Generation Cellular Communication Research Articles

Highly Directive Microstrip Array Antenna with FSS for Future Generation Cellular Communication at THz Band

To establish a successful future generation cellular communication system in the Terahertz (THz) regime, there is a need to design high-directivity antennas, which will allow the signal to propagate beyond 0.1 km. Simultaneously, design wide bandwidth (BW) antennas to facilitate transmitting the information at a data rate up to 0.1 Tb/s. Two sets of microstrip array antennas have been designed, optimized, and simulated with the CST MWS simulator, in a hybrid fed with uniform amplitude distribution technique, the $$1{\text{st}}$$ one without frequency selective surface (FSS) feature and $$2{\text{nd}}$$ one with the FSS feature for further enhancing the antenna gain. To verify the simulation results of the $$1{\text{st}} - 2{\text{nd }}$$ antennas design, which simulated with the CST MWS simulator, these designs have been validated with the ANSYS HFSS simulator, and the simulation results obtained out of both simulators were close to each other. These antennas can establish a successful short-range 6G cellular communication system at the THz band.

Study of techniques to improve performance of patch antennas for 5G applications at millimeter wave (mmW) frequencies

Millimeter wave (mmW) frequency signals of 28 GHz and 38 GHz that are being explored for implementing next generation cellular communication network (i.e. 5G) suffer from severe attenuation in the outdoor environment. Therefore, efficient and intelligent antenna design techniques are needed for proper transmission and reception of signals at mmW frequencies. Beamforming, multiple input multiple output (MIMO) and space division multiple access (SDMA) are important requirements of mmW 5G network, and these technologies are heavily dependent upon antenna design and implementation. This paper presents various contemporary techniques for improving performance parameters of patch antennas for 5G implementation at mmW frequencies. These performance parameters include gain, bandwidth, directivity, suppression of surface waves, ease of design, compactness, and mutual coupling between antenna elements for MIMO system. This study also highlights the benefits and drawbacks of each of these techniques discussed in the paper.

Base Station Selection for Hybrid TDOA/RTT/DOA Positioning in Mixed LOS/NLOS Environment.

The fifth generation (5G) cellular communication system is designed to support Time Difference of Arrival (TDOA), Round-Trip Time (RTT), and Direction of Arrival (DOA) measurements for indoor positioning. To mitigate the positioning error caused by non-line-of-sight (NLOS), existing base station selection methods identify channel conditions and only use line-of-sight (LOS) signals for positioning. However, different selected base station combination would lead to a different geometric dilution of precision (GDOP), base station selection based only on channel condition is not fully applicable for the hybrid positioning. This paper derives the GDOP for the hybrid TDOA, RTT, and DOA positioning, and proposes a GDOP-assisted base station selection method, which is based on both channel conditions and GDOP value changes. The simulation shows that using the proposed base station selection method could lead to higher positioning accuracy than base station selection based only on channel condition. In the simulation, in the side region of the scenario, where the change of selected base station combination causes a notable increment in GDOP value, the positioning accuracy improvement caused by the proposed method is greater than that in the center region.

Performance analysis for uplink NOMA‐based cellular network with M2M/H2H co‐existence

Owing to the growing proliferation of machine type communication devices and other high-end devices in conventional human-to-human (H2H) communication, it is inevitable that these types of communications will co-exist with each other in the next generation of cellular communications. This study investigates an uplink cellular network with machine-to-machine (M2M) and H2H co-existence, where a machine type communication gateway is deployed as a relay in the cellular network to forward the M2M messages to the base station (BS). Non-orthogonal multiple access (NOMA) has been adopted to transmit the data of H2H and M2M communications to the BS simultaneously. Considering the different delay-sensitive transmissions of M2M/H2H communications, the expressions for outage probability and effective capacity (EC) are theoretically derived with the constraints of quality-of-service requirements. Simulation results show that the NOMA scheme outperforms the orthogonal multiple access in terms of outage probability and EC.

5G Massive Multiple Input and Multiple Output System with Maximum Spectral Performance

Massive MIMO is the presently maximum compelling sub-6 GHz physical-layer era for destiny wireless access. Excellent spectral overall performance finished through manner of spatial multiplexing of many terminals inside the equal time-frequency resource. The 5G structures are characterized through excessive transmission records prices, 1Gbps and above, so large bandwidth transmission is expected. The most vital objectives within the 5G wireless systems design is to deal with the excessive inter photograph interference (ISI) as a consequence of the high statistics fees, and using the accessible spectral bandwidth in resourceful way.MC-CDMA is categorized in to two methods that is ODFM and CDMA. Efficient useful resource allocation is the principle trouble within the development of fourth generation cellular communication systems. For utilizing the internet and multimedia a maximum data fee is preferred, so in this paper the general performance of MC-CDMA systems the usage of Sylow theorem for grouping this is executed that's a spectrum allocation technique is presented. This paper particularly analyzes the presence of Additive white Gaussian Noise (AWGN) in MC-CDMA utilizing QPSK for special variety of subcarrier, exclusive wide sort of customers with the help of MATLAB tool. This paper shows the reduction in BER and power allocation among the MC-CDMA and massive-MIMO.

Introduction to indoor networking concepts and challenges in LiFi

LiFi is networked, bidirectional wireless communication with light. It is used to connect fixed and mobile devices at very high data rates by harnessing the visible light and infrared spectrum. Combined, these spectral resources are 2600 times larger than the entire radio frequency (RF) spectrum. This paper provides the motivation behind why LiFi is a very timely technology, especially for 6th generation (6G) cellular communications. It discusses and reviews essential networking technologies, such as interference mitigation and hybrid LiFi/Wi-Fi networking topologies. We also consider the seamless integration of LiFi into existing wireless networks to form heterogeneous networks across the optical and RF domains and discuss implications and solutions in terms of load balancing. Finally, we provide the results of a real-world hybrid LiFi/Wi-Fi network deployment in a software defined networking testbed. In addition, results from a LiFi deployment in a school classroom are provided, which show that Wi-Fi network performance can be improved significantly by offloading traffic to the LiFi.

Fbmc System With Low Density Parity Check (Ldpc) Coding For Efficient Communications In 5g

Channel coding is a complicated subject, but vital in cellular communications, which is used for detection and correction of the bit errors caused by various types of noises, interferences. In 3rd generation and 4th Generation (3G and 4G) cellular communications, Turbo codes are predominantly used and currently 3GPP standardization group considering the Low Density Parity Check (LDPC) code in 5G, due to its requirements of 20GB throughput, ultra low latencies and massive Internet of Things. In 5G Communication Filter Bank Multi Carrier (FBMC) wave form is considered for 5G and beyond communication for non-orthogonal communications due to its superior side-lobe suppression characteristics and also no need to use the cyclic prefix, which will save the bandwidth. With FBMC based systems, the Bit Error Rate (BER) performance is still not able to reach the LTE level, which uses Orthogonal Frequency Division Multiplexing (OFDM). In this paper, to achieve a better BER performance, it is proposed to use the LDPC coding with FBMC waveform for 5G communication and was simulated with Keysight SystemVue Software. The BER analysis is performed for both coded and uncoded data transmission for FBMC system with three different modulations: QPSK, 16QAM, 64QAM. The simulated results shows that the LDPC coding with 1/2 code rate is better than other code rates 2/3, 3/4 and 5/6.

EEDOS: an energy-efficient and delay-aware offloading scheme based on device to device collaboration in mobile edge computing

Device to device (D2D) communication and mobile edge computing (MEC) are two promising technologies in fifth generation (5G) cellular mobile communication. Besides MEC, a new task offloading technique attracts the attention as D2D collaboration. However, there is lack of integrated D2D and MEC framework to address the energy and delay costs in a joint approach. This work, proposes an energy efficient and delay-aware offloading scheme (EEDOS) based on D2D collaboration in MEC. In EEDOS, mobile devices can offload their task to the MEC or an idle mobile device in their proximity. The task execution and offloading to the MEC or an idle nearby device is formulated, and the optimization problem is defined. The whole process of allocating proper offloading destination is designed in the edge server. EEDOS, classifies offloading requests according to the deadline and energy constraint of requesting device. Then, it finds the proper offloading destination by utilising the maximum matching with minimum cost graph algorithm. Through simulation, we show that EEDOS achieves 95 percent of energy efficiency in comparison of no-offloading task execution and outperforms existing studies in term of energy efficiency with an improved delay in task execution. Moreover, EEDOS is capable of performing more successful task offloading and requires less edge server resources.

An Improved Jacobi-Based Detector for Massive MIMO Systems

Massive multiple-input-multiple-output (MIMO) is one of the key technologies in the fifth generation (5G) cellular communication systems. For uplink massive MIMO systems, the typical linear detection such as minimum mean square error (MMSE) presents a near-optimal performance. Due to the required direct matrix inverse, however, the MMSE detection algorithm becomes computationally very expensive, especially when the number of users is large. For achieving the high detection accuracy as well as reducing the computational complexity in massive MIMO systems, we propose an improved Jacobi iterative algorithm by accelerating the convergence rate in the signal detection process.Specifically, the steepest descent (SD) method is utilized to achieve an efficient searching direction. Then, the whole-correction method is applied to update the iterative process. As the result, the fast convergence and the low computationally complexity of the proposed Jacobi-based algorithm are obtained and proved. Simulation results also demonstrate that the proposed algorithm performs better than the conventional algorithms in terms of the bit error rate (BER) and achieves a near-optimal detection accuracy as the typical MMSE detector, but utilizing a small number of iterations.

A Survey on Massive MIMO Systems in Presence of Channel and Hardware Impairments.

Massive multiple input multiple output (MIMO) technology is one of the promising technologies for fifth generation (5G) cellular communications. In this technology, each cell has a base station (BS) with a large number of antennas, allowing the simultaneous use of the same resources (e.g., frequency and/or time slots) by multiple users of a cell. Therefore, massive MIMO systems can bring very high spectral and power efficiencies. However, this technology faces some important issues that need to be addressed. One of these issues is the performance degradation due to hardware impairments, since low-cost RF chains need to be employed. Another issue is the channel estimation and channel aging effects, especially in fast mobility environments. In this paper we will perform a comprehensive study on these two issues considering two of the most promising candidate waveforms for massive MIMO systems: Orthogonal frequency division multiplexing (OFDM) and single-carrier frequency domain processing (SC-FDP). The studies and the results show that hardware impairments and inaccurate channel knowledge can degrade the performance of massive MIMO systems extensively. However, using suitable low complex estimation and compensation techniques and also selecting a suitable waveform can reduce these effects.

Design and Performance Comparison of Rotated Y-Shaped Antenna Using Different Metamaterial Surfaces for 5G Mobile Devices

In this paper, a rotated Y-shaped antenna is designed and compared in terms of performance using a conventional and EBG ground planes for future Fifth Generation (5G) cellular communication system. The rotated Y-shaped antenn... | Find, read and cite all the research you need on Tech Science Press

Analysis of Packet Throughput in Small Cell Networks Under Clustered Dynamic TDD

Small cell networks under dynamic time-division duplex (D-TDD) transmission have emerged as a promising solution to accommodate the varied uplink (UL) and downlink (DL) traffic in next generation cellular mobile communication networks. By allowing each cell to individually configure its communication direction, D-TDD allocates resources to accommodate whichever transmission direction needs it most. However, with unaligned transmissions, the interference increases and limits the performance of mean packet throughput (MPT). In this paper, we study the small cell networks under D-TDD with cell clustering being the interference mitigation technique (clustered D-TDD). By leveraging stochastic geometry and queuing theory, we develop an analytical framework that captures both spatial and temporal randomness. We study the MPT whose analytical expression is verified via simulation, and based on the analysis, we explore the impact from different network and service parameters. In particular, numerical results show that there is an optimal cluster size for DL MPT, while UL MPT always benefits from increasing cluster size. By grouping cells into clusters, the clustered D-TDD can provide the flexible service compared with static time-division duplex (S-TDD), and provide significant improvement over a traditional D-TDD in terms of UL MPT at a small cost of DL MPT.

Proactive content delivery for vehicles over cellular networks: The fundamental benefits of computing and caching

The emergence of self-driving technologies implies that a future vehicle will likely become an entertainment center that demands personalized multimedia contents with very high quality. The surge of vehicular content demand brings significant challenges for the fifth generation (5G) cellular communication network. To cope with the challenge of massive content delivery, previous studies suggested that the 5G mobile edge network should be designed to integrate communication, computing, and cache (3C) resources to enable advanced functionalities such as proactive content delivery and in-network caching. However, the fundamental benefits achievable by computing and caching in mobile communications networks are not yet properly understood. This paper proposes a novel theoretical framework to characterize the tradeoff among computing, cache, and communication resources required by the mobile edge network to fulfill the task of content delivery. Analytical and numerical results are obtained to characterize the 3C resource tradeoff curve. These results reveal key insights into the fundamental benefits of computing and caching in vehicular mobile content delivery networks.

Investigation on Interference Mitigation Schemes for Next Generation Cellular Communications

The fanciful quick development and exponential increment of advanced mobile phones the remote info activity request is additional within the returning years. That forces reexamining current remote cell arranges thanks to the shortage of the accessible vary. 2 noteworthy difficulties for advancing future Evolution (LTE) systems area unit to accomplish improved cell scope and framework limit contrasted and broadband Code Division Multiple Access (WCDMA) framework. Powerful use of radio assets and thick vary use is at the middle to realize these objectives. Be that because it might, thick repeat use might increment between cell electric resistance, that so extraordinarily restricts the limit of shoppers within the framework. Between cell obstruction will limit general framework execution as so much as output and preternatural productivity, significantly for the shoppers set at the cell edge region. later on, cautious administration of between cell obstructions finishes up vital to boost LTE framework execution. during this paper, obstruction alleviation plans for LTE downlink systems area unit investigated. The eNB and also the Mobile-Femto as each provide similar assets and transfer speed. This has created AN electric resistance issue from the downlink signs of every alternative to their UEs. this examination has adjusted a adept repeat use conspire that worked powerfully finished separation and accomplished increased outcomes within the flag quality and output of Macro and Mobile-Femto UE once contrasted with past electric resistance administration plans e.g. Partial Frequency use factor1 (NoFFR-3) and uncomplete Frequency use factor3 (FFR-3). Keywords: The fanciful quick development and exponential increment of advanced mobile phones the remote info activity request is additional within the returning years. That forces reexamining current remote cell arranges thanks to the shortage of the accessible vary. 2 noteworthy difficulties for advancing future Evolution (LTE) systems area unit to accomplish improved cell scope and framework limit contrasted and broadband Code Division Multiple Access (WCDMA) framework. Powerful use of radio assets and thick vary use is at the middle to realize these objectives. Be that because it might, thick repeat use might increment between cell electric resistance, that so extraordinarily restricts the limit of shoppers within the framework. Between cell obstruction will limit general framework execution as so much as output and preternatural productivity, significantly for the shoppers set at the cell edge region. later on, cautious administration of between cell obstructions finishes up vital to boost LTE framework execution. during this paper, obstruction alleviation plans for LTE downlink systems area unit investigated. The eNB and also the Mobile-Femto as each provide similar assets and transfer speed. This has created AN electric resistance issue from the downlink signs of every alternative to their UEs. this examination has adjusted a adept repeat use conspire that worked powerfully finished separation and accomplished increased outcomes within the flag quality and output of Macro and Mobile-Femto UE once contrasted with past electric resistance administration plans e.g. Partial Frequency use factor1 (NoFFR-3) and uncomplete Frequency use factor3 (FFR-3).

Millimeter Wave Beam-Selection Using Out-of-Band Spatial Information

Millimeter wave (mmWave) communication is one feasible solution for high data-rate applications like vehicular-to-everything communication and next generation cellular communication. Configuring mmWave links, which can be done through channel estimation or beam-selection, however, is a source of significant overhead. In this paper, we propose using spatial information extracted at sub-6 GHz to help establish the mmWave link. Assuming a fully digital architecture at sub-6 GHz; and an analog architecture at mmWave, we outline a strategy to extract spatial information from sub-6 GHz and its use in mmWave compressed beam-selection. Specifically, we formulate compressed beam-selection as a weighted sparse signal recovery problem, and obtain the weighting information from sub-6 GHz channels. In addition, we outline a structured precoder/combiner design to tailor the training to out-of-band information. We also extend the proposed out-of-band aided compressed beam-selection approach to leverage information from all active subcarriers at mmWave. To simulate multi-band frequency dependent channels, we review the prior work on frequency dependent channel behavior and outline a multi-frequency channel model. The simulation results for achievable rate show that out-of-band aided beam-selection can considerably reduce the training overhead of in-band only beam-selection.

Patch array antenna with high gain using EBG superstrate for future 5G cellular networks

In this paper, a new patch array antenna operating at three bands frequencies at 25GHz, 28GHz and 38GHz for the upcoming fifth generation (5G) cellular communication is presented. And it is specially designed to improve the gain with a good radiation behavior. The proposed array antenna comprises two patch antennas fed by a 1-to-2 Wilkinson power divider. A dielectric layer of an Electromagnetic Band Gap (EBG) superstrate is applied above the array antenna for further gain improvement. This array antenna is designed with CST Microwave Studio. Simulated results show the effectiveness of the proposed antenna for improving the gain more than 12 dBi. Due to the remarkable performance of the proposed antenna array, it can be suitable to be used in 5G network communication.

A New Framework of Filter Bank Multi-Carrier: Getting Rid of Subband Orthogonality

Filter bank multi-carrier (FBMC) entitles many advantages over orthogonal frequency division multiplexing (OFDM) and is considered to be a more competitive waveform in the future generation cellular communications. In current FBMC, the prototype filter is deliberately designed to meet the perfect reconstruction (PR) constraint to establish subband orthogonality in real domain, which may not be optimal from communication perspective. In this paper, we challenge the necessity of PR constraint by proposing a new FBMC framework, which directly accepts non-orthogonal transmission. The resulting imperfect reconstruction FBMC (iPR-FBMC) has several advantages over its PR FBMC counterpart: 1) the constraint on the prototype filter is relaxed; 2) more importantly, the prototype filter can now be optimized with new goal of improving the detection performance rather than having to meet the PR condition; and 3) it allows for more flexible subband management in multi-user scenario. We will show how those advantages can be exploited. Simulations show that with moderate increase in computational complexity, the proposed iPR-FBMC with optimized prototype filter has superior bit error rate (BER) performance to existing FBMC with PR constraint and even outperforms OFDM, especially in highly frequency selective channels. The findings may shed light into potential research on non-orthogonal FBMC without PR constraint.

Design and Performance Comparison of W-OFDM Under the Nonlinear HPA Environment

Recently, the spectral efficiency improvement of wireless and cellular communications is very important. Several waveforms have been proposed in order to satisfy key performance indicators of the 5th generation (5G) cellular communication. Universal filtered multi-carrier (UFMC) and filter bank multi-carrier (FBMC) and the filtered orthogonal frequency division multiplexing are typical candidate for 5G waveform, but they have some advantages and problems as well. In this paper, a weighted orthogonal frequency division multiplexing (W-OFDM) is considered since W-OFDM has pretty low complexity and comparable merits. In this paper, at first, we describe the system model and operation principle about UFMC, FBMC, and W-OFDM system. Next, we evaluate the out-of-band (OOB) power spectrum and bit error rate (BER) performance of these systems in the linear or nonlinear HPA. Simulation results show that OOB power spectrum and BER performance of UFMC, FBMC, and W-OFDM are similar in the linear operation. From the implementation point of view, if these performance and characteristics are similar, low-complexity is very decisive for the communication processing speed that is very important to the low latency and ultra-fast processing in the receiver. Additionally, under the nonlinear HPA environment, W-OFDM system is more advantageous because W-OFDM system uses a simple time-domain windowing technique in order to reduce OOB power.

Frame Structure Design and Analysis for Millimeter Wave Cellular Systems

The millimeter-wave (mmWave) frequencies have attracted considerable attention for fifth generation (5G) cellular communication as they offer orders of magnitude greater bandwidth than current systems. However, the medium access control (MAC) layer may need to be significantly redesigned to support the highly directional transmissions, and the demand for ultra-low latencies and high peak rates expected in mmWave communication. To address these challenges, we present a novel mmWave MAC layer frame structure with a number of enhancements, including flexible, highly granular transmission times, dynamic control signal locations, extended messaging, and the ability to efficiently multiplex directional control signals. Analytic formulas are derived for the utilization and control overhead as a function of control periodicity, number of users, traffic statistics, signal-to-noise ratio, and antenna gains. Importantly, the analysis can incorporate various front-end MIMO capability assumptions-a critical feature of mmWave. Under realistic system and traffic assumptions, the analysis reveals that the proposed flexible frame structure design offers significant benefits over designs with fixed frame structures similar to current 4G long-term evolution. It is also shown that the fully digital beamforming architectures offer significantly lower overhead compared with analog and hybrid beamforming under equivalent power budgets.

Guest Editorial Special Issue on 5G Wireless Systems With Massive MIMO

The goals of the fifth generation (5G) cellular communication systems are to achieve 10–100 times higher typical user data rates, ranging from 1 to 10 Gbps in dense urban environments. 5G may support 10–100 times more connected devices. Furthermore, the energy efficiency for low-power massive machine communications is to be improved more than ten times. However, there is no clear roadmap to achieve such high performance targets. The introduction of new technologies in 5G systems is necessary. The aim of the papers in this special section highlight how massive MIMOmeet 5G requirements with developing mobile networks. These papers focus on new technologies being investigated that have great potential to let massive MIMO be practical.