Pub Date : 2001-11-01DOI: 10.1109/ISIT.2001.936178
C. Chong, V. Tarokh
We present a QPSK coding scheme for use in multicarrier communications. The scheme supports simple encoding and extremely simple maximum likelihood (ML) decoding algorithms for orthogonal frequency division multiplexing (OFDM) applications. Moreover, all the codewords have a peak-to-mean envelope power ratio (PMEPR) of at most 4.
{"title":"A simple encodable/decodable OFDM QPSK code with low peak-to-mean envelope power ratio","authors":"C. Chong, V. Tarokh","doi":"10.1109/ISIT.2001.936178","DOIUrl":"https://doi.org/10.1109/ISIT.2001.936178","url":null,"abstract":"We present a QPSK coding scheme for use in multicarrier communications. The scheme supports simple encoding and extremely simple maximum likelihood (ML) decoding algorithms for orthogonal frequency division multiplexing (OFDM) applications. Moreover, all the codewords have a peak-to-mean envelope power ratio (PMEPR) of at most 4.","PeriodicalId":433761,"journal":{"name":"Proceedings. 2001 IEEE International Symposium on Information Theory (IEEE Cat. No.01CH37252)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122836148","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 : 2001-11-01DOI: 10.1109/ISIT.2001.935953
O. Collins, N. Vasudev
The parameters of a mechanical or electrical system are usually determined by making as many measurements as there are degrees of freedom. This article demonstrates that increasing the number of measurements made on a system beyond this minimum can reduce the effect of measurement errors. The possible systems to which this technique may be applied are too diverse to be captured by a simple and compact analytical formulation. Thus, we discuss techniques for three different measurement models: scalar difference measurements, complex product measurements, and scalar additive measurements. All have both a compact mathematical formalization and wide practical applicability. A simple example of a measurement problem discussed is the generation of a binary ruler using a compass and a straight edge. Error is introduced whenever the mid-point of a line is found. The straight-forward approach to the ruler's construction is iterative bisection of the distance between two adjacent points till the required resolution is obtained. The maximum error introduced using this procedure scales logarithmically with the number of points. The accuracy may be improved by bisecting the distance from one of the end points to an already obtained point iteratively. Using this technique the error of any constructed point can be bounded by a constant, i.e., it does not scale with the number of points. We show, for three broad classes of measurements, that, as the measurement redundancy increases, the residual error falls to a small constant value. The overall effect is analogous to the improvements in communications reliability demonstrated by the coding theorem. Only scalar difference measurements are considered.
{"title":"The effect of redundancy on measurement","authors":"O. Collins, N. Vasudev","doi":"10.1109/ISIT.2001.935953","DOIUrl":"https://doi.org/10.1109/ISIT.2001.935953","url":null,"abstract":"The parameters of a mechanical or electrical system are usually determined by making as many measurements as there are degrees of freedom. This article demonstrates that increasing the number of measurements made on a system beyond this minimum can reduce the effect of measurement errors. The possible systems to which this technique may be applied are too diverse to be captured by a simple and compact analytical formulation. Thus, we discuss techniques for three different measurement models: scalar difference measurements, complex product measurements, and scalar additive measurements. All have both a compact mathematical formalization and wide practical applicability. A simple example of a measurement problem discussed is the generation of a binary ruler using a compass and a straight edge. Error is introduced whenever the mid-point of a line is found. The straight-forward approach to the ruler's construction is iterative bisection of the distance between two adjacent points till the required resolution is obtained. The maximum error introduced using this procedure scales logarithmically with the number of points. The accuracy may be improved by bisecting the distance from one of the end points to an already obtained point iteratively. Using this technique the error of any constructed point can be bounded by a constant, i.e., it does not scale with the number of points. We show, for three broad classes of measurements, that, as the measurement redundancy increases, the residual error falls to a small constant value. The overall effect is analogous to the improvements in communications reliability demonstrated by the coding theorem. Only scalar difference measurements are considered.","PeriodicalId":433761,"journal":{"name":"Proceedings. 2001 IEEE International Symposium on Information Theory (IEEE Cat. No.01CH37252)","volume":"41 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124699187","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 : 2001-09-12DOI: 10.1109/ISIT.2001.936049
N. Sidiropoulos
In 1911, Caratheodory et al. published a result that is a cornerstone of line spectra (harmonic) analysis and modern parametric harmonic retrieval. This result was later popularized by Pisarenko, and is widely known in the spectral analysis community as "Caratheodory's parameterization". The uniqueness part of Caratheodory's result specifies the condition under which one can uniquely recover the frequencies (spectral lines) in a finite sum of one-dimensional harmonics, given a finite set of measurements. The multidimensional case is of interest in a variety of problems, including joint multiuser/multipath carrier offset, angle, and delay estimation, yet the associated model identifiability problem has not been thoroughly addressed. This is the subject of the main theorem in this paper. The proof relies on a previous result regarding the uniqueness of low-rank decomposition of N-way arrays.
{"title":"Identifiability of harmonic parameterization in N dimensions","authors":"N. Sidiropoulos","doi":"10.1109/ISIT.2001.936049","DOIUrl":"https://doi.org/10.1109/ISIT.2001.936049","url":null,"abstract":"In 1911, Caratheodory et al. published a result that is a cornerstone of line spectra (harmonic) analysis and modern parametric harmonic retrieval. This result was later popularized by Pisarenko, and is widely known in the spectral analysis community as \"Caratheodory's parameterization\". The uniqueness part of Caratheodory's result specifies the condition under which one can uniquely recover the frequencies (spectral lines) in a finite sum of one-dimensional harmonics, given a finite set of measurements. The multidimensional case is of interest in a variety of problems, including joint multiuser/multipath carrier offset, angle, and delay estimation, yet the associated model identifiability problem has not been thoroughly addressed. This is the subject of the main theorem in this paper. The proof relies on a previous result regarding the uniqueness of low-rank decomposition of N-way arrays.","PeriodicalId":433761,"journal":{"name":"Proceedings. 2001 IEEE International Symposium on Information Theory (IEEE Cat. No.01CH37252)","volume":"78 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133278748","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 : 2001-09-12DOI: 10.1109/ISIT.2001.935987
F. Alajaji, Po-Ning Chen, Z. Rached
In a previous work, Poor and Verdu (1995) established an upper bound to the reliability function of arbitrary single-user discrete-time channels with memory. They also conjectured that their bound is tight for all coding rates. In this work, we demonstrate via a counterexample involving memoryless binary erasure channels that the Poor-Verdu upper bound is, unfortunately, not tight at low rates. We also examine possible improvements to this bound.
{"title":"On the Poor-Verdu conjecture for the reliability function of channels with memory","authors":"F. Alajaji, Po-Ning Chen, Z. Rached","doi":"10.1109/ISIT.2001.935987","DOIUrl":"https://doi.org/10.1109/ISIT.2001.935987","url":null,"abstract":"In a previous work, Poor and Verdu (1995) established an upper bound to the reliability function of arbitrary single-user discrete-time channels with memory. They also conjectured that their bound is tight for all coding rates. In this work, we demonstrate via a counterexample involving memoryless binary erasure channels that the Poor-Verdu upper bound is, unfortunately, not tight at low rates. We also examine possible improvements to this bound.","PeriodicalId":433761,"journal":{"name":"Proceedings. 2001 IEEE International Symposium on Information Theory (IEEE Cat. No.01CH37252)","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132334323","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 : 2001-09-12DOI: 10.1109/ISIT.2001.935991
P. Viswanath, V. Anantharam
We consider code division multiaccess (DS-CDMA) with colored additive Gaussian noise. The best "performance" (by an appropriate choice of powers and signature sequences of the users) of this multiple access scheme is a function of the constraints/requirements of the individual users and of the structure of the additive colored noise. The thesis of this paper is that this function has a saddle property: it is convex in the covariance of the additive noise and concave in the user constraints/requirements. By working on a partial order on probability measures (the Schur-order or the order of dilation), we strengthen this thesis by showing that the performance of CDMA is Schur-order preserving. In other words, the more skewed the user constraints/requirements are, the performance decreases. On the other hand, the more skewed the covariance of the additive noise is, the performance increases. In contrast, we show that this saddle function property breaks down if the signature sequences cannot be specifically designed and are instead chosen randomly.
{"title":"A Schur-saddle function property in CDMA","authors":"P. Viswanath, V. Anantharam","doi":"10.1109/ISIT.2001.935991","DOIUrl":"https://doi.org/10.1109/ISIT.2001.935991","url":null,"abstract":"We consider code division multiaccess (DS-CDMA) with colored additive Gaussian noise. The best \"performance\" (by an appropriate choice of powers and signature sequences of the users) of this multiple access scheme is a function of the constraints/requirements of the individual users and of the structure of the additive colored noise. The thesis of this paper is that this function has a saddle property: it is convex in the covariance of the additive noise and concave in the user constraints/requirements. By working on a partial order on probability measures (the Schur-order or the order of dilation), we strengthen this thesis by showing that the performance of CDMA is Schur-order preserving. In other words, the more skewed the user constraints/requirements are, the performance decreases. On the other hand, the more skewed the covariance of the additive noise is, the performance increases. In contrast, we show that this saddle function property breaks down if the signature sequences cannot be specifically designed and are instead chosen randomly.","PeriodicalId":433761,"journal":{"name":"Proceedings. 2001 IEEE International Symposium on Information Theory (IEEE Cat. No.01CH37252)","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129238433","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 : 2001-09-12DOI: 10.1109/ISIT.2001.936137
K. Kamakura, I. Sasase
Conventionally, optical CDMA systems with on-off keying (OOK) require a time duration equalling a signature sequence length to transmit only one bit. Since the crosscorrelation between the signature sequences results in multi-access interference (MAI), the signature sequences are designed so that their weight distribution is sparse for their long length, and then MAI rarely occurs. With this view, optical orthogonal codes (OOC) are investigated, which are characterized by a quadruple (L,W,/spl lambda//sub a/,/spl lambda//sub c/), where L and W are length and weight of sequences, respectively, and /spl lambda//sub a/, and /spl lambda//sub c/, are maximum off-peak autocorrelation and maximum crosscorrelation, respectively. Thus, the use of OOC makes the effect of MAI small, but has to spend a long duration for one bit. In this paper, we propose an embedded modulation scheme, where an asymmetric error correcting (AEC) code is embedded in an OOC used for identification in optical CDMA. We show that the proposed scheme achieves the same bit error rate (BER) as conventional systems, with less average number of photons.
{"title":"A new modulation scheme using asymmetric error correcting code embedded in optical orthogonal code for optical CDMA","authors":"K. Kamakura, I. Sasase","doi":"10.1109/ISIT.2001.936137","DOIUrl":"https://doi.org/10.1109/ISIT.2001.936137","url":null,"abstract":"Conventionally, optical CDMA systems with on-off keying (OOK) require a time duration equalling a signature sequence length to transmit only one bit. Since the crosscorrelation between the signature sequences results in multi-access interference (MAI), the signature sequences are designed so that their weight distribution is sparse for their long length, and then MAI rarely occurs. With this view, optical orthogonal codes (OOC) are investigated, which are characterized by a quadruple (L,W,/spl lambda//sub a/,/spl lambda//sub c/), where L and W are length and weight of sequences, respectively, and /spl lambda//sub a/, and /spl lambda//sub c/, are maximum off-peak autocorrelation and maximum crosscorrelation, respectively. Thus, the use of OOC makes the effect of MAI small, but has to spend a long duration for one bit. In this paper, we propose an embedded modulation scheme, where an asymmetric error correcting (AEC) code is embedded in an OOC used for identification in optical CDMA. We show that the proposed scheme achieves the same bit error rate (BER) as conventional systems, with less average number of photons.","PeriodicalId":433761,"journal":{"name":"Proceedings. 2001 IEEE International Symposium on Information Theory (IEEE Cat. No.01CH37252)","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115489989","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 : 2001-09-12DOI: 10.1109/ISIT.2001.935917
S. Jafar, S. Vishwanath, A. Goldsmith
We analyze the capacity region for the multiple access channel with multiple transmit and receive antennas. For Rayleigh fading with perfect channel state information at the receiver (CSIR) and only a knowledge of the spatial correlations at the transmitter, we determine the optimal transmit strategies to achieve the points on the boundary of the capacity region under various correlation models.
{"title":"Vector MAC capacity region with covariance feedback","authors":"S. Jafar, S. Vishwanath, A. Goldsmith","doi":"10.1109/ISIT.2001.935917","DOIUrl":"https://doi.org/10.1109/ISIT.2001.935917","url":null,"abstract":"We analyze the capacity region for the multiple access channel with multiple transmit and receive antennas. For Rayleigh fading with perfect channel state information at the receiver (CSIR) and only a knowledge of the spatial correlations at the transmitter, we determine the optimal transmit strategies to achieve the points on the boundary of the capacity region under various correlation models.","PeriodicalId":433761,"journal":{"name":"Proceedings. 2001 IEEE International Symposium on Information Theory (IEEE Cat. No.01CH37252)","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132180803","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 : 2001-09-12DOI: 10.1109/ISIT.2001.935882
T. Oskiper, H. V. Poor
A new recursive M-ary change detection algorithm is described.
提出了一种新的递归矩阵变化检测算法。
{"title":"Matrix CUSUM: a recursive multi-hypothesis change detection algorithm","authors":"T. Oskiper, H. V. Poor","doi":"10.1109/ISIT.2001.935882","DOIUrl":"https://doi.org/10.1109/ISIT.2001.935882","url":null,"abstract":"A new recursive M-ary change detection algorithm is described.","PeriodicalId":433761,"journal":{"name":"Proceedings. 2001 IEEE International Symposium on Information Theory (IEEE Cat. No.01CH37252)","volume":"197 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121405334","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 : 2001-09-12DOI: 10.1109/ISIT.2001.936036
S. Buzzi, M. Lops, H. Poor
The problem of delay estimation in DS/CDMA systems employing aperiodic spreading codes is considered. A blind procedure is proposed, which does not require the use of known training symbols nor does it rely on the knowledge of other users' signature waveforms. This procedure can be implemented recursively and has a computational complexity that is quadratic in the processing gain. Simulation results reveal that the proposed algorithm provides delay estimates with an error smaller than 10% of the CDMA system chip interval.
{"title":"A blind delay estimation algorithm for long-code DS/CDMA systems","authors":"S. Buzzi, M. Lops, H. Poor","doi":"10.1109/ISIT.2001.936036","DOIUrl":"https://doi.org/10.1109/ISIT.2001.936036","url":null,"abstract":"The problem of delay estimation in DS/CDMA systems employing aperiodic spreading codes is considered. A blind procedure is proposed, which does not require the use of known training symbols nor does it rely on the knowledge of other users' signature waveforms. This procedure can be implemented recursively and has a computational complexity that is quadratic in the processing gain. Simulation results reveal that the proposed algorithm provides delay estimates with an error smaller than 10% of the CDMA system chip interval.","PeriodicalId":433761,"journal":{"name":"Proceedings. 2001 IEEE International Symposium on Information Theory (IEEE Cat. No.01CH37252)","volume":"72 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127141209","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 : 2001-09-12DOI: 10.1109/ISIT.2001.936164
M. Chiang, T. Cover
We show that the duality between channel capacity and data compression is retained when state information is available to the sender, to the receiver, to both, or to neither. We also present a unified theory for different cases of channel capacity with state information, which extends existing results to arbitrary pairs of i.i.d. state information (S/sub 1/, S/sub 2/) available at the sender and at the receiver, respectively. The general formula C=max(p(u, |s/sub 1/))[I(U; S/sub 2/, Y)-I(U; S/sub 1/)] assumes the same form as the Wyner-Ziv rate distortion function with state information. The Wyner-Ziv formula also unifies four special cases of the rate distortion problem with the state information.
{"title":"Unified duality between channel capacity and rate distortion with state information","authors":"M. Chiang, T. Cover","doi":"10.1109/ISIT.2001.936164","DOIUrl":"https://doi.org/10.1109/ISIT.2001.936164","url":null,"abstract":"We show that the duality between channel capacity and data compression is retained when state information is available to the sender, to the receiver, to both, or to neither. We also present a unified theory for different cases of channel capacity with state information, which extends existing results to arbitrary pairs of i.i.d. state information (S/sub 1/, S/sub 2/) available at the sender and at the receiver, respectively. The general formula C=max(p(u, |s/sub 1/))[I(U; S/sub 2/, Y)-I(U; S/sub 1/)] assumes the same form as the Wyner-Ziv rate distortion function with state information. The Wyner-Ziv formula also unifies four special cases of the rate distortion problem with the state information.","PeriodicalId":433761,"journal":{"name":"Proceedings. 2001 IEEE International Symposium on Information Theory (IEEE Cat. No.01CH37252)","volume":"19 1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126301874","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}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：