Pub Date : 2005-10-31DOI: 10.1109/ISIT.2005.1523362
T. Miyazawa, I. Sasase
In optical code division multiple access (CDMA) networks, the system which equips tunable transmitters and fixed receivers (i.e. TTFR) achieves simple configuration and protocols. However, when there are other simultaneous users who transmits pulses with the same code, large amount of multiple access interferences (MAIs) cause serious performance degradation. In this paper, we propose second encoding scheme in which first-encoded optical pulses are further encoded by the second optical orthogonal code (OOC) assigned to the transmitter. The proposed system with second encoding scheme can achieve higher processing gain in the correlator than the conventional system without second encoding scheme because the number of weights increases due to the second encoding. This results in the mitigation of the effect of MAIs. We analyze performance of the proposed system and show that the proposed system with second coding scheme can achieve better bit error probability than the conventional system without second encoding scheme
{"title":"Mitigation of MAIs by the second encoding scheme in TTFR-based optical CDMA systems","authors":"T. Miyazawa, I. Sasase","doi":"10.1109/ISIT.2005.1523362","DOIUrl":"https://doi.org/10.1109/ISIT.2005.1523362","url":null,"abstract":"In optical code division multiple access (CDMA) networks, the system which equips tunable transmitters and fixed receivers (i.e. TTFR) achieves simple configuration and protocols. However, when there are other simultaneous users who transmits pulses with the same code, large amount of multiple access interferences (MAIs) cause serious performance degradation. In this paper, we propose second encoding scheme in which first-encoded optical pulses are further encoded by the second optical orthogonal code (OOC) assigned to the transmitter. The proposed system with second encoding scheme can achieve higher processing gain in the correlator than the conventional system without second encoding scheme because the number of weights increases due to the second encoding. This results in the mitigation of the effect of MAIs. We analyze performance of the proposed system and show that the proposed system with second coding scheme can achieve better bit error probability than the conventional system without second encoding scheme","PeriodicalId":166130,"journal":{"name":"Proceedings. International Symposium on Information Theory, 2005. ISIT 2005.","volume":"95 34 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129209712","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}
Li and Li conjectured that in an undirected network with multiple unicast sessions, network coding does not lead to any coding gain. Surprisingly enough, this conjecture could not so far be verified even for the simple network consisting of K3,2 with four source-sink pairs. Using entropy calculus, we provide the first verification of the Li-Li conjecture for this network. We extend our bound to the case of an arbitrary directed bipartite network
{"title":"On the capacity of multiple unicast sessions in undirected graphs","authors":"K. Jain, V. Vazirani, G. Yuval","doi":"10.1109/TIT.2006.874543","DOIUrl":"https://doi.org/10.1109/TIT.2006.874543","url":null,"abstract":"Li and Li conjectured that in an undirected network with multiple unicast sessions, network coding does not lead to any coding gain. Surprisingly enough, this conjecture could not so far be verified even for the simple network consisting of K3,2 with four source-sink pairs. Using entropy calculus, we provide the first verification of the Li-Li conjecture for this network. We extend our bound to the case of an arbitrary directed bipartite network","PeriodicalId":166130,"journal":{"name":"Proceedings. International Symposium on Information Theory, 2005. ISIT 2005.","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123935386","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.2005.1523389
Teng Li, Xiaowei Jin, O. Collins
This paper presents a new coding scheme with capacity approaching performance for correlated fading channels with unknown state. The transceiver employs a deep interleaver to decompose the original channel into a bank of independent fading sub-channels. Sub-channels are successively decoded and decisions are fed back as new training symbols. The unknown state of each sub-channel can be estimated from past channel observations and future channel outputs. We show that the sub-channel has the same capacity as the original channel, given a sufficiently large estimation window. Therefore, the correlated fading channel capacity can be approached if each sub-channel uses an optimized capacity achieving code. Simulations show a universal performance within 1 dB of capacity upper bound regardless of fading rate. The scheme is also robust against decision feedback errors when the sub-channels use a long LDPC code
{"title":"Approaching capacity on correlated fading channels with unknown state","authors":"Teng Li, Xiaowei Jin, O. Collins","doi":"10.1109/ISIT.2005.1523389","DOIUrl":"https://doi.org/10.1109/ISIT.2005.1523389","url":null,"abstract":"This paper presents a new coding scheme with capacity approaching performance for correlated fading channels with unknown state. The transceiver employs a deep interleaver to decompose the original channel into a bank of independent fading sub-channels. Sub-channels are successively decoded and decisions are fed back as new training symbols. The unknown state of each sub-channel can be estimated from past channel observations and future channel outputs. We show that the sub-channel has the same capacity as the original channel, given a sufficiently large estimation window. Therefore, the correlated fading channel capacity can be approached if each sub-channel uses an optimized capacity achieving code. Simulations show a universal performance within 1 dB of capacity upper bound regardless of fading rate. The scheme is also robust against decision feedback errors when the sub-channels use a long LDPC code","PeriodicalId":166130,"journal":{"name":"Proceedings. International Symposium on Information Theory, 2005. ISIT 2005.","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123969289","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.2005.1523465
B. Fortescue, H. Lo
We present explicit bounds on the classical communication cost and inefficiency of entanglement dilution via the Lo-Popescu protocol, for the case of two-term (single-qubit) entangled states. By considering a two-stage dilution, we consequently use prior results to obtain meaningful bounds on the classical communication cost and inefficiency of dilution between two-term partially entangled states
{"title":"Inefficiency and classical communication bounds for conversion between partially entangled pure bipartite quantum states","authors":"B. Fortescue, H. Lo","doi":"10.1109/ISIT.2005.1523465","DOIUrl":"https://doi.org/10.1109/ISIT.2005.1523465","url":null,"abstract":"We present explicit bounds on the classical communication cost and inefficiency of entanglement dilution via the Lo-Popescu protocol, for the case of two-term (single-qubit) entangled states. By considering a two-stage dilution, we consequently use prior results to obtain meaningful bounds on the classical communication cost and inefficiency of dilution between two-term partially entangled states","PeriodicalId":166130,"journal":{"name":"Proceedings. International Symposium on Information Theory, 2005. ISIT 2005.","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123991163","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.2005.1523383
R. Bansal, J. Sau
We consider the problem of designing weakly universal codes for stationary and ergodic processes with countable alphabet and present a set of algorithms. First two algorithms use a combination of an integer coding algorithm and Lempel-Ziv algorithms (incremental parsing based algorithm and one based on recurrence times). Third algorithm converts the source into a finite alphabet process in step one through an integer coding algorithm and then uses LZ-78 in second step. Asymptotic optimality of all three is proved in full generality. We make use of Shannon-McMillan-Breiman theorem for countable alphabet and its extension for asymptotically mean stationary processes
{"title":"Weakly universal LZ-extended codes for sources with countable alphabet","authors":"R. Bansal, J. Sau","doi":"10.1109/ISIT.2005.1523383","DOIUrl":"https://doi.org/10.1109/ISIT.2005.1523383","url":null,"abstract":"We consider the problem of designing weakly universal codes for stationary and ergodic processes with countable alphabet and present a set of algorithms. First two algorithms use a combination of an integer coding algorithm and Lempel-Ziv algorithms (incremental parsing based algorithm and one based on recurrence times). Third algorithm converts the source into a finite alphabet process in step one through an integer coding algorithm and then uses LZ-78 in second step. Asymptotic optimality of all three is proved in full generality. We make use of Shannon-McMillan-Breiman theorem for countable alphabet and its extension for asymptotically mean stationary processes","PeriodicalId":166130,"journal":{"name":"Proceedings. International Symposium on Information Theory, 2005. ISIT 2005.","volume":"106 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123719178","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.2005.1523625
Ioannis Kontoyiannis, Brian Lucena
Suppose we are allowed to observe two equally noisy versions of some signal X, where the level of the noise is fixed. We are given a choice: we can either observe two independent noisy versions of X, or two correlated ones. We show that, contrary to what classical statistical intuition suggests, it is often the case that correlated data is more valuable than independent data. We investigate this phenomenon in a variety of contexts, we give numerous examples for standard families of channels, and we present general sufficient conditions for deciding this dilemma. One of these conditions draws an interesting connection with the information-theoretic notion of "synergy," which has received a lot of attention in the neuroscience literature recently
{"title":"Mutual information, synergy and some curious phenomena for simple channels","authors":"Ioannis Kontoyiannis, Brian Lucena","doi":"10.1109/ISIT.2005.1523625","DOIUrl":"https://doi.org/10.1109/ISIT.2005.1523625","url":null,"abstract":"Suppose we are allowed to observe two equally noisy versions of some signal X, where the level of the noise is fixed. We are given a choice: we can either observe two independent noisy versions of X, or two correlated ones. We show that, contrary to what classical statistical intuition suggests, it is often the case that correlated data is more valuable than independent data. We investigate this phenomenon in a variety of contexts, we give numerous examples for standard families of channels, and we present general sufficient conditions for deciding this dilemma. One of these conditions draws an interesting connection with the information-theoretic notion of \"synergy,\" which has received a lot of attention in the neuroscience literature recently","PeriodicalId":166130,"journal":{"name":"Proceedings. International Symposium on Information Theory, 2005. ISIT 2005.","volume":"495 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116326072","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.2005.1523694
T. Chan
It is well-known that linear network codes are sufficient to achieve maximal network throughput (or bandwidth utilization efficiency) in the single-session multicast scenario. However, it is not known whether they are still optimal in maximizing network throughput in the multiple-session scenario (either single-source or multiple-source ones). In this paper, we prove that a more general class of network codes - group network codes - are sufficient to achieve the maximal throughput in the single-source multiple-session multicast scenario
{"title":"On the optimality of group network codes","authors":"T. Chan","doi":"10.1109/ISIT.2005.1523694","DOIUrl":"https://doi.org/10.1109/ISIT.2005.1523694","url":null,"abstract":"It is well-known that linear network codes are sufficient to achieve maximal network throughput (or bandwidth utilization efficiency) in the single-session multicast scenario. However, it is not known whether they are still optimal in maximizing network throughput in the multiple-session scenario (either single-source or multiple-source ones). In this paper, we prove that a more general class of network codes - group network codes - are sufficient to achieve the maximal throughput in the single-source multiple-session multicast scenario","PeriodicalId":166130,"journal":{"name":"Proceedings. International Symposium on Information Theory, 2005. ISIT 2005.","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116500357","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.2005.1523712
U. Sripati, B. Rajan, V. Shashidhar
It is known that multi-antenna transmissions over frequency-selective channels can provide a diversity gain that is product of the number of transmit antennas, the receive antennas and the length of the channel impulse response. Liu, Xin and Giannakis have studied multi-antenna orthogonal frequency division multiplexing (OFDM) through frequency-selective Rayleigh-fading channels and have introduced the concept of space-time frequency (STF) coding to enable maximum diversity and high coding gains. It is known that under some conditions, an n-length cyclic code C over Fqm (n|qm - 1, and m les n) can have fullrank i.e Rankq(C) = m. Designs for space-time codes suitable for both quasi-static fading channels and block-fading channels have been derived from n length cyclic codes over Fqm. In this paper, we present a simplified design of STF codes using designs derived from cyclic codes to obtain group space-time-frequency (GSTF) codes for frequency selective Rayleigh fading channels. These codes achieve maximum diversity gain
众所周知，在频率选择信道上的多天线传输可以提供分集增益，该分集增益是发射天线数量、接收天线数量和信道脉冲响应长度的乘积。Liu, Xin和Giannakis通过频率选择瑞利衰落信道研究了多天线正交频分复用(OFDM)，并引入了时空频率(STF)编码的概念，以实现最大的分集和高编码增益。已知在某些条件下，Fqm上的n长循环码C (n|qm - 1, m les n)可以具有全秩，即Rankq(C) = m。基于Fqm上的n长循环码，已经设计出适合准静态衰落信道和块衰落信道的空时码。在本文中，我们提出了一种简化的STF码设计，使用循环码的设计来获得频率选择性瑞利衰落信道的群空时频(GSTF)码。这些码实现了最大的分集增益
{"title":"Full-diversity group space-time-frequency (GSTF) codes from cyclic codes","authors":"U. Sripati, B. Rajan, V. Shashidhar","doi":"10.1109/ISIT.2005.1523712","DOIUrl":"https://doi.org/10.1109/ISIT.2005.1523712","url":null,"abstract":"It is known that multi-antenna transmissions over frequency-selective channels can provide a diversity gain that is product of the number of transmit antennas, the receive antennas and the length of the channel impulse response. Liu, Xin and Giannakis have studied multi-antenna orthogonal frequency division multiplexing (OFDM) through frequency-selective Rayleigh-fading channels and have introduced the concept of space-time frequency (STF) coding to enable maximum diversity and high coding gains. It is known that under some conditions, an n-length cyclic code C over Fqm (n|qm - 1, and m les n) can have fullrank i.e Rankq(C) = m. Designs for space-time codes suitable for both quasi-static fading channels and block-fading channels have been derived from n length cyclic codes over Fqm. In this paper, we present a simplified design of STF codes using designs derived from cyclic codes to obtain group space-time-frequency (GSTF) codes for frequency selective Rayleigh fading channels. These codes achieve maximum diversity gain","PeriodicalId":166130,"journal":{"name":"Proceedings. International Symposium on Information Theory, 2005. ISIT 2005.","volume":"39 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121709815","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.2005.1523310
K. Iwata
This paper revisits a multiple-access communication system for correlated sources with an array of independent channels in view of information spectrum method, and characterizes new necessary and sufficient conditions for the separation theorem holds for general class of sources and channels. This result increases the understanding of the source-channel separation theorem. Moreover, this theorem has not only theoretical, but also has a practical aspect, because the separation principle of this paper can divide communication systems for sending correlated sources over an array of independent channels into general correlated source coding subsystems and general channel coding subsystems. We also provide the necessary and sufficient conditions for the transmission of general correlated sources over general MAC by using the information spectrum method
{"title":"On multiple-access communication system for general correlated sources with an array of general independent channels","authors":"K. Iwata","doi":"10.1109/ISIT.2005.1523310","DOIUrl":"https://doi.org/10.1109/ISIT.2005.1523310","url":null,"abstract":"This paper revisits a multiple-access communication system for correlated sources with an array of independent channels in view of information spectrum method, and characterizes new necessary and sufficient conditions for the separation theorem holds for general class of sources and channels. This result increases the understanding of the source-channel separation theorem. Moreover, this theorem has not only theoretical, but also has a practical aspect, because the separation principle of this paper can divide communication systems for sending correlated sources over an array of independent channels into general correlated source coding subsystems and general channel coding subsystems. We also provide the necessary and sufficient conditions for the transmission of general correlated sources over general MAC by using the information spectrum method","PeriodicalId":166130,"journal":{"name":"Proceedings. International Symposium on Information Theory, 2005. ISIT 2005.","volume":"15 2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125625337","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.2005.1523738
A. Orlitsky, N. Santhanam, K. Viswanathan, Narayana Zhang
We obtain bounds on the probability that the n'th variable in a stationary random process differs from all previous ones, and use it to show that the pattern entropy rate of any finite-entropy stationary process equals the process entropy rate. In the particular case of i.i.d. processes we also bound the speed at which the per-symbol pattern entropy converges to the sequence entropy
{"title":"Innovation and pattern entropy of stationary processes","authors":"A. Orlitsky, N. Santhanam, K. Viswanathan, Narayana Zhang","doi":"10.1109/ISIT.2005.1523738","DOIUrl":"https://doi.org/10.1109/ISIT.2005.1523738","url":null,"abstract":"We obtain bounds on the probability that the n'th variable in a stationary random process differs from all previous ones, and use it to show that the pattern entropy rate of any finite-entropy stationary process equals the process entropy rate. In the particular case of i.i.d. processes we also bound the speed at which the per-symbol pattern entropy converges to the sequence entropy","PeriodicalId":166130,"journal":{"name":"Proceedings. International Symposium on Information Theory, 2005. ISIT 2005.","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127954161","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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