Smoothed Global Soft Decision에 근거한 음성 향상 기법

조규행(Q-Haing Jo),박윤식(Yun-Sik Park),장준혁(Joon-Hyuk Chang) 대한전자공학회 2007 電子工學會論文誌-SP (Signal processing) Vol.44 No.6

본 논문에서는 잡음 환경에서의 음성 향상을 위해 향상된 Global Soft Decision (GSD) 기법을 제안한다. 통계적 모델을 바탕으로 한 음성 향상과 관련한 연구에서 GSD는 음성의 꼬리 부분에서 취약하다고 알려져 있으며, 이를 개선하기 위해 Smoothed Global Likelihood Ratio (SGLR)를 바탕으로 한 새로운 음성 향상 기법을 GSD에 적용한다. 제안된 방법은 다양한 잡음 환경에서 MOS 실험을 바탕으로 기존의 연구와 비교하였으며 우수한 성능을 보여주었다. In this paper, we propose an improved global soft decision for speech enhancement in noise environments. From an examination of statistical model-based speech enhancement, it is shown that the global soft decision has a fundamental drawback at the offset region of speech signals. To overcome the drawback, we apply a new speech enhancement method based on a smoothed Global likelihood ratio to the global soft decision. Performances of the proposed method are evaluated by subjective tests under various environments and yield better results compared with the reported speech enhancement method.

음성 부재 확률을 이용한 음성 강화 이득 수정 기법

최재훈(Jae-Hun Choi),장준혁(Joon-Hyuk Chang) 大韓電子工學會 2010 電子工學會論文誌-SP (Signal processing) Vol.47 No.1

본 논문에서는 배경 잡음 환경에서 배경 잡음에 의해 저하된 음성 신호의 명료도를 soft decision 기반의 음성 부재 확률을 이용하여 음성 강화 이득을 수정함으로써 음성의 명료도를 보다 향상시키는 기법을 제안한다. 배경 잡음 환경에서 저하된 음성의 명료도를 향상시키기 위한 기존의 음성 강화 기법으로써 soft decision을 이용하여 오염된 음성 신호로부터 깨끗한 음성신호만 증폭시키는 알고리즘이 제안되었다. 기존의 음성 강화 기법 보다 음성 구간과 비음성 구간 및 전이 구간에서 강인한 음성 강화 이득을 추정하기 위하여 soft decision 기반의 음성 부재 확률 (Speech Absence Probability)을 음성 강화 이득에 통합한 음성 강화 이득 수정 알고리즘을 제안한다. 제안된 음성 강화 기법의 성능은 다양한 배경 잡음 환경에서 ITU-T P.800의 주관적인 음질 측정 방법인 (Comparison Category Rating) 테스트에 의해서 평가되었으며, 기존의 음성 강화 기법과 비교하여 향상된 성능을 보여주었다. In this paper, we propose a robust speech reinforcement technique to enhance the intelligibility of the degraded speech signal under the ambient noise environments based on soft decision scheme incorporating a speech absence probability (SAP) with speech reinforcement gains. Since the ambient noise significantly decreases the intelligibility of the speech signal, the speech reinforcement approach to amplify the estimated clean speech signal from the background noise environments for improving the intelligibility and clarity of the corrupted speech signal was proposed. In order to estimate the robust reinforcement gain rather than the conventional speech reinforcement method between speech active periods and nonspeech periods or transient intervals, we propose the speech reinforcement algorithm based on soft decision applying the SAP to the estimation of speech reinforcement gains. The performances of the proposed algorithm are evaluated by the Comparison Category Rating (CCR) of the measurement for subjective determination of transmission quality in ITU-T P.800 under various ambient noise environments and show better performances compared with the conventional method.

Low-Complexity Non-Iterative Soft-Decision BCH Decoder Architecture for WBAN Applications

Boseok Jung,Taesung Kim,Hanho Lee 대한전자공학회 2016 Journal of semiconductor technology and science Vol.16 No.4

This paper presents a low-complexity non-iterative soft-decision Bose-Chaudhuri-Hocquenghem (SD-BCH) decoder architecture and design technique for wireless body area networks (WBANs). A SDBCH decoder with test syndrome computation, a syndrome calculator, Chien search and metric check, and error location decision is proposed. The proposed SD-BCH decoder not only uses test syndromes, but also does not have an iteration process. The proposed SD-BCH decoder provides a 0.75~1 ㏈ coding gain compared to a hard-decision BCH (HD-BCH) decoder, and almost similar coding gain compared to a conventional SD-BCH decoder. The proposed SD-BCH (63, 51) decoder was designed and implemented using 90-㎚ CMOS standard cell technology. Synthesis results show that the proposed non-iterative SD-BCH decoder using a serial structure can lead to a 75% reduction in hardware complexity and a clock speed 3.8 times faster than a conventional SD-BCH decoder.

무선 인지 시스템에서 협력 스펙트럼 센싱을 위한 최적화된 경판정 방식

이소영(So Young Lee),김진영(Jin Young Kim) 한국전자파학회 2011 한국전자파학회논문지 Vol.22 No.4

본 논문에서는 개별 센싱 결과를 결합하기 위해 센싱의 성능은 연판정 방식보다 낮지만, 시스템의 부담이 적고 비교적 단순한 방식인 경판정 방식을 적용하였으며, 센싱의 성능을 높이기 위해 각 CR 기기의 검출 확률을 반영하여 가중치를 설정하고, 계산된 가중치가 개별 센싱 결과에 재반영되어 결합하는 최적화된 경판정 방식을 제안한다. 기존의 경판정 방식과 달리 가중치를 적용하여 센싱 성능을 높이도록 하였고, 모의 실험 및 분석을 통하여 성능을 나타내었다. 1차 사용자의 신호는 OFDM 기반의 시스템을 가정하였고, 1차 사용자와 CR 기기 사이의 무선 채널은 가우시안(Gaussian) 채널로 모델링하였다. In this paper, we use hard decision method for cooperative spectrum sensing. Sensing performance adopting hard decision is lower than soft decision but system load is low and the process is relatively simple when the combining scheme is hard decision compared to soft decision. In order to improve sensing performance, we propose optimal hard decision method applying weight that is based on a probability of individual sensing. Unlike conventional hard decision, we try to improve sensing performance applying weight and show the performance of the proposed method from the simulation results and performance analysis. The signal of licensed user is OFDM signal and the wireless channel between a licensed user and CR systems is modeled as Gaussian channel.

Soft-Decision-and-Forward Protocol for Cooperative Communication Networks with Multiple Antennas

Yang, Jae-Dong,Song, Kyoung-Young,No, Jong-Seon,Shin, Dong-Joan The Korea Institute of Information and Commucation 2011 Journal of communications and networks Vol.13 No.3

In this paper, a cooperative relaying protocol called soft-decision-and-forward (SDF) with multiple antennas in each node is introduced. SDF protocol exploits the soft decision source symbol values from the received signal at the relay node. For orthogonal transmission (OT), orthogonal codes including Alamouti code are used and for non-orthogonal transmission (NT), distributed space-time codes are designed by using a quasi-orthogonal space-time block code. The optimal maximum likelihood (ML) decoders for the proposed protocol with low decoding complexity are proposed. For OT, the ML decoders are derived as symbolwise decoders while for NT, the ML decoders are derived as pairwise decoders. It can be seen through simulations that SDF protocol outperforms AF protocol for both OT and NT.

Soft-Decision-and-Forward Protocol for Cooperative Communication Networks with Multiple Antennas

양재동,송경영,노종선,신동준 한국통신학회 2011 Journal of communications and networks Vol.13 No.3

In this paper, a cooperative relaying protocol called soft-decision-and-forward (SDF) with multiple antennas in each node is introduced. SDF protocol exploits the soft decision source symbol values from the received signal at the relay node. For orthogonal transmission (OT), orthogonal codes including Alamouti code are used and for non-orthogonal transmission (NT), distributed space-time codes are designed by using a quasi-orthogonal space-time block code. The optimal maximum likelihood (ML) decoders for the proposed protocolwith low decoding complexity are proposed. For OT, the ML decoders are derived as symbolwise decoders while for NT, the ML decoders are derived as pairwise decoders. It can be seen through simulations that SDF protocol outperforms AF protocol for both OT and NT.

NEW APPROACHES OF INVERSE SOFT ROUGH SETS AND THEIR APPLICATIONS IN A DECISION MAKING PROBLEM

DEMIRTAS, NAIME,HUSSAIN, SABIR,DALKILIC, ORHAN The Korean Society for Computational and Applied M 2020 Journal of applied mathematics & informatics Vol.38 No.3

We present inverse soft rough sets by using inverse soft sets and soft rough sets. We study different approaches for inverse soft rough set and examine the relationships between them. We also discuss and explore the basic properties for these approaches. Moreover we develop an algorithm following these concepts and apply it to a decision-making problem to demonstrate the applicability of the proposed methods.

New Approaches of Inverse Soft Rough Sets and their Applications in a Decision Making Problem

Naime Demirtas,Sabir Hussain,Orhan Dalkilic 한국전산응용수학회 2020 Journal of applied mathematics & informatics Vol.38 No.3

We present inverse soft rough sets by using inverse soft sets and soft rough sets. We study different approaches for inverse soft rough set and examine the relationships between them. We also discuss and explore the basic properties for these approaches. Moreover we develop an algorithm following these concepts and apply it to a decision-making problem to demonstrate the applicability of the proposed methods.

Low-Complexity Non-Iterative Soft-Decision BCH Decoder Architecture for WBAN Applications

Jung, Boseok,Kim, Taesung,Lee, Hanho The Institute of Electronics and Information Engin 2016 Journal of semiconductor technology and science Vol.16 No.4

This paper presents a low-complexity non-iterative soft-decision Bose-Chaudhuri-Hocquenghem (SD-BCH) decoder architecture and design technique for wireless body area networks (WBANs). A SD-BCH decoder with test syndrome computation, a syndrome calculator, Chien search and metric check, and error location decision is proposed. The proposed SD-BCH decoder not only uses test syndromes, but also does not have an iteration process. The proposed SD-BCH decoder provides a 0.75~1 dB coding gain compared to a hard-decision BCH (HD-BCH) decoder, and almost similar coding gain compared to a conventional SD-BCH decoder. The proposed SD-BCH (63, 51) decoder was designed and implemented using 90-nm CMOS standard cell technology. Synthesis results show that the proposed non-iterative SD-BCH decoder using a serial structure can lead to a 75% reduction in hardware complexity and a clock speed 3.8 times faster than a conventional SD-BCH decoder.

Supporting Trusted Soft Decision Scheme Using Volatility Decay in Cooperative Spectrum Sensing

( Feng Zhao ),( Jingyu Feng ) 한국인터넷정보학회 2016 KSII Transactions on Internet and Information Syst Vol.10 No.5

Cooperative spectrum sensing (CSS) for vacant licensed bands is one of the key techniques in cognitive radio networks. Currently, sequential probability ratio test scheme (SPRT) is considered as a powerful soft decision approach to improve the sensing result for CSS. However, SPRT assumes all secondary users (SU) are honest, and thus offering opportunities for malicious SUs to launch the spectrum sensing data falsification attack (SSDF attack). To combat such misbehaved behaviors, recent efforts have been made to trust mechanism. In this paper, we argue that powering SPRT with traditional trust mechanism is not enough. Dynamic SSDF attackers can maintain high trust in an alternant process of submitting honest or false sensing data, resulting in difficultly detecting them. Noting that the trust value of dymamic SSDF attackers behave highly volatile, a novel trusted SPRT scheme (VSPRT) based on volatility decay analysis is proposed in this paper to mitigate the harmful effect of dynamic SSDF attackers in the process of the soft-decision data fusion, and thus improving the accuracy of the final sensing result. Simulation results show that the VSPRT scheme outperforms the conventional SPRT schemes.