An innovative detection method of high frequency BPSK signal with low signal-to-noise ratio

Based on chaotic oscillator system, this paper proposes a novel method on high frequency low signal- to-noise ratio BPSK（ Binary Phase Shift Keying） signal detection. Chaotic oscillator system is a typical non-lin- ear system which is sensitive to periodic signals and immune to noise at the same time. Those properties make it possible to detect low signal-to-noise ratio signals. The BPSK signal is a common signal type which is widely used in modern communication. Starting from the analysis of advantages of chaotic, os~.illator system and signal features of the BPSK signal, we put forward a unique method that can detect low signar-to-noise ratio BPSK sig- nals with high frequency. The simulation results show that the novel method can dclct.t low signal-to-noise ratio BPSK signals with frequency in an order of magnitude of l0s Hz, and the input Signal-to-Noise Ratio threshold can be -20 dB.

Novel Metrics for Mutation Analysis

A measure of the“goodness”or efficiency of the test suite is used to determine the proficiency of a test suite.The appropriateness of the test suite is determined through mutation analysis.Several Finite State Machine(FSM)mutants are produced in mutation analysis by injecting errors against hypotheses.These mutants serve as test subjects for the test suite(TS).The effectiveness of the test suite is proportional to the number of eliminated mutants.The most effective test suite is the one that removes the most significant number of mutants at the optimal time.It is difficult to determine the fault detection ratio of the system.Because it is difficult to identify the system’s potential flaws precisely.In mutation testing,the Fault Detection Ratio(FDR)metric is currently used to express the adequacy of a test suite.However,there are some issues with this metric.If both test suites have the same defect detection rate,the smaller of the two tests is preferred.The test case(TC)is affected by the same issue.The smaller two test cases with identical performance are assumed to have superior performance.Another difficulty involves time.The performance of numerous vehicles claiming to have a perfect mutant capture time is problematic.Our study developed three metrics to address these issues:FDR/|TS|,FDR/|TC|,and FDR/|Time|;In this context,most used test generation tools were examined and tested using the developed metrics.Thanks to the metrics we have developed,the research contributes to eliminating the problems related to performance measurement by integrating the missing parameters into the system.

A Survey on Low Complexity Detectors for OTFS Systems

The newly emerging orthogonal time frequency space(OTFS)modulation can ob⁃tain delay-Doppler diversity gain to significantly improve the system performance in high mobility wireless communication scenarios such as vehicle-to-everything(V2X),high-speed railway and unmanned aerial vehicles(UAV),by employing inverse symplectic finite Fouri⁃er transform(ISFFT)and symplectic finite Fourier transform(SFFT).However,OTFS modu⁃lation will dramatically increase system complexity,especially at the receiver side.Thus,de⁃signing low complexity OTFS receiver is a key issue for OTFS modulation to be adopted by new-generation wireless communication systems.In this paper,we review low complexity OTFS detectors and provide some insights on future researches.We firstly present the OTFS system model and basic principles,followed by an overview of OTFS detector structures,classifications and comparative discussion.We also survey the principles of OTFS detection algorithms.Furthermore,we discuss the design of hybrid OTFS and orthogonal frequency di⁃vision multiplexing(OFDM)detectors in single user and multi-user multi-waveform commu⁃nication systems.Finally,we address the main challenges in designing low complexity OT⁃FS detectors and identify some future research directions.

Efficient Data Integrity Using Enhanced Secret Sharing Scheme for MANET

Mobile Ad Hoc Networks consist of nodes which are wireless and get organized based on the transmission requirement. These nodes are mobile nodes, so they communicate with each other without any fixed access point. This type of network faces several attacks because of its mobility nature. In MANET, black hole attacks may cause packet dropping or misrouting of packets during transmission from sender to receiver. This may lead to performance degradation in the network. To surmount this issue, we propose the modified secret sharing scheme to provide the data protection from unauthorized nodes, consistency of data and genuineness. In this algorithm, initially the identification of black hole attacks is achieved and followed by data protection from malicious nodes and also this scheme checks for the reality of the data. Here, we detect the misbehaviour that is dropping or misrouting using verifiable secret sharing scheme. The proposed algorithm achieves the better packet delivery ratio, misbehaviour detection efficiency, fewer packets overhead and end-to-end delay than the existing schemes. These can be viewed in the simulation results.

Weight sequential log-likelihood ratio detect algorithm with malicious users removing

Due to the openness of the cognitive radio network, spectrum sensing data falsification （SSDF） can attack the spectrum sensing easily, while there is no effective algorithm proposed in current research work, so this paper introduces the malicious users removing to the weight sequential probability radio test （WSPRT）. The terminals＇ weight is weighted by the accuracy of their spectrum sensing information, which can also be used to detect the malicious user. If one terminal owns a low weight, it can be treated as malicious user, and should be removed from the aggregation center. Simulation results show that the improved WSPRT can achieve higher performance compared with the other two conventional sequential detection methods under different number of malicious users.

A study of the strong pulses detected from PSR B0656+14 using the Urumqi 25-m radio telescope at 1540 MHz

We report on the properties of strong pulses from PSR B0656＋14 by analyzing the data obtained using the Urumqi 25-m radio telescope at 1540 MHz from August 2007 to September 2010.In 44 h of observational data,a total of 67 pulses with signal-to-noise ratios above a 5σthreshold were detected.The peak flux densities of these pulses are 58 to 194 times that of the average profile,and their pulse energies are 3 to 68 times that of the average pulse.These pulses are clustered around phases about 5-ahead of the peak of the average profile.Compared with the width of the average profile,they are relatively narrow,with the full widths at half-maximum ranging from 0.28 ° to 1.78 °.The distribution of pulse-energies follows a lognormal distribution.These sporadic strong pulses detected from PSR B0656＋14 have different characteristics from both typical giant pulses and its regular pulses.