Pub Date : 2011-06-01DOI: 10.4108/ICST.CROWNCOM.2011.245872
Daniela Tuninetti, N. Devroye, Yasaman Keshtkarjahromi
We consider a Gaussian point-to-point secondary link which co-exists with a Gaussian point-to-point primary link, and is permitted to transmit within the primary user's interference margin — a simple but realistic channel model for underlay cognitive systems. Under this assumption, we are interested in quantifying the secondary user rate gains when the secondary users have knowledge of the primary link's codebook. This may be exploited at the secondary transmitter or receiver — we focus on the latter. As first proposed by Popovski et al., this codebook knowledge may be exploited to opportunistically — when channel conditions permit — either fully cancel the primary user interference at the secondary receiver, or otherwise treat it as noise. In this work, we propose an achievable rate region in which the primary user transmits according to an information theoretic broadcast strategy, but otherwise remains oblivious to the secondary user operation. The secondary receiver exploits the primary codebooks, together with its broadcast strategy transmission to decode a portion of the primary message, thereby opportunistically partially canceling the primary user interference seen at the secondary receiver and thus straddles the two extremes between fully decoding and treating the interference as noise as presented by Popovski et al. Interestingly, it is shown that this broadcast strategy does not outperform Popovski et al.'s simple “all or nothing” strategy. We thus seek to tighten outer bounds on the secondary user's channel capacity. The inclusion of an average power constraint on the secondary link furthermore allows us to develop a new, tighter outer bound for this channel, which is numerically evaluated and compared to the inner bounds.
{"title":"On cognitive channels with an oblivion constraint","authors":"Daniela Tuninetti, N. Devroye, Yasaman Keshtkarjahromi","doi":"10.4108/ICST.CROWNCOM.2011.245872","DOIUrl":"https://doi.org/10.4108/ICST.CROWNCOM.2011.245872","url":null,"abstract":"We consider a Gaussian point-to-point secondary link which co-exists with a Gaussian point-to-point primary link, and is permitted to transmit within the primary user's interference margin — a simple but realistic channel model for underlay cognitive systems. Under this assumption, we are interested in quantifying the secondary user rate gains when the secondary users have knowledge of the primary link's codebook. This may be exploited at the secondary transmitter or receiver — we focus on the latter. As first proposed by Popovski et al., this codebook knowledge may be exploited to opportunistically — when channel conditions permit — either fully cancel the primary user interference at the secondary receiver, or otherwise treat it as noise. In this work, we propose an achievable rate region in which the primary user transmits according to an information theoretic broadcast strategy, but otherwise remains oblivious to the secondary user operation. The secondary receiver exploits the primary codebooks, together with its broadcast strategy transmission to decode a portion of the primary message, thereby opportunistically partially canceling the primary user interference seen at the secondary receiver and thus straddles the two extremes between fully decoding and treating the interference as noise as presented by Popovski et al. Interestingly, it is shown that this broadcast strategy does not outperform Popovski et al.'s simple “all or nothing” strategy. We thus seek to tighten outer bounds on the secondary user's channel capacity. The inclusion of an average power constraint on the secondary link furthermore allows us to develop a new, tighter outer bound for this channel, which is numerically evaluated and compared to the inner bounds.","PeriodicalId":249175,"journal":{"name":"2011 6th International ICST Conference on Cognitive Radio Oriented Wireless Networks and Communications (CROWNCOM)","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123748696","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2011-06-01DOI: 10.4108/ICST.CROWNCOM.2011.245900
P. Dmochowski, Peter J. Smith, M. Shafi, H. Suraweera
We examine the effect of transmit antenna selection on the secondary user (SU) and primary user (PU) capacity in a multiple-input single-output cognitive radio system. We consider antenna selection with the aim of improving SU and PU capacity and mitigating the effects of incomplete channel knowledge by the SU. Under a minimum PU signal-to-interference-and-noise ratio constraint, analytical and semi-analytical expressions for the permissible SU transmit power are derived, which are used in obtaining capacity cumulative distribution functions by means of simulations. We show that PU antenna selection is effective at reducing the SU blocking probability, the probability that it cannot transmit, while SU antenna selection leads to significant gains in its capacity. Antenna selection at the SU is also shown to effectively compensate for incomplete channel knowledge and can be used to achieve moderate improvements in PU capacity.
{"title":"Impact of antenna selection on cognitive radio system capacity","authors":"P. Dmochowski, Peter J. Smith, M. Shafi, H. Suraweera","doi":"10.4108/ICST.CROWNCOM.2011.245900","DOIUrl":"https://doi.org/10.4108/ICST.CROWNCOM.2011.245900","url":null,"abstract":"We examine the effect of transmit antenna selection on the secondary user (SU) and primary user (PU) capacity in a multiple-input single-output cognitive radio system. We consider antenna selection with the aim of improving SU and PU capacity and mitigating the effects of incomplete channel knowledge by the SU. Under a minimum PU signal-to-interference-and-noise ratio constraint, analytical and semi-analytical expressions for the permissible SU transmit power are derived, which are used in obtaining capacity cumulative distribution functions by means of simulations. We show that PU antenna selection is effective at reducing the SU blocking probability, the probability that it cannot transmit, while SU antenna selection leads to significant gains in its capacity. Antenna selection at the SU is also shown to effectively compensate for incomplete channel knowledge and can be used to achieve moderate improvements in PU capacity.","PeriodicalId":249175,"journal":{"name":"2011 6th International ICST Conference on Cognitive Radio Oriented Wireless Networks and Communications (CROWNCOM)","volume":"36 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121984976","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2011-06-01DOI: 10.4108/ICST.CROWNCOM.2011.245771
Woongsup Lee, D. Cho
Cooperative transmission can improve the performance of wireless ad-hoc systems due to its spatial multiplexing gain. Given that multiple cooperative relays which belong to the same source-destination pair can transmit simultaneously in the cooperative transmission, it is different from normal data transmission in which only one source node transmits in a single source-destination pair. Therefore, a new distributed scheduling algorithm for wireless ad-hoc systems should be devised. To this end, we propose a distributed scheduling algorithm for wireless ad-hoc systems with cooperative transmission in which multiple cooperative relays can transmit at the same time by using Amplify-and-Forward or Decode-and-Forward scheme. By using the elastic exclusive distance which is the minimum distance between two active cooperative transmission sets, the outage probability of cooperative transmissions can be greatly reduced compared to that of conventional scheduling scheme. Through performance analysis and simulation results, we show that the proposed scheme can enhance the performance of the system.
{"title":"Distributed scheduling algorithm for cooperative transmission with multiple relays","authors":"Woongsup Lee, D. Cho","doi":"10.4108/ICST.CROWNCOM.2011.245771","DOIUrl":"https://doi.org/10.4108/ICST.CROWNCOM.2011.245771","url":null,"abstract":"Cooperative transmission can improve the performance of wireless ad-hoc systems due to its spatial multiplexing gain. Given that multiple cooperative relays which belong to the same source-destination pair can transmit simultaneously in the cooperative transmission, it is different from normal data transmission in which only one source node transmits in a single source-destination pair. Therefore, a new distributed scheduling algorithm for wireless ad-hoc systems should be devised. To this end, we propose a distributed scheduling algorithm for wireless ad-hoc systems with cooperative transmission in which multiple cooperative relays can transmit at the same time by using Amplify-and-Forward or Decode-and-Forward scheme. By using the elastic exclusive distance which is the minimum distance between two active cooperative transmission sets, the outage probability of cooperative transmissions can be greatly reduced compared to that of conventional scheduling scheme. Through performance analysis and simulation results, we show that the proposed scheme can enhance the performance of the system.","PeriodicalId":249175,"journal":{"name":"2011 6th International ICST Conference on Cognitive Radio Oriented Wireless Networks and Communications (CROWNCOM)","volume":"116 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115211438","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2011-06-01DOI: 10.4108/ICST.CROWNCOM.2011.246248
K. Qaraqe, Zied Bouida, M. Abdallah, Mohamed-Slim Alouini
Under the scenario of an underlay cognitive radio network, we propose in this paper an adaptive scheme using switched transmit diversity and adaptive modulation in order to minimize the average number of switched branches at the secondary transmitter while increasing the capacity of the secondary link. The proposed switching efficient scheme (SES) uses the scan and wait (SWC) combining technique where a transmission occurs only when a branch with an acceptable performance is found, otherwise data is buffered. In our scheme, the modulation constellation size and the used transmit branch are determined to achieve the highest spectral efficiency with a minimum processing power, given the fading channel conditions, the required error rate performance, and a peak interference constraint to the primary receiver. Selected numerical examples show that the SES scheme minimizes the average number of switched branches for the average and the high secondary signal-to-noise ratio range. This improvement comes at the expense of a small delay introduced by the SWC technique. For reference, we also compare the performance of the SES scheme to the selection diversity scheme (SDS) where the best branch verifying the modulation mode and the interference constraint is always selected.
{"title":"Joint switched transmit diversity and adaptive modulation in spectrum sharing systems","authors":"K. Qaraqe, Zied Bouida, M. Abdallah, Mohamed-Slim Alouini","doi":"10.4108/ICST.CROWNCOM.2011.246248","DOIUrl":"https://doi.org/10.4108/ICST.CROWNCOM.2011.246248","url":null,"abstract":"Under the scenario of an underlay cognitive radio network, we propose in this paper an adaptive scheme using switched transmit diversity and adaptive modulation in order to minimize the average number of switched branches at the secondary transmitter while increasing the capacity of the secondary link. The proposed switching efficient scheme (SES) uses the scan and wait (SWC) combining technique where a transmission occurs only when a branch with an acceptable performance is found, otherwise data is buffered. In our scheme, the modulation constellation size and the used transmit branch are determined to achieve the highest spectral efficiency with a minimum processing power, given the fading channel conditions, the required error rate performance, and a peak interference constraint to the primary receiver. Selected numerical examples show that the SES scheme minimizes the average number of switched branches for the average and the high secondary signal-to-noise ratio range. This improvement comes at the expense of a small delay introduced by the SWC technique. For reference, we also compare the performance of the SES scheme to the selection diversity scheme (SDS) where the best branch verifying the modulation mode and the interference constraint is always selected.","PeriodicalId":249175,"journal":{"name":"2011 6th International ICST Conference on Cognitive Radio Oriented Wireless Networks and Communications (CROWNCOM)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130402706","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2011-06-01DOI: 10.4108/ICST.CROWNCOM.2011.245766
I. Wajid, Hristina Nikolaeva, M. Pesavento
The problem of multi-user worst-case robust downlink beamforming and power allocation in a cognitive radio (CR) framework is studied. The goal is to minimize the total transmitted power while providing the secondary users (SUs) with a minimum acceptable quality-of-service (QoS), with additional constraints on the total interference leaked to the primary network (PN). An iterative algorithm has been proposed to solve this problem. In each iteration the algorithm approximates the worst-case covariance mismatch from the solution of the previous iteration und performs a fixed-point iteration that is based on uplink-downlink duality. Computer simulations show that the proposed technique converges to the global optimal solution at reduced computational complexity compared to the existing methods that rely on convex optimization.
{"title":"Iterative robust downlink beamforming in cognitive radio networks","authors":"I. Wajid, Hristina Nikolaeva, M. Pesavento","doi":"10.4108/ICST.CROWNCOM.2011.245766","DOIUrl":"https://doi.org/10.4108/ICST.CROWNCOM.2011.245766","url":null,"abstract":"The problem of multi-user worst-case robust downlink beamforming and power allocation in a cognitive radio (CR) framework is studied. The goal is to minimize the total transmitted power while providing the secondary users (SUs) with a minimum acceptable quality-of-service (QoS), with additional constraints on the total interference leaked to the primary network (PN). An iterative algorithm has been proposed to solve this problem. In each iteration the algorithm approximates the worst-case covariance mismatch from the solution of the previous iteration und performs a fixed-point iteration that is based on uplink-downlink duality. Computer simulations show that the proposed technique converges to the global optimal solution at reduced computational complexity compared to the existing methods that rely on convex optimization.","PeriodicalId":249175,"journal":{"name":"2011 6th International ICST Conference on Cognitive Radio Oriented Wireless Networks and Communications (CROWNCOM)","volume":"65 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124415973","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2011-06-01DOI: 10.4108/ICST.CROWNCOM.2011.245876
K. Umebayashi, Yasuo Suzuki, Janne J. Lehtomäki
Time domain spectrum sharing between primary user (PU) and cognitive radio (CR) networks is considered. The Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA) protocol is suitable for this type of spectrum sharing with unslotted access in which PUs and secondary users (SUs) are asynchronous. The goal is to maximize the average throughput of the SUs while guaranteeing the average throughput of the PUs. To achieve this, in our proposal the CR network adaptively changes its minimum contention window size (CWmin), depending on the channel occupancy rate (COR) from the PU network. The COR is approximately proportional to the average throughput and is estimated based on the observed traffic. In this paper, we analytically derive the optimum CWmin to maximize the COR of the CR network, while guaranteeing the COR of the PU network. In addition, to further protect saturated (high load) PUs, we also propose using a margin in the CWmin selection process. The simulation results show that the proposed approach does maximize the COR of the CR network and that it does converge faster in dynamic situations than the previous proposals. Also, the simulation results show the effectiveness of the proposed approach with margin.
考虑了主用户(PU)网络和认知无线电(CR)网络之间的时域频谱共享。CSMA/CA (Carrier Sense Multiple Access with Collision Avoidance)协议适用于这种pu和secondary user (secondary user)异步的无槽接入频谱共享。目标是在保证pu的平均吞吐量的同时，最大限度地提高su的平均吞吐量。为了实现这一点，在我们的建议中，CR网络根据来自PU网络的通道占用率(COR)自适应地改变其最小争用窗口大小(CWmin)。COR大约与平均吞吐量成正比，并根据观察到的流量进行估计。本文在保证PU网络的COR的前提下，对CR网络的最优CWmin进行了解析推导。此外，为了进一步保护饱和(高负载)pu，我们还建议在CWmin选择过程中使用余量。仿真结果表明，该方法能最大限度地提高CR网络的COR值，并且在动态情况下收敛速度快于以往的方法。仿真结果表明了该方法在考虑余量时的有效性。
{"title":"Dynamic selection of CWmin in cognitive radio networks for protecting IEEE 802.11 primary users","authors":"K. Umebayashi, Yasuo Suzuki, Janne J. Lehtomäki","doi":"10.4108/ICST.CROWNCOM.2011.245876","DOIUrl":"https://doi.org/10.4108/ICST.CROWNCOM.2011.245876","url":null,"abstract":"Time domain spectrum sharing between primary user (PU) and cognitive radio (CR) networks is considered. The Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA) protocol is suitable for this type of spectrum sharing with unslotted access in which PUs and secondary users (SUs) are asynchronous. The goal is to maximize the average throughput of the SUs while guaranteeing the average throughput of the PUs. To achieve this, in our proposal the CR network adaptively changes its minimum contention window size (CWmin), depending on the channel occupancy rate (COR) from the PU network. The COR is approximately proportional to the average throughput and is estimated based on the observed traffic. In this paper, we analytically derive the optimum CWmin to maximize the COR of the CR network, while guaranteeing the COR of the PU network. In addition, to further protect saturated (high load) PUs, we also propose using a margin in the CWmin selection process. The simulation results show that the proposed approach does maximize the COR of the CR network and that it does converge faster in dynamic situations than the previous proposals. Also, the simulation results show the effectiveness of the proposed approach with margin.","PeriodicalId":249175,"journal":{"name":"2011 6th International ICST Conference on Cognitive Radio Oriented Wireless Networks and Communications (CROWNCOM)","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132283172","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2011-06-01DOI: 10.4108/ICST.CROWNCOM.2011.245821
S. Kameda, H. Oguma, N. Izuka, F. Yamagata, Y. Asano, Y. Yamazaki, S. Tanifuji, N. Suematsu, T. Takagi, K. Tsubouchi
This paper proposes a heterogeneous wireless communication network with soft handover in the application layer. The proposed network requires no upgrades of wireless infrastructure and mobile terminals to evolve the present homogeneous networks to the proposed heterogeneous network. Only installing application programs on the content server side and the mobile terminal side is required. The performance of the proposed network has been evaluated in a field trial using a mobile broadband wireless access (MBWA) air interface with wide coverage and a wireless local area network (WLAN) air interface with high throughput. The field trial results show that the maximum value of the handover outage time is only 170 ms. The proposed heterogeneous wireless communication network is promising since both high throughput and wide coverage area are attained by a combination of the proposed handover scheme with the present homogeneous wireless networks.
{"title":"Proposal of heterogeneous wireless communication network with soft handover in application layer: Feasibility study based on field trial results","authors":"S. Kameda, H. Oguma, N. Izuka, F. Yamagata, Y. Asano, Y. Yamazaki, S. Tanifuji, N. Suematsu, T. Takagi, K. Tsubouchi","doi":"10.4108/ICST.CROWNCOM.2011.245821","DOIUrl":"https://doi.org/10.4108/ICST.CROWNCOM.2011.245821","url":null,"abstract":"This paper proposes a heterogeneous wireless communication network with soft handover in the application layer. The proposed network requires no upgrades of wireless infrastructure and mobile terminals to evolve the present homogeneous networks to the proposed heterogeneous network. Only installing application programs on the content server side and the mobile terminal side is required. The performance of the proposed network has been evaluated in a field trial using a mobile broadband wireless access (MBWA) air interface with wide coverage and a wireless local area network (WLAN) air interface with high throughput. The field trial results show that the maximum value of the handover outage time is only 170 ms. The proposed heterogeneous wireless communication network is promising since both high throughput and wide coverage area are attained by a combination of the proposed handover scheme with the present homogeneous wireless networks.","PeriodicalId":249175,"journal":{"name":"2011 6th International ICST Conference on Cognitive Radio Oriented Wireless Networks and Communications (CROWNCOM)","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127610931","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2011-06-01DOI: 10.4108/ICST.CROWNCOM.2011.246162
G. Villardi, H. Harada, G. Abreu
We address the problem of interference between cognitive wireless networks coexisting in the TV White Space (TVWS). We perform stochastic geometry analysis in order to evaluate the service area secondary cognitive devices can expect under mild to severe interference of neighboring networks. From our analysis, we foresee severe service area reduction, especially in densely populated areas, indicating a future need for coexistence techniques tailored to enable communication in TVWS while preventing harmful interference between cognitive wireless networks. Furthermore, we give a concise overview of the current activities undergoing in international standardization bodies towards the realization of communications in the TVWS.
{"title":"Stochastic-geometric model of expected service area for cognitive TV White Space wireless networks","authors":"G. Villardi, H. Harada, G. Abreu","doi":"10.4108/ICST.CROWNCOM.2011.246162","DOIUrl":"https://doi.org/10.4108/ICST.CROWNCOM.2011.246162","url":null,"abstract":"We address the problem of interference between cognitive wireless networks coexisting in the TV White Space (TVWS). We perform stochastic geometry analysis in order to evaluate the service area secondary cognitive devices can expect under mild to severe interference of neighboring networks. From our analysis, we foresee severe service area reduction, especially in densely populated areas, indicating a future need for coexistence techniques tailored to enable communication in TVWS while preventing harmful interference between cognitive wireless networks. Furthermore, we give a concise overview of the current activities undergoing in international standardization bodies towards the realization of communications in the TVWS.","PeriodicalId":249175,"journal":{"name":"2011 6th International ICST Conference on Cognitive Radio Oriented Wireless Networks and Communications (CROWNCOM)","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125420248","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2011-06-01DOI: 10.4108/ICST.CROWNCOM.2011.245924
K. Ishizu, H. Murakami, H. Harada
This paper proposes a spectrum sharing type cognitive radio system integrated with a dedicated radio system called out-of-band pilot channel (OPC). The OPC notifies the radio configuration information of cognitive base station (CBS), such as operational frequency and PHY/MAC parameters, to cognitive terminal (CT) so that the CT does not need to sense throughout a large range of potential frequency bands and immediately configure itself to connect to the CBS. Experimental evaluation shows that the proposed system takes 2.80 seconds to obtain the information on accessible CBS, whereas the conventional system without the OPC takes 8.09 seconds for sensing just 4 frequency channels. It is confirmed that the proposed system achieves a drastic time reduction to obtain the CBS radio configuration information.
本文提出了一种频谱共享型认知无线电系统，该系统与专用的带外导频信道(OPC)相结合。OPC将认知基站(cognitive base station, CBS)的工作频率、PHY/MAC参数等无线电配置信息通知给认知终端(cognitive terminal, CT)，使认知终端不需要在大范围的潜在频带内感知并立即配置自己与CBS连接。实验评估表明，该系统获取可访问CBS上的信息需要2.80秒，而传统的无OPC系统仅感知4个频率通道需要8.09秒。实验结果表明，该系统大大缩短了获取CBS无线电配置信息的时间。
{"title":"Feasibility study on spectrum sharing type cognitive radio system with outband pilot channel","authors":"K. Ishizu, H. Murakami, H. Harada","doi":"10.4108/ICST.CROWNCOM.2011.245924","DOIUrl":"https://doi.org/10.4108/ICST.CROWNCOM.2011.245924","url":null,"abstract":"This paper proposes a spectrum sharing type cognitive radio system integrated with a dedicated radio system called out-of-band pilot channel (OPC). The OPC notifies the radio configuration information of cognitive base station (CBS), such as operational frequency and PHY/MAC parameters, to cognitive terminal (CT) so that the CT does not need to sense throughout a large range of potential frequency bands and immediately configure itself to connect to the CBS. Experimental evaluation shows that the proposed system takes 2.80 seconds to obtain the information on accessible CBS, whereas the conventional system without the OPC takes 8.09 seconds for sensing just 4 frequency channels. It is confirmed that the proposed system achieves a drastic time reduction to obtain the CBS radio configuration information.","PeriodicalId":249175,"journal":{"name":"2011 6th International ICST Conference on Cognitive Radio Oriented Wireless Networks and Communications (CROWNCOM)","volume":"154 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115416951","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2011-06-01DOI: 10.4108/ICST.CROWNCOM.2011.245855
Xitao Gong, A. Ispas, G. Ascheid
This paper studies cooperative spectrum sensing in cognitive radio networks. Both the sensing and the reporting channels are assumed to be either slow or fast fading channels. In a practical system, due to the lack of cooperation between the primary and secondary users, the power of the primary signal, the channel state information of the sensing channels as well as the noise power level are unknown. We first provide an analytically tractable signal model using a Gaussian approximation and then propose generalized likelihood ratio test (GLRT) methods for the design of the corresponding detectors. The basic idea lies in the fact that the unknown parameters can be estimated by exploiting hidden information in the sample covariance matrix of the received signals. The effectiveness of the proposed GLRT-based sensing methods are validated through numerical results.
{"title":"GLRT-based cooperative sensing in cognitive radio networks with partial CSI","authors":"Xitao Gong, A. Ispas, G. Ascheid","doi":"10.4108/ICST.CROWNCOM.2011.245855","DOIUrl":"https://doi.org/10.4108/ICST.CROWNCOM.2011.245855","url":null,"abstract":"This paper studies cooperative spectrum sensing in cognitive radio networks. Both the sensing and the reporting channels are assumed to be either slow or fast fading channels. In a practical system, due to the lack of cooperation between the primary and secondary users, the power of the primary signal, the channel state information of the sensing channels as well as the noise power level are unknown. We first provide an analytically tractable signal model using a Gaussian approximation and then propose generalized likelihood ratio test (GLRT) methods for the design of the corresponding detectors. The basic idea lies in the fact that the unknown parameters can be estimated by exploiting hidden information in the sample covariance matrix of the received signals. The effectiveness of the proposed GLRT-based sensing methods are validated through numerical results.","PeriodicalId":249175,"journal":{"name":"2011 6th International ICST Conference on Cognitive Radio Oriented Wireless Networks and Communications (CROWNCOM)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129565750","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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