2022/3

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Dual Band Microstrip Semicircular Slot Patch Antenna for WLAN and WIMAX Applications
(Společnost pro radioelektronické inženýrství, 2022-09) Mushtaq, M. T.; Shah, S. M. A.; Munir, S.; Hussain, M.; Iqbal, J.; Khan, U. H.
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 Surface (DGS) technique for the improvement 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 x 26.6 mm2. The fabricated antenna provides a good reflection coefficient of -48dB and -44.5dB at a center frequency of 3.4GHz and 5.5GHz. Gain achieved by the antenna is 2.72dB and 3.87dB 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.
Low Latency SC Decoder Architecture for Interleaved Polar Codes
(Společnost pro radioelektronické inženýrství, 2022-09) Jali, N.; Muralidhar, P.; Patri, S. R.
Interleaved polar (I-Polar) codes, a new facet of polar codes to achieve better channel capacity, is designed by placing the interleaver and deinterleaver blocks midway between the stages of the polar codes. Low latency hardware optimization makes their implementation even more suitable for ultra-reliable low latency applications. This study proposes an optimal hardware design for low latency interleaved polar codes by reframing the last stage of the interleaved successive cancellation decoder. A high-speed adder-subtractor is used to reduce the latency further, thus increasing the speed of operation. Interleaving data in the proposed polar codes augment BER performance compared to conventional (n, k) polar codes. The proposed I-Polar codes are synthesized using Synopsys design compiler (SDC) in CMOS 65-nm technology. Results show that the latency is reduced by 50.5% on average compared to the conventional polar codes as high-speed adder and merged processing elements are used. Moreover, the average gate count and power are reduced by 14% and 40.56%, respectively.
An EMC Susceptibility Study of Integrated Basic Bandgap Voltage Reference Cores
(Společnost pro radioelektronické inženýrství, 2022-09) Krolak, D.; Horsky, P.
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.
Energy Efficiency Optimization for D2D Underlay Communication in Distributed Antenna System over Composite Fading Channels
(Společnost pro radioelektronické inženýrství, 2022-09) Wang, G. Y.; Dhaka, A.; Teng, T.; Yu, K.
Device-to-Device (D2D) communication is a potential technology to improve the spectral and energy efficiency (EE) of communication networks. In this paper, we study energy-efficient power allocation (PA) schemes in uplink distributed antenna system (DAS) with device-to-device underlay communication. Our goal is to maximize the total EE of all D2D pairs while guaranteeing the data rate and transmit power requirements of the cellular user and D2D links. To solve this non-convex constrained optimization problem, we propose an energy-efficient near-optimal PA algorithm based on the concave-convex procedure and fractional programming theory. This near-optimal algorithm can achieve the EE performance close to the optimal exhaustive search. To reduce the complexity, we furthermore present an efficient sub-optimal algorithm with the antenna selection method which can obtain the closed-form power allocation expressions. Simulation results demonstrate the significant EE performance of our proposed PA schemes.
Spectrum Map Construction Based on Optimized Sensor Selection and Adaptive Kriging Model
(Společnost pro radioelektronické inženýrství, 2022-09) Ding, Z.; Zhang, J.; Liu, Y.; Wang, J.; Chen, G.; Cao, L.
Spectrum map (SM) is an important tool to reflect the spectrum usage in the electromagnetic environment. To address the problems of low precision and poor efficiency in the SM construction, this paper develops a novel SM construction approach based on the artificial bee colony enabled sensor layout optimization and an adaptive Kriging model based on spatial autocorrelation. Considering the significant autocorrelation between sensor attributes caused by the exponentially decaying shadow fading of signal propagation, the sensor estimation groups are established, and the estimation results are obtained by the Kriging model. The simulation results show that the proposed SM construction scheme can not only effectively reduce the overhead of sensor resources but also obtain a high SM construction accuracy. Extensive simulation results show that the proposed method can reduce the RMSE of SM construction by 37.56%, 25.32% and 12.89% respectively compared with Random-OK when the standard deviation of shadow fading is 1 dB, 3 dB and 6 dB.

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