Pub Date : 2008-12-01DOI: 10.1109/ISITA.2008.4895537
Yue Liu, Jun Ning, Jinhong Yuan
In this paper, we propose a scheme to reduce the computation complexity of min-sum (MS) algorithm for decoding of nonbinary low-density parity-check (LDPC) codes over GF(q). Previously, MS algorithm reduced the decoding complexity by lowering the size of the configuration set for each variable node through a sorting. In the proposed scheme, we modify the MS algorithm by minimizing the size of the configuration set for each variable node through a filtering. In the filtering, the reduction of the set size can be controlled by a preset threshold. This way we can reduce the complexity more efficiently. Simulation results show, compared to the previous EMS algorithm, the complexity of proposed scheme is reduced with a negligible degradation in the code performance.
{"title":"Modified min-sum algorithm with threshold filtering for nonbinary LDPC codes over GF(q)","authors":"Yue Liu, Jun Ning, Jinhong Yuan","doi":"10.1109/ISITA.2008.4895537","DOIUrl":"https://doi.org/10.1109/ISITA.2008.4895537","url":null,"abstract":"In this paper, we propose a scheme to reduce the computation complexity of min-sum (MS) algorithm for decoding of nonbinary low-density parity-check (LDPC) codes over GF(q). Previously, MS algorithm reduced the decoding complexity by lowering the size of the configuration set for each variable node through a sorting. In the proposed scheme, we modify the MS algorithm by minimizing the size of the configuration set for each variable node through a filtering. In the filtering, the reduction of the set size can be controlled by a preset threshold. This way we can reduce the complexity more efficiently. Simulation results show, compared to the previous EMS algorithm, the complexity of proposed scheme is reduced with a negligible degradation in the code performance.","PeriodicalId":338675,"journal":{"name":"2008 International Symposium on Information Theory and Its Applications","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124254352","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 : 2008-12-01DOI: 10.1109/ISITA.2008.4895563
M. Stasiak, J. Wiewióra, P. Zwierzykowski
The paper presents a new analytical method for blocking probability determination in the WCDMA interface of the UMTS network with priorities. In our considerations we use a new model fo the full-availability group servicing PCT1 and PCT2 multi-rate traffic with priorities. The proposed scheme is applicable for cost-effective WCDMA resource management in 3G mobile networks and can be easily applied to network capacity calculations.
{"title":"The analytical model of the WCDMA interface with priorities in the UMTS network","authors":"M. Stasiak, J. Wiewióra, P. Zwierzykowski","doi":"10.1109/ISITA.2008.4895563","DOIUrl":"https://doi.org/10.1109/ISITA.2008.4895563","url":null,"abstract":"The paper presents a new analytical method for blocking probability determination in the WCDMA interface of the UMTS network with priorities. In our considerations we use a new model fo the full-availability group servicing PCT1 and PCT2 multi-rate traffic with priorities. The proposed scheme is applicable for cost-effective WCDMA resource management in 3G mobile networks and can be easily applied to network capacity calculations.","PeriodicalId":338675,"journal":{"name":"2008 International Symposium on Information Theory and Its Applications","volume":"37 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123432671","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 : 2008-12-01DOI: 10.1109/ISITA.2008.4895402
N. Ksairi, P. Bianchi, P. Ciblat, W. Hachem
In this paper, we investigate the issue of power control and sub-carrier assignment in a downlink OFDMA system. We assume that a certain part of the available bandwidth is likely to be reused by the different base stations (and is thus subject to multicell interference) and that the other part of the bandwidth is shared in an orthogonal way between them (and is thus protected from multicell interference). Although this problem of multicell resource allocation is non-convex, we provide, in the limit of large number of users, the general form of its global solution. As a byproduct, we characterize the optimal value of the frequency reuse factor.
{"title":"Resource allocation for the downlink of OFDMA cellular networks and optimization of the reuse factor","authors":"N. Ksairi, P. Bianchi, P. Ciblat, W. Hachem","doi":"10.1109/ISITA.2008.4895402","DOIUrl":"https://doi.org/10.1109/ISITA.2008.4895402","url":null,"abstract":"In this paper, we investigate the issue of power control and sub-carrier assignment in a downlink OFDMA system. We assume that a certain part of the available bandwidth is likely to be reused by the different base stations (and is thus subject to multicell interference) and that the other part of the bandwidth is shared in an orthogonal way between them (and is thus protected from multicell interference). Although this problem of multicell resource allocation is non-convex, we provide, in the limit of large number of users, the general form of its global solution. As a byproduct, we characterize the optimal value of the frequency reuse factor.","PeriodicalId":338675,"journal":{"name":"2008 International Symposium on Information Theory and Its Applications","volume":"55 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121671352","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 : 2008-12-01DOI: 10.1109/ISITA.2008.4895413
M. Baldi, F. Bambozzi, F. Chiaraluce
This paper presents a new class of easily invertible circulant matrices, defined by exploiting the isomorphism from the ring Mn of n times n circulant matrices over GF(p) to the ring Rn = GF(p)[x]/(xn - 1) of the polynomials modulo (xn - 1). Such class contains matrices free of 4-length cycles that, if sparse, can be included in the parity check matrix of QC-LDPC codes. Bounds for the weight of their inverses are also determined, that are useful for designing sparse generator matrices for these error correcting codes.
{"title":"A class of invertible circulant matrices for QC-LDPC codes","authors":"M. Baldi, F. Bambozzi, F. Chiaraluce","doi":"10.1109/ISITA.2008.4895413","DOIUrl":"https://doi.org/10.1109/ISITA.2008.4895413","url":null,"abstract":"This paper presents a new class of easily invertible circulant matrices, defined by exploiting the isomorphism from the ring Mn of n times n circulant matrices over GF(p) to the ring Rn = GF(p)[x]/(xn - 1) of the polynomials modulo (xn - 1). Such class contains matrices free of 4-length cycles that, if sparse, can be included in the parity check matrix of QC-LDPC codes. Bounds for the weight of their inverses are also determined, that are useful for designing sparse generator matrices for these error correcting codes.","PeriodicalId":338675,"journal":{"name":"2008 International Symposium on Information Theory and Its Applications","volume":"49 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124956437","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 : 2008-12-01DOI: 10.1109/ISITA.2008.4895495
M. N. Khormuji, M. Skoglund
We consider a two-hop relay channel with a random parameter in the second hop. We present two main strategies for the case when the random parameter is known non-casually at the source. We then introduce the Gaussian two-hop channel with known interference as one instance of the general model, and present achievable-rate results.
{"title":"Two-hop transmission with second-hop channel state information","authors":"M. N. Khormuji, M. Skoglund","doi":"10.1109/ISITA.2008.4895495","DOIUrl":"https://doi.org/10.1109/ISITA.2008.4895495","url":null,"abstract":"We consider a two-hop relay channel with a random parameter in the second hop. We present two main strategies for the case when the random parameter is known non-casually at the source. We then introduce the Gaussian two-hop channel with known interference as one instance of the general model, and present achievable-rate results.","PeriodicalId":338675,"journal":{"name":"2008 International Symposium on Information Theory and Its Applications","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125219887","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 : 2008-12-01DOI: 10.1109/ISITA.2008.4895422
M. Trivellato, N. Benvenuto
The paper considers state estimation in networked control systems (NCS) where observations from multiple sensors are subject to random delays and packet losses. We derive the minimum error covariance estimator and the optimum estimator with constant gains as a low-complexity solution. Generalizations to account for the effects of measurements quantization and limited transmission bandwidth are investigated for a stable system. Assuming a simple scalar system, we show how the proposed framework can be exploited for the design of NCS. In particular we investigate i) cross-layer optimization of quantization processes and network resource allocation and ii) comparison between single-hop and multi-hop communication protocols. We show that simple BPSK and single-hop communication protocols provide close to optimum performance in applications dealing with state estimation of a stable system.
{"title":"On estimation in networked control systems with random delays and partial observation losses","authors":"M. Trivellato, N. Benvenuto","doi":"10.1109/ISITA.2008.4895422","DOIUrl":"https://doi.org/10.1109/ISITA.2008.4895422","url":null,"abstract":"The paper considers state estimation in networked control systems (NCS) where observations from multiple sensors are subject to random delays and packet losses. We derive the minimum error covariance estimator and the optimum estimator with constant gains as a low-complexity solution. Generalizations to account for the effects of measurements quantization and limited transmission bandwidth are investigated for a stable system. Assuming a simple scalar system, we show how the proposed framework can be exploited for the design of NCS. In particular we investigate i) cross-layer optimization of quantization processes and network resource allocation and ii) comparison between single-hop and multi-hop communication protocols. We show that simple BPSK and single-hop communication protocols provide close to optimum performance in applications dealing with state estimation of a stable system.","PeriodicalId":338675,"journal":{"name":"2008 International Symposium on Information Theory and Its Applications","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131868635","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 : 2008-12-01DOI: 10.1109/ISITA.2008.4895548
C. Sung, Ping Hu, K. Leung
For the multiuser parallel relay network in which two users want to communicate with a destination through a parallel relay channel, we propose several coding strategies and derive their achievable rate regions. The results are analyzed and the strategies are shown to approach or achieve the outer bound under certain channel conditions.
{"title":"The multiuser Gaussian parallel relay network","authors":"C. Sung, Ping Hu, K. Leung","doi":"10.1109/ISITA.2008.4895548","DOIUrl":"https://doi.org/10.1109/ISITA.2008.4895548","url":null,"abstract":"For the multiuser parallel relay network in which two users want to communicate with a destination through a parallel relay channel, we propose several coding strategies and derive their achievable rate regions. The results are analyzed and the strategies are shown to approach or achieve the outer bound under certain channel conditions.","PeriodicalId":338675,"journal":{"name":"2008 International Symposium on Information Theory and Its Applications","volume":"37 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130564371","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 : 2008-12-01DOI: 10.1109/ISITA.2008.4895570
Kenji Hamano, Hirosuke Yamamoto
In this paper, a new randomness test is proposed based on the T-complexity of a T-code, which is a variable-length self-synchronizing code introduced by Titchener in 1984. The proposed test can be used instead of the Lempel-Ziv compression test, which was removed from the NIST statistical test suite because the LZ-complexity has a defect such that its distribution of P-values is strictly discrete for random sequences of length 106. We show that T-complexity has almost ideal continuous distribution of P-values for the same sequences. In order to calculate T-complexity, a new T-decomposition algorithm is also proposed to realize forward parsing for a given sequence although the original T-decomposition uses backward parsing. Furthermore, it is shown that the proposed randomness test can detect undesirable pseudorandom numbers that the NIST statistical test suite cannot detect.
{"title":"A randomness test based on T-codes","authors":"Kenji Hamano, Hirosuke Yamamoto","doi":"10.1109/ISITA.2008.4895570","DOIUrl":"https://doi.org/10.1109/ISITA.2008.4895570","url":null,"abstract":"In this paper, a new randomness test is proposed based on the T-complexity of a T-code, which is a variable-length self-synchronizing code introduced by Titchener in 1984. The proposed test can be used instead of the Lempel-Ziv compression test, which was removed from the NIST statistical test suite because the LZ-complexity has a defect such that its distribution of P-values is strictly discrete for random sequences of length 106. We show that T-complexity has almost ideal continuous distribution of P-values for the same sequences. In order to calculate T-complexity, a new T-decomposition algorithm is also proposed to realize forward parsing for a given sequence although the original T-decomposition uses backward parsing. Furthermore, it is shown that the proposed randomness test can detect undesirable pseudorandom numbers that the NIST statistical test suite cannot detect.","PeriodicalId":338675,"journal":{"name":"2008 International Symposium on Information Theory and Its Applications","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122312694","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 : 2008-12-01DOI: 10.1109/ISITA.2008.4895520
D. Vasudevan, S. B. Korada
We consider the following communication problem over a directed graph. A source node wants to transmit a common message to a set of receiver nodes along with a private message to each of the receivers. We show a class of networks for which the achievable rate region is given by the cut-set bounds.
{"title":"On broadcast with a common message over networks","authors":"D. Vasudevan, S. B. Korada","doi":"10.1109/ISITA.2008.4895520","DOIUrl":"https://doi.org/10.1109/ISITA.2008.4895520","url":null,"abstract":"We consider the following communication problem over a directed graph. A source node wants to transmit a common message to a set of receiver nodes along with a private message to each of the receivers. We show a class of networks for which the achievable rate region is given by the cut-set bounds.","PeriodicalId":338675,"journal":{"name":"2008 International Symposium on Information Theory and Its Applications","volume":"65 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131069221","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 : 2008-12-01DOI: 10.1109/ISITA.2008.4895506
N. Kashyap
We introduce the vertex-cut bound as a tool for analyzing the constraint complexity of realizations of a given code on an arbitrary graph. We then use this bound to obtain non-trivial lower bounds on the constraint complexity of such realizations. Our bounds enable us to show, for example, that codes that are good from an error-correcting standpoint cannot have cycle-free realizations with low constraint complexity.
{"title":"The Vertex-Cut Bound and its applications","authors":"N. Kashyap","doi":"10.1109/ISITA.2008.4895506","DOIUrl":"https://doi.org/10.1109/ISITA.2008.4895506","url":null,"abstract":"We introduce the vertex-cut bound as a tool for analyzing the constraint complexity of realizations of a given code on an arbitrary graph. We then use this bound to obtain non-trivial lower bounds on the constraint complexity of such realizations. Our bounds enable us to show, for example, that codes that are good from an error-correcting standpoint cannot have cycle-free realizations with low constraint complexity.","PeriodicalId":338675,"journal":{"name":"2008 International Symposium on Information Theory and Its Applications","volume":"39 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134094909","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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