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RISS 인기검색어
- 검색키워드
- 저자 : Ning Han(한저) (검색결과 5 건)
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A Spectral Correlation Based Detection Method for Spectrum Sensing in Cognitive Radio
한저,송정익,손성환,김재명,Han Ning,Song Jeong-Ig,Sohn Sung-Hwan,Kim Jae-Moung The Korea Institute of Information and Commucation 2006 韓國通信學會論文誌 Vol.31 No.7C
Cognitive radio, which is designed to dynamically adapt its transmission to the environments, is believed to be one of the fundamental techniques for future spectrum utilization. As the first step of cognitive radio, spectrum sensing is treated as the most important technique, through which cognition is well explained. In this paper, we propose a spectral correlation based detection method for spectrum sensing. An unlicensed secondary user system operating in TV broadcast bands is taken as an example. Based on the cyclostationarity of communication signals, spectral correlation function is used to minimize the effect of random noise and interference. Energy measurement and peak detection based criteria are proposed. Simulation results show that the proposed detection method outperforms the energy detection and is more suitable for spectrum sensing in cognitive radios.
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An Enhanced Energy Detector for WRAN Systems Using Maximum-to-Mean Power Ratio
정관파,한저,손성환,김재명,Zheng, Guanbo,Han, Ning,Sohn, Sung-Hwan,Kim, Jae-Moung The Korea Institute of Information and Commucation 2008 韓國通信學會論文誌 Vol.33 No.4A
Spectrum sensing is the key challenge in implementing cognitive radio system, which enables unlicensed users to identify "white holes" in the spectrum allocated to primary users and utilize them efficiently. Recent studies have proposed three major sensing methods for WRAN systems, including matched filter, energy and feature detector. However, there are some drawbacks along with them. In this paper, we propose an enhanced energy detector that extends the ability of conventional one, which can differentiate the primary users from each other as well as the noise with different maximum-to-mean power ratio. Furthermore, a novel structure of cognitive radio detector employing the proposed algorithm is also analyzed to implement spectrum sensing. The simulation result shows that our proposed scheme performs well in the individual sensing environment and can satisfy the requirement with high detection probability.
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An Efficient Weighted-Collaborative Sensing Scheme in Cognitive Radio
황효가,한저,정관파,손성환,김재명,Huang, Xiaoge,Han, Ning,Zheng, Guanbo,Sohn, Sung-Hwan,Kim, Jae-Moung The Korea Institute of Information and Commucation 2007 韓國通信學會論文誌 Vol.32 No.10A
Cognitive Radio is an advanced enabling techlology for efficient utilization of under-utilized spectrum since it is able to sense the temporally available spectrum and adapt its parameters to fully utilize the frequency band. Recent investigation suggests that spectrum sensing is compromised when a cognitive radio user suffers from the environment with fading or shadowing. In order to combat the effect, collaborative sensing is considered to be a promising way, which combines the sensing result of each user to achieve good performance. However, the conventional collaborative sensing is not efficient when users suffer different fading environments. In this paper, we propose a weighted-collaborative scheme that considers using the weights of each collaborative CR user, which can achieve better sensing performance under both fast and slow fading environments. The analysis of the simulation resultsproves that the weighted-collaborative scheme improves sensing performance obviously and outperforms the conventional method.
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A Novel Detection Method of the Satellite Phone Signal based on Array Antennas
김윤봉,송정익,한저,김재명,Kim, Yun-Bong,Song, Jeong-Ig,Ning, Han,Kim, Jae-Moung Korea Society of Satellite Technology 2007 한국위성정보통신학회논문지 Vol.2 No.2
위성통신시스템은 넓은 커버리지를 바탕으로 광범위한 지역에 통신을 가능하게 하는 장점을 가지고 있다. 그러나 위성통신 시스템에 할당된 주파수 대역의 사용률은 셀룰러 시스템과 같은 다른 무선통신시스템과 비교할 때 상당히 낮은 효율을 보인다. 그러므로 할당된 주파수를 이용하여 부가적인 서비스를 제공하고, 주파수 효율을 높이기 위한 방법들이 연구되고 있다. 본 논문에서는 허가 대역에서 새로운 서비스를 적용할 수 있는지에 관하여 분석해보고, 새로운 서비스를 적용하기 위하여 가장 중요한 부분인 위성 터미널의 신호를 정확하게 검출하는 방법을 제안한다. 제안하는 방법은 간섭을 회피하기 위하여 Spectrum Sensing과 Eigenvalue 검출하고, 결론을 통하여 터미널의 신호를 검출하고 성능을 분석한다. The Satellite Mobile Communication System holds several advantages, such as wide coverage that guarantees the communication in a huge area. It is suitable in the ocean and forest and especially in emergency situation. However, the licensed frequency is not always occupied within all coverage and all the time. The actual utilization rate is relatively low compared to other wireless communications such as cellular systems. There are a large amount of white spaces in its coverage. Therefore, it is necessary to consider introducing additional services such as data communication, in order to increase the spectrum utilization as well as the revenue of the Satellite service provider. In this paper, we first analyze the possibility to implement new services in the licensed band of satellite mobile phone by its provider. Then we address the most significant issue for the implementation of current service, which is how to accurately detect the satellite mobile terminals. Finally, we suggest two new possible solutions namely, eigenvalue detection based methods to find out the existence of transmitted signal from the satellite mobile terminals.
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An Enhanced Energy Detector for WRAN Systems Using Maximum-to-Mean Power Ratio
Guanbo Zheng(정관파),Ning Han(한저),Sunghwan Sohn(손성환),Jaemoung Kim(김재명) 한국통신학회 2008 韓國通信學會論文誌 Vol.33 No.4A
Spectrum sensing is the key challenge in implementing cognitive radio system, which enables unlicensed users to identify “white holes” in the spectrum allocated to primary users and utilize them efficiently. Recent studies have proposed three major sensing methods for WRAN systems, including matched filter, energy and feature detector. However, there are some drawbacks along with them. In this paper, we propose an enhanced energy detector that extends the ability of conventional one, which can differentiate the primary users from each other as well as the noise with different maximum-to-mean power ratio. Furthermore, a novel structure of cognitive radio detector employing the proposed algorithm is also analyzed to implement spectrum sensing. The simulation result shows that our proposed scheme performs well in the individual sensing environment and can satisfy the requirement with high detection probability.
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