Future 5G Communication Research Articles

Implementation of designed OCDMA code in RoF for future 5G communication

Implementation of designed OCDMA code in RoF for future 5G communication

Photonics-based all-dielectric horn antenna for millimeter waves in 5G and 6G applications

This work introduces a cost-effective photonics-based approach for fast-implementing horn antennas operating in millimeter-wave frequencies (mm-waves). Instead of using conventional metallic guiding structures, we employed an all-dielectric quarter-wave stack Bragg mirror photonic design. As a proof-of-concept, we used five semi-spherical air-polylactic acid bilayers stacked with a conical (horn-like) aperture fabricated through a one-step 3D printing process. The prototype, with a bandwidth of 2.6 GHz (from 24.96 to 27.50 GHz), was fed by the WR28 standard waveguide mechanism with measured gain ranging from 10.6 to 13.9 dBi (between 25 and 27 GHz). These outcomes demonstrate our idea's suitability for alternative design of high-frequency antennas for future 5G and 6G wireless communications systems, overcoming the precision constraints of traditional manufacturing methods.

High cost-effective photonic assisted in-band interference cancellation scheme for centralized radio access network towards future 5G communication

A photonic-assisted scheme capable of self-interference cancellation (SIC) and image rejection mixing (IRM) is demonstrated to solve the intractable problem of in-band interference for in-band full duplex (IBFD) systems with high frequency and large bandwidth. In the proposed scheme, a single optical path configuration is constructed based on an integrated modulator applied as the main device. The SIC operation is implemented in the optical domain making it immune to the influence caused by fiber dispersion. Owing to the intermediate frequency (IF) signal amplitude regulation mechanism under the combined action of fiber dispersion induced phase and double sideband (DSB) modulation, the scheme can realize IRM without increasing the system complexity. Experimental results show that the 50 MHz 16-quadrature amplitude modulation (16-QAM) signal of interest (SOI) centered at different frequencies are down-converted to 2.5 GHz. The depth of SIC and image-rejection (IR) is over 35 dB and 25 dB after transmitted through a span of 10.1 km optical fiber. The received 16-QAM down-converted signal can be recovered with an error vector magnitude (EVM) which satisfies the requirement of 3GPP-specified EVM limit. The signal recovery performance, SIC depth and image rejection ratio (IRR) under different signal to interference ratio (SIR) is also investigated. In addition, a comparison of relevant literature with this scheme from the perspective of technical discussion is also presented. The proposed scheme can realize effective functional integration with compact structure, simple parameter tuning mechanism, improved stability and high cost-effectiveness to solve the in-band interference problem which is of great value to be applied in IBFD centralized radio access networks (CRAN) towards future 5G communication.

Design and analysis the performance of triangular patch antenna for THz applications

Modern technology advancement requires a more extensive data rate to convey information more rapidly than ever. Improved bandwidth can satisfy the need for high-speed transmission demand. In order to achieve significantly increased bandwidth for a high data rate communication, the antenna design at the THz band is essential. The microstrip patch antenna is one of the most prominent antennas for THz band applications such future 5G communication systems and advanced wireless communication system. This paper proposed a triangular patch antenna for THz applications where FR4 is used at the substrate as an insulator and Graphene at the patch as a conductor. Moreover, we improve the performance of the proposed antenna by modifying the shape of the patch and ground (GND) layer. We modify the patch shape by cutting the corner edge of the triangular patch. Moreover, the GND layer is modified with horizontally partial ground. The size of the proposed antenna is set to 160×120 µm2. We analyze the performance of the proposed antenna using CST simulation software. Based on the simulation results, the proposed antenna with a modified patch and GND shape shows wide bandwidth of 1.27 THz and minimal return loss of -33.22 dB at a resonant frequency of 2.28 THz. Additionally, the gain and efficiency of the suggested antenna show good improvement. Therefore, the proposed triangular patch antenna with a modified patch and GND shape is expected to be suitable for high-speed THz applications.

Polyimide resins with superior thermal stability, dielectric properties, and solubility obtained by introducing trifluoromethyl and diphenylpyridine with different bulk pendant groups

Three polyimides (PI-p, PI-t, and PI-n) containing a 2,6-di(4-aminophenyl) pyridine body and different pendant groups are reported in this study. The resulting polyimide films exhibit excellent dielectric properties, with a dielectric constant of 2.91–2.62@10GHz and a dielectric loss in the range of 0.00939–0.00808@10GHz. Through computer simulation, the dielectric constant and dielectric loss of the polyimides are found to decrease with increasing pendant group volume. Moreover, the resulting strong and flexible polyimide films exhibit excellent thermal stability, with decomposition temperatures (at a 5% weight loss) in the range of 532.3–552 °C and glass-transition temperatures in the range of 343.7–376.4 °C. TGA/FTIR/MS experiments indicate that the thermal stability of the resin containing the methyl phenyl group is worse due to the degradation of the methyl group at low temperatures. In addition, the three polyimides also show excellent solubility and transparency. These superior properties indicate that the PI series is an ideal candidate material for future 5G communications.

Design of high gain base station antenna array for mm-wave cellular communication systems

Millimeter wave (mm-Wave) wireless communication systems require high gain antennas to overcome path loss effects and thereby enhance system coverage. This paper presents the design and analysis of an antenna array for high gain performance of future mm-wave 5G communication systems. The proposed antenna is based on planar microstrip technology and fabricated on 0.254 mm thick dielectric substrate (Rogers-5880) having a relative permittivity of 2.2 and loss tangent of 0.0009. The single radiating element used to construct the antenna array is a microstrip patch that has a configuration resembling a two-pronged fork. The single radiator has a realized gain of 7.6 dBi. To achieve the gain required by 5G base stations, a 64-element array antenna design is proposed which has a bore side gain of 21.2 dBi at 37.2 GHz. The 8 × 8, 8 × 16, and 8 × 32 antenna array designs described here were simulated and optimized using CST Microwave Studio, which is a 3D full-wave electromagnetic solver. The overall characteristics of the array in terms of reflection-coefficient and radiation patterns makes the proposed design suitable for mm-Wave 5G and other communication systems.

Design and analysis of microstrip patch antenna for 5G wireless communication systems

Due to lower latency, greater transmission speed, wider bandwidth, and the possibility to connect with greater multiple devices, fifth-generation (5G) networks are far better than 4G. In this study, a microstrip patch antenna operating at 28 GHz is investigated and modeled for future 5G communication technologies. The substrate used in this work for the antenna is Rogers RT/Duroid5880. Dielectric of the substrate is 2.2 and thickness is 0.3451 mm. CST software is used to simulate the antenna as it is convenient to use. From the simulation, the return loss, gain, radiation efficiency, side-lobe level was found to be -38.348 dB, 8.198dB, 77%, and -18.3 dB respectively. The result found from this simulation is better than the works took place in the past. As a result, it can be utilized as a capable candidate for 5G wireless technology. The results of this proposed antenna are superior to those of existing antennas published in recent scientific journals. As a result, it's likely that this antenna will meet the needs of 5G wireless communication systems.

Design and Simulation of Rectangular Microstrip Patch Antennas (45 GHz and 60 GHz) for V-band Applications

In this article, two wideband microstrip rectangular patch antennas have been designed and simulated for V band communication systems at resonant frequencies 45 GHz and 60 GHz. Rogers RO4730G3 is used as substrate dielectric with dielectric constant 2.98. The dimensions of the antennas are 6.23mm*6.7mm*0.7mm and 6mm*6.4mm*0.7mm respectively, with very simple geometrical configuration. To investigate the performance, the designs were then simulated using (CST) Studio Suite software package. The dimensions have been well studied and optimized to obtain acceptable results of Voltage Standing Wave Ration (VSWR), return loss, gain, bandwidth (BW) and radiation pattern. The 45 GHz antenna provides a gain of 6.73 dBi with the BW of 5.5 GHz and 1.03 of VSWR. Meanwhile, the 60 GHz design offers 6.92 dBi of gain with BW of 11.57 GHz and 1.05 of VSWR. The achieved results illustrate that both designs provide a good performance and are applicable for future 5G communication systems or any applications in the V band region.

Reconfigurable circular patch MIMO antenna for 5G (sub‐6 GHz) and WLAN applications

SummaryIn this article, a circular patch microstrip feed line monopole radiator with a dimension of 15 × 20 × 1.6 mm3 is proposed. An inverted L‐shaped stub is employed in the partial ground plane to achieve optimum bandwidth, radiation pattern and radiation efficiency. To further cover the sub‐6 GHz spectrum (3.4–3.8 GHz) for future 5G communications, a two‐element MIMO antenna configuration is designed by utilising the single element antenna. The edge‐to‐edge distance between the two elements is 0.15λ0 (15 mm). The propose antenna achieved dual‐operating bands of 3.35–4.60 and 4.93–5.19 GHz in the diode (D) = ON state. The minimum isolation between 3.35–3.94 and 4.99–5.16 GHz frequency range is −14.5 and −12.5 dB, respectively, by incorporating a rectangular stub between two inverted L‐shaped stubs. The MIMO antenna has a peak gain of 2.68 dBi at 5.1 GHz frequency. The average total efficiency at port‐1 between 3.35–3.94 and 4.93–5.19 GHz frequency range is 65%, whereas at port‐2 is 75%. In terms of the envelop correlation coefficient (ECC), mean effective gain (MEG) and total active reflection coefficient (TARC), the proposed antenna's diversity performance characteristics are investigated and the obtained values are 0.09, ±3 and −3 dB, respectively. The suggested MIMO antenna is designed on a FR4 substrate with a dielectric constant of 4.4 and an electrical dimension of 0.34λ0 × 0.20λ0 × 0.015λ0 mm3 (where λ0 represents the free space wavelength at lower cut‐off frequency [2.95 GHz]). Therefore, the proposed antenna can find applications for rain or fog as well as for identification and tracking (weather radar) on S‐band at 3 GHz frequency, 5G (sub‐6 GHz) and WLAN applications.

A compact quad element MIMO antenna for LTE/5G (sub-6 GHz) applications

Abstract In this paper, a compact I shaped monopole radiator with a dimension of 24 × 22 × 1.6 mm3 is proposed. The monopole radiator achieved an impedance bandwidth of 1.46 GHz (4.06–5.52 GHz) using partial ground plane. Further to cover the sub-6 GHz spectrum (3.4–3.6 GHz) for future 5G communications, a four-element multi-input multi-output (MIMO) antenna configuration is designed by utilizing the single element antenna. The operation bandwidth of 2.27 GHz (3.37–5.64 GHz) is enhanced by using a tapered microstrip feed line. Isolation is increased upto 40 dB over the operating band (3.37–5.64 GHz) by using a modified rectangular stub in the partial ground plane. This stub also provides a decoupling path and consequently limited amount of current couples to the neighbouring element due to surface waves. The modified stub suppress the surface waves and the near fields reducing the coupling between the antennas keeping it below −10 dB for the whole desired frequency range. Therefore, the proposed MIMO antenna achieved wide bandwidth of (3.37–5.64 GHz) and minimum isolation between antenna elements 1 & 4 is −10 dB in 3.4–3.6 GHz frequency band, whereas −15 dB between 3.8 and 5.64 GHz frequency band. The suggested MIMO antenna is designed on a FR4 substrate with a dielectric constant of 4.4 and a loss tangent of 0.02 and a 0.45λ 0 × 0.45λ 0 dimension. In terms of the envelope correlation coefficient (ECC), diversity gain (DG), mean effective gain (MEG), total active reflection coefficient (TARC), isolation between the ports, and channel capacity loss (CCL), the proposed antenna’s diversity performance characteristics are investigated and the obtained values are 0.04, 9.98, ±3, −11, −15 dB, 0.10 bits/s/Hz respectively. The antenna prototypes have been fabricated, and the measurements and simulations have been found to be in close agreement. Therefore, the proposed MIMO antenna covers n77/n78/n79 for 5G (sub-6 GHz) and LTE bands of 42/43/46.

A digital SIW-slot antenna array with FPGA implementation of beamforming

The future satellite platform and 5G communication systems place high demands on antennas, in which the antenna should offer low-cost, lightweight, electronically steerable features. In this paper, the design of a digital slot antenna element based on substrate integrated waveguide (SIW) is proposed. SIW guides the microwave inside the substrate confined with planar metallic covers and through-hole synthetized side-walls in conventional applications, and can also radiate the microwave towards free space in antenna applications through opening slots in its metallic covers. The slot antenna element is realized by implementing PIN diodes across the gaps on both sides of the pad in the center of the slot antenna, to provide the switching freedom of the slot antenna element between radiating and non-radiating states. Besides, radial decoupling stubs are introduced into the bias line so as to reduce the leakage of the energy in the SIW structure. Applying a series of on/off states to the diodes produces various radiation patterns, thus wide range scanning is possible supposing that enough array elements are equipped. Finally, a digital SIW-slot array composed of 8 by 4 elements with tunable field programmable gate array circuits are fabricated and measured. The measured results validate the reconfigurable characteristics for the radiation pattern of the proposed digital SIW-slot antenna array without heavy engineering of phase shifter in conventional antenna arrays. The antenna is consisted by 4 by 8 elements and its dimension, simulated gain and radiation efficiency are 145 mm times 127 mm times 1.524 mm, 15 dBi and 53.5%, respectively. Our designed SIW antenna has the advantage of both size and weight. Furthermore, its digitalized control of beamforming allows a programming-friendly interface for smart antenna development.

Reconfigurable dual element dual band MIMO antenna for 5G (Sub-6 GHz) and WLAN applications

PurposeThis study aims to present dual band reconfigurable MIMO antenna for 5G (sub-6 GHz) and WLAN applications.Design/methodology/approachTo achieve optimum bandwidth, radiation pattern and radiation efficiency, the defected ground structure (DGS) and a rectangular stub connected with the DGS are used. To further cover the sub-6 GHz spectrum (3.4–3.6 GHz) for future 5G communications, a two-element multi-input multi-output (MIMO) antenna configuration is designed by using the single element antenna. The proposed reconfigurable MIMO antenna using a PIN diode is designed on an FR4 substrate with a dielectric constant of 4.4 and a loss tangent of 0.02 and a 35 × 20 × 1.6 mm3 dimension.FindingsThe proposed antenna achieved dual operating bands of 3.4–4.1 GHz (5 G sub-6GHz applications) and 4.99–5.16 GHz (WLAN application) in the D = ON state. For D = OFF state, the proposed antenna achieved 3.55–3.65 GHz and 3.66–4.05 GHz frequency bands for 5G (sub-6GHz) applications. In terms of the envelop correlation coefficient, diversity gain, mean effective gain, total active reflection coefficient and isolation between the ports, the proposed antenna’s diversity performance characteristics are investigated and the obtained values are 0.05, 9.9 dB, ±3dB, −4dB, −15dB, respectively.Research limitations/implicationsThe fabricated prototype antenna on FR4 substrate has measurable parameters that are in good agreement with the simulated findings. Due to hardware design limitations, there is a minor difference between software and hardware results.Originality/valueThe proposed MIMO antenna is compact and reconfigurable for 5G (sub-6GHz) and WLAN applications, and from the graph, the measurements and simulations have been found to be in close agreement.

Design of Circularly Polarized Compact Size Wearable Antenna for UWB and 5G Application

The proposed work shows the textile antenna design for the IEEE C band and future 5G communication. The proposed antenna #2 is compact with the size of 0.674λ × 0.712λ and it is designed using jeans fabric as the dielectric substrate of ε r = 1.7 and thickness = 4 mm. The values of the S11 parameter of the antenna are below −10 dB, with a high gain of around 15 dB. The antenna is radiating with two frequency bands from 4 to 18 GHz and 24 to 58 GHz; in addition to this, the proposed antenna acts as a notch filter for the 8–12 GHz frequency band. The bandwidth achieved for the antenna is 4 GHz and greater than 34 GHz. The bending analysis of the antenna has been carried out at a radius of 80 mm and an angle of 90°. The value of simulated group delays for the proposed antenna is constant and varies from 0.02138 to 0.4251 ns, and the measured values range from 0.0507 to 0.6425 ns. The proposed antenna can be used for WiMAX, 5G and GPS applications.

Original Application of Stop-Band Negative Group Delay Microwave Passive Circuit for Two-Step Stair Phase Shifter Designing

This paper investigates on the theorization, design, fabrication and measurement of original phase shifter (PS) operating with two-step stair phase behavior. The innovative stair PS is designed with unfamiliar stop-band (SB) negative group delay (NGD) passive circuit. The elementary unfamiliar SB-NGD topology constituted by resistive, inductive, and capacitive lumped network is described. Acting as an RF and microwave circuit, the S-matrix model is expressed in function the RLC-network parameters. Thus, the canonical form of unfamiliar SB-NGD transfer function (TF) represented by the transmission coefficient is established. The unfamiliar SB-NGD circuit equations in terms of the NGD parameters are formulated. The established theory is validated comparing the calculated, simulated, and measured S-parameters and group delays (GDs). Results with a very good agreement showing unfamiliar SB-NGD behavior are observed around the central frequency 2.45 GHz and bandwidth of 100 MHz. An innovative application of unfamiliar SB-NGD function for the communication system front-end is developed. The developed application concept of unfamiliar SB-NGD circuit is illustrated by designing a microwave device operating as a PS presenting a two-step stair response completely original behavior. The basic theory, design and implementation of the two-step stair PS concept are introduced. To validate the two-step stair PS principle, a proof of concept (PoC) is designed based distributed element based inductive and capacitive microstrip elements. The simulated and measured results of the PS PoC are in good agreement. The experimental results confirm the feasibility of two-step stair PS with phase jumping from −70°±4° (from 2 GHz to 2.3 GHz) to −104°±2° (from 2.6 GHz to 3.0 GHz). The investigated unfamiliar SB-NGD function-based stair PS is promising for future development 5G and 6G communication system.

Turbo-coded Ultra Long Haul System with Probabilistic Shaped 16QAM Modulation

With the rapid growth and development of 5G (5th Generation Mobile Communication Technology) and the incoming of 6G (6th Generation Mobile Communication Technology), the demand for high-speed and flexible communication solutions is becoming far more urgent. Within this paper, a novel code modulation scheme based on PS (probabilistic shaping) and Turbo code is proposed with its effectiveness is confirmed by the results of simulation. The results inform that in an optical fiber communication system with 56 Gb/s rate and 3000 km transmission distance, when the SNR (signal-noise ratio) is greater than 3.5 dB, the Turbo-coded PS-16QAM modulation format can achieve reliable transmission. The proposed scheme performs the best in BER (bit error ratio) and average launch power in the four cases of uniform 16QAM, PS-16QAM, Turbo-coded 16QAM with and itself. The proposed scheme is a potential solution in the future 5G communication.

Analysis of Propagation Characteristics for Various Subway Tunnel Scenarios at 28 GHz

In order to meet the higher data transmission rate requirements of subway communication services, the millimeter wave (mmWave) broadband communication is considered as a potential solution in 5G technology. Based on the channel measurement data in subway tunnels, this paper uses ray-tracing (RT) simulation to predict the propagation characteristics of the 28 GHz millimeter wave frequency band in different tunnel scenarios. A large number of simulations based on ray-tracing software have been carried out for tunnel models with different bending radiuses and different slopes, and we further compared the simulation results with the real time measurement data of various subway tunnels. The large-scale and small-scale propagation characteristics of the channel, such as path loss (PL), root mean square delay spread (RMS-DS), and angle spread (AS), for different tunnel scenarios are analyzed, and it was found that the tunnel with a greater slope causes larger path loss and root mean square delay spread. Furthermore, in the curved tunnel, the angle spread of the azimuth angle is larger than that in a straight tunnel. The proposed results can provide a reference for the design of future 5G communication systems in subway tunnels.

Compact Photonic-Crystals Based Isolator Using Ni–Zn Gyromagnetic Ferrite Posts

A Faraday rotation isolator is conventionally achieved by connecting a matched load to a three-port circulator. It obtains superior performance (isolation > 20 dB) at the inevitable cost of non-ideal size. In order to adapt to the miniaturizations and integrations required for future 5G communication systems, it is particularly important to reduce the size of the devices. This work demonstrates a photonic crystal-based isolator design, comprising a unique reflecting cavity and a built-in fan-shaped coupler, where four Ni–Zn ferrite posts achieve the rotations. The design with the compact size of about 46.6 × 41.6 × 4.32 mm3 obtains excellent forward transmission efficiency and reverse isolation of 0.50 dB and 44.20 dB, respectively.

A Compact, Dual-Band Antenna with Defected Ground Structure for 5G Applications

In this paper, a novel dual-band monopole planar antenna is presented. The antenna is operated in 28/38[Formula: see text]GHz and has a bandwidth of 0.5/0.7[Formula: see text]GHz to operate in 5G frequency bands. Additionally, it exhibits a stable omni-directional radiation pattern with high gain characteristics, which helps to improve the performance of future 5G communication devices. The radiation efficiency achieved more than 94% throughout its operating bands. The numerical analysis has been carried out using a three-dimensional (3D) full-wave electromagnetic solver (ANSYS HFSS). In order to validate the numerical analysis, the proposed antenna has been fabricated and shows a good agreement with simulated results. The antenna has been designed and fabricated on Roger RT/Duroid 5880 dielectric substrate. This paper paves a new idea to design dual-band, simple and miniaturized single-element monopole planar antennas, which would be a good candidate for future millimeter-wave 5G communication systems.

Compact and novel coupled line microstrip bandpass filter based on stepped impedance resonators for millimetre-wave communications

Abstract This paper presents a compact and the low-cost coupled line band-pass filter with application to future generation millimetre-waves and 5G communications. The proposed approach of the filter design is based on the coupled-line and centre tapped upper and lower stepped impedance resonators. These resonators generate the sharp rejection, wide bandwidth, and abet to realize the compact filter. A detailed theoretical as well as the numerical analysis of the filter has also been investigated. As a demonstration, the proposed band-pass filter configuration has been designed and fabricated at the 33.5 GHz frequency using a low-cost PCB technique. It has observed that the proposed filter, results in a better return loss and the low insertion loss. The experimental results has been presented and compared with the simulated results and has found quite satisfactory. Moreover the results obtained validate a good agreement with each other.

A Planar 2×2 MIMO Antenna Array for 5G Smartphones

Here, a planar 2×2 MIMO configuration for the 5G smartphone has been presented. A single element modified planar tree profile shape (MPTPS) antenna is implemented to investigate the suitability in future 5G communication for different sub-6 GHz spectrum band. The size of the single MPTPS antenna is 40 × 25 mm2. The electronic band gap (EBG) and partial ground plane (PGP) techniques have been utilized to tune this antenna. The antenna works from 2.81 – 7.23 GHz, with a (VSWR < 2) bandwidth of 4.42 GHz that covers all the mid-range sub-6 GHz 5G frequencies. It also has a comparatively good gain of 3.14 dBi, high efficiency of 96% and a bi-directional radiation pattern. The antenna has been implemented in a 145 × 75 mm2 smartphone mainboard with MIMO configuration using polarization diversity. More than -21.1 dB isolation has been found between different ports. A good gain of as high as 6.59 dBi is observed for the MIMO in the band. Also, as MIMO performance, excellent envelope correlation coefficient of less than 0.0029 and minimum diversity gain of 9.9853 has been observed. The investigation has been further stretched by adding a liquid crystal display (LCD) for radiation performance and a hand phantom to assess the performance in terms of specific absorption rate (SAR). It is observed that the SAR value is as low as 0.887641 at 3.5 GHz. This design will motivate the researcher to develop high performance MIMO arrays for 5G smartphones.