Pub Date : 2007-12-26DOI: 10.1109/IWSSC.2007.4409406
F. Muhammad, L. Franck, S. Farrell
Challenging networks require transmission protocols able to deal with the specificities of the environment. These adverse conditions include very long delays (delays in hours are normal), episodic connectivity, asymmetric data rates, higher bit error rate (The raw BERs are in the order of 10-2), very high free space losses (around 250-300 dB) and power constraints that may severely compromise the effectiveness of standard transport protocols. Transmissions protocols must also relieve applications and other upper-layer protocols (like the bundle protocol from the Delay Tolerant Network architecture) from the need to deal with the characteristics of intervening communications networks and services. In this paper we analyse the impacts of parameters such as loss probability and propagation delay on Licklider Transmission Protocol (LTP) [1], [2] and the newly proposed Licklider Transmission Protocol-(LTP-T) [3] following a comparative study of both the protocols.
{"title":"Transmission protocols for challenging networks: LTP and LTP-T","authors":"F. Muhammad, L. Franck, S. Farrell","doi":"10.1109/IWSSC.2007.4409406","DOIUrl":"https://doi.org/10.1109/IWSSC.2007.4409406","url":null,"abstract":"Challenging networks require transmission protocols able to deal with the specificities of the environment. These adverse conditions include very long delays (delays in hours are normal), episodic connectivity, asymmetric data rates, higher bit error rate (The raw BERs are in the order of 10-2), very high free space losses (around 250-300 dB) and power constraints that may severely compromise the effectiveness of standard transport protocols. Transmissions protocols must also relieve applications and other upper-layer protocols (like the bundle protocol from the Delay Tolerant Network architecture) from the need to deal with the characteristics of intervening communications networks and services. In this paper we analyse the impacts of parameters such as loss probability and propagation delay on Licklider Transmission Protocol (LTP) [1], [2] and the newly proposed Licklider Transmission Protocol-(LTP-T) [3] following a comparative study of both the protocols.","PeriodicalId":286578,"journal":{"name":"2007 International Workshop on Satellite and Space Communications","volume":"197 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-12-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121150573","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 : 2007-12-26DOI: 10.1109/IWSSC.2007.4409391
M. Diaz, N. Courville, C. Mosquera, G. Liva, G. Corazza
This contribution explores the use of interference mitigation techniques applied to broadband satellite systems with co-channel interference. In particular, our focus is on nonlinear precoding techniques, borrowing ideas from the theory of broadcast MIMO channels. A number of schemes are compared, including several implementations of Tomlinson-Harashima precoding and their linear precoding counterparts. Simulations on realistic scenarios show potential improvements of non-linear precoding with respect to linear interference mitigation and classical countermeasures based on frequency division among beams. Also, we identify several practical issues related to the implementation of Tomlinson-Harashima Precoding in satellite communication systems.
{"title":"Non-Linear Interference Mitigation for Broadband Multimedia Satellite Systems","authors":"M. Diaz, N. Courville, C. Mosquera, G. Liva, G. Corazza","doi":"10.1109/IWSSC.2007.4409391","DOIUrl":"https://doi.org/10.1109/IWSSC.2007.4409391","url":null,"abstract":"This contribution explores the use of interference mitigation techniques applied to broadband satellite systems with co-channel interference. In particular, our focus is on nonlinear precoding techniques, borrowing ideas from the theory of broadcast MIMO channels. A number of schemes are compared, including several implementations of Tomlinson-Harashima precoding and their linear precoding counterparts. Simulations on realistic scenarios show potential improvements of non-linear precoding with respect to linear interference mitigation and classical countermeasures based on frequency division among beams. Also, we identify several practical issues related to the implementation of Tomlinson-Harashima Precoding in satellite communication systems.","PeriodicalId":286578,"journal":{"name":"2007 International Workshop on Satellite and Space Communications","volume":"90 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-12-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116564293","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 : 2007-12-26DOI: 10.1109/IWSSC.2007.4409416
S. Bayhan, G. Giir, F. Alagoz
Spectrum scarcity experienced due to low utilization of some spectrum bands shows that there is a need for new regulations for spectrum allocation. Static allocation over a wide area, usually a city, makes the spectrum use non efficient. In order to use spectrum more efficiently, cognitive radio concept has been introduced. A cognitive radio is a paradigm for wireless communication in which either network or wireless node itself changes particular transmission or reception parameters to execute its tasks efficiently without interfering with the licensed users. Therefore, cognitive radio (CR) is promising to address portability, interoperability and quick and cost effective development, upgrade and maintenance of waveforms among multiple and varying communications platforms to enable an integrated and ubiquitous communication infrastructure. In this paper, we present a novel concept, namely high altitude platform (HAP) driven smart radios (HDSR), where CR devices are dynamically configured and policies for dynamic spectrum access are beamed with the assistance of a HAP and a back end satellite subsystem. The "proof-of-concept" for the proposed system is performed by a set of simulations. In these simulations, some primary IEEE 802.11b/g users communicate in infrastructure mode through three base stations while some secondary users having different priorities for the available spectrum communicate opportunistically.
{"title":"High Altitude Platform (HAP) Driven Smart Radios: A Novel Concept","authors":"S. Bayhan, G. Giir, F. Alagoz","doi":"10.1109/IWSSC.2007.4409416","DOIUrl":"https://doi.org/10.1109/IWSSC.2007.4409416","url":null,"abstract":"Spectrum scarcity experienced due to low utilization of some spectrum bands shows that there is a need for new regulations for spectrum allocation. Static allocation over a wide area, usually a city, makes the spectrum use non efficient. In order to use spectrum more efficiently, cognitive radio concept has been introduced. A cognitive radio is a paradigm for wireless communication in which either network or wireless node itself changes particular transmission or reception parameters to execute its tasks efficiently without interfering with the licensed users. Therefore, cognitive radio (CR) is promising to address portability, interoperability and quick and cost effective development, upgrade and maintenance of waveforms among multiple and varying communications platforms to enable an integrated and ubiquitous communication infrastructure. In this paper, we present a novel concept, namely high altitude platform (HAP) driven smart radios (HDSR), where CR devices are dynamically configured and policies for dynamic spectrum access are beamed with the assistance of a HAP and a back end satellite subsystem. The \"proof-of-concept\" for the proposed system is performed by a set of simulations. In these simulations, some primary IEEE 802.11b/g users communicate in infrastructure mode through three base stations while some secondary users having different priorities for the available spectrum communicate opportunistically.","PeriodicalId":286578,"journal":{"name":"2007 International Workshop on Satellite and Space Communications","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-12-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130997729","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 : 2007-12-26DOI: 10.1109/IWSSC.2007.4409433
F. Lo Piccolo, N. B. Melazzi, D. Giustiniano
This position paper aims at proposing a new relative localization strategy for GSM cellular networks. We in particular consider a GSM network scenario where only a limited number of mobile phones is at known positions. This is the case of mobile phones which are equipped with satellite navigation receivers and know their absolute position. Such mobile phones will be referred to as located mobile phones. Mobile phones which either are not equipped with satellite navigation receivers or are out of coverage of their satellite navigation receivers do not know their absolute position and they will be referred to as un-located mobile phones. In both cases un-located mobile phones do not know their absolute position. Relative localization means then to locate the un-located mobile phones by exploiting the presence of neighbor located mobile phones and the communication capabilities of all GSM mobile phones. The idea arises from the observation that existing GPS-based positioning methods for GSM networks allow positioning only the GPS-enabled mobile phones that are in line of sight with at least four satellites. On the contrary, relative localization would allow locating both GPS-unequipped mobile phones and GPS-enabled mobile phones which are out of coverage. The proposed localization scheme is based on power level measurements, and it does not require network infrastructure changes, differently from positioning methods based on timing measurements. In this paper we identify and analyze the main related issues, and we sketch a possible solution.
{"title":"Power-measurement-based relative localization in GSM cellular networks","authors":"F. Lo Piccolo, N. B. Melazzi, D. Giustiniano","doi":"10.1109/IWSSC.2007.4409433","DOIUrl":"https://doi.org/10.1109/IWSSC.2007.4409433","url":null,"abstract":"This position paper aims at proposing a new relative localization strategy for GSM cellular networks. We in particular consider a GSM network scenario where only a limited number of mobile phones is at known positions. This is the case of mobile phones which are equipped with satellite navigation receivers and know their absolute position. Such mobile phones will be referred to as located mobile phones. Mobile phones which either are not equipped with satellite navigation receivers or are out of coverage of their satellite navigation receivers do not know their absolute position and they will be referred to as un-located mobile phones. In both cases un-located mobile phones do not know their absolute position. Relative localization means then to locate the un-located mobile phones by exploiting the presence of neighbor located mobile phones and the communication capabilities of all GSM mobile phones. The idea arises from the observation that existing GPS-based positioning methods for GSM networks allow positioning only the GPS-enabled mobile phones that are in line of sight with at least four satellites. On the contrary, relative localization would allow locating both GPS-unequipped mobile phones and GPS-enabled mobile phones which are out of coverage. The proposed localization scheme is based on power level measurements, and it does not require network infrastructure changes, differently from positioning methods based on timing measurements. In this paper we identify and analyze the main related issues, and we sketch a possible solution.","PeriodicalId":286578,"journal":{"name":"2007 International Workshop on Satellite and Space Communications","volume":"119 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-12-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132375315","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 : 2007-12-26DOI: 10.1109/IWSSC.2007.4409409
L. Wood, C. Peoples, G. Parr, B. Scotney, A. Moore
We examine how the design of the Transmission Control Protocol (TCP) implicitly presumes a limited range of path delays and distances between communicating endpoints. We show that TCP is less suited to larger delays due to the interaction of various timers present in TCP implementations that limit performance and, eventually, the ability to communicate at all as distances increase. The resulting performance and protocol radius metrics that we establish by simulation indicate how the TCP protocol performs with increasing distance radius between two communicating nodes, and show the boundaries where the protocol undergoes visible performance changes. This allows us to assess the suitability of TCP for long-delay communication, including for deep-space links.
{"title":"TCP's protocol radius: the distance where timers prevent communication","authors":"L. Wood, C. Peoples, G. Parr, B. Scotney, A. Moore","doi":"10.1109/IWSSC.2007.4409409","DOIUrl":"https://doi.org/10.1109/IWSSC.2007.4409409","url":null,"abstract":"We examine how the design of the Transmission Control Protocol (TCP) implicitly presumes a limited range of path delays and distances between communicating endpoints. We show that TCP is less suited to larger delays due to the interaction of various timers present in TCP implementations that limit performance and, eventually, the ability to communicate at all as distances increase. The resulting performance and protocol radius metrics that we establish by simulation indicate how the TCP protocol performs with increasing distance radius between two communicating nodes, and show the boundaries where the protocol undergoes visible performance changes. This allows us to assess the suitability of TCP for long-delay communication, including for deep-space links.","PeriodicalId":286578,"journal":{"name":"2007 International Workshop on Satellite and Space Communications","volume":"74 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-12-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121904476","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 : 2007-12-26DOI: 10.1109/IWSSC.2007.4409385
K. Liolis, A. Bolea-Alamaac, R. Prieto-Cerdeira, A. Panagopoulos, A. Martellucci
The candidate frequency bands for the extension of the DVB-S2/RCS broadband satellite systems to fully support mobility are the Ku (12/14 GHz) and Ka (20/30 GHz). At these frequencies, rainfall is a significant propagation impairment which has to be taken into account together with other propagation effects due to mobility, such as multipath, shadowing and blockage. Experimental measurement campaigns conducted so far for Ku/Ka-band land mobile satellite (LMS) channels have mainly focused on the characterization of the mobility effects and have not considered any possible relation between the mobility and rainfall effects. However, recent limited work has indicated that these two fading sources are not independent. The present analysis represents a first approximation addressing this open problem. Emphasis is put on the line-of-sight (LOS) state of a Ku/Ka-band LMS channel, which can be modeled by the Ricean distribution and a high K-factor. A novel analytical model relating the Ricean K-factor with the rain fading effects is presented based on which, an analytical prediction model for the distribution of the Ricean K-factor is derived. The proposed analysis is flexible, can be applied on a global scale and incorporate the impact of several important operational, climatic and geometrical parameters of a mobile satellite system on its channel multipath behavior. Useful numerical results are provided, the need for further experimental verification data is pointed out and specific future planned work is also mentioned.
{"title":"On the Relation between Mobility and Rainfall Effects in Ku/Ka-band Line-of-Sight Land Mobile Satellite Channels: An Analytical Statistical Approach","authors":"K. Liolis, A. Bolea-Alamaac, R. Prieto-Cerdeira, A. Panagopoulos, A. Martellucci","doi":"10.1109/IWSSC.2007.4409385","DOIUrl":"https://doi.org/10.1109/IWSSC.2007.4409385","url":null,"abstract":"The candidate frequency bands for the extension of the DVB-S2/RCS broadband satellite systems to fully support mobility are the Ku (12/14 GHz) and Ka (20/30 GHz). At these frequencies, rainfall is a significant propagation impairment which has to be taken into account together with other propagation effects due to mobility, such as multipath, shadowing and blockage. Experimental measurement campaigns conducted so far for Ku/Ka-band land mobile satellite (LMS) channels have mainly focused on the characterization of the mobility effects and have not considered any possible relation between the mobility and rainfall effects. However, recent limited work has indicated that these two fading sources are not independent. The present analysis represents a first approximation addressing this open problem. Emphasis is put on the line-of-sight (LOS) state of a Ku/Ka-band LMS channel, which can be modeled by the Ricean distribution and a high K-factor. A novel analytical model relating the Ricean K-factor with the rain fading effects is presented based on which, an analytical prediction model for the distribution of the Ricean K-factor is derived. The proposed analysis is flexible, can be applied on a global scale and incorporate the impact of several important operational, climatic and geometrical parameters of a mobile satellite system on its channel multipath behavior. Useful numerical results are provided, the need for further experimental verification data is pointed out and specific future planned work is also mentioned.","PeriodicalId":286578,"journal":{"name":"2007 International Workshop on Satellite and Space Communications","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-12-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129207673","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 : 2007-12-26DOI: 10.1109/IWSSC.2007.4409429
S. Ramachandran, G. Fairhurs, M. Luglio, C. Roseti, S. Provenzano
Traditional modular layering schemes have served a major part in the development of a variety of protocols. However, as the physical layer impairments become more unpredictable, a cross layer design (CLD) which is dynamic in nature provides better performance. CLD introduces new challenges in protocol design as well as in the area of security. Using numerical analysis, we show that a link layer design employing header compression and cross layer signalling to protect protocol headers can limit packet discarding. This paper also reviews the IPsec protocol and describes how IPsec can be modified for cross layer architecture.
{"title":"Network Layer Security: Design for A Cross Layer Architecture","authors":"S. Ramachandran, G. Fairhurs, M. Luglio, C. Roseti, S. Provenzano","doi":"10.1109/IWSSC.2007.4409429","DOIUrl":"https://doi.org/10.1109/IWSSC.2007.4409429","url":null,"abstract":"Traditional modular layering schemes have served a major part in the development of a variety of protocols. However, as the physical layer impairments become more unpredictable, a cross layer design (CLD) which is dynamic in nature provides better performance. CLD introduces new challenges in protocol design as well as in the area of security. Using numerical analysis, we show that a link layer design employing header compression and cross layer signalling to protect protocol headers can limit packet discarding. This paper also reviews the IPsec protocol and describes how IPsec can be modified for cross layer architecture.","PeriodicalId":286578,"journal":{"name":"2007 International Workshop on Satellite and Space Communications","volume":"27 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-12-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125327866","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 : 2007-12-26DOI: 10.1109/IWSSC.2007.4409426
S. Cioni, A. Vanelli-Coralli, G. Corazza, J. Vicario, M. Castro
In this paper, we propose a single-input multiple- output (SIMO) diversity technique to improve the link reliability of a satellite communications system. In particular, the DVB-S2 communication system is investigated in a land mobile satellite environment. Realistic physical layer simulations are carried out to better evaluate the possible gain of using multiple receiving antennas at the receiver side. A hybrid selection technique of the available antennas is presented to reduce the complexity and the cost of the user terminal.
{"title":"SIMO Diversity with Antenna Selection for DVB-S2/RCS in LMS Scenarios","authors":"S. Cioni, A. Vanelli-Coralli, G. Corazza, J. Vicario, M. Castro","doi":"10.1109/IWSSC.2007.4409426","DOIUrl":"https://doi.org/10.1109/IWSSC.2007.4409426","url":null,"abstract":"In this paper, we propose a single-input multiple- output (SIMO) diversity technique to improve the link reliability of a satellite communications system. In particular, the DVB-S2 communication system is investigated in a land mobile satellite environment. Realistic physical layer simulations are carried out to better evaluate the possible gain of using multiple receiving antennas at the receiver side. A hybrid selection technique of the available antennas is presented to reduce the complexity and the cost of the user terminal.","PeriodicalId":286578,"journal":{"name":"2007 International Workshop on Satellite and Space Communications","volume":"28 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-12-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133572511","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 : 2007-12-26DOI: 10.1109/IWSSC.2007.4409393
A. Vanelli-Coralli, G. Corazza, G. Karagiannidis, P. Mathiopoulos, D. Michalopoulos, Carlos Mosquera, S. Papaharalabos, Sandro Scalise
A panoramic view on the study and design of digital satellite communication links is the focus of this paper. Starting from the characterization of satellite propagation channel in different application environments (from broadcast to fixed terminals, to broadband mobile satellite access), we address physical layer aspects related to satellite communications in the attempt of providing the reader with an overview of the new trends and open issues in this field.
{"title":"Satellite Communications: Research Trends and Open Issues","authors":"A. Vanelli-Coralli, G. Corazza, G. Karagiannidis, P. Mathiopoulos, D. Michalopoulos, Carlos Mosquera, S. Papaharalabos, Sandro Scalise","doi":"10.1109/IWSSC.2007.4409393","DOIUrl":"https://doi.org/10.1109/IWSSC.2007.4409393","url":null,"abstract":"A panoramic view on the study and design of digital satellite communication links is the focus of this paper. Starting from the characterization of satellite propagation channel in different application environments (from broadcast to fixed terminals, to broadband mobile satellite access), we address physical layer aspects related to satellite communications in the attempt of providing the reader with an overview of the new trends and open issues in this field.","PeriodicalId":286578,"journal":{"name":"2007 International Workshop on Satellite and Space Communications","volume":"56 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-12-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133165324","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 : 2007-12-26DOI: 10.1109/IWSSC.2007.4409419
A. Das, M. Miller
A new approach to detect the onset of saturation (1dB output compression point) at remote terminals is proposed in this paper. The proposed approach dithers the transmit power of periodic ranging bursts by a known amount and then estimates the received difference in Signal to Noise Ratio (SNR) and uses this metric to indicate whether the operating point of the Power Amplifier is in the linear range or not. The Expectation-Maximization (EM) Algorithm is used to achieve the ML estimate of the received SNR and is compared to the Cramer-Rao Lower Bound (CRLB). Application of this algorithm to a commercial satellite broadband system as well as simplifications to the algorithm to make it easier for implementation on FPGAs, are also discussed.
{"title":"Remote non-linearity detection via burst power dithering and EM based SNR Estimation","authors":"A. Das, M. Miller","doi":"10.1109/IWSSC.2007.4409419","DOIUrl":"https://doi.org/10.1109/IWSSC.2007.4409419","url":null,"abstract":"A new approach to detect the onset of saturation (1dB output compression point) at remote terminals is proposed in this paper. The proposed approach dithers the transmit power of periodic ranging bursts by a known amount and then estimates the received difference in Signal to Noise Ratio (SNR) and uses this metric to indicate whether the operating point of the Power Amplifier is in the linear range or not. The Expectation-Maximization (EM) Algorithm is used to achieve the ML estimate of the received SNR and is compared to the Cramer-Rao Lower Bound (CRLB). Application of this algorithm to a commercial satellite broadband system as well as simplifications to the algorithm to make it easier for implementation on FPGAs, are also discussed.","PeriodicalId":286578,"journal":{"name":"2007 International Workshop on Satellite and Space Communications","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-12-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117131980","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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