• Title/Summary/Keyword: Signal Detection Probability

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A Method to enhance the Performance of Spectrum Sensing Under a Random Traffic of Primary User (1차 사용자의 랜덤 트래픽하에서 스펙트럼 센싱의 성능을 향상시키기 위한 방법)

  • Kong, Hyung-Yun
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.13 no.6
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    • pp.87-92
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    • 2013
  • This paper focuses on analyzing the effects of primary user (PU) signal arrival on the local spectrum sensing performance. The probability for signal arrival at a sample in the sensing time is uniformly distributed in the sensing time. We first analyze the main factor that causes the degradation in the detection results in the conventional energy detection (CED) under the uniformly random arrival of the PU-signal. Thus we propose an approach in order to enhance the detection performance, in which an estimator which detects the arrival of the PU signal cooperates with a composite energy detection. The mathematical analysis and numerical simulation has validated the outperformance of the proposed approach compared to the CED.

Adaptive Energy Detection for Spectrum Sensing in Cognitive Radio (인지 무선 시스템에서 스펙트럼 감지를 위한 적응 에너지 검파)

  • Lim, Chang-Heon
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.47 no.8
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    • pp.42-46
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    • 2010
  • Energy detection based spectrum sensing compares the energy of a received signal from a primary user with a detection threshold and decides whether it is active or not in the frequency band of interest. Here the detection threshold depends on not only a target false alarm probability but also the level of the noise energy in the band. So, if the noise energy changes, the detection threshold must be adjusted accordingly to maintain the given false alarm probability. Most previous works on energy detection for spectrum sensing are based on the assumption that noise energy is known a priori. In this paper, we present a new energy detection scheme updating its detection threshold under the assumption that the noise is white, and analyze its detection performance. Analytic results show that the proposed scheme can maintain a target false alarm rate without regard to the noise energy level and its spectrum sensing performance gets better as the time bandwidth product of the signal used to estimate the noise energy increases.

The Study of CFAR(Constant False Alarm Rate) process for a helicopter mounted millimeter wave radar system

  • Kim In Kyu;Moon Sang Man;Kim Hyoun Kyoung;Lee Sang Jong;Kim Tae Sik;Lee Hae Chang
    • Proceedings of the IEEK Conference
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    • 2004.08c
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    • pp.890-895
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    • 2004
  • This paper describes constant alarm rates process of millimeter wave radar that exits on non-stationary target detection schemes in the ground clutter conditions. The comparison of various CFAR processes such as CA(Cell-Average)-CFAR, GO(Greatest Of)/SO(Smallest Of)-CFAR and OS(Order Statistics)-CFAR performance are applied. Using matlab software, we show the performance and loss between detection probability and signal to noise ratio. When rang bins increase, this results show the OS-CFAR process performance is better than any others and satisfies the optimal detection probability without loss of detection in the homogeneous clutter.

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A Study on Watermark Technique for Copyright Protection of Digital Images (디지털 영상물의 저작권 보호를 위한 워터마크 기술에 관한 연구)

  • Hong, Min-Suk;Park, Kang-Seo;Chung, Tae-Yun;Shin, Joon-In;Park, Sang-Hui
    • Proceedings of the KIEE Conference
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    • 1998.11b
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    • pp.606-608
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    • 1998
  • Digital watermarking is the technique which embeds the invisible signal into multimedia data such as audio, video, images, for copyright protection, including owner identification and copy control information. In this paper, a new watermark detection algorithm by local masking cross covariance between watermarked signal and pseudo noise signal is proposed. The proposed algorithm enhances the detection probability for embedding information. Since reducing detection errors for the weak embedding signals, the algorithm improves the image quality and robusts against illegal attack to delete the embedding information and data compression applications such as JPEG and MPEGs.

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Rake-Based Cellular Radar Receiver Design for Moving Target Detection in Multipath Channel

  • Kim, Yeejung;Jeong, Myungdeuk;Han, Youngnam
    • ETRI Journal
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    • v.36 no.5
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    • pp.799-807
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    • 2014
  • In this paper, we design a rake-based cellular radar receiver (CRR) scheme to detect a moving target located in a multipath environment. The modules of Doppler filter banks, threshold level test, and target detection module are newly introduced into the conventional rake receiver so that it can function as a radar system. The proposed CRR tests the Doppler-shift frequency and signal-to-noise ratio of the received signal against predefined threshold levels to determine detection and then calculates target velocities and ranges. The system performance is evaluated in terms of detection probability and the maximum detection range under a Nakagami-n channel that reflects the multipath environment.

Bayesian Onset Measure of sEMG for Fall Prediction (베이지안 기반의 근전도 발화 측정을 이용한 낙상의 예측)

  • Seongsik Park;Keehoon Kim
    • The Journal of Korea Robotics Society
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    • v.19 no.2
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    • pp.213-220
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    • 2024
  • Fall detection and prevention technologies play a pivotal role in ensuring the well-being of individuals, particularly those living independently, where falls can result in severe consequences. This paper addresses the challenge of accurate and quick fall detection by proposing a Bayesian probability-based measure applied to surface electromyography (sEMG) signals. The proposed algorithm based on a Bayesian filter that divides the sEMG signal into transient and steady states. The ratio of posterior probabilities, considering the inclusion or exclusion of the transient state, serves as a scale to gauge the dominance of the transient state in the current signal. Experimental results demonstrate that this approach enhances the accuracy and expedites the detection time compared to existing methods. The study suggests broader applications beyond fall detection, anticipating future research in diverse human-robot interface benefiting from the proposed methodology.

Prior Maximum Likelihood Detection Verifier Design in MIMO Receivers (MIMO 수신기에서 사전 Maximum Likelihood 검파 검증기 설계)

  • Jeon, Hyoung-Goo;Bae, Jin-Ho;Lee, Dong-Hoon
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.33 no.11A
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    • pp.1063-1071
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    • 2008
  • This paper proposes a prior maximum likelihood (ML) detection verifier which has an ability to verify if the zero forcing (ZF) detection results are identical to the ML detection results. Since more than 90% of ZF detection results are identical to ML detection results, the proposed verifier makes it possible to omit the computationally complex ML detection in 90% cases of MIMO signal detections. The proposed verifier is designed by using the diversity gain obtained from converting MIMO signal into single input multiple output (SIMO) signals. In the proposed method, single input multiple output (SIMO) signals for each transmit antenna are separated from MIMO signals after the MIMO signals are detected by ZF method. Computer simulations show that the true alarm probability of the proposed verifier is more than 80% and the false alarm probability is less than $10^{-4}$.

The Performance Analysis of the Initial Synchronization for the Direct Sequence Spread Spectrum Communication under the Rician Fading Channel (Rician Fading Channel에서의 직접대역확산통신용 초기동기 성능분석)

  • Lim, Myoung-Seob
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.9 no.1
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    • pp.43-51
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    • 1998
  • In this paper, the performance about the CDMA inital synchronization under the Rician fading channel, which is actively studied as a CAI for IMT2000(FPLMTS) is analyzed. Through the performance analysis with the double dwell serial search code acquisition, the minimum mean initial synchronization acquisition time vs signal detection threshold value and first dwell duration time respectively with parameters of false alarm probability, detection probability and test PN chips is presented and the results show the mean initial synchronization acquisition time is increased with lower slope than Rayleigh fading as the threshold value of the initial synchronization acquisition decision is increased.

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A Study on the Performance Analysis of Sidelobe Blanker using Matrix Pencil Method (Matrix Pencil Method 기반의 부엽차단기 성능분석 연구)

  • Yeo, Min-Young;Lee, Kang-In;Yang, Hoon-Gee;Park, Gyu-Churl;Chung, Young-Seek
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.66 no.8
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    • pp.1242-1249
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    • 2017
  • In this paper, we propose a new algorithm for the performance analysis of the sidelobe blanker (SLB) in radar system, which is based on the matrix pencil method (MPM). In general, the SLB in radar is composed of the main antenna, the auxiliary antenna, and the processing unit. The auxiliary antenna with wide beamwidth receives interference signals such as jamming or clutter signals. The main antenna with high gain receives the target signal in the main beam and the interference signals in the sidelobe. In this paper the Swerling model is used as the target echo signal by considering a probabilistic radar cross section (RCS) of the target. To estimate the SLB performance it needs to calculate the probability of target detection and the probability of blanking the interference by using the signals received from the main and auxiliary antennas. The detection probability and the blanking probability include multiple summations of infinite series with infinite integrations, of which convergence rate is very slow. Increase of summation range to improve the calculation accuracy may lead to an overflow error in computer simulations. In this paper, to resolve the above problems, we used the MPM to calculate a summation of infinite series and improved the calculation accuracy and the convergence rate.

Performance Analysis of a CE-CPSK modulated code acquisition system for nonlinear amplified DS-CDMA signal (비선형 전력증폭기로 인한 CE-CPSK 변조된 DS-CDMA 초기동기 시스템의 성능분석)

  • Kim Seong-Cheol
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.10 no.1
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    • pp.49-56
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    • 2006
  • In this paper, to overcome the effect of nonlinear power amplifier, CE-CPSK(Constant Envelope Continuous Phase Shift Keying)modulation method which has the constant envelope and continuous phase characteristics is proposed. The code acquisition performances of the CE-CPSK modulated system and BPSK system are analyzed. And the performance is evaluated in terms of mean acquisition time and detection probability with the output backoff of the amplifier in multiuser environment. Results performed in a channel having a high degree of AM nonlinearity(AM-to-AM conversion), have shown that the CE-CPSK signal, when passed through class C-nonlinear Amplifier, has a spectrum with greatly reduced sidelobes compared to the conventional BPSK signal. The code acquisition performance of a CE-CPSK modulation system is better than that of BPSK system with nonlinear amplified multiuser environments.