Wireless Personal Communications最新文献

Nowadays, wireless communication system plays great roles in our daily activities and different improvements are requiring because the number of users increase from time to time. At the same time, users need high throughput and link reliability. The forthcoming generation of wireless communication will have to deal with some core requirements for serving large number of users simultaneously, upholding high throughput for each user, assuring less energy consumption, etc. Inter-user interference has a major impact when a wireless communication link has a large number of users. To maintain a particular desired quality of service, sophisticated transmission mechanisms such as interference cancellation need be implemented. As a result, MU-massive MIMO with extremely huge antenna arrays is recommended. The term "MU-massive MIMO" refers to a system with hundreds or thousands of antennas servicing tens of thousands of customers.Inter-user interference was greatly decreased once the channel vectors were closely orthogonal. As a result, high data rates can be supplied to multiple users at the same time. In this work, researcher investigated performance evaluation of a MU-massive MIMO utilizing different precoding schemes (like, MMSE, ZF, MRT) over nakagami-m fading channel with CSI at base station and users’ terminal. In addition, the researcher analyzed the outcome of pilot reuse factors and shaping (m) parameter.

This paper presents microstrip patch antenna array inspired by split ring resonators (SRR) for 5.8 GHz applications. The proposed microstrip patch antenna array inspired by split ring resonators is designed using FR-4 material with dielectric constant of 4.4, 1.6-mm thick substrate and loss tangent of 0.02. The split ring resonator has been loaded into the designed microstrip antenna array. Unloaded antenna arrays have a gain of 5.41 dB at 5.8 GHz, However split ring resonator-loaded antenna arrays provide a gain of 7.28 dB at the same 5.8 GHz resonant frequency. This microstrip patch antenna array inspired by split ring resonators is simulated using 3DEM of Mentor graphics electromagnetic simulator. To verify the theoretical and simulated results, antenna measurements are being prepared.

Although the design of spectrum switching has been studied, little is known about how random user movement affects the handoff. This issue can occur when a user moves to a new location. In this paper, the authors present a framework that verifies the necessity of spectrum handoff to improve the performance of the system by employing machine learning (ML) techniques. Some of these include the Logistic Regression, KNN Algorithm, SVM Algorithm, Naïve Bayes Classifier, Decision Tree Classification and Random Forest Algorithm. The system is implemented on a real-time dataset where all the users are separated in power domain using the concept of non-orthogonal multiple access (NOMA) technique. The dataset values are prepared using a software-defined radio experimental setup, which is used to analyse the performance of various ML techniques in terms of confusion matrix, specificity, precision, F1_score, sensitivity and accuracy. The performance of proposed system is compared with the literature and shown a significant improvement that proves the evidence of our findings.

With increased vehicular traffic on roadways, traffic jams and accidents are common, leading to substantial social and financial losses. Early detection of roadway accidents is beneficial as help can be directed to the accident site quickly, saving the lives of the injured. With this goal, an intelligent accident detection system is proposed in this paper using a Vehicular Adhoc Network model. Each vehicle has an on-board unit with multiple sensors in the proposed work. Outputs of these sensors, which monitor the condition of the driver and the vehicle, are input to a fuzzy logic controller for quick detection of an accident. The proposed system is validated by designing and implementing a hardware prototype. When an accident is detected, the proposed hardware uses a low-range radio (LoRa) transceiver network to send messages to a central server. After receiving the message from a vehicle, the server can inform a nearby ambulance. It can also identify the shortest path to a nearby hospital using Dijkstra’s algorithm and inform the ambulance. This would facilitate timely treatment of the accident victim(s).

A vehicular ad hoc network (VANET) includes groups of stationary or moving vehicles linked by a wireless network. The significant usage of VANET is to offer comfort and safety to drivers in road environments. VANET provides a communication framework that aids in minimizing accidents. Also, sharing data in VANET is time-sensitive and necessitates vigorous and quick network link formation. However, appropriate routing is critical to avoid the streaming issues that occur in VANET applications. This research area is of great concern to the researchers, and this work intends to propose a new Cluster-based VANET routing model with steps like (a) optimal cluster head selection (CHS) and (b) appropriate gateway selection for data transmission. Here, the optimal CHS takes place considering the Packet delivery ratio (PDR), mean routing load, end-to-end (e2e) Delay, Throughput, and packet overhead. This paper introduced a new Customized hunger’s foraging honey badger with a Dynamic multi-objective non-sorted genetic algorithm (CHFHB-DMNSGA). Also, the gateway selection is done under two objectives: Vehicular gateway mobility and receiver signal strength, respectively. Finally, the paper presented a comparative assessment to validate the effectiveness of the adopted algorithm CHFHB-DMNSGA over the other algorithms like R-NSGA-II, NSGA-III, NSGA-II, HBA, HGS, ABC, FF, CSO, ACO, LA, MHB-GA, GA-FF, and HFCHBO.

The person re-identification is the process of identifying a person of interest from the crowded scenes taken from different camera networks. With the performance saturation under different camera views and environmental settings, the research focus for person Re-ID has facing more challenging issues. Some of them are illumination, pose variation, viewpoint changes and, occlusions. To overcome these issues, we proposed a novel feature extraction method called GLOGT and pose learning-based re-identification procedure in our previous research papers. Later we came to know that the image-based analysis is more important to prove the efficiency of a novel person re-identification method. So here we conducted some important experiments to analyze the efficiency of the proposed techniques using the benchmark datasets. From the result analysis, it shows that the proposed techniques outperforming other existing techniques with a good accuracy level. Since the pose estimation-based method extracting the features based on the pose priority, reduces the training testing comparisons also. Since the GLOGT feature is a combination of three types of feature representation, one feature suppresses due to some issues, at that point the remaining will dominate and gives higher accuracy for identification.

Indoor navigation framework plays a significant role in day today life. In the outdoor application, GPS signals identifies the exact location or points of the user, but it is not true in indoor scenarios. To overcome this issue there are various techniques have been devised to predict the position and identify the location of the user in the indoor application. These include attaching sensors to the shoes or suites or ceiling of the building and using WIFI signals to predict the position and navigate user to the destination. But not all the time this is possible as the sensors may get damaged and signal interferences may lead to large accumulated errors in the results. This paper proposes a novel technique to predict the position and navigate the user making use of the sensors present in the smartphone. Use of smartphone eliminates the need for external sensors to be attached to the shoes or suits, as it has inbuilt magnetometer, accelerometer, and gyroscope. The data generated by these sensors are used to estimate the pitch and roll values and also the heading information. The step count and the time at which the user performs each step are calculated using peak detection algorithm. A rule-based algorithm is proposed to estimate the step length and the smart phone beacon signals are used to provide the heading information. A voice based guiding facility is also built in to alert the user in case he selects the wrong path. With all these features, the proposed system certainly helps the user to navigate correctly from source location to the intended destination. The experiments are carried out in different scenarios under various realistic conditions and the results displays that, the proposed method achieves a high position accuracy with significant reduction in the error (less than 2.5%) and performs well compared to the conventional estimation methods. The performance is assessed in terms of displacement and root mean square error and compared with the position-estimation method (Poulose in IEEE Access 7: 11165–11177, 2019).

This article presents a systematic design and optimization process for a compact 0.27λ₀ × 0.31λ₀ multiband monopole antenna for Internet of Vehicles (IoV) applications, including navigation, Vehicle to Infrastructure (V2I), Wi-Max, and 5G. The antenna’s modified ground plane enables installation within a shark-fin module on a car roof, aligning with its low-profile dimensions and high performance. Structural modifications to the initial antenna element, including the T-shaped structure and integrated stub between quad rings, enable circular polarization in the GPS L1 band. With simulated total radiation efficiency exceeding 60% at four bands, numerical simulations and physical fabrication on an FR-4 substrate are followed by antenna radiation measurement in an anechoic chamber. The measured gain at 1.575 GHz, 2.6 GHz, 4.8 GHz, and 8 GHz is 1 dBi, 2.2 dBi, 3.2 dBi, and 3.8 dBi, respectively. Additionally, ray tracing techniques evaluate the antenna’s performance when mounted on a car, considering interactions with other vehicular antennas and infrastructure in urban propagation scenarios. Urban propagation analysis illustrates efficient operation, characterized by minimal delay time, favorable line of sight, and controlled path loss at frequencies 2.6 GHz and 4.8 GHz. These findings demonstrate the antenna’s potential for adoption in the automotive industry.

In the present times, the concept of cloud computing has played a significant role at the global level. With this approach, users can able to customize their services as per their needs. By having the connection of internet users can get able to serve various kinds of services like on-demand access, storage space, software building platforms, data recovery, etc., and pay only for that service that they have consumed. Enormous challenges in the cloud domain such as fault tolerance, energy efficiency, scheduling, resource provisioning, load balancing, etc. This paper is focused on load balancing domain. This can be defined as a redistribution of the workload among various available virtual machines in such an identical manner that would lead to a balanced state. This paper presents the evaluative and inclusive review of numerous load balancing (LB) methods. Quality of services(QoS) is vital role that contain various parameters to evaluate the load balancing methods in respect of makespan, speedup, cost, throughput, etc. This paper is highlighted numerous of load balancing methods with their brief explaination, platform used, different simulator and tools used by these methods and based on QoS parameters.

Quadrature Amplitude Modulation (QAM) is a multi-level modulation scheme applied to achieve high data transmission rates. In the 16-QAM scheme, high Peak-to-Average Ratio (PAPR) is an issue as wireless communication devices are required to be small with high power efficiency. To resolve this issue, hexagonal constellation symbol mapping has been proposed to reduce the PAPR. In a real environment, Orthogonal Frequency Division Multiplexing (OFDM) systems are sensitive to signal distortions such as multipath channel and frequency offsets. When the pilot signals are used to compensate the signal distortion, the combination of pilot signals and mapping need to be considered. The paper investigates the PAPR of the hexagonal constellations and examines the relationship between the PAPR and the interval of pilot signal in OFDM system. Bit Error Rate (BER) performance are evaluated with computer simulations.