Cognitive spectrum utilization in Ka band multibeam satellite communications (original) (raw)
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Cognitive Radio for Ka Band Satellite Communications
32nd AIAA International Communications Satellite Systems Conference, 2014
The satellite communication data traffic is increasing dramatically over the coming years. High throughput multibeam satellite networks in Ka band are potentially able to accommodate the upcoming high data rate demands. However, there is only 500 MHz of exclusive band for download and the same amount for upload. This spectrum shortage impose a barrier in order to satisfy the increasing demands. Cognitive satellite communication in Ka band is considered in this paper in order to potentially provide an additional 4.4 GHz bandwidth for downlink and uplink fixed-satellite-services. In this way, it is expected that the problem of spectrum scarcity for future generation of satellite networks is alleviated to a great extent. The underlying scenarios and enabling techniques are discussed in detail, and finally we investigate the implementation issues related to the considered techniques.
Spectrum awareness and exploitation for Cognitive Radio Satellite Communications
2015 European Conference on Networks and Communications (EuCNC), 2015
The Digital Agenda for Europe (DAE) sets forth ambitious requirements for broadband communications, in which Satellite Communications (SatCom) play a major role. In this context, spectrum sharing techniques offer unprecedented opportunities to increase capacity and reduce costs in order to allow SatCom to meet the DAE objectives. The EU FP7 Project CoRaSat is assessing Cognitive Radio (CR) techniques for Ka-band SatCom scenarios, showing that coexistence between Fixed Satellite Service (FSS) and Broadcasting Satellite System (BSS)/Fixed Service (FS) links would introduce significant benefits in non-exclusive frequency bands. In this paper, spectrum awareness and exploitation techniques are analyzed. Simulation results show that significant improvements can be obtained in both spectrum utilization (up to 2.4 GHz of additional spectrum) and available throughput (up to 600% increase).
This paper addresses the cognitive Geostationary Orbit (GSO) satellite uplink where satellite terminals reuse frequency bands of Fixed-Service (FS) terrestrial microwave links which are the incumbent users in the Ka 27.5-29.5 GHz band. In the scenario considered herein, the transmitted power of the cognitive satellite user has to ensure that the interference impact on potentially present FS links does not exceed the regulatory interference limitations. In order to satisfy the interference constraint and assuming the existence of a complete and reliable FS database, this paper proposes a Joint Power and Carrier Allocation (JPCA) strategy to enable the cognitive uplink access to GSO Fixed Satellite Service (FSS) terminals. The proposed approach identifies the worst FS link per user in terms of interference and divides the amount of tolerable interference among the maximum number of FSS terminal users that can potentially interfere with it. In so doing, the cognitive system is guarante...
Technical Challenges for Cognitive Radio Application in Satellite Communications
Proceedings of the 9th International Conference on Cognitive Radio Oriented Wireless Networks, 2014
During the last years, spectrum scarcity has become one of the major issues for the development of new communication systems. Cognitive Radio (CR) approaches have gained an ever increasing attention from system designers and operators, as they promise a more efficient utilization of the available spectral resources. In this context, while the application of CRs in terrestrial scenarios has been widely considered from both theoretical and practical viewpoints, their exploitation in satellite communications is still a rather unexplored area. In this paper, we address the definition of several satellite communications scenarios, where cognitive radio techniques promise to introduce significant benefits, and we discuss the major enablers and the associated challenges.
Resource allocation for cognitive Satellite Communications in Ka-band (17.7–19.7 GHz)
2015 IEEE International Conference on Communication Workshop (ICCW), 2015
In this paper, we consider the problem of resource allocation in the context of cognitive Satellite Communications (SatCom). In particular, we focus on the cognitive downlink access by Geostationary (GEO) Fixed Satellite Service (FSS) terminals in the band 17.7-19.7 GHz, where the incumbent users are Fixed-Service (FS) microwave links. Assuming a multiple Low Noise Block Converter (LNB) satellite receiver at the cognitive FSS terminal-side, an efficient receive beamforming technique combined with carrier allocation is proposed in order to maximize the overall downlink throughput as well as to improve the beam availability. The proposed cognitive exploitation framework allows the flexibility of using non-exclusive spectrum for the FSS downlink system, thus improving the overall system throughput. More importantly, the proposed approach is validated with the help of numerical results considering realistic system parameters.
Cognitive Radio Scenarios for Satellite Communications: The CoRaSat Approach
This paper presents initial results of the recently kicked-off FP7 ICT STREP project “CoRaSat” (Cognitive Radio for Satellite Communications) [1]. Focus is put on the preliminary identification of the scenarios which are suitable for the applicability of Cognitive Radio technology over Satellite Communications (SatCom). The considered frequency bands include Ka-band, Ku-band, C-band and S-band, where regulatory and coordination constraints exist. An initial mapping of broadband and narrowband SatCom use cases on each identified scenario is also provided. Moreover, several challenges associated to the applicability of Cognitive Radio over SatCom in the identified scenarios are presented, which form the basis of the market/business, regulatory, standardization and technological framework of CoRaSat. Furthermore, ongoing and future work of the CoRaSat project is outlined.
Cognitive Satellite Terrestrial Radios
2010 IEEE Global Telecommunications Conference GLOBECOM 2010, 2010
In this paper we present the concept of cognitive satellite terrestrial radios (CSTR) for hybrid satellite-terrestrial systems (HSTS). The cognitive radio (CR) technology is being motivated by the radio regulatory bodies for efficient utilization of the radio spectrum. The future satellite ground terminals therefore need to integrate and co-exist with the spectrally crowded terrestrial wireless systems and hence we propose the idea of CSTR. The key issues are addressed and the concepts of developing CR based satellite ground terminals in HSTS for dynamic spectrum access on the ground are presented. Furthermore, the concept of 3D-Spatial reuse of the spectrum is also presented using the CSTR considering low elevated satellite ground stations. Two particular HSTS applications to illustrate the CSTR concept, a) the hybrid satellite-UWB (ultra wideband) communication system for personal area networks (PAN) with short range on ground communications, and b) the hybrid satellite-WRAN (wireless regional area networks) for long range on ground communications are presented. In both the applications the satellite uplink and the terrestrial radios adopt the CR functionalities. The key enabling technologies and their integrated architecture for the CSTR are also presented.
Joint Carrier Allocation and Beamforming for cognitive SatComs in Ka-band (17.3–18.1 GHz)
2015 IEEE International Conference on Communications (ICC), 2015
Herein, we study the spectral coexistence of Geostationary (GEO) Fixed Satellite Services (FSS) downlink and Broadcasting Satellite Services (BSS) feeder links in the Ka-band (17.3 − 18.1 GHz) which is primarily allocated for BSS feeder links. Firstly, a novel cognitive spectrum exploitation framework is proposed in order to utilize the available band efficiently. Subsequently, based on the interference analysis carried out between these systems, two cognitive approaches, namely Carrier Allocation (CA) and Beamforming (BF), are investigated under the considered framework assuming the availability of an accurate Radio Environment Map (REM). The employed techniques allow the flexibility of using additional shared carriers for the FSS downlink system along with the already available exclusive carriers (19.7 − 20.2 GHz), thus increasing the overall system throughput. It is shown that a significant improvement in the per beam throughput as well as in the beam availability can be achieved by applying CA and BF approaches in the considered scenario.
Implementation Issues of Cognitive Radio techniques for Ka-band (17.7–19.7 GHz) SatComs
2014 7th Advanced Satellite Multimedia Systems Conference and the 13th Signal Processing for Space Communications Workshop (ASMS/SPSC), 2014
The usable satellite spectrum has become scarce due to continuously increasing demand for broadband multimedia, broadcast and interactive services. In this context, investigating efficient spectrum coexistence techniques is a crucial challenge in order to enhance the spectral efficiency of future satellite systems. Herein, we study a satellite-terrestrial coexistence scenario where a Fixed Satellite Service (FSS) downlink coexists with the Fixed Service (FS) point to point microwave links in the Ka-band (17.7-19.7 GHz). First, we identify various practical challenges and provide possible solutions in order to allow this coexistence. Then we propose four different sensing and avoidance schemes in order to protect FSS satellite terminals from the harmful FS interference. Further, we evaluate the performance of one of the proposed solutions in the considered scenario with the help of theoretical and numerical analysis. More specifically, we focus on harmful FS detection problem in order to guarantee the sufficient protection of FSS terminals. It is shown that the FS harmful interference can be reliably detected with the help of an additional dipole antenna and this solution further overcomes the noise uncertainty problem encountered while sensing with the satellite dish.
Cognitive Zone for Broadband Satellite Communication in 17.3-17.7 GHz Band
IEEE Wireless Communications Letters, 2015
Deploying high throughput satellite systems in Ka band to accommodate the ever increasing demand for high data rates hits a spectrum barrier. Cognitive spectrum utilization of the allocated frequency bands to other services is a potential solution. Designing a cognitive zone around incumbent broadcasting satellite service (BSS) feeder links beyond which the cognitive fixed satellite service (FSS) terminals can freely utilize the same frequency band is considered in this paper. In addition, we show that there is a rain rate called rain wall, above which cognitive downlink communications becomes infeasible.