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This work evaluates the performance of frequency-modulated noise reduction-differential chaos shift keying (FM-NR–DCSK) when using a compound chaotic sequence (CCS) under a multipath fading channel. To construct a more complex and random CCS, the outputs of chaotic maps like the logistic map, tent map, Chebyshev map and Henon map are incorporated. In this scheme, the CCS is first frequency-modulated (FM) to generate a signal with constant energy per bit. This improves the bit error rate (BER) performance of noise reduction-differential chaos shift keying (NR–DCSK). The functionality of the CCS-based FM-NR–DCSK system is being assessed in the presence of both additive white Gaussian noise (AWGN) and alpha–mu (α–µ) fading to determine its efficacy. In conclusion, we analyse the effectiveness of the CCS compared to other existing chaotic maps. [ABSTRACT FROM AUTHOR]

Channel equalisation performs a crucial role in practical wireless communication environment to reduce the consequence of intersymbol interference (ISI), noise and other channel distortions. Different adaptive signal processing algorithms tuned by multiple effective weight update mechanisms have been proposed and verified for designing the channel equaliser. In this paper, a sparse-based reweighted zero attracting incremental least mean square/fourth (ILMS/F) algorithm is anticipated to model an efficient adaptive decision feedback channel equaliser by taking the quadrature amplitude modulation (QAM)-modulated signal as transmitted signal which is passed through a nonlinear channel. The performance of the equaliser based on the proposed sparse-based ILMS/F has been analysed by using software and hardware platforms. The mean square error (MSE) table and bit error rate (BER) plots of the proposed algorithm have been compared with different conventional algorithms using MATLAB simulation and the hardware implementation of the proposed equaliser by using the FPGA platform has been evaluated in this paper. Moreover, the FPGA implementation of the proposed sparse incremental least mean square/fourth (ILMS/F) algorithm validates the robustness of the algorithm. [ABSTRACT FROM AUTHOR]

In the practical continuous-variable quantum key distribution (CV-QKD) system, the postprocessing process, particularly the error correction part, significantly impacts the system performance. Multi-edge type low-density parity-check (MET-LDPC) codes are suitable for CV-QKD systems because of their Shannon-limit-approaching performance at a low signal-to-noise ratio (SNR). However, the process of designing a low-rate MET-LDPC code with good performance is extremely complicated. Thus, we introduce Raptor-like LDPC (RL-LDPC) codes into the CV-QKD system, exhibiting both the rate compatible property of the Raptor code and capacity-approaching performance of MET-LDPC codes. Moreover, this technique can significantly reduce the cost of constructing a new matrix. We design the RL-LDPC matrix with a code rate of 0.02 and easily and effectively adjust this rate from 0.016 to 0.034. Simulation results show that we can achieve more than 98% reconciliation efficiency in a range of code rate variation using only one RL-LDPC code that can support high-speed decoding with an SNR less than −16.45 dB. This code allows the system to maintain a high key extraction rate under various SNRs, paving the way for practical applications of CV-QKD systems with different transmission distances. [ABSTRACT FROM AUTHOR]

The level of electromagnetic radiation (EMR) exposure increases day by day as natural consequences of technological developments. In recent years, the increasing use of cellular systems has made it necessary to measure and evaluate EMR originating from base stations. In this study, broadband and band selective electric field strength (E) measurements were taken at four different times in order to evaluate the change of short term E in Atakum district of Samsun, Turkey. The measurements were collected from 46 different locations using a SRM 3006 and a PMM 8053 EMR meter in a band from 100 kHz to 3 GHz, and the maximum E (Emax) and the average E (Eavg) were recorded. The highest values have been noticed in these measurements at 9.45 V/m and 17.53 V/m for Eavg and Emax respectively. Apart from these measurements, 24 hour long term E measurements were taken at a location where the highest value was observed and analyzed, to observe the change of Es during a day. At the end of the study, a tentative mathematical model that helps in computing the total E of the medium with 95% accuracy, was obtained.

A hybrid-scheduling method, consisting of packing algorithm, genetic algorithm and priority promotion algorithm, was proposed for time-triggered CAN in this paper. We divided the basic cycles (BC) into synchronous phase for transmitting time-triggered messages and asynchronous phase for transmitting event-triggered messages. At the each end of BC, fault-tolerant windows were designed to improve the fault-tolerance. The First Fit Increasing and the genetic algorithm scheduled and optimized the transmission of time-triggered messages in the synchronous phase, and the priority promotion algorithm optimized the transmission of event-triggered messages in the synchronous phase. For the communication application of a TTCAN-based turbofan distributed control system, the new scheduling method improved the bandwidth utilization and arbitrary windows utilization to 99% and 9.3%. [ABSTRACT FROM AUTHOR]