fabricated using a single layer of FR4 substrate for modern wireless applications. The first printed slot antenna with etched stair-step topology in the ground plane is proposed to achieve the single-band operation. This topology is based on two components of asymmetrical step-impedance resonator (SIR) and one component of symmetrical SIR. The first designed printed slot antenna satisfies the requirements of WLAN applications at 5.75 GHz. The second printed slot antenna is a developed version of the first one with one inserted component of symmetrical SIR and one asymmetrical SIR component to be operated as a multiband antenna applicable for WiMAX, WLAN, and X-band downlink satellite systems at 3.5, 5.75, and 7.75 GHz, respectively. The proposed antennas have small sizes, and competitive electrical specifications than many reported SIR and non-SIR antennas in the literature.

Design of Miniaturized Tri-Band Microstrip Bandpass Filter Using Meandered Stubs for WLAN and Wi-Max Band

In this paper, a miniaturized tri-band microstrip bandpass filter is designed using three sets of shorted stub-loaded stepped impedance resonators (SSLSIRs). One pair of resonators have meandered short stub-loaded resonator (MSSLSIR) to further reduce the dimensions of the whole tri-band filter. The operating frequencies of the SSLSIRs and MSSLSIR are designed for the applications in the WLAN (2.45/5.2 GHz) and Wi-MAX (3.5 GHz) systems, respectively. The proposed filter is advantageous in terms of size miniaturization up to 0.013 × 0.012 (is guide wavelength) and in terms of good control over the passbands. The simulated and measured results are both in good agreement.

NOVEL SIMPLE DESIGN AND ANALYSIS OF WI-MAX TRANSCEIVER USING MATLAB-SIMULINK

This paper provides analysis of WiMAX systems from its background to their architectures highlighting merits and demerits, topologies, structures and looks deep into transceiver systems architecture, then specializes on the radio frequency (RF) front-end part of the WiMAX transceiver system in which a model is designed. Thereafter, the model is implemented in MATLAB Simulink and the results are investigated and analyzed.