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In conventional healthcare, real-time monitoring of patient records and information mining for timely diagnosis of chronic diseases under certain health conditions is a crucial process. Chronic diseases, if not diagnosed in time, may result in patients’ death. In modern medical and healthcare systems, Internet of Things (IoT) driven ecosystems use autonomous sensors to sense and track patients’ medical conditions and suggest appropriate actions. In this paper, a novel IoT and machine learning (ML)-based hybrid approach is proposed that considers multiple perspectives for early detection and monitoring of 6 different chronic diseases such as COVID-19, pneumonia, diabetes, heart disease, brain tumor, and Alzheimer’s. The results from multiple ML models are compared for accuracy, precision, recall, F1 score, and area under the curve (AUC) as a performance measure. The proposed approach is validated in the cloud-based environment using benchmark and real-world datasets. The statistical analyses on the datasets using ANOVA tests show that the accuracy results of different classifiers are significantly different. This will help the healthcare sector and doctors in the early diagnosis of chronic diseases.

With the increasing demand for high-speed mobile transmissions for 5G networks, the cooperative relay-aided non-orthogonal multiple access (CR-NOMA) has been highly considered. An efficient and reliable CR-NOMA not only depends on the network mechanism but on the network coding strategy at the relay. Even though conventional strategies have broadly been studied, they suffer from noise accumulation and interference. Lately, the compute-and-forward (CpF) strategy has been identified as a potential technique to mitigate interference and enhance outage probability. In this study, the authors present a mathematical formulation to examine the performance of CpF on downlink CR-NOMA. In the proposed formulation, a two-stage downlink cooperative relay network is considered to obtain analytical closed-form expressions of outage probability and bit error rate. The outage probabilities and bit error rates of existing relaying strategies are compared regarding the network model. The theoretical analysis shows that CpF requires half the number of relays desirable in amplify-and-forward and decode-and-forward strategies to achieve a proportionate outage probability in CR-NOMA. Finally, we present results to show that at a lower signal-to-noise ratio, the integration of CpF and NOMA enhances error performance irrespective of the number of users.

This letter presents a new broadband circularly polarized (CP) planar monopole antenna with a simple structure and compact size. Broadband CP operation is achieved by vertically extending one side of the ground plane, while a cross-shaped monopole structure and the presence of a slot in the ground plane assure a broad impedance bandwidth. The antenna is successfully simulated, and a prototype is fabricated. Measurement results indicate that the 3 dB axial-ratio bandwidth is about 42.6% (2.6 GHz, 4.8–7.4 GHz), fully covered by a –10 dB impedance bandwidth of 55.5% (3.35 GHz, 4.36–7.71 GHz). Furthermore, the proposed antenna can be used together with a metallic reflector to obtain directive radiation patterns with enhanced broadside gain.

In this paper, we present an approximate expression for spatial correlation of cylindrical and uniform rectangular arrays regarding the maximum power of offset distributions useful for evaluating geometry-based stochastic channel models. The underlying concept of the proposed spatial correlation expression is that the maximum power of arrival varies relative to the offset distribution in the azimuth and zenith domains. Verification is accomplished with the help of computer simulation, where perfect agreement between theoretical and Monte Carlo simulation results is found. Toward the implementation of large-scale MIMO transmitters in constrained physical spaces to accomplish the demands for the next generation of wireless systems, we examine the effect of the proposed spatial correlation model on the downlink (DL) performance of massive multi-input-multi-output (MIMO) system. Results illustrate that the DL capacity does not demonstrate any sensitivity to the effect of correlation by increasing the number of elements in a realistic massive MIMO channel. Surprisingly, while the spatial correlation restricts the DL capacity at a reduced number of transmit antennas, the restriction becomes insignificant as the number of transmit antennas increases. This supports existing developments that user channels decorrelate when the number of antennas at the base station increases. Finally, experimental results show that separation of more than half wavelength is inadequate to decorrelate the antenna elements.

In this paper, we investigate the performance of channel inversion schemes for interference cancellation with compensation network in multi-user MIMO broadcasting channel. To achieve good performance, mutual coupling between two-element compact arrays is characterized by the receiving mutual impedance method (RMIM) to formulate the compensation network-operating matrix. A prototype of two-element compensation network with an insertion loss between input and output ports better than 11 dB is fabricated. We demonstrate results to confirm that output voltages of decoupling network can effectively be removed off the coupling effect. A typical standard MIMO channel model is presented, and system performance is evaluated when coupling effects existed and after decoupling process. Bit error performance results also indicate the promising potentials of regularized channel inversion scheme with efficient decoupling scheme in massive MIMO system.

We explore the dependency of MIMO performance on azimuthal spread (AS) and elevation spread (ES) using correlated-based stochastic models (CBSMs). We represent the transmitter as uniform rectangular array (URA), and derive an analytical function for spatial correlation, in terms of maximum power when phase gradient of the incident wave follows a Student’s t-distribution. We model the correlated-based stochastic MIMO system to investigate the usefulness of the analytical function, under the condition that the magnitude and phase of mutual coupling and consequently the coupling matrix of the coupled receiving monopole array differs much from that of the decoupled array. Verification is achieved with the help of simulation results, which support the existing fact that the azimuthal spread is the fundamental determinant of system capacity. However, we observed that lower values of AS and ES increase the rate of deterioration in the symbol error rate (SER) and not antenna spacing after decoupling process.

In this letter, we derive a closed-form expression for the spatial fading correlation (SFC) of a uniform rectangular array useful for evaluating correlated-based stochastic models. The underlying concept of the proposed model is that the true distribution of power is relative to the total power of the incident wave and dependent on azimuthal and elevation spreads. Verification is accomplished with the help of computer simulation where excellent agreement is found between theoretical and simulation results. Results support the existing developments that the SFC decreases as the antenna separation or azimuthal spread increases. For performance evaluation, we model the multiple-input–multiple-output channel on the assumption that the coupling matrix of the coupled receiving array differs from the decoupled array. Results highlight the promising potentials of the proposed model with an effective decoupling process. However, we observed that lower estimations of azimuthal spread and elevation spread increase the rate of deterioration in the bit error rate and not antenna spacing.

In this paper, we derive a closed-form expression for three-dimensional (3D) spatial fading correlation (SFC) of a uniform circular array (UCA) useful for evaluating geometry-based stochastic channel models (GBSMs). The fundamental idea of the proposed model is that the total power of the incident wave is relative to the true distribution of power and dependent on the azimuthal spread (AS) and elevation spread (ES). This generalized closed-form expression permits the presentation of ES at all levels which renders the expression helpful for examining the degree of flexibility offered by ES in 3D multi-input and multi-output (MIMO) channel modeling. To minimize the effect of mutual coupling on MIMO performance using the SFC expression, the geometry-based channel is evaluated before and after decoupling process at the mobile station (MS). Finally, the present investigations demonstrate the joint contribution of AS and ES on 3D MIMO performance under Gaussian and Student's t-distributions.

This paper presents the design of a compact circularly polarized square slot antenna fed by a G-shaped strip feedline. The 3-dB axial ratio (AR) band can be achieved by simply extending the feedline with a G-shaped monopole. To extend the AR bandwidth achieved by the G-patch, perturbations in the form of a U-strip and an L-shaped slot are introduced in the wide slot and ground plane respectively. Measured results showed a wide 3-dB axial ratio bandwidth of 37.1% (4.5–6.55 GHz) and an impedance bandwidth of 70.1% (3.32–6.95 GHz). The proposed antenna is suitable for wideband circular polarization applications in the IEEE C-band.

A tri-band planar monopole antenna with dual band circular polarization for 3G, WiMAX and WLAN applications is presented. The antenna consists of monopole arms on one side of an FR4 substrate attached to a slotted feedline and a slotted ground plane on the other side of the same substrate. The antenna has a total size of 25 × 35 × 1.6 mm3. Measured results show that the antenna has a −10 dB impedance bandwidth of 9.7% (2.05–2.26 GHz) for the lower band, 11.3% (3.41–3.82 GHz) for the middle band and 60.2% (4.89–9.11 GHz) for the upper band. The simulated axial ratio (AR) bandwidths are 4.4% (3.55–3.71 GHz) and 57.9% GHz (4.69–8.52 GHz).

In this paper, we present an approximate expression for the spatial correlation of massive MIMO antenna topologies. The underlying concept of the proposed model is that the total power is relative to the true distribution of power in the azimuth and zenith domains. Simulation results using measured distribution of angles of departure (AOD) support the existing fact that massive MIMO convergence metrics do not demonstrate any sensitivity to antenna topology.

We present the performance comparison of 40, 80 and 112 Gb/s polarization division multiplexing (PDM)-differential quadrature phase shift keying (DQPSK) optical label switching system with frequency swept coherent detected spectral amplitude code (SAC) labels in simulation. Direct detection is selected to demodulate the PDM payload in the receiver. The SAC label is frequency-swept coherently detected. The label and payload signal performances are assessed by the eye diagram opening factor and bit error rate (BER) as function of received optical power (ROP) and optical signal to noise ratio (OSNR). For back-to-back (BTB) system and 156, 138 and 120 km transmission for 40, 80 and 112 Gb/s respectively, label eye opening factors are 0.93 and 0.85 for 40 Gb/s, 0.94 and 0.86 for 80 Gb/s and 0.93 and 0.90 for 112Gb/s respectively, while payload optical signal-to-noise ratio are 29.9, 25.6, 23.4 dB and the payload received optical power are −11.5, −12.6 and −13.3 dBm for a bit error rate of 10−9 after 156, 138 and 120 km for 40, 80 and 112 Gb/s respectively. The payload could well be demodulated after 1,800, 1,260 and 900 km transmission for 40, 80 and 112 Gb/s respectively at a BER of 10−3 using forward error correction (FEC).

We explore combined effect of spatial correlation and mutual coupling matrix, and its subsequent effects on performance of multiple input multiple output (MIMO) systems After the decoupling process. We will also look at a correlation based stochastic channel model with the linear antenna arrays as the signal source. For the purpose of understanding, it is assumed that fading is correlated at both transmitter and receiver sides, in spite of the fact that the decoupling network enhances isolation between Receiving antenna array. In this paper, we model the transmit the antenna array in CST Microwave Studio, as a uniform linear Array with monopoles as antenna elements. On the receiving side, the scattering parameters of the coupled and decoupled monopole Array are measured in an anechoic chamber. The theoretical analysis and simulation results show the joint dependency of the system capacity on an angle of arrival (AoA) and antenna element spacing, with enhanced system performance at reduced AoAs with Increased antenna element separation. Consequently, essential benefits of MIMO system performance can be achieved with an efficient decoupling network while boosting the signal sources by adding further antenna elements.