Pub Date : 2011-11-01DOI: 10.1109/ISWCS.2011.6125422
M. Gastpar, A. Lapidoth, Y. Steinberg, M. Wigger
A coding scheme for the two-receivers Gaussian broadcast channel (BC) with feedback is proposed. For some asymmetric settings it achieves new rate pairs. Moreover, it achieves prelog 2 when the noises at the two receivers are fully positively correlated and of unequal variances, thus allowing us to complete the characterization of the prelog of the two-receivers Gaussian BC with feedback. The new achievable rates also allow us to determine the asymptotic power offset when the noises at the two receivers are uncorrelated.
{"title":"New achievable rates for the Gaussian broadcast channel with feedback","authors":"M. Gastpar, A. Lapidoth, Y. Steinberg, M. Wigger","doi":"10.1109/ISWCS.2011.6125422","DOIUrl":"https://doi.org/10.1109/ISWCS.2011.6125422","url":null,"abstract":"A coding scheme for the two-receivers Gaussian broadcast channel (BC) with feedback is proposed. For some asymmetric settings it achieves new rate pairs. Moreover, it achieves prelog 2 when the noises at the two receivers are fully positively correlated and of unequal variances, thus allowing us to complete the characterization of the prelog of the two-receivers Gaussian BC with feedback. The new achievable rates also allow us to determine the asymptotic power offset when the noises at the two receivers are uncorrelated.","PeriodicalId":414065,"journal":{"name":"2011 8th International Symposium on Wireless Communication Systems","volume":"65 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115214807","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 : 2011-11-01DOI: 10.1109/ISWCS.2011.6125290
A. Engels, M. Neunerdt, R. Mathar, H. M. Abdullah
Availability of ubiquitous wireless services is taken for granted by most of the people. Therefore, network operators have to deploy and to operate large radio networks that, particularly, support broadband services and applications. One effect is a growing cell density, i.e., the number of required base stations increases. On the other hand, there are people that are afraid of getting harmed by electromagnetic radiation emitted by base stations or there are people that just dislike the prevalence of base station antennas. Both types of people's attitude refer to the field of user acceptance. A high deficiency in acceptance might lead to public disputes, political disputes, and negative economical consequences. To counteract such trends preventively, we propose a mathematical optimization model that allows for planning wireless network infrastructure with respect to user acceptance. While keeping technical and economical aspects as primarily considered planning criteria, we propose a multi-objective optimization model that takes into account user acceptance as an objective. Numerical results demonstrate effects of this approach compared to application of a conventional planning model.
{"title":"Acceptance as a success factor for planning wireless network infrastructure","authors":"A. Engels, M. Neunerdt, R. Mathar, H. M. Abdullah","doi":"10.1109/ISWCS.2011.6125290","DOIUrl":"https://doi.org/10.1109/ISWCS.2011.6125290","url":null,"abstract":"Availability of ubiquitous wireless services is taken for granted by most of the people. Therefore, network operators have to deploy and to operate large radio networks that, particularly, support broadband services and applications. One effect is a growing cell density, i.e., the number of required base stations increases. On the other hand, there are people that are afraid of getting harmed by electromagnetic radiation emitted by base stations or there are people that just dislike the prevalence of base station antennas. Both types of people's attitude refer to the field of user acceptance. A high deficiency in acceptance might lead to public disputes, political disputes, and negative economical consequences. To counteract such trends preventively, we propose a mathematical optimization model that allows for planning wireless network infrastructure with respect to user acceptance. While keeping technical and economical aspects as primarily considered planning criteria, we propose a multi-objective optimization model that takes into account user acceptance as an objective. Numerical results demonstrate effects of this approach compared to application of a conventional planning model.","PeriodicalId":414065,"journal":{"name":"2011 8th International Symposium on Wireless Communication Systems","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127415832","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 : 2011-11-01DOI: 10.1109/ISWCS.2011.6125270
F. Yilmaz, Mohamed-Slim Alouini
Ergodic capacity and average bit error rate have been widely used to compare the performance of different wireless communication systems. As such recent scientific research and studies revealed strong impact of designing and implementing wireless technologies based on these two performance indicators. However and to the best of our knowledge, the direct links between these two performance indicators have not been explicitly proposed in the literature so far. In this paper, we propose novel relations between the ergodic capacity and the average bit error rate of an overall communication system using binary modulation schemes for signaling with a limited bandwidth and operating over generalized fading channels. More specifically, we show that these two performance measures can be represented in terms of each other, without the need to know the exact end-to-end statistical characterization of the communication channel. We validate the correctness and accuracy of our newly proposed relations and illustrated their usefulness by considering some classical examples.
{"title":"Novel relations between the ergodic capacity and the average bit error rate","authors":"F. Yilmaz, Mohamed-Slim Alouini","doi":"10.1109/ISWCS.2011.6125270","DOIUrl":"https://doi.org/10.1109/ISWCS.2011.6125270","url":null,"abstract":"Ergodic capacity and average bit error rate have been widely used to compare the performance of different wireless communication systems. As such recent scientific research and studies revealed strong impact of designing and implementing wireless technologies based on these two performance indicators. However and to the best of our knowledge, the direct links between these two performance indicators have not been explicitly proposed in the literature so far. In this paper, we propose novel relations between the ergodic capacity and the average bit error rate of an overall communication system using binary modulation schemes for signaling with a limited bandwidth and operating over generalized fading channels. More specifically, we show that these two performance measures can be represented in terms of each other, without the need to know the exact end-to-end statistical characterization of the communication channel. We validate the correctness and accuracy of our newly proposed relations and illustrated their usefulness by considering some classical examples.","PeriodicalId":414065,"journal":{"name":"2011 8th International Symposium on Wireless Communication Systems","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126909205","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 : 2011-11-01DOI: 10.1109/ISWCS.2011.6125428
Frederick Knabe, C. Huppert
We consider a two-user broadcast channel with quantization at the receiver side. In previous work, it was shown that this channel is non-degraded and transmission schemes based on superpositioning of the users' input signals were discussed. In this work, we propose a transmission strategy based on Tomlinson-Harashima precoding. With this strategy, successive decoding at the receivers is avoided. Thus, the number of quantization bits and with it the receiver complexity can be reduced considerably with a small loss in the achievable rates. Thus, a good trade-off between receiver complexity and performance is established.
{"title":"Reducing the receiver complexity by applying Tomlinson-Harashima precoding in quantized broadcast channels","authors":"Frederick Knabe, C. Huppert","doi":"10.1109/ISWCS.2011.6125428","DOIUrl":"https://doi.org/10.1109/ISWCS.2011.6125428","url":null,"abstract":"We consider a two-user broadcast channel with quantization at the receiver side. In previous work, it was shown that this channel is non-degraded and transmission schemes based on superpositioning of the users' input signals were discussed. In this work, we propose a transmission strategy based on Tomlinson-Harashima precoding. With this strategy, successive decoding at the receivers is avoided. Thus, the number of quantization bits and with it the receiver complexity can be reduced considerably with a small loss in the achievable rates. Thus, a good trade-off between receiver complexity and performance is established.","PeriodicalId":414065,"journal":{"name":"2011 8th International Symposium on Wireless Communication Systems","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123722756","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 : 2011-11-01DOI: 10.1109/ISWCS.2011.6125351
R. S. Ganesan, A. Klein
We consider a multi-carrier multi-user two-way relay network with multiple single antenna node pairs and a single non-regenerative relay with two antennas. In a conventional multi-user two-way relaying scheme where different node pairs transmit their data streams on different subcarriers, only one data stream per channel use can be achieved. Taking into account that the nodes can perform self interference cancellation, one antenna at the relay is sufficient to achieve one data stream per channel use. Hence, the two antennas at the relay are not fully utilized. In this paper, using the interference alignment technique in space-frequency dimensions, it is shown that when the number of users in the system is large, almost two data streams per channel use are achievable. The gain comes from the joint consideration of the spatial and frequency dimensions at the relay. A new projection based interference alignment algorithm is proposed. The ideas of signal alignment and channel alignment [1] are used to achieve the interference alignment solution. Furthermore, for the performance improvement of the proposed interference alignment scheme at moderate Signal to Noise Ratios (SNRs), a new gradient based method for optimization of the projection space at the relay is proposed.
{"title":"Projection based space-frequency interference alignment in a multi-carrier multi-user two-way relay network","authors":"R. S. Ganesan, A. Klein","doi":"10.1109/ISWCS.2011.6125351","DOIUrl":"https://doi.org/10.1109/ISWCS.2011.6125351","url":null,"abstract":"We consider a multi-carrier multi-user two-way relay network with multiple single antenna node pairs and a single non-regenerative relay with two antennas. In a conventional multi-user two-way relaying scheme where different node pairs transmit their data streams on different subcarriers, only one data stream per channel use can be achieved. Taking into account that the nodes can perform self interference cancellation, one antenna at the relay is sufficient to achieve one data stream per channel use. Hence, the two antennas at the relay are not fully utilized. In this paper, using the interference alignment technique in space-frequency dimensions, it is shown that when the number of users in the system is large, almost two data streams per channel use are achievable. The gain comes from the joint consideration of the spatial and frequency dimensions at the relay. A new projection based interference alignment algorithm is proposed. The ideas of signal alignment and channel alignment [1] are used to achieve the interference alignment solution. Furthermore, for the performance improvement of the proposed interference alignment scheme at moderate Signal to Noise Ratios (SNRs), a new gradient based method for optimization of the projection space at the relay is proposed.","PeriodicalId":414065,"journal":{"name":"2011 8th International Symposium on Wireless Communication Systems","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130530935","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 : 2011-11-01DOI: 10.1109/ISWCS.2011.6125374
A. Awada, B. Wegmann, I. Viering, A. Klein
The increase in demand for wireless data communication has incited mobile operators to deploy new radio access technologies (RATs) overlaying with legacy ones. Flexible usage of multiple RATs and trouble-free inter-RAT operation require the optimization of the configuration parameters of different RATs. One approach to optimize these parameters is to try different default network-wide settings for all cells and apply the best in terms of network performance. Another approach is to manually optimize the parameters of the cells having problems with the aid of drive tests and expert knowledge. The major problem with these two approaches is that they require human intervention and increase operational expenditures. In this paper, a general and decentralized self-optimizing algorithm for the inter-RAT configuration parameters is proposed. The algorithm optimizes the configuration parameters on a cell-pair basis and runs only in the base stations of the newly installed RAT. As a testing use case, the proposed algorithm is applied to optimize the configuration parameters related to inter-RAT mobility handovers. Simulation results have shown that the proposed optimization algorithm outperforms the default network-wide settings and converges to a stable operation point that significantly improves the network performance.
{"title":"Self-Optimization Algorithm for Inter-RAT Configuration Parameters","authors":"A. Awada, B. Wegmann, I. Viering, A. Klein","doi":"10.1109/ISWCS.2011.6125374","DOIUrl":"https://doi.org/10.1109/ISWCS.2011.6125374","url":null,"abstract":"The increase in demand for wireless data communication has incited mobile operators to deploy new radio access technologies (RATs) overlaying with legacy ones. Flexible usage of multiple RATs and trouble-free inter-RAT operation require the optimization of the configuration parameters of different RATs. One approach to optimize these parameters is to try different default network-wide settings for all cells and apply the best in terms of network performance. Another approach is to manually optimize the parameters of the cells having problems with the aid of drive tests and expert knowledge. The major problem with these two approaches is that they require human intervention and increase operational expenditures. In this paper, a general and decentralized self-optimizing algorithm for the inter-RAT configuration parameters is proposed. The algorithm optimizes the configuration parameters on a cell-pair basis and runs only in the base stations of the newly installed RAT. As a testing use case, the proposed algorithm is applied to optimize the configuration parameters related to inter-RAT mobility handovers. Simulation results have shown that the proposed optimization algorithm outperforms the default network-wide settings and converges to a stable operation point that significantly improves the network performance.","PeriodicalId":414065,"journal":{"name":"2011 8th International Symposium on Wireless Communication Systems","volume":"78 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129544677","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 : 2011-11-01DOI: 10.1109/ISWCS.2011.6125445
J. Lachowski, M. Maternia, Jakub Gorzynski
Multicarrier operation offers significant gains by bandwidth extension as well as by its inherent ability to exploit diversity while transmitting on different adjacent carrier frequencies. A natural enhancement of this technique is multiband operation, since at different non-adjacent bands even more diverse radio conditions are to be found. Furthermore, since penetration of Third Generation (3G)-capable mobile devices is increasing, operators may consider to reuse 900 MHz band used by Global System for Mobile Communications (GSM) to enhance experience of growing 3G users' community. It is expected that the usage of 900 MHz band will not only expand bandwidth available for transmission but it will also bring significant gains especially for cell edge users, who often suffer from heavy interference conditions. This paper describes effects of utilizing available bands other than 2100 MHz in a multicarrier operation mode.
{"title":"Multiband and multicarrier operations in HSDPA","authors":"J. Lachowski, M. Maternia, Jakub Gorzynski","doi":"10.1109/ISWCS.2011.6125445","DOIUrl":"https://doi.org/10.1109/ISWCS.2011.6125445","url":null,"abstract":"Multicarrier operation offers significant gains by bandwidth extension as well as by its inherent ability to exploit diversity while transmitting on different adjacent carrier frequencies. A natural enhancement of this technique is multiband operation, since at different non-adjacent bands even more diverse radio conditions are to be found. Furthermore, since penetration of Third Generation (3G)-capable mobile devices is increasing, operators may consider to reuse 900 MHz band used by Global System for Mobile Communications (GSM) to enhance experience of growing 3G users' community. It is expected that the usage of 900 MHz band will not only expand bandwidth available for transmission but it will also bring significant gains especially for cell edge users, who often suffer from heavy interference conditions. This paper describes effects of utilizing available bands other than 2100 MHz in a multicarrier operation mode.","PeriodicalId":414065,"journal":{"name":"2011 8th International Symposium on Wireless Communication Systems","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133861749","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 : 2011-11-01DOI: 10.1109/ISWCS.2011.6125269
I. Sason
This paper applies several concentration inequalities to prove concentration results for the crest factor of OFDM signals. The considered approaches are, to the best of our knowledge, new in the context of establishing concentration for OFDM signals.
{"title":"On the concentration of the crest factor for OFDM signals","authors":"I. Sason","doi":"10.1109/ISWCS.2011.6125269","DOIUrl":"https://doi.org/10.1109/ISWCS.2011.6125269","url":null,"abstract":"This paper applies several concentration inequalities to prove concentration results for the crest factor of OFDM signals. The considered approaches are, to the best of our knowledge, new in the context of establishing concentration for OFDM signals.","PeriodicalId":414065,"journal":{"name":"2011 8th International Symposium on Wireless Communication Systems","volume":"217 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134099675","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 : 2011-11-01DOI: 10.1109/ISWCS.2011.6125280
M. Reyer, Alexander Schaper, R. Mathar
Rate and power allocation in OFDM systems is discussed extensively in literature. These approaches are either based on a finite set of realizable rates or make use of a continuous rate-power function. The motivation of this correspondence was to investigate how to transfer efficiently continuous rate allocations to realizable ones. To increase performance, we suggest to skip some realizable rates. Then, our proposed algorithm for single-user resource allocation on the set of realizable rates produces the same allocation independent of the initialization. This algorithm achieves the optimal solution when the given lower and upper bound for the optimum are identical. Furthermore, we suggest an initialization procedure which comes very close to this allocation. Finally, we present simulation results to assess some quantity measures of our approach.
{"title":"Resource allocation in OFDM systems — Efficiency as basis for allocation and initialization","authors":"M. Reyer, Alexander Schaper, R. Mathar","doi":"10.1109/ISWCS.2011.6125280","DOIUrl":"https://doi.org/10.1109/ISWCS.2011.6125280","url":null,"abstract":"Rate and power allocation in OFDM systems is discussed extensively in literature. These approaches are either based on a finite set of realizable rates or make use of a continuous rate-power function. The motivation of this correspondence was to investigate how to transfer efficiently continuous rate allocations to realizable ones. To increase performance, we suggest to skip some realizable rates. Then, our proposed algorithm for single-user resource allocation on the set of realizable rates produces the same allocation independent of the initialization. This algorithm achieves the optimal solution when the given lower and upper bound for the optimum are identical. Furthermore, we suggest an initialization procedure which comes very close to this allocation. Finally, we present simulation results to assess some quantity measures of our approach.","PeriodicalId":414065,"journal":{"name":"2011 8th International Symposium on Wireless Communication Systems","volume":"49 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133333174","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 : 2011-11-01DOI: 10.1109/ISWCS.2011.6125390
A. G. Uchoa, Cornelius T. Healy, R. D. Lamare, R. Souza
We propose an algorithm to design Root-Check LDPC codes based on Progressive Edge Growth (PEG) techniques for block-fading channels. The proposed algorithm imposes some restrictions on the traditional PEG algorithm to ensure that the LDPC code generated is Root-Check with the largest possible girth. The performance is investigated by means of the outage probability. By doing so, the codes generated by our proposed algorithm are shown to outperform the existing methods for generating Root-Check LDPC codes.
{"title":"LDPC codes based on Progressive Edge Growth techniques for block fading channels","authors":"A. G. Uchoa, Cornelius T. Healy, R. D. Lamare, R. Souza","doi":"10.1109/ISWCS.2011.6125390","DOIUrl":"https://doi.org/10.1109/ISWCS.2011.6125390","url":null,"abstract":"We propose an algorithm to design Root-Check LDPC codes based on Progressive Edge Growth (PEG) techniques for block-fading channels. The proposed algorithm imposes some restrictions on the traditional PEG algorithm to ensure that the LDPC code generated is Root-Check with the largest possible girth. The performance is investigated by means of the outage probability. By doing so, the codes generated by our proposed algorithm are shown to outperform the existing methods for generating Root-Check LDPC codes.","PeriodicalId":414065,"journal":{"name":"2011 8th International Symposium on Wireless Communication Systems","volume":"367 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132792663","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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