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Spectrum Leasing via Cooperation for Enhanced Physical-Layer Secrecy [article]

Keonkook Lee, Chan-Byoung Chae, Joonhyuk Kang
2012 arXiv   pre-print
Spectrum leasing via cooperation refers to the possibility of primary users leasing a portion of the spectral resources to secondary users in exchange for cooperation. In the presence of an eavesdropper, this correspondence proposes a novel application of this concept in which the secondary cooperation aims at improving secrecy of the primary network by creating more interference to the eavesdropper than to the primary receiver. To generate the interference in a positive way, this work studies
more » ... n optimal design of a beamformer at the secondary transmitter with multiple antennas that maximizes a secrecy rate of the primary network while satisfying a required rate for the secondary network. Moreover, we investigate two scenarios depending upon the operation of the eavesdropper: i) the eavesdropper treats the interference by the secondary transmission as an additive noise (single-user decoding) and ii) the eavesdropper tries to decode and remove the secondary signal (joint decoding). Numerical results confirm that, for a wide range of required secondary rate constraints, the proposed spectrum-leasing strategy increases the secrecy rate of the primary network compared to the case of no spectrum leasing.
arXiv:1205.0085v1 fatcat:c4tepol5tjhtzf3hr3z5ghtkpy

A novel orthogonal space-time-frequency block code for OFDM systems

Keonkook Lee, Youngok Kim, Joonhyuk Kang
2009 IEEE Communications Letters  
Lee and J.  ... 
doi:10.1109/lcomm.2009.090680 fatcat:or4j2kcs5rcjha5nlngkoip3sy

Spectrum Leasing via Cooperation for Enhanced Physical-Layer Secrecy

Keonkook Lee, Chan-Byoung Chae, Joonhyuk Kang
2013 IEEE Transactions on Vehicular Technology  
Spectrum leasing via cooperation refers to the possibility for primary users to lease part of the spectral resources to secondary users in exchange for cooperation. This paper proposes a novel implementation of this concept in which secondary cooperation aims at improving the secrecy of the primary link. In particular, a secondary transmission with multiple antennas creates interference on both primary and eavesdropping receivers but an appropriately designed beamformer may impair more the
more » ... dropper's reception and thus enhance primary secrecy. The optimal design of the secondary beamformer that maximizes the primary secrecy rate while guaranteeing a minimal secondary rate is studied. It is proved that the problem can be solved in a domain that includes only two real numbers irrespective of the number of antennas. Numerical results show that the proposed spectrum leasing strategy increases the primary secrecy rate compared to the case of no spectrum leasing for a wide range of secondary minimum rate constraints. Index Terms-Physical security, spectrum leasing, Pareto boundary, interference channel.
doi:10.1109/tvt.2013.2269617 fatcat:gszg3wmwsvdizco2ngiddvhczu

Spectrum Leasing via Cooperation for Enhanced Physical-Layer Secrecy

Keonkook Lee, Osvaldo Simeone, Chan-Byoung Chae, Joonhyuk Kang
2011 2011 IEEE International Conference on Communications (ICC)  
Spectrum leasing via cooperation refers to the possibility for primary users to lease part of the spectral resources to secondary users in exchange for cooperation. This paper proposes a novel implementation of this concept in which secondary cooperation aims at improving the secrecy of the primary link. In particular, a secondary transmission with multiple antennas creates interference on both primary and eavesdropping receivers but an appropriately designed beamformer may impair more the
more » ... dropper's reception and thus enhance primary secrecy. The optimal design of the secondary beamformer that maximizes the primary secrecy rate while guaranteeing a minimal secondary rate is studied. It is proved that the problem can be solved in a domain that includes only two real numbers irrespective of the number of antennas. Numerical results show that the proposed spectrum leasing strategy increases the primary secrecy rate compared to the case of no spectrum leasing for a wide range of secondary minimum rate constraints. Index Terms-Physical security, spectrum leasing, Pareto boundary, interference channel.
doi:10.1109/icc.2011.5963501 dblp:conf/icc/LeeSCK11 fatcat:qkoohpdeqrecnppa6m6p552pbi

MIMO Transceiver Designs for Spatial Sensing in Cognitive Radio Networks

Keonkook Lee, Chan-Byoung Chae, Robert W. Heath, Joonhyuk Kang
2011 IEEE Transactions on Wireless Communications  
We propose transceiver algorithms in cognitive radio networks where the cognitive users are equipped with multiple antennas. Prior work has focused on the design of precoding matrices to suppress interference to the primary receivers. This work considers designs of precoding and decoding matrices for spatial sensing to achieve two objectives: i) to prevent interference to the primary receivers and ii) to remove the interference, due to primary transmissions, at the secondary receiver. With
more » ... e antenna primary terminals and two antenna cognitive terminals, a linear transceiver design has been introduced under a global channel state information (CSI) assumption [1]. In this letter, multiple antenna primary and cognitive terminals and three different CSI scenarios depending upon the amount of CSI are studied: i) local CSI, ii) global CSI, and iii) local CSI with side information. When local CSI is available, we leverage prior work and employ the projected-channel singular value decomposition (P-SVD). In the global CSI scenario, we propose a joint transmitter-receiver design under the assumption of full CSI of all the users at the secondary transceiver. To reduce the feedback overhead, we also propose a new iterative algorithm that exploits only local CSI with side information. In this algorithm, the secondary transmitter and receiver iteratively update precoding and decoding matrices based on the local CSI and side information (precoding/decoding matrices at the previous iteration step) to maximize the rate of the secondary link while maintaining the zero-interference constraint. Convergence is established in the special case of single stream beamforming. Numerical results confirm that the proposed joint design and the iterative algorithm show better achievable rate performance than the P-SVD technique at the expense, respectively, of CSI knowledge and side information.
doi:10.1109/twc.2011.092711.101305 fatcat:cd6trlvcjfds3mj74lyo2xclo4

Energy efficiency analysis with circuit power consumption in massive MIMO systems

Daehan Ha, Keonkook Lee, Joonhyuk Kang
2013 2013 IEEE 24th Annual International Symposium on Personal, Indoor, and Mobile Radio Communications (PIMRC)  
It was shown that the required transmit power to support a target achievable rate is inversely proportional to the number of antennas in massive multiple-input multipleoutput (MIMO) systems [1]. However, the consumed power of the massive MIMO systems should include not only transmit power but also the fundamental power for operating the circuit at the transmitter, because the effect of circuit power consumption is more serious when the transmitter is equipped with massive number of antennas.
more » ... ce, to analyze the exact power consumption of massive MIMO systems, we investigate the energy efficiency for multiple cellular systems with large-scale antenna arrays under a consideration of circuit power consumption of each antenna. In particular, we propose a new power consumption model that considers not only transmit power on the power amplifier but also circuit power dissipated by analog devices and residually lossy factors in base stations (BSs). Through new energy efficiency formulation based on the proposed power consumption model, we analyze the tendency of the energy efficiency as the number of antennas increases and can see that the energy efficiency becomes a quasi-concave function with respect to the number of antennas. Finally, from the derived function of the energy efficiency, we determine the number of antennas to provide the maximum energy efficiency.
doi:10.1109/pimrc.2013.6666272 dblp:conf/pimrc/HaLK13 fatcat:v42h37csgndalod2r6wg4dlkke

Transmit beamforming with imperfect CSIT in spectrum leasing for physical-layer security

Seongah Jeong, Keonkook Lee, Joonhyuk Kang, Youngseok Baek, Bontae Koo
2012 2012 IEEE Consumer Communications and Networking Conference (CCNC)  
In spectrum leasing, primary users (PUs) lease the part of their spectral resources to secondary users (SUs) in exchange for appropriate remuneration. In this paper, we consider spectrum leasing via cooperation for physical-layer security that the secondary cooperation exists for improving the primary secrecy rate while maintaining its quality of service (QoS). Unlike the previous researches with the perfect channel state information (CSI) at transmitter (CSIT) assumption, we study when no
more » ... mation regarding the eavesdropper is available at the transmitter. This imperfect CSIT makes the SU's transmission strategy limited. To find the optimal transmission technique for the SU, we formulate a problem appropriate for the imperfect CSIT case. By using the proposed problem, we design the optimal transmit beamforming for the SU. Also, we analyze the ergodic rate of the secondary link at high signal-to-noise ratio (SNR) when the secondary cooperation focuses only on maximizing the primary secrecy rate for the viable choice of the secondary QoS level. The numerical result shows that the primary secrecy rate by the proposed transmit beamforming is comparable to that based on the perfect CSIT. Index Terms-Physical security, spectrum leasing, interference channel, imperfect channel state information.
doi:10.1109/ccnc.2012.6181182 dblp:conf/ccnc/JeongLKBK12 fatcat:heyasofmb5dpzantikvrylyjoy