Pub Date : 2011-12-01DOI: 10.1109/ISWCS.2011.6125330
H. Nishimura, M. Inamori, Y. Sanada, M. Ghavami
A precoded transmit path diversity in OFDM has been proposed to shift the signal processing burdens for fractional sampling (FS) from a receiver to a transmitter. It achieves path diversity without oversampling the received signal at the receiver side on time invariant channels. However, it does not take time variant channels into consideration. On time variant channels, inter-carrier interference (ICI) deteriorates the BER performance. In this paper, the precoding for both ICI suppression and path diversity combining at the transmitter side has been proposed. It can achieve ICI suppression and path diversity without any specific signal processing at the receiver.
{"title":"Transmit precoding scheme for ICI suppression and path diversity in FS-OFDM","authors":"H. Nishimura, M. Inamori, Y. Sanada, M. Ghavami","doi":"10.1109/ISWCS.2011.6125330","DOIUrl":"https://doi.org/10.1109/ISWCS.2011.6125330","url":null,"abstract":"A precoded transmit path diversity in OFDM has been proposed to shift the signal processing burdens for fractional sampling (FS) from a receiver to a transmitter. It achieves path diversity without oversampling the received signal at the receiver side on time invariant channels. However, it does not take time variant channels into consideration. On time variant channels, inter-carrier interference (ICI) deteriorates the BER performance. In this paper, the precoding for both ICI suppression and path diversity combining at the transmitter side has been proposed. It can achieve ICI suppression and path diversity without any specific signal processing at the receiver.","PeriodicalId":414065,"journal":{"name":"2011 8th International Symposium on Wireless Communication Systems","volume":"39 1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130734696","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 : 2011-11-06DOI: 10.1109/ISWCS.2011.6125388
Li Li, D. Kaleshi, Z. Fan
One of the key challenges for cooperative relaying multi-rate wireless networks is the integration and interaction of relaying with link adaptation algorithms, in particular under incomplete and/or imprecise channel state information conditions. In this paper we propose a practical cooperative relaying link adaptation medium access protocol that considers the historical link quality to enable the relay terminal to adjust its transmission relaying rate by estimating the error probability based on past packet transmission history. Simulation results show that this protocol achieves significant performance improvement in terms of end-to-end throughput and energy efficiency for different network conditions compared with other link adaptation algorithms. It also has the best performance of the direct transmission without perfect knowledge of current channel condition.
{"title":"CORELA: A cooperative relaying enhanced link adaptation algorithm for IEEE 802.11 WLANs","authors":"Li Li, D. Kaleshi, Z. Fan","doi":"10.1109/ISWCS.2011.6125388","DOIUrl":"https://doi.org/10.1109/ISWCS.2011.6125388","url":null,"abstract":"One of the key challenges for cooperative relaying multi-rate wireless networks is the integration and interaction of relaying with link adaptation algorithms, in particular under incomplete and/or imprecise channel state information conditions. In this paper we propose a practical cooperative relaying link adaptation medium access protocol that considers the historical link quality to enable the relay terminal to adjust its transmission relaying rate by estimating the error probability based on past packet transmission history. Simulation results show that this protocol achieves significant performance improvement in terms of end-to-end throughput and energy efficiency for different network conditions compared with other link adaptation algorithms. It also has the best performance of the direct transmission without perfect knowledge of current channel condition.","PeriodicalId":414065,"journal":{"name":"2011 8th International Symposium on Wireless Communication Systems","volume":"63 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122639193","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 : 2011-11-06DOI: 10.1109/ISWCS.2011.6125364
R. Hermenier, F. Rossetto, M. Berioli
Robust Header Compression (ROHC) has been successfully included in some wireless standards in order to reduce the excessive IP overhead for small packets, for instance Voice over IP frames. So far, there is limited understanding on how the ROHC performance depends on the design parameters and the characteristics of the wireless channel. In this paper we propose an analytical model that provides simple expressions for the probability of losing synchronization as a function of the mentioned parameters, and also yields insightful relationships between the design variables and the desired system performance. The results are validated against sophisticated and realistic models of ROHC.
{"title":"A simple analytical model for Robust Header Compression in correlated wireless links","authors":"R. Hermenier, F. Rossetto, M. Berioli","doi":"10.1109/ISWCS.2011.6125364","DOIUrl":"https://doi.org/10.1109/ISWCS.2011.6125364","url":null,"abstract":"Robust Header Compression (ROHC) has been successfully included in some wireless standards in order to reduce the excessive IP overhead for small packets, for instance Voice over IP frames. So far, there is limited understanding on how the ROHC performance depends on the design parameters and the characteristics of the wireless channel. In this paper we propose an analytical model that provides simple expressions for the probability of losing synchronization as a function of the mentioned parameters, and also yields insightful relationships between the design variables and the desired system performance. The results are validated against sophisticated and realistic models of ROHC.","PeriodicalId":414065,"journal":{"name":"2011 8th International Symposium on Wireless Communication Systems","volume":"50 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114905734","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.2011.6125362
E. Abbe
This work provides an overview of some polar coding results in network settings, in particular the joint polarization of correlated sources for Slepian-Wolf coding. New directions and recent progress are then discussed, in particular how to use joint polarization of correlated sources for deterministic broadcast channels and secret key generation.
{"title":"Polar coding in networks: Known results and new directions","authors":"E. Abbe","doi":"10.1109/ISWCS.2011.6125362","DOIUrl":"https://doi.org/10.1109/ISWCS.2011.6125362","url":null,"abstract":"This work provides an overview of some polar coding results in network settings, in particular the joint polarization of correlated sources for Slepian-Wolf coding. New directions and recent progress are then discussed, in particular how to use joint polarization of correlated sources for deterministic broadcast channels and secret key generation.","PeriodicalId":414065,"journal":{"name":"2011 8th International Symposium on Wireless Communication Systems","volume":"48 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":"124399297","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.2011.6125419
U. Wijewardhana, Nandana Rajatheva
In this paper, power allocation for cognitive wireless network is investigated with the spectrum underlay strategy where primary users (PUs) and cognitive users (CUs) communicate via the same channel. We propose a scheme based on geometric programming to maximize the capacity of CUs keeping the interference to the PUs due to CUs below a threshold value maintaining the quality of service for the primary network. Then we extend the system to a relay assisted primary link scenario and simulation results show that simultaneous transmission in both primary links is possible when using the proposed power allocation method.
{"title":"Power allocation for cognitive ad hoc network with relay assisted primary link","authors":"U. Wijewardhana, Nandana Rajatheva","doi":"10.1109/ISWCS.2011.6125419","DOIUrl":"https://doi.org/10.1109/ISWCS.2011.6125419","url":null,"abstract":"In this paper, power allocation for cognitive wireless network is investigated with the spectrum underlay strategy where primary users (PUs) and cognitive users (CUs) communicate via the same channel. We propose a scheme based on geometric programming to maximize the capacity of CUs keeping the interference to the PUs due to CUs below a threshold value maintaining the quality of service for the primary network. Then we extend the system to a relay assisted primary link scenario and simulation results show that simultaneous transmission in both primary links is possible when using the proposed power allocation method.","PeriodicalId":414065,"journal":{"name":"2011 8th International Symposium on Wireless Communication Systems","volume":"18 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":"117161452","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.2011.6125382
R. Hoefel, A. Camara
This paper presents a joint time and frequency synchronization scheme suitable for IEEE 802.11n devices. It is derived theoretical expressions to analyze the performance of the IEEE 802.11n physical layer operating with soft-decision Viterbi decoding over spatial correlated and uncorrelated flat fading Rayleigh channels, with time-frequency impairments and a realistic channel estimation procedure.
{"title":"Performance of IEEE 802.11n with time-frequency impairments over flat fading channels","authors":"R. Hoefel, A. Camara","doi":"10.1109/ISWCS.2011.6125382","DOIUrl":"https://doi.org/10.1109/ISWCS.2011.6125382","url":null,"abstract":"This paper presents a joint time and frequency synchronization scheme suitable for IEEE 802.11n devices. It is derived theoretical expressions to analyze the performance of the IEEE 802.11n physical layer operating with soft-decision Viterbi decoding over spatial correlated and uncorrelated flat fading Rayleigh channels, with time-frequency impairments and a realistic channel estimation procedure.","PeriodicalId":414065,"journal":{"name":"2011 8th International Symposium on Wireless Communication Systems","volume":"11 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":"127212247","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.2011.6125369
Javier Lafuente-Martinez, Á. Hernández-Solana, A. Valdovinos
In this paper, we study how to improve the performance of an SC-FDMA cellular system by reusing frequency resources on a per-sector basis, in a tri-sectorized multi-cell scenario. We consider a typical cell-based Fractional Frequency Reuse (FFR) scheme as a reference, and we propose two novel sector-based Inter-Cell Interference Coordination (ICIC) schemes. Our simulations show that, in comparison to the cell-based proposals, our novel schemes succeed on increasing the supported traffic load, while guaranteeing the required level of Quality of Service (QoS) for real-time traffic.
{"title":"Sector-based Radio Resource Management for SC-FDMA cellular systems","authors":"Javier Lafuente-Martinez, Á. Hernández-Solana, A. Valdovinos","doi":"10.1109/ISWCS.2011.6125369","DOIUrl":"https://doi.org/10.1109/ISWCS.2011.6125369","url":null,"abstract":"In this paper, we study how to improve the performance of an SC-FDMA cellular system by reusing frequency resources on a per-sector basis, in a tri-sectorized multi-cell scenario. We consider a typical cell-based Fractional Frequency Reuse (FFR) scheme as a reference, and we propose two novel sector-based Inter-Cell Interference Coordination (ICIC) schemes. Our simulations show that, in comparison to the cell-based proposals, our novel schemes succeed on increasing the supported traffic load, while guaranteeing the required level of Quality of Service (QoS) for real-time traffic.","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":"125410035","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.2011.6125450
F. A. Monteiro, F. Kschischang
In general, lattice problems are simple to describe but rather hard to solve optimally. Several suboptimal solutions have been proposed for the closest vector problem (CVP), which is central in multiple-input multiple-output (MIMO) communication systems. It is known that some lattices have a trellis representation, however, those lattices require very particular geometries that are not found in lattices randomly generated. In this paper we show that for the typical number of dimensions used in MIMO communication, with high probability, there exists a synthetic lattice that is a member of the family of lattices that have a trellis representation and which is sufficiently close to any given random lattice. For that purpose we present a method to find a trellis-oriented basis for a given random lattice. The basis vectors of the synthetic lattice and the basis vectors of the original lattice are close and for finite alphabets the two lattices are roughly the same in the region of interest. Therefore, the optimal decision (Voronoi) regions of both lattices chiefly overlap. A linear transformation then focuses the original lattice onto the synthetic one, known to have a trellis representation. This minimizes the distortion of the Voronoi regions associated with maximum-likelihood detection and therefore the performance attained in the MIMO-CVP is close to optimal.
{"title":"Trellis detection for random lattices","authors":"F. A. Monteiro, F. Kschischang","doi":"10.1109/ISWCS.2011.6125450","DOIUrl":"https://doi.org/10.1109/ISWCS.2011.6125450","url":null,"abstract":"In general, lattice problems are simple to describe but rather hard to solve optimally. Several suboptimal solutions have been proposed for the closest vector problem (CVP), which is central in multiple-input multiple-output (MIMO) communication systems. It is known that some lattices have a trellis representation, however, those lattices require very particular geometries that are not found in lattices randomly generated. In this paper we show that for the typical number of dimensions used in MIMO communication, with high probability, there exists a synthetic lattice that is a member of the family of lattices that have a trellis representation and which is sufficiently close to any given random lattice. For that purpose we present a method to find a trellis-oriented basis for a given random lattice. The basis vectors of the synthetic lattice and the basis vectors of the original lattice are close and for finite alphabets the two lattices are roughly the same in the region of interest. Therefore, the optimal decision (Voronoi) regions of both lattices chiefly overlap. A linear transformation then focuses the original lattice onto the synthetic one, known to have a trellis representation. This minimizes the distortion of the Voronoi regions associated with maximum-likelihood detection and therefore the performance attained in the MIMO-CVP is close to optimal.","PeriodicalId":414065,"journal":{"name":"2011 8th International Symposium on Wireless Communication Systems","volume":"92 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":"128499045","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.2011.6125281
Masashige Shirakabe, A. Morimoto, N. Miki
In Long-Term Evolution (LTE)-Advanced, heterogeneous networks where femtocells and picocells are overlaid onto macrocells are extensively discussed in addition to traditional well-planned macrocell deployment to improve further the system throughput. In heterogeneous network deployment, combined usage of inter-cell interference coordination (ICIC) and cell range expansion (CRE) is very effective in improving the system and cell-edge throughput. In this combined usage, the fraction of the sets of user equipment (UEs) connected to the picocells, which are controlled through CRE, and that connected to macrocells affect the gain from the ICIC. Therefore, this paper evaluates the performance of ICIC and CRE in picocell deployments in the LTE-Advanced downlink. Simulation results (4 picocells and 30 UEs are located within 1 macrocell) assuming a full buffer model show that when the CRE offset value is set between 8 to 20 dB, almost the same user throughput performance is obtained by allocating the appropriate resources to protect UEs that connect to the picocells.
{"title":"Performance evaluation of inter-cell interference coordination and cell range expansion in heterogeneous networks for LTE-Advanced downlink","authors":"Masashige Shirakabe, A. Morimoto, N. Miki","doi":"10.1109/ISWCS.2011.6125281","DOIUrl":"https://doi.org/10.1109/ISWCS.2011.6125281","url":null,"abstract":"In Long-Term Evolution (LTE)-Advanced, heterogeneous networks where femtocells and picocells are overlaid onto macrocells are extensively discussed in addition to traditional well-planned macrocell deployment to improve further the system throughput. In heterogeneous network deployment, combined usage of inter-cell interference coordination (ICIC) and cell range expansion (CRE) is very effective in improving the system and cell-edge throughput. In this combined usage, the fraction of the sets of user equipment (UEs) connected to the picocells, which are controlled through CRE, and that connected to macrocells affect the gain from the ICIC. Therefore, this paper evaluates the performance of ICIC and CRE in picocell deployments in the LTE-Advanced downlink. Simulation results (4 picocells and 30 UEs are located within 1 macrocell) assuming a full buffer model show that when the CRE offset value is set between 8 to 20 dB, almost the same user throughput performance is obtained by allocating the appropriate resources to protect UEs that connect to the picocells.","PeriodicalId":414065,"journal":{"name":"2011 8th International Symposium on Wireless Communication Systems","volume":"34 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":"128353397","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.2011.6125307
Erbao Li, K. Gunnam, D. Declercq
In this paper, we propose a new method to implement the Extended Min-Sum (EMS) algorithm based on trellis representation of inputting messages to the check node. The original EMS reduces the decoding complexity by choosing only nm most reliable values and by introducing the idea of configuration sets conf(nm, nc), where nc is the number of deviations from the most reliable output configuration. We propose to work directly on the deviation space by building a configuration trellis based on delta messages, which serves as a new reliability measure. The algorithm is called trellis-EMS (T-EMS). By using the new trellis representation, only nc+1 minimum values from each row of the trellis need to be considered, which reduces the ordering complexity. The trellis representation in the deviation space also reduces the number of output configurations tested, without any performance degradation. Our method is especially suitable for moderate field size q and large check node degree nonbinary LDPC codes.
{"title":"Trellis based Extended Min-Sum for decoding nonbinary LDPC codes","authors":"Erbao Li, K. Gunnam, D. Declercq","doi":"10.1109/ISWCS.2011.6125307","DOIUrl":"https://doi.org/10.1109/ISWCS.2011.6125307","url":null,"abstract":"In this paper, we propose a new method to implement the Extended Min-Sum (EMS) algorithm based on trellis representation of inputting messages to the check node. The original EMS reduces the decoding complexity by choosing only nm most reliable values and by introducing the idea of configuration sets conf(nm, nc), where nc is the number of deviations from the most reliable output configuration. We propose to work directly on the deviation space by building a configuration trellis based on delta messages, which serves as a new reliability measure. The algorithm is called trellis-EMS (T-EMS). By using the new trellis representation, only nc+1 minimum values from each row of the trellis need to be considered, which reduces the ordering complexity. The trellis representation in the deviation space also reduces the number of output configurations tested, without any performance degradation. Our method is especially suitable for moderate field size q and large check node degree nonbinary LDPC codes.","PeriodicalId":414065,"journal":{"name":"2011 8th International Symposium on Wireless Communication Systems","volume":"127 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":"124222527","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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