Abstract: . Non-Orthogonal Multiple Access (NOMA) tech-nique is a remarkable component of 5G wireless networks; since NOMA immensely augments the spectral efficiency and serves all users fairly. To accomplish these, efficient power allocation is crucial for improving the NOMA system’s performance. Accordingly, in this article, we formulate a power allocation optimization issue, which concentrates on enrich-ing the system sum-throughput, by realizing the transmitted power constraint and also fulfilling the minimum throughput for each user. However, to tackle this mentioned optimization problem, a Modified Artificial Bee Colony (MABC) algorithm is proposed. Besides, the designed MABC algorithm obtains optimal powers among multiplexed users on every sub-channel. Further, simulation results illustrate that the presented power allocation scheme-based NOMA system’s sum throughput is higher than the original ABC-based power allocation and other state-of-the-art power allocation schemes. Moreover, the MABC method swiftly converges to optimal solutions compared to the original ABC algorithm under selected control parameters.

Abstract: . This paper proposes a distributed Reed-Solomon coded cooperative labeling diversity (DRSCC-LD) scheme over the Rayleigh frequency-flat fast fading channel to further improve the BER performance. The non-binary Reed-Solomon (RS) code with more consecutive roots is applied at the relay to provide additional redundancy. As a novel diversity technique, labeling diversity (LD) with three different mappers is employed in the proposed DRSCC-LD scheme utilizing 16-QAM and 64-QAM, respectively, which may achieve diversity gain and greatly decrease the error floor (EF). Be-sides, a reduced-complexity detection algorithm based on a variable signal subset (RC-VSS) is proposed to lower the complexity of detection at both relay and destination. The proposed critical SNR-assisted (CSA) joint decoding algorithm then collaborates with the joint detection based on the RC-VSS algorithm to improve the overall BER performance. Theoretical analysis and Monte Carlo simulated results reveal that the proposed DRSCC-LD scheme clearly outperforms its corresponding non-cooperative RS coded scheme by a gain of more than 7 dB and the existing schemes by a margin of more than 3.5 dB under the identical conditions, respectively.

Abstract: . Surgical telementoring is an advanced telemedicine concept where the expert surgeon guides the onsite novice present at the remote location. The efficient telementoring system requires the wireless transmission of high-quality surgical video with less bitrate in less time. The bit rate of the surgical video can be decreased by segmenting the surgical incision region and removing the background region. The High Efficiency Video Coding (HEVC) standard has provided promising results for surgical telementoring applications. But the Rate-Distortion Optimization (RDO) search process in HEVC increases the complexity that in turn increases the encoding time. We propose the method which involves the segmentation of the surgical incision region using the Kernelized Correlation Filter (KCF) object tracking technique. The segmented region is encoded by the complexity-efficient Scalable HEVC (SHVC) to meet the resolution of an end-user device. The complexity of SHVC is decreased by using the Convolutional Neural Network (CNN) and Long- and Short- Term Memory (LSTM) to predict the Coding Tree Unit (CTU) structure. The results show that the proposed method decreases the bitrate significantly for segmented surgical video sequences without degradation in Peak Signal-to-Noise Ratio (PSNR). These results are obtained for the surgical video sequences with slow-moving objects. Furthermore, the CNN + LSTM approach reduces the encoding time of standard SHVC by 51% with negligible Rate-Distortion (RD) performance loss.

Abstract: . A simple approach to improve both the bandwidth and isolation of the Wilkinson power divider for using in L-band satellite communications is presented in this paper. To enhance the bandwidth, a multi-section method based on the Chebychev impedance transformation is employed. In order to improve the isolation performance between output ports, the values of isolation resistors are carefully determined by using the iterative approximation method combined with an investigation procedure. In order to validate the proposed design, a two-way and eight-way power divider prototypes were fabricated and tested on a Rogers RO4003C material. Good agreements between simulations and measurements are obtained in a frequency range from 0.8 GHz to 2.2 GHz. The two-way power divider had a fractional bandwidth of 106% with an isolation of better than 30 dB. The eight-way power divider achieved the bandwidth and isolation of 109% and better than 24 dB, respectively. Both the power dividers exhibit the phase imbalance of less than 3 degrees, and amplitude imbalance of less than 0.02 dB. Compared with the other works, the proposed power dividers deliver broader bandwidth and improved isolation while still retaining good insertion loss, low phase and amplitude imbalance in the operation frequency range.

Abstract: . In this paper, the design and hardware implementation of a squared open-loop resonator (SOLR)-based microstrip diplexer with high isolation, low insertion loss, and high selectivity are introduced. We employed four SOLRs, with each pair of coupled SOLRs used to build a high selectivity bandpass filter (BPF). To assemble the proposed diplexer, the designed BPFs are linked together via a T-junction combiner that is matched to the two filters and the antenna port. For transmit and receive modes, the proposed diplexer has two resonance frequencies of f t = 1.81 GHz and f r = 2.03 GHz, respectively achieving a small frequency space ratio of R = 0.114. The simulated structure exhibits good insertion losses of about 1.98 dB and 1.9 dB for the two channels, respectively, with fractional bandwidths of 2.25% at 1.81 GHz and 3% at 2.03 GHz. For 1.81 GHz and 2.03 GHz, the simulated isolation values are 58 dB and 46 dB, respectively. While the fabricated structure exhibits better insertion losses of about 1.25 dB and 1.22 dB at the measured transmit and receive frequencies of 1.801 GHz and 2.001 GHz, respectively, with smaller fractional bandwidths of 2.23% at 1.801 GHz and 2.98% at 2.001 GHz. For 1.801 GHz and 2.001 GHz, the measured isolation values are 48.99 dB and 57.02 dB, respectively.

Abstract: . Massive multi-input multi-output (MIMO) has attracted significant interest in academia and industry, which can efficiently increase the transmission rate. However, the error rate of conventional channel equalizations in massive MIMO systems may be high owing to the dynamic channel states in practical conditions. To solve this problem, in this paper, we propose an improved channel equalization framework based on the deep neural network (DNN). Based on the analyzed relationship between the input and output of the DNN, the data can be recovered without the channel state information. Furthermore, aiming at reducing the convergence time and enhancing the learning ability of the DNN, a classification weighted algorithm is proposed to optimize the cost function of the DNN, which is named as classification weighted deep neural network (CW-DNN). Simulation results demonstrate that compared to conventional counterparts, the proposed CW-DNN based equalizer can achieve a better normalized mean square error (NMSE). Upon approximating the optimal neural network parameters with the significantly improved convergence speed and reduced training time of the network, under the condition of the fixed learning rate.

Abstract: . In this paper, a novel high-sensitivity broadband rectifier is proposed aiming at ambient radio frequency (RF) energy harvesting. Traditionally, voltage doubling rectifying circuit is used to design high-sensitivity rectifier. But when the input power is lower, the rectifying efficiency is significantly reduced. Therefore, an improved parallel half-wave rectifying circuit is proposed in this article which can convert RF energy in the whole period. And the proposed rectifying circuit can work better in lower power environment and has a higher efficiency level. Besides, the impedance match is also important component of rectifier. Due to the nonlinearity and complexity of rectifying circuit, achieving wideband matching network is a challenge. Thus, a design approach of broadband impedance circuit is given in this study. Combining with the proposed high-sensitivity rectifying circuit, a high-sensitivity wideband rectifier can be generated, when the input power is –15 dBm, –20 dBm, –25 dBm, the efficiency is 43%, 32%, 20%, respectively. Finally, a second-order wideband rectifier with high sensitivity is realized, and the range of bandwidth can cover four main frequency bands of GSM 900 MHz, GSM 1800 MHz, UMTS 2100 MHz, WLAN 2400 MHz. To verify the validity, the rectifier is fabricated and measured, and the measurement has a good agreement with simulation results.

Abstract: . By the recent improvement of the internet of things (IoT), the need to implement wireless networks is increasing. It is a challenge to balance between battery lifetime of the different sensors and network lifetime. Many studies proved the importance of using clustering and Mobile Data Collectors (MDCs) to extend the operating time of sensor nodes. A mobile data collector is used to gather the data recorded by the nodes over a short transmission range. The proposed approach aims to decrease the energy consumption of each sensor node by using the Genetic Algorithm (GA) and mobile data collector. So, we suggest a clustering algorithm to find suitable Cluster Heads and form clusters. Then, we employ the genetic algorithm to construct an optimal data gathering path for MDC. Computer simulation proves that the proposed approach out-performs existing ones.

Abstract: . This paper deals with a method of designing PID controllers. Generalized Laguerre functions were used for this task. Generalized Laguerre functions generate an orthogonal base in the time domain and the operator domain. This property of generalized Laguerre functions is benefi-cially used for the design of the PID controller. Parameters for generalized Laguerre function PID controllers are computed from the Laguerre series of the open loop and the Laguerre series of the ideal open loop. To satisfy this goal, the plant transfer function, the controller transfer function, and the ideal open loop transfer function are transformed into a generalized Laguerre functions base. Three examples are shown to present this method.

Abstract: . A dual band microstrip antenna for WIMAX and WLAN applications is analyzed and presented in this paper. The proposed antenna has semicircular slot in patch and Defected Ground Structure (DGS) technique for the im-provement of its bandwidth and gain. Computer Simulation Technology (CST) software is used to design and simulate the performance characteristics. The proposed antenna has the dimensions as 28 × 26 . 6 𝑚𝑚 2 . The fabricated antenna provides a good reflection coefficient of –48 dB and –44.5 dB at a center frequency of 3.4 GHz and 5.5 GHz. Gain achieved by the antenna is 2.72 dB and 3.87 dB for WLAN and WIMAX application. Good agreements have been found between simulated and measured results. These results confirm that the fabricated antenna is very promising for WLAN and WIMAX applications.

Abstract: . This paper presents a new algorithm of the singular value decomposition (SVD) in the wavelet domain for ground penetrating radar (GPR) to remove direct coupled waves. In fact, direct coupled waves commonly disturb the reflecting waves from underground targets. Besides, the amplitude and energy of direct coupled waves are large, which reduces the resolution of the images to the targets and ad-versely affects the subsequent image interpretation work. The GPR signal is decomposed into several levels by Wavelet to obtain approximation components and detailed components of each level. The information of targets is contained in big eigenvalues of detail components, while the direct coupled waves are contained in small ones. Therefore, the SVD in the wavelet domain can reduce the misjudgment of effective signals and improve the signal to noise ratio (SNR) of GPR signals. The simulated and field GPR data show that the SVD in the wavelet domain denoising method has better results for direct coupled wave removal than the traditional methods, which validates the effectiveness of the proposed denoising method.

Abstract: . This paper presents a comparative EMC susceptibility study of various integrated bandgap voltage reference cores. Conventional well-known bandgap references based on Kuijk, Brokaw and Tsividis concepts with reduced count of bipolar junction transistors in the core were analyzed. On top of the EMC susceptibility comparison, basic parameters like temperature drift, sensitivity to an operational amplifier input offset and line regulation are also discussed. The influence of a collector leakage current compensation at high temperatures is investigated as well.

Abstract: . The bit error rate (BER) performance of spatial modulation (SM) can be further improved by applying quasi-cyclic low-density parity-check (QC-LDPC) codes recommended in 5G to SM. It motivates us to propose a QC-LDPC coded SM (QC-LDPCC-SM) scheme, where SM signals are protected by QC-LDPC codes. To estimate the channel state information at the receiver, a novel iterative joint channel estimation and data detection based on variable block length (IJCEDD-VBL) for SM is presented. In standard 5G LDPC codes, the parity-check matrix contains multiple submatrices, and then we can construct two different QC-LDPC codes by suitably selecting the submatrices. Thus, the QC-LDPCC-SM scheme can be effectively ex-tended to cooperative scenarios when deploying the generated LDPC codes at the source and relay, respectively. We develop an analytical approach for the BER performance of the proposed schemes. The simulation and theoretical results are in good agreement at high signal-to-noise ratio (SNR). Furthermore, the proposed coded cooperative scheme outperforms its corresponding non-cooperative counterpart and the existing scheme. The numerical results also validate the effectiveness of the proposed channel estimation scheme.

Abstract: . The increasing trend in air traffic density will continue in the near future with the addition of different aerial vehicles. Before the Mode-S protocol, Mode A and Mode C were in use; however, the Mode A/C configuration was only usable in sparsely dense air traffic. One of the useful features of Mode-S is the ability of probabilistic interrogation. However, there has not yet been a sophisti-cated algorithm for many close aircraft. Considering a futuristic air environment with a swarm of drones and airbuses equipped with transponders, we utilized the probabilistic interrogation feature of Mode-S and designed an algorithm. The proposed algorithm is able to collect close aircraft information in a relatively short time. There has also been created a high-level Mode-S uplink and downlink communication simulator in order to exchange all-call communication and record the algorithm’s performance in terms of time and number of interrogations sent.

Abstract: . This article describes a multi-spot tracking system for free space optic communications systems suitable for tracking optical terminals observed within the field-of-view of a wide angle telescope. The article explains the con-version of the terminal position to the position in the plane of the tracking sensor and the subsequent recognition and tracking of terminals. In the first part of the article camera image processing is described. Then, basic projection of optical terminal into the tracking sensor plane (into the active surface of a camera) is expressed by using geometry and matrix optics. Afterwards, the angle resolution of optical terminal in plane of the receiver is obtained by using the Airy disk approximation. The basic projection is then extended to the calculation of the Earth-satellite system followed by spot tracking, where method for determining the optical terminal and the state machine is explained.

Abstract: ,

Abstract: . To verify the adaptability of unmanned aerial vehicle (UAV) datalinks to the electromagnetic environment comprising broad-spectrum high-power microwave radiation, strong electromagnetic pulse (EMP) tests were conducted using ultra wideband (UWB) radiation source at different radiation field strengths and repetition frequencies. For UAV datalinks, interference, disturbance, degradation and other effects were found in the tests. The electromagnetic energy coupling path of the broad-spec-trum high-power microwave radiation was determined by adjusting the test status of UAV datalink as well as by protecting its key parts. The radio frequency front end, power cable and terminal interfaces on the housing surface were found to be weak electromagnetic links. The methods of the protection of radio frequency front end and power cable against strong EMPs were proposed. In addition, protection effects obtained by using different protection modules of radio frequency front end as well as by apply-ing power spike pulse suppressors were compared and validated.

Abstract: . Honey adulteration is common in the food industry as it provides a cheaper alternative for the user to con-sume honey. However, it has been abused by industry runners with unsavory practices. As a result, it leads to busi-ness fraudulency. Pure honey is very precious due to its powerful health-giving properties. It raises the attention of beekeepers, wholesalers, food manufacturers, retailers, and consumers because this issue has been sensationally reported in mass media. Enforcement of the law is initiated to mitigate the abuse and fraudulency. It also motivates scientists, technologists, and engineers to strive for an effective solution. The microwave sensing method is well known in agricultural products and food. Hence, dielectric and reflection responses are explored to study the potential of the development of an instrumentation system for gaug-ing edible honey. In this work, the dielectric and reflection measurement was conducted using Agilent E8362B PNA Network Analyzer in conjunction with Agilent 85070E Performance Probe from 0.5 GHz to 4.5 GHz. Dielectric and reflection measurements were conducted to investigate dielectric behavior and mismatch impedance due to water and sucrose content in honey. It can be noticed that the dielectric constant, ε ', decreases as frequency increases. In the meantime, ε ' decreases with the decrement of water and the increment of sucrose content for Honey Gold and Trigona Honey. Meanwhile, for water adulterated Honey Gold and Trigona Honey, the loss factor, ε " decreases when frequencies increase. In addition, ε " decreases when the water content is < 36% and < 43% for Honey Gold and Trigona Honey, respectively. It can be found that at 1 GHz to 4 GHz, ε " increases when sucrose content increases which is applicable for Honey Gold and Trigona Honey. In reflection measurement, the magnitude of reflection coefficient, | Γ | decreases when frequency increases for all percentage of water and sucrose content for both kinds of honey. Withal, phase, – φ increases as frequency increases for water adulterated honey. – φ varies insignificantly when sucrose content increases for sucrose adulterated honey.

Abstract: With the development of the fifth generation (5G) wireless networks, the dense, heterogeneous and irregular network architecture puts forward higher requirements for inter-cell interference coordination (ICIC) technology. How to combine the existing technology to suppress inter-cell interference has become a focus worthy of research. This paper proposes a novel ICIC scheme that combines three-dimensional (3D) multi-level soft frequency reuse (ML-SFR) and coordinated multi-point (CoMP) transmission technology. Based on the scheme, a model of ML-SFR and CoMP is built for different scenarios. Finally, the information rates of users at the cell edge and the entire cell are analyzed through simulation, respectively. The results show that the proposed scheme is superior to the traditional anti-interference technology in suppressing inter-cell interference. The proposed scheme can effectively improve the transmission performance of the 5G wireless networks.