Pub Date : 2005-10-31DOI: 10.1109/ISIT.2005.1523521
Gopal Pandurangan, W. Szpankowski
We present a universal algorithm for the classical online problem of caching or demand paging. We consider the caching problem when the page request sequence is drawn from an unknown probability distribution and the goal is to devise an efficient algorithm whose performance is close to the optimal online algorithm which has full knowledge of the underlying distribution. Most previous works have devised such algorithms for specific classes of distributions with the assumption that the algorithm has full knowledge of the source. In this paper, we present a universal and simple algorithm based on pattern matching for mixing sources (includes Markov sources). The expected performance of our algorithm is within 4 + o(1) times the optimal online algorithm (which has full knowledge of the input model and can use unbounded resources)
{"title":"A universal online caching algorithm based on pattern matching","authors":"Gopal Pandurangan, W. Szpankowski","doi":"10.1109/ISIT.2005.1523521","DOIUrl":"https://doi.org/10.1109/ISIT.2005.1523521","url":null,"abstract":"We present a universal algorithm for the classical online problem of caching or demand paging. We consider the caching problem when the page request sequence is drawn from an unknown probability distribution and the goal is to devise an efficient algorithm whose performance is close to the optimal online algorithm which has full knowledge of the underlying distribution. Most previous works have devised such algorithms for specific classes of distributions with the assumption that the algorithm has full knowledge of the source. In this paper, we present a universal and simple algorithm based on pattern matching for mixing sources (includes Markov sources). The expected performance of our algorithm is within 4 + o(1) times the optimal online algorithm (which has full knowledge of the input model and can use unbounded resources)","PeriodicalId":92224,"journal":{"name":"International Symposium on Information Theory and its Applications. International Symposium on Information Theory and its Applications","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2005-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77451332","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 : 2005-10-31DOI: 10.1109/ISIT.2005.1523441
T. Philosof, R. Zamir
We investigate the sum-capacity loss for using uncorrelated Gaussian inputs over multiple-input multiple-output (MIMO) power-constrained linear additive-noise channels in multi-user configurations. We show that the sum-capacity loss is bounded by a universal constant which depends only on the total number of input and output dimensions of the channel, but is independent of the channel matrix, the noise distribution and the number of users. Specifically, for a multiple-access channel with a total number of nt transmit antennas and base-station with nr receive antennas, the sum-capacity loss is at most C* = min{1/2, nr/2nt log2(1 + nt/nr)} bit per input dimension (or 1 bit per transmit antenna per second per Hertz). If we restrict attention to Gaussian noises, then the capacity loss is upper bounded by CG* = min{0.265, 0.265nr/nt log2(nt/nr)}, and this bound is tight for certain channel matrices and noise spectra. We show also that the same bounds hold for the sum-capacity loss of uncorrelated Gaussian input over linear MIMO broadcast channels, input distribution being interpreted either in terms of the equivalent point-to-point channel with Sato condition, or as the output distribution of a "dirty-paper" transmitter. One implication of these results is the limited value of coherence and water-filling in spatial transmission. Another implication is the limited capacity loss in multi-user configurations relative to the fully cooperative (point-to-point) channel
{"title":"The cost of uncorrelation and non-cooperation in MIMO channels","authors":"T. Philosof, R. Zamir","doi":"10.1109/ISIT.2005.1523441","DOIUrl":"https://doi.org/10.1109/ISIT.2005.1523441","url":null,"abstract":"We investigate the sum-capacity loss for using uncorrelated Gaussian inputs over multiple-input multiple-output (MIMO) power-constrained linear additive-noise channels in multi-user configurations. We show that the sum-capacity loss is bounded by a universal constant which depends only on the total number of input and output dimensions of the channel, but is independent of the channel matrix, the noise distribution and the number of users. Specifically, for a multiple-access channel with a total number of nt transmit antennas and base-station with nr receive antennas, the sum-capacity loss is at most C* = min{1/2, nr/2nt log2(1 + nt/nr)} bit per input dimension (or 1 bit per transmit antenna per second per Hertz). If we restrict attention to Gaussian noises, then the capacity loss is upper bounded by CG* = min{0.265, 0.265nr/nt log2(nt/nr)}, and this bound is tight for certain channel matrices and noise spectra. We show also that the same bounds hold for the sum-capacity loss of uncorrelated Gaussian input over linear MIMO broadcast channels, input distribution being interpreted either in terms of the equivalent point-to-point channel with Sato condition, or as the output distribution of a \"dirty-paper\" transmitter. One implication of these results is the limited value of coherence and water-filling in spatial transmission. Another implication is the limited capacity loss in multi-user configurations relative to the fully cooperative (point-to-point) channel","PeriodicalId":92224,"journal":{"name":"International Symposium on Information Theory and its Applications. International Symposium on Information Theory and its Applications","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2005-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90546696","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 : 2005-10-31DOI: 10.1109/ISIT.2005.1523475
M. Katz, S. Shamai
We consider a wireless network where a remote source sends information to one of two co-located users, and where the second user can serve as a relay. The source's transmission is subjected to quasi-static flat Rayleigh fading, while the transmission of the relay experiences a fixed amplitude gain with a uniform random phase, capturing its close proximity to the destination. All communications share the same time/bandwidth resources, and channel state information is known only to the receivers. We propose relaying protocols which are based on Wyner-Ziv quantization at the relay, and demonstrate their high efficiency (in terms of expected throughput) with respect to previously reported relaying schemes based on amplify-and-forward and decode-and-forward. A salient feature of these protocols is that the relay need not know the actual fading gain experienced by the destination in order to perform the quantization. We also consider a hybrid amplify-quantize-decode and-forward scheme which exhibits superior performance
{"title":"Relaying protocols for two co-located users","authors":"M. Katz, S. Shamai","doi":"10.1109/ISIT.2005.1523475","DOIUrl":"https://doi.org/10.1109/ISIT.2005.1523475","url":null,"abstract":"We consider a wireless network where a remote source sends information to one of two co-located users, and where the second user can serve as a relay. The source's transmission is subjected to quasi-static flat Rayleigh fading, while the transmission of the relay experiences a fixed amplitude gain with a uniform random phase, capturing its close proximity to the destination. All communications share the same time/bandwidth resources, and channel state information is known only to the receivers. We propose relaying protocols which are based on Wyner-Ziv quantization at the relay, and demonstrate their high efficiency (in terms of expected throughput) with respect to previously reported relaying schemes based on amplify-and-forward and decode-and-forward. A salient feature of these protocols is that the relay need not know the actual fading gain experienced by the destination in order to perform the quantization. We also consider a hybrid amplify-quantize-decode and-forward scheme which exhibits superior performance","PeriodicalId":92224,"journal":{"name":"International Symposium on Information Theory and its Applications. International Symposium on Information Theory and its Applications","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2005-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77340428","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 : 2005-01-01DOI: 10.1109/ISIT.2005.1523439
S. D. Rooij, P. Grünwald
We analyse the behaviour of the ML plug-in code, also known as the Rissanen-Dawid prequential ML code, relative to single parameter exponential families M. If the data are i.i.d. according to an (essentially) arbitrary P, then the redundancy grows at 1/2c log n. We find that, in contrast to other important universal codes such as the 2-part MDL, Shtarkov and Bayesian codes where c = 1, here c equals the ratio between the variance of P and the variance of the element of M that is closest to P in KL-divergence. We show how this behaviour can impair model selection performance in a simple setting in which we select between the Poisson and geometric models
{"title":"MDL model selection using the ML plug-in code","authors":"S. D. Rooij, P. Grünwald","doi":"10.1109/ISIT.2005.1523439","DOIUrl":"https://doi.org/10.1109/ISIT.2005.1523439","url":null,"abstract":"We analyse the behaviour of the ML plug-in code, also known as the Rissanen-Dawid prequential ML code, relative to single parameter exponential families M. If the data are i.i.d. according to an (essentially) arbitrary P, then the redundancy grows at 1/2c log n. We find that, in contrast to other important universal codes such as the 2-part MDL, Shtarkov and Bayesian codes where c = 1, here c equals the ratio between the variance of P and the variance of the element of M that is closest to P in KL-divergence. We show how this behaviour can impair model selection performance in a simple setting in which we select between the Poisson and geometric models","PeriodicalId":92224,"journal":{"name":"International Symposium on Information Theory and its Applications. International Symposium on Information Theory and its Applications","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2005-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84394909","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 : 2005-01-01DOI: 10.1109/ISIT.2005.1523651
A. Mohammad, IV WilliamWeeks
{"title":"Simulation-based estimation of the capacity of full-surface channels","authors":"A. Mohammad, IV WilliamWeeks","doi":"10.1109/ISIT.2005.1523651","DOIUrl":"https://doi.org/10.1109/ISIT.2005.1523651","url":null,"abstract":"","PeriodicalId":92224,"journal":{"name":"International Symposium on Information Theory and its Applications. International Symposium on Information Theory and its Applications","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2005-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76460580","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 : 2004-06-27DOI: 10.1109/ISIT.2004.1365249
S. Pradhan
This paper describes the source coding of the information signals with feedforward Gaussian sources. A stationary memoryless Gaussian source with zero-mean and variance, and with mean squared error as the distortion measure, gives a deterministic scheme that achieves the optimal rate-distortion bound using simple uniform scalar quantizers. To reconstruct source codes, the decoder uses the optimal Shannon rate-distortion function and achieves channel coding with feedback.
{"title":"Source coding with feedforward: Gaussian sources","authors":"S. Pradhan","doi":"10.1109/ISIT.2004.1365249","DOIUrl":"https://doi.org/10.1109/ISIT.2004.1365249","url":null,"abstract":"This paper describes the source coding of the information signals with feedforward Gaussian sources. A stationary memoryless Gaussian source with zero-mean and variance, and with mean squared error as the distortion measure, gives a deterministic scheme that achieves the optimal rate-distortion bound using simple uniform scalar quantizers. To reconstruct source codes, the decoder uses the optimal Shannon rate-distortion function and achieves channel coding with feedback.","PeriodicalId":92224,"journal":{"name":"International Symposium on Information Theory and its Applications. International Symposium on Information Theory and its Applications","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2004-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78399498","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 : 2004-06-27DOI: 10.1109/ISIT.2004.1365403
R. Omrani, O. Moreno, P. V. Kumar
Two new optimal constructions of optical orthogonal codes with lambdages2 are introduced. The first is based on a previous construction for the case lambda=1. The second is based on difference sets. A new bound for optical orthogonal codes based on a known bound for constant weight codes is introduced. This bound is used to prove the optimality of our constructions
{"title":"Optimal optical orthogonal codes with lambda > 1","authors":"R. Omrani, O. Moreno, P. V. Kumar","doi":"10.1109/ISIT.2004.1365403","DOIUrl":"https://doi.org/10.1109/ISIT.2004.1365403","url":null,"abstract":"Two new optimal constructions of optical orthogonal codes with lambdages2 are introduced. The first is based on a previous construction for the case lambda=1. The second is based on difference sets. A new bound for optical orthogonal codes based on a known bound for constant weight codes is introduced. This bound is used to prove the optimality of our constructions","PeriodicalId":92224,"journal":{"name":"International Symposium on Information Theory and its Applications. International Symposium on Information Theory and its Applications","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2004-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72747949","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 : 2004-06-27DOI: 10.1109/ISIT.2004.1365525
P. Gaborit, Carmen-Simona Nedeloaia, A. Wassermann
We compute the weight enumerators of various quadratic residue (QR) codes over F/sub 2/ and F/sub 3/, together with certain codes of related families like the duadic codes. We use a parallel algorithm to find the number of codewords of a given (not too high) weight, from which we deduce by usual classical methods for selfdual and isodual codes over F/sub 2/ and F/sub 3/ their associated, previously unknown, weight enumerators. We compute weight enumerators for lengths as high as 152 for binary codes (except for n=138 for which one lacks the number of codewords of weight 34) and 84 for ternary codes.
{"title":"Weight enumerators of duadic and quadratic residue codes","authors":"P. Gaborit, Carmen-Simona Nedeloaia, A. Wassermann","doi":"10.1109/ISIT.2004.1365525","DOIUrl":"https://doi.org/10.1109/ISIT.2004.1365525","url":null,"abstract":"We compute the weight enumerators of various quadratic residue (QR) codes over F/sub 2/ and F/sub 3/, together with certain codes of related families like the duadic codes. We use a parallel algorithm to find the number of codewords of a given (not too high) weight, from which we deduce by usual classical methods for selfdual and isodual codes over F/sub 2/ and F/sub 3/ their associated, previously unknown, weight enumerators. We compute weight enumerators for lengths as high as 152 for binary codes (except for n=138 for which one lacks the number of codewords of weight 34) and 84 for ternary codes.","PeriodicalId":92224,"journal":{"name":"International Symposium on Information Theory and its Applications. International Symposium on Information Theory and its Applications","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2004-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77454359","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 : 2004-06-27DOI: 10.1109/ISIT.2004.1365123
Xiaohu Tang, P. Udaya, P. Fan
This paper presents the generalized Udaya Sidiqi sequences which are the interleaved version of Gold like binary sequences of period satisfying the Welch bound maximum out of phase correlations. The sequences have large linear complexity and low correlations and are useful in code division multiple access (CDMA) communication systems and cryptography. A direct method to compute the correlation using the trace sequence representation and a sequence from a quadratic form are presented.
{"title":"Generalized binary Udaya-Siddiqi sequences","authors":"Xiaohu Tang, P. Udaya, P. Fan","doi":"10.1109/ISIT.2004.1365123","DOIUrl":"https://doi.org/10.1109/ISIT.2004.1365123","url":null,"abstract":"This paper presents the generalized Udaya Sidiqi sequences which are the interleaved version of Gold like binary sequences of period satisfying the Welch bound maximum out of phase correlations. The sequences have large linear complexity and low correlations and are useful in code division multiple access (CDMA) communication systems and cryptography. A direct method to compute the correlation using the trace sequence representation and a sequence from a quadratic form are presented.","PeriodicalId":92224,"journal":{"name":"International Symposium on Information Theory and its Applications. International Symposium on Information Theory and its Applications","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2004-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78189427","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 : 2004-06-27DOI: 10.1109/ISIT.2004.1365040
Liang-Liang Xie, P. Kumar
This paper proposes a new coding scheme and proved a new achievable rate formula for the Gaussian case. The scheme is simpler and avoids some inconvenient techniques (e.g., the Slepian-Wolf partitioning), in giving the same achievable rate for the single relay case. More importantly, this new coding scheme is easier to extend to the multiple level relay case, and generally achieves higher rates. Here we present the results for the discrete memoryless case. The paper also goes on to obtain the capacity of some relay channels under fading, which is the first significant capacity result for such channels, and one, which may possibly constitute a breakthrough in the field.
{"title":"An achievable rate for the multiple level relay channel","authors":"Liang-Liang Xie, P. Kumar","doi":"10.1109/ISIT.2004.1365040","DOIUrl":"https://doi.org/10.1109/ISIT.2004.1365040","url":null,"abstract":"This paper proposes a new coding scheme and proved a new achievable rate formula for the Gaussian case. The scheme is simpler and avoids some inconvenient techniques (e.g., the Slepian-Wolf partitioning), in giving the same achievable rate for the single relay case. More importantly, this new coding scheme is easier to extend to the multiple level relay case, and generally achieves higher rates. Here we present the results for the discrete memoryless case. The paper also goes on to obtain the capacity of some relay channels under fading, which is the first significant capacity result for such channels, and one, which may possibly constitute a breakthrough in the field.","PeriodicalId":92224,"journal":{"name":"International Symposium on Information Theory and its Applications. International Symposium on Information Theory and its Applications","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2004-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83514727","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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