Language：English   Publishing type：Research paper (international conference proceedings)  

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Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1109/ACCESS.2024.3401471

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Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：Springer Nature Switzerland  

DOI： 10.1007/978-3-031-57942-4_37

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Authorship：Lead author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：Elsevier  

DOI： 10.1016/j.comnet.2023.110078

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Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：Springer  

DOI： 10.1007/978-3-031-28694-0_55

Scopus

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Publishing type：Research paper (international conference proceedings)   Publisher：Springer  

DOI： 10.1007/978-3-030-99584-3_15

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Other Link： https://dblp.uni-trier.de/db/conf/aina/aina2022-1.html#WatanabeKK22

Authorship：Lead author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：The Institute of Electronics, Information and Communication Engineers  

<p>This paper investigates an adversarial model in the scenario of private information retrieval (PIR) from n coded storage servers, called Byzantine adversary. The Byzantine adversary is defined as the one altering b server responses and erasing u server responses to a user's query. In this paper, two types of Byzantine adversaries are considered; 1) the classic omniscient type that has the full knowledge on n servers as considered in existing literature, and 2) the reasonable limited-knowledge type that has information on only b+u servers, i.e., servers under the adversary's control. For these two types, this paper reveals that the resistance of a PIR scheme, i.e., the condition of b and u to correctly obtain the desired message, can be expressed in terms of a code parameter called the coset distance of linear codes employed in the scheme. For the omniscient type, the derived condition expressed by the coset distance is tighter and more precise than the estimation of the resistance by the minimum Hamming weight of the codes considered in existing researches. Furthermore, this paper also clarifies that if the adversary is limited-knowledge, the resistance of a PIR scheme could exceed that for the case of the omniscient type. Namely, PIR schemes can increase their resistance to Byzantine adversaries by allowing the limitation on adversary's knowledge.</p>

DOI： 10.1587/transfun.2020DMP0018

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Publishing type：Research paper (scientific journal)  

DOI： 10.1587/transfun.2020CIP0026

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Other Link： https://dblp.uni-trier.de/db/journals/ieiceta/ieiceta104.html#KoikeHKI21

Language：English   Publisher：Institute of Electronics, Information and Communications Engineers (IEICE)  

<p>In private information retrieval (PIR) from coded storage servers, consider the case where some of servers are Byzantine adversaries and unresponsive. There have been proposed several specialized schemes guaranteeing that the user can correctly obtain the desired message even in the adversarial situation. However, to the best of our knowledge, such resistance to the adversaries in PIR schemes based on arbitrary codes have been not precisely characterized. In this paper, we reveal that the exact resistance to Byzantine and unresponsive servers is expressed in terms of the coset distance of linear codes in linear PIR schemes based on arbitrary storage code.</p>

DOI： 10.1587/comex.2020xbl0055

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Publishing type：Research paper (scientific journal)  

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Publishing type：Research paper (international conference proceedings)   Publisher：IEEE  

DOI： 10.1109/LCN.2018.8638129

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Publishing type：Research paper (international conference proceedings)   Publisher：ACM  

DOI： 10.1145/3125719.3132089

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Language：English   Publisher：The Institute of Electronics, Information and Communication Engineers  

<p>Content-centric networking (CCN) is an emerging networking architecture that is being actively investigated in both the research and industrial communities. In the latest version of CCN, a large number of interests have to be issued when large content is retrieved. Since CCN routers have to search several tables for each incoming interest, this could cause a serious problem of router workload. In order to solve this problem, this paper introduces a novel strategy of "grouping" multiple interests with common information and "packing" them to a special interest called the list interest. Our list interest is designed to co-operate with the manifest of CCN as its dual. This paper demonstrates that by skipping and terminating several search steps using the common information in the list interest, the router can search its tables for the list interest-based request with dramatically smaller complexity than the case of the standard interest-based request. Furthermore, we also consider the deployment of list interests and design a novel TCP-like congestion control method for list interests to employ them just like standard interests.</p>

DOI： 10.1587/transcom.2016CNP0004

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Publishing type：Research paper (international conference proceedings)   Publisher：IEEE  

DOI： 10.1109/GLOCOM.2016.7842348

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Publishing type：Research paper (international conference proceedings)   Publisher：ACM  

DOI： 10.1145/2984356.2984360

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Publishing type：Research paper (international conference proceedings)   Publisher：IEEE Computer Society  

DOI： 10.1109/AINA.2016.32

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Language：English   Publishing type：Research paper (international conference proceedings)  

DOI： 10.1109/MASS.2015.20

Web of Science

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Language：English   Publishing type：Research paper (international conference proceedings)  

DOI： 10.1109/MASS.2015.24

Web of Science

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Publishing type：Research paper (scientific journal)   Publisher：Institute of Electrical {\&} Electronics Engineers ({IEEE})  

By extending the notion of minimum rank distance, this paper introduces two
new relative code parameters of a linear code C_1 of length n over a field
extension and its subcode C_2. One is called the relative
dimension/intersection profile (RDIP), and the other is called the relative
generalized rank weight (RGRW). We clarify their basic properties and the
relation between the RGRW and the minimum rank distance. As applications of the
RDIP and the RGRW, the security performance and the error correction capability
of secure network coding, guaranteed independently of the underlying network
code, are analyzed and clarified. We propose a construction of secure network
coding scheme, and analyze its security performance and error correction
capability as an example of applications of the RDIP and the RGRW. Silva and
Kschischang showed the existence of a secure network coding in which no part of
the secret message is revealed to the adversary even if any dim C_1-1 links are
wiretapped, which is guaranteed over any underlying network code. However, the
explicit construction of such a scheme remained an open problem. Our new
construction is just one instance of secure network coding that solves this
open problem.

DOI： 10.1109/TIT.2015.2429713

arXiv

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Publishing type：Research paper (international conference proceedings)   Publisher：Institute of Electrical {\&} Electronics Engineers ({IEEE})  

DOI： 10.1109/ifipnetworking.2015.7145300

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Language：English   Publisher：The Institute of Electronics, Information and Communication Engineers  

This paper proposes a coding scheme to securely store a secret file in a distributed storage system that uses an arbitrary regenerating code. Our scheme encodes the secret file to the input of a certain regenerating code by using the coset coding scheme with a maximum rank distance (MRD) code. We show that our scheme can protect the secret file from being leaked to an eavesdropper in the distributed storage system. Existing security schemes for distributed storage systems are based on specific regenerating codes, and they cannot be used with other regenerating codes. In contrast, our scheme can guarantee the security against the eavesdropper independently of the construction of the underlying regenerating code.

DOI： 10.1587/comex.2.442

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Language：English   Publisher：The Institute of Electronics, Information and Communication Engineers  

DOI： 10.1587/transfun.E95.A.2067

Scopus

CiNii Books

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Other Link： https://www.wikidata.org/entity/Q57735066

Language：English   Publisher：IEEE  

DOI： 10.1109/Allerton.2012.6483264

Scopus

arXiv

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Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：IEEE  

DOI： 10.1109/ISIT.2012.6283510

Scopus

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Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：IEEE  

DOI： 10.1109/Allerton.2011.6120269

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Language：English   Publisher：The Institute of Electronics, Information and Communication Engineers  

This paper presents a novel technique to realize Karnin et al.'s (k,n)-threshold schemes over binary field extensions as a software. Our realization uses the matrix representation of finite fields and matrix-vector multiplications, and enables rapid operations in software implementation. The theoretical evaluation and computer simulation reveal that our realization of Karnin et al.'s scheme achieves much faster processing time than the ordinary symbol oriented realization of the scheme. Further, we show that our realization has comparable performance to the existing exclusive-OR-based fast schemes of Fujii et al. and Kurihara et al.

DOI： 10.1587/transfun.E94.A.1375

CiNii Books

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Language：English   Publishing type：Research paper (international conference proceedings)  

Web of Science

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Language：Japanese   Publisher：The Institute of Image Information and Television Engineers  

In this paper, we present an authentication mechanism for ISDB-T broadcast streams, especially a One-Seg broadcast stream, which is suitable for low-power devices. Our method makes it possible to authenticate data streams at a low computational cost. The method requires a small memory for buffering to process the broadcast stream and is resistant to packet-loss. We evaluated the computational cost of our method by computer simulation and theoretical estimation, and we show here that our method achieved good properties for authenticating data streams broadcast through lossy channels, e.g. wireless channels. Furthermore, we developed a mobile phone that can authenticate One-Seg broadcast streams with our method, and we report the effectiveness of our scheme here.

DOI： 10.3169/itej.64.1921

CiNii Books

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Publishing type：Research paper (international conference proceedings)   Publisher：SciTePress  

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Publishing type：Research paper (international conference proceedings)   Publisher：Springer  

DOI： 10.1007/978-3-642-25206-8_12

Scopus

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Language：English   Publishing type：Research paper (international conference proceedings)  

DOI： 10.1007/978-3-642-11145-7_5

Web of Science

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Language：English   Publisher：The Institute of Electronics, Information and Communication Engineers  

Shamir's (k, n)-threshold secret sharing scheme (threshold scheme) has two problems: a heavy computational cost is required to make shares and recover the secret, and a large storage capacity is needed to retain all the shares. As a solution to the heavy computational cost problem, several fast threshold schemes have been proposed. On the other hand, threshold ramp secret sharing schemes (ramp scheme) have been proposed in order to reduce each bit-size of shares in Shamir's scheme. However, there is no fast ramp scheme which has both low computational cost and low storage requirements. This paper proposes a new (k, L, n)-threshold ramp secret sharing scheme which uses just EXCLUSIVE-OR(XOR) operations to make shares and recover the secret at a low computational cost. Moreover, by proving that the fast (k, n)-threshold scheme in conjunction with a method to reduce the number of random numbers is an ideal secret sharing scheme, we show that our fast ramp scheme is able to reduce each bit-size of shares by allowing some degradation of security similar to the existing ramp schemes based on Shamir's threshold scheme.

DOI： 10.1587/transfun.E92.A.1808

CiNii Books

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Language：English   Publisher：The Institute of Electronics, Information and Communication Engineers  

In Shamir's (k,n)-threshold secret sharing scheme (threshold scheme) [1], a heavy computational cost is required to make n shares and recover the secret from k shares. As a solution to this problem, several fast threshold schemes have been proposed. However, there is no fast ideal (k,n)-threshold scheme, where k and n are arbitrary. This paper proposes a new fast (k,n)-threshold scheme which uses just EXCLUSIVE-OR (XOR) operations to make n shares and recover the secret from k shares. We prove that every combination of k or more participants can recover the secret, but every group of less than k participants cannot obtain any information about the secret in the proposed scheme. Moreover, the proposed scheme is an ideal secret sharing scheme similar to Shamir's scheme, in which every bitsize of shares equals that of the secret. We also evaluate the efficiency of the scheme, and show that our scheme realizes operations that are much faster than Shamir's.

DOI： 10.1093/ietfec/e91-a.9.2365

CiNii Books

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Language：English   Publishing type：Research paper (international conference proceedings)  

DOI： 10.1007/978-3-540-85886-7_31

Web of Science

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Language：English   Publisher：The Institute of Electronics, Information and Communication Engineers  

In Shamir's (k, n)-threshold secret sharing scheme [1], a heavy computational cost is required to make n shares and recover the secret from k shares. As a solution to this problem, several fast threshold schemes have been proposed. However, there is no fast ideal (k, n)-threshold scheme, where k&ge;3 and n is arbitrary. This paper proposes a new fast (3, n)-threshold scheme by using just EXCLUSIVE-OR (XOR) operations to make shares and recover the secret, which is an ideal secret sharing scheme similar to Shamir's scheme. Furthermore, we evaluate the efficiency of the scheme, and show that it is more efficient than Shamir's in terms of computational cost. Moreover, we suggest a fast (k, n)-threshold scheme can be constructed in a similar way by increasing the sets of random numbers constructing pieces of shares.

DOI： 10.1093/ietfec/e91-a.1.127

CiNii Books

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Language：English   Publishing type：Research paper (scientific journal)  

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Language：Japanese   Publisher：The Institute of Electronics, Information and Communication Engineers  

CiNii Books

CiNii Research

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Language：Japanese   Publisher：The Institute of Electronics, Information and Communication Engineers  

CiNii Books

CiNii Research

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Language：Japanese   Publisher：The Institute of Electronics, Information and Communication Engineers  

In this paper, we first introduce Shamir&rsquo;s construction of the (k; n)-threshold scheme as a typical linear secret-sharing scheme and explain the construction of the (k; l; n)-threshold ramp scheme proposed by Yamamoto and Blakley-Meadows as its extension. Then, by generalizing threshold ramp schemes with a linear code C1 and its subcode C2, we represent a linear secret-sharing scheme in terms of C1 and C2. As examples, we represent Shamir&rsquo;s (k; n)-threshold scheme and the (k; l; n)-threshold ramp scheme of Yamamoto and Blakley-Meadows using linear codes. Furthermore, we show that in linear secret-sharing schemes, the maximum amount of information leakage of a secret message and their strong security are characterized by the relative generalized Hamming weights (RGHW&rsquo;s) of C1 and C2 when every share is an element of a finite field.

DOI： 10.1587/essfr.9.14

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Other Link： https://dblp.uni-trier.de/db/journals/iacr/iacr2008.html#KuriharaKFT08

Language：Japanese   Publisher：技術情報協会  

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Event date： 2024.9

Language：Japanese   Presentation type：Oral presentation (general)  

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Event date： 2024.3

Language：Japanese   Presentation type：Oral presentation (general)  

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Event date： 2024.3

Language：Japanese   Presentation type：Oral presentation (general)  

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Event date： 2023.10 - 2023.11

Language：Japanese   Presentation type：Oral presentation (general)  

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Event date： 2023.3

Presentation type：Oral presentation (general)  

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Event date： 2022.10

Language：Japanese  

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Event date： 2021.3

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Event date： 2021

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Event date： 2020.9

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Event date： 2019.9

Language：English  

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Event date： 2019.9

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Event date： 2016.9

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Event date： 2016.3

Language：English  

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Event date： 2016.3

Language：Japanese  

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Event date： 2015.3

Language：Japanese  

In this paper, we first introduce Shamir's construction of the (k, n)-threshold scheme as a typical linear secret sharing scheme, and explain the construction of the (k, l, n)-threshold ramp scheme proposed by Yamamoto and Blakley-Meadows as its extension. Then, by generalizing the threshold ramp schemes with a general linear code C_1 and its subcode C_2, we introduce an expression of linear secret sharing scheme in terms of C_1 and C_2. As examples, we express Shamir's (k, n)-threshold scheme and the (k, l, n)-threshold ramp scheme of Yamamoto and Blakley-Meadows by linear codes. Furthermore, we show that in linear secret sharing schemes, the maximum amount of the information leakage of the secret message and their strong security are expressed in terms of the relative generalized Hamming weights (RGHW's) of C_1 and C_2 when every share is an element of a finite field. We also present detailed examples of this security analysis to help readers to gain understanding of the analytic technique.

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Event date： 2015.3

Language：Japanese  

Content-Centric Networking (CCN) has been recently attracting increasing attention as a future Internet architecture. In the CCN, a client has to follow the one-to-one matching principle between the request and the content chunk, and issue a network message called an Interest as a request to its corresponding content chunk called a Content Object. This implies that in the retrieval of a large content, a large number of interests are issued and CCN routers may suffer from the heavy workload and network traffic. To solve this problem, methods to aggregate multiple Interest messages to one Interest has been proposed. However, existing congestion control methods for CCN are not compatible with the aggregated interests, and as far as we know, no congestion control method for the aggregated Interests have been proposed yet. We propose TCP-like congestion control method designed for the interest aggregation. By the evaluation through computer simulations, it is clarified that our proposed method can control congestion in CCN similar to the TCP in the current Internet.

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Event date： 2015.3

Language：Japanese  

In this paper, we first introduce Shamir's construction of the (k, n)-threshold scheme as a typical linear secret sharing scheme, and explain the construction of the (k, l, n)-threshold ramp scheme proposed by Yamamoto and Blakley-Meadows as its extension. Then, by generalizing the threshold ramp schemes with a general linear code C_1 and its subcode C_2, we introduce an expression of linear secret sharing scheme in terms of C_1 and C_2. As examples, we express Shamir's (k, n)-threshold scheme and the (k, l, n)-threshold ramp scheme of Yamamoto and Blakley-Meadows by linear codes. Furthermore, we show that in linear secret sharing schemes, the maximum amount of the information leakage of the secret message and their strong security are expressed in terms of the relative generalized Hamming weights (RGHW's) of C_1 and C_2 when every share is an element of a finite field. We also present detailed examples of this security analysis to help readers to gain understanding of the analytic technique.

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Event date： 2015.3

Language：Japanese  

In the current Internet, many applications are based on DNS, the centralized name resolution system, assuming hosts are interconnected at all times. Such applications are not available in the network in a disaster, which is divided into several fragmented pieces. ICN (Information Centric Network) has itself a routing function toward each content, and there were several proposals to apply ICN to the disaster environment. These existing methods can only use the content caches on the way to the original content, and cannot use effectively all the available content caches within the limited network resources in the disaster. For effective caching, this paper investigates the optimization of potential based routing, resistant to topology changes in a disaster. consider the optimization of the strong potential routing to changes in the topology.

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Event date： 2015.3

Language：Japanese  

In this paper, we first introduce Shamir's construction of the (k, n)-threshold scheme as a typical linear secret sharing scheme, and explain the construction of the (k, l, n)-threshold ramp scheme proposed by Yamamoto and Blakley-Meadows as its extension. Then, by generalizing the threshold ramp schemes with a general linear code C_1 and its subcode C_2, we introduce an expression of linear secret sharing scheme in terms of C_1 and C_2. As examples, we express Shamir's (k, n)-threshold scheme and the (k, l, n)-threshold ramp scheme of Yamamoto and Blakley-Meadows by linear codes. Furthermore, we show that in linear secret sharing schemes, the maximum amount of the information leakage of the secret message and their strong security are expressed in terms of the relative generalized Hamming weights (RGHW's) of C_1 and C_2 when every share is an element of a finite field. We also present detailed examples of this security analysis to help readers to gain understanding of the analytic technique.

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Event date： 2015.3

Language：English  

In Named Data Networking (NDN), security is imposed on contents instead of end-to-end connections; therefore, every content contains a signature to prove its authenticity and integrity. While this property has many significant advantages, it causes big message overhead in some cases, especially if the content size is small. This overhead further increases if the content is generated by multiple authorities, e.g., in a moderator-controlled information sharing service, and needs to contain multiple signatures. We propose the use of Identity-Based Aggregate Signatures (IBAS) to decrease this overhead. Also, we provide a proof-of-concept IBAS implementation in NDN and compare its performance with existing Public Key Infrastructure RSA signatures.

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Event date： 2015.2

Language：Japanese  

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Event date： 2015.2

Language：Japanese  

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Event date： 2014.12

Language：Japanese   Presentation type：Oral presentation (invited, special)  

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Event date： 2011.7

Language：English  

Secret sharing scheme is an important tool for the management of secret information. For secret sharing scheme based on linear block codes, the amount of information leaked to adversaries has not been investigated. Hence, in existing constructions of secret sharing scheme based on arbitrary linear codes, some elements of a secret vector might leak out deterministically from a non-qualified set, like weakly-secure ramp threshold schemes. In this paper, we first define anti-access set as a set from which no element is deterministically leaked. We also introduce the conditions of a linear code and its dual code such that a specified set becomes an anti-access set in secret sharing scheme using the code. Then, we propose a secret sharing scheme based on a linear code C^⊥ whose dual code C is defined by a systematic parity check matrix. This realizes a similar access structure to threshold access structures, and every non-qualified set whose cardinality is less than or equal to α are anti-access sets (called α-strongly-secure). Further, we show that this construction is completely characterized by the generalized Hamming weight and the MDS-rank of C.

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Event date： 2010.8

Language：Japanese  

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Event date： 2010.3

Language：Japanese  

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Event date： 2010.1

Language：English   Presentation type：Oral presentation (general)  

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Event date： 2010.1

Language：English   Presentation type：Oral presentation (general)  

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Event date： 2009.7

Language：English  

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Event date： 2009.6

Language：English  

Hash functions using stream ciphers as components perform fast on a variety of platforms. However, stream-cipher-based hash functions (SCHs) have not been studied sufficiently yet. In this paper, we present a model of SCHs consisting of two parts: a pre-computation phase and a stream cipher phase. We apply this model to existing broken SCHs, Abacus and Boole, and analyze the vulnerabilities corresponding to existing attacks for each part of our model. By applying our model to these algorithms, weak parts in the algorithms are revealed, and we show that these vulnerabilities can be removed by minor modifications to each part. Furthermore, we clarify the requirements for the pre-computation phase and the stream cipher phase to realize secure SCHs.

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Event date： 2009.6

Language：English  

Hash functions using stream ciphers as components perform fast on a variety of platforms. However, stream-cipher-based hash functions (SCHs) have not been studied sufficiently yet. In this paper, we present a model of SCHs consisting of two parts: a pre-computation phase and a stream cipher phase. We apply this model to existing broken SCHs, Abacus and Boole, and analyze the vulnerabilities corresponding to existing attacks for each part of our model. By applying our model to these algorithms, weak parts in the algorithms are revealed, and we show that these vulnerabilities can be removed by minor modifications to each part. Furthermore, we clarify the requirements for the pre-computation phase and the stream cipher phase to realize secure SCHs.

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Event date： 2009.3

Language：English  

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Event date： 2008.10

Language：English   Presentation type：Oral presentation (general)  

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Event date： 2008.3

Language：Japanese  

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Event date： 2007.8

Language：English  

This paper proposes several extensions of fast (k,n)-threshold schemes which use EXCLUSIVE-OR(XOR) operations. We introduced the new concept of singular point of divided pieces of shares in part one. Several methods using singular point based on fast (k,n)-threshold schemes are proposed in this paper. These comprise a fast threshold ramp scheme and a method to embed additional information into shares. Similar to a ramp scheme based on Shamir's threshold scheme, our fast ramp scheme realizes to reduce each bit-size of shares instead of degradation of security. On the other hand, a method to embed additional information allows only participants who pre-shared the authorities with the dealer to recover not only the secret but also the additional information corresponding to the authority from k shares. Thus, this embedding method can realize a distributed subliminal channel (storage) between the dealer and the trusted participant, simple access control method and so on, which use the property of secret sharing schemes.

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Event date： 2007.8

Language：English  

This paper proposes several extensions of fast (k,n)-threshold schemes which use EXCLUSIVE-OR(XOR) operations. Existing fast threshold schemes need to calculate inverse matrices in recovery phase and hence these operations on software/hardware are delayed due to conditional branching in calculation of invese matrices. We introduce a new method to calculate a particular matrix in a recovery algorithm. Our method does not need to make a generator matrix for shares or to calculate inverse matrices of block matrices. The particular matrix which denotes the combination of divided pieces of shares to recover the secret is calculated by rote only from the share indexes. Futhermore, our method can be implemented without "IF" statement (conditional branching) by using word-wise XOR operations, cyclic shift operations and bit shift operations. Thus, our method can be operated more rapidly than existing schemes on software and hardware.

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Event date： 2007.5

Language：English  

In Shamir's (k,n)-threshold secret sharing scheme, a heavy computational cost is required to recover the secret from k shares. As a solution to this problem, several fast threshold schemes are proposed. However, there is no fast ideal (k,n)-threshold scheme, where k >_ 4 and n is arbitrary. This paper proposes a new fast (4,n)-threshold scheme using just EXCLUSIVE-OR(XOR) operations to make shares and recover the secret, which is an ideal secret sharing scheme similar to Shamir's scheme. Furthermore, we extend and generalize the (4,n)-threshold scheme to a new fast (k,n)-threshold scheme using XOR operations with arbitrary k and n, which is also an ideal secret sharing scheme.

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Event date： 2007.1

Language：Japanese   Presentation type：Oral presentation (general)  

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Event date： 2007.1

Language：Japanese   Presentation type：Oral presentation (general)  

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Event date： 2005.12

Language：Japanese  

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Event date： 2005.12

Language：Japanese  

PA(Product Accumulate) codes achieve perfomance near the Shannon limit for BPSK, have low encoding and decoding complexity, and have flexible rate adaptivity for all rates above 1/2. In this paper, we propose a new method of application of PA codes to multilevel modulation with multilevel coding and BICM-ID(Bit Interleaved Coded Modulation with Iterative Decoding). First, to adjust code rate flexibly, we investigate perfomances of PA codes and GPA (Generalized Product Accumulate) codes that have two different single parity check codes as component codes, and we show a procedure to design PA codes or GPA codes with different component codes for wide range of code rate. Next, we identify labeling methods that give the lowest decoding error probability for BICM-ID and multilevel coding. Computer simulation demonstrates that multilevel coding systems and BICM-ID systems with PA codes or GPA codes designed with our procedure give performances near the Shannon limit.

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Event date： 2005.12

Language：Japanese  

PA (Product Accumulate) codes achieve perfomance near the Shannon limit for BPSK, have low encoding and decoding complexity, and have flexible rate adaptivity for all rates above 1/2. In this paper, we propose a new method of application of PA codes to multilevel modulation with multilevel coding and BICM-ID (Bit Interleaved Coded Modulation with Iterative Decoding). First, to adjust code rate flexibly, we investigate perfomances of PA codes and GPA (Generalized Product Accumulate) codes that have two different single parity check codes as component codes, and we show a procedure to design PA codes or GPA codes with different component codes for wide range of code rate. Next, we identify labeling methods that give the lowest decoding error probability for BICM-ID and multilevel coding. Computer simulation demonstrates that multilevel coding systems and BICM-ID systems with PA codes or GPA codes designed with our procedure give performances near the Shannon limit.

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Event date： 2004.8

Language：Japanese  

This paper proposes a software radio receiver which utilizes an RF filter bank in the front end and optimally combines the signals whose bandwidth is divided by the filter bank. This method assumes the future solid state advanced integrated circuit technologies in RF filters, RF receiving circuit and A/D converters (ADC). The optimal combining utilizing the multiple input linear equalizer regenerates the wide band signal in baseband from the discrete complex envelopes that are sampled from the outputs of filters constructing the RF filter bank. The equalizer uses chirp signal as the training signal. Time alignment of the complex impulse response to the chirp signal yields the complex impulse response of the combining circuit. The combiner circuit minimizes the difference between the complex impulse response and the desired impulse response, and it becomes the matched filter. Computer simulation is conducted in order to evaluate the reception performance by utilizing Gaussian bandpass filter for the filter bank. Both single carrier roll-off and OFDM multicarrier signals are examined. The simulation shows the dependences of eye pattern and that of bit error rate (BER) upon the number of bits of ADC, and dependence of BER upon an out-of-band interference signal. The results show the superiority of the filter bank receiver to the digital filter receiver.

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Language：Japanese  

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Language：English  

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Language：Japanese   Presentation type：Oral presentation (general)  

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Applicant：KDDI株式会社

Application no：特願2016-184651  Date applied：2016.9

Announcement no：特開2018-049473  Date announced：2018.3

Patent/Registration no：特許6590774  Date registered：2019.9 

J-GLOBAL

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Applicant：KDDI株式会社

Application no：特願2016-184652  Date applied：2016.9

Announcement no：特開2018-049474  Date announced：2018.3

Patent/Registration no：特許第6591946号  Date registered：2019.9 

J-GLOBAL

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Applicant：KDDI株式会社

Application no：特願2016-184652  Date applied：2016.9

Announcement no：特開2018-049474  Date announced：2018.3

Patent/Registration no：特許6591946  Date registered：2019.9 

J-GLOBAL

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Applicant：KDDI株式会社

Application no：特願2016-184651  Date applied：2016.9

Announcement no：特開2018-049473  Date announced：2018.3

Patent/Registration no：特許第6590774号  Date registered：2019.9 

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Application no：特願2016-097363  Date applied：2016.5

Announcement no：特開2017-204836  Date announced：2017.11

Patent/Registration no：特許6549518  Date registered：2019.7 

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Applicant：KDDI株式会社

Application no：特願2016-097363  Date applied：2016.5

Announcement no：特開2017-204836  Date announced：2017.11

Patent/Registration no：特許第6549518号  Date registered：2019.7 

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Application no：特願2016-023963  Date applied：2016.2

Announcement no：特開2017-142675  Date announced：2017.8

Patent/Registration no：特許第6516692号  Date registered：2019.4 

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Applicant：KDDI株式会社

Application no：特願2016-023963  Date applied：2016.2

Announcement no：特開2017-142675  Date announced：2017.8

Patent/Registration no：特許6516692  Date registered：2019.4 

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Applicant：株式会社KDDI総合研究所

Application no：特願2015-249820  Date applied：2015.12

Announcement no：特開2017-118243  Date announced：2017.6

Patent/Registration no：特許第6546846号  Date registered：2019.6 

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Application no：特願2015-157483  Date applied：2015.8

Announcement no：特開2017-037411  Date announced：2017.2

Patent/Registration no：特許第6495777号  Date registered：2019.3 

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Applicant：KDDI株式会社

Application no：特願2015-157483  Date applied：2015.8

Announcement no：特開2017-037411  Date announced：2017.2

Patent/Registration no：特許6495777  Date registered：2019.3 

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Application no：特願2014-254509  Date applied：2014.12

Announcement no：特開2016-115209  Date announced：2016.6

Patent/Registration no：特許6403566  Date registered：2018.9 

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Application no：特願2013-171720  Date applied：2013.8

Announcement no：特開2015-041880  Date announced：2015.3

Patent/Registration no：特許6095522 

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Application no：特願2013-171720  Date applied：2013.8

Announcement no：特開2015-041880  Date announced：2015.3

Patent/Registration no：特許第6095522号  Date issued：2017.2

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Application no：特願2013-057291  Date applied：2013.3

Announcement no：特開2014-068337  Date announced：2014.4

Patent/Registration no：特許5826202 

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Application no：特願2013-057291  Date applied：2013.3

Announcement no：特開2014-068337  Date announced：2014.4

Patent/Registration no：特許第5826202号  Date issued：2015.10

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Application no：特願2012-009782  Date applied：2012.1

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Patent/Registration no：特許第5801211号  Date issued：2015.9

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Patent/Registration no：特許5801211 

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Announcement no：特開2011-004206  Date announced：2011.1

Patent/Registration no：特許第5388716号  Date issued：2013.10

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Announcement no：特開2010-268181  Date announced：2010.11

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Announcement no：特開2010-266632  Date announced：2010.11

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Application no：特願2009-117282  Date applied：2009.5

Announcement no：特開2010-268181  Date announced：2010.11

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Announcement no：特開2010-266632  Date announced：2010.11

Patent/Registration no：特許第5388684号  Date issued：2013.10

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Application no：特願2008-138450  Date applied：2008.5

Announcement no：特開2009-288338  Date announced：2009.12

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Applicant：東芝ソリューション株式会社, KDDI株式会社

Application no：特願2008-019453  Date applied：2008.1

Announcement no：特開2009-180912  Date announced：2009.8

Patent/Registration no：特許第4925345号  Date issued：2012.2

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Application no：特願2008-019453  Date applied：2008.1

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Announcement no：特開2009-182375  Date announced：2009.8

Patent/Registration no：特許第5191751号  Date issued：2013.2

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Applicant：京セラ株式会社, KDDI株式会社

Application no：特願2007-249394  Date applied：2007.9

Announcement no：特開2009-081658  Date announced：2009.4

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Application no：特願2007-249394  Date applied：2007.9

Announcement no：特開2009-081658  Date announced：2009.4

Patent/Registration no：特許第5101967号  Date issued：2012.10

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Application no：特願2007-247849  Date applied：2007.9

Announcement no：特開2009-081560  Date announced：2009.4

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Application no：特願2007-247733  Date applied：2007.9

Announcement no：特開2009-081549  Date announced：2009.4

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Applicant：京セラ株式会社, KDDI株式会社

Application no：特願2007-247833  Date applied：2007.9

Announcement no：特開2009-081556  Date announced：2009.4

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Applicant：京セラ株式会社, KDDI株式会社

Application no：特願2007-247872  Date applied：2007.9

Announcement no：特開2009-081564  Date announced：2009.4

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Applicant：京セラ株式会社, KDDI株式会社

Application no：特願2007-247733  Date applied：2007.9

Announcement no：特開2009-081549  Date announced：2009.4

Patent/Registration no：特許第5053013号  Date issued：2012.8

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Applicant：京セラ株式会社, KDDI株式会社

Application no：特願2007-247833  Date applied：2007.9

Announcement no：特開2009-081556  Date announced：2009.4

Patent/Registration no：特許第5053014号  Date issued：2012.8

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Application no：特願2007-204602  Date applied：2007.8

Announcement no：特開2009-042307  Date announced：2009.2

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Applicant：KDDI株式会社

Application no：特願2007-204602  Date applied：2007.8

Announcement no：特開2009-042307  Date announced：2009.2

Patent/Registration no：特許第5065802号  Date issued：2012.8

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Application no：特願2007-202645  Date applied：2007.8

Announcement no：特開2009-037094  Date announced：2009.2

Patent/Registration no：特許第5134303号  Date issued：2012.11

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Application no：特願2007-202644  Date applied：2007.8

Announcement no：特開2009-037093  Date announced：2009.2

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Application no：特願2007-202645  Date applied：2007.8

Announcement no：特開2009-037094  Date announced：2009.2

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Applicant：KDDI株式会社

Application no：特願2007-202644  Date applied：2007.8

Announcement no：特開2009-037093  Date announced：2009.2

Patent/Registration no：特許第5065795号  Date issued：2012.8

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Applicant：KDDI株式会社

Application no：特願2007-194423  Date applied：2007.7

Announcement no：特開2009-033401  Date announced：2009.2

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Applicant：KDDI株式会社

Application no：特願2007-194422  Date applied：2007.7

Announcement no：特開2009-033400  Date announced：2009.2

Patent/Registration no：特許第5096826号  Date issued：2012.9

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Applicant：KDDI株式会社

Application no：特願2007-194422  Date applied：2007.7

Announcement no：特開2009-033400  Date announced：2009.2

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Applicant：KDDI株式会社

Application no：特願2007-194423  Date applied：2007.7

Announcement no：特開2009-033401  Date announced：2009.2

Patent/Registration no：特許第5084389号  Date issued：2012.9

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Applicant：KDDI株式会社

Application no：特願2007-182070  Date applied：2007.7

Announcement no：特開2009-021765  Date announced：2009.1

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Applicant：KDDI株式会社

Application no：特願2007-182070  Date applied：2007.7

Announcement no：特開2009-021765  Date announced：2009.1

Patent/Registration no：特許第5189799号  Date issued：2013.2

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Applicant：KDDI株式会社

Application no：特願2007-130074  Date applied：2007.5

Announcement no：特開2008-288750  Date announced：2008.11

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Applicant：KDDI株式会社

Application no：特願2007-130074  Date applied：2007.5

Announcement no：特開2008-288750  Date announced：2008.11

Patent/Registration no：特許第5065755号  Date issued：2012.8

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Applicant：KDDI株式会社

Application no：特願2007-117399  Date applied：2007.4

Announcement no：特開2008-278022  Date announced：2008.11

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Applicant：KDDI株式会社

Application no：特願2007-117399  Date applied：2007.4

Announcement no：特開2008-278022  Date announced：2008.11

Patent/Registration no：特許第4999533号  Date issued：2012.5

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Applicant：KDDI株式会社

Application no：特願2007-104899  Date applied：2007.4

Announcement no：特開2008-262040  Date announced：2008.10

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Applicant：KDDI株式会社

Application no：特願2007-104899  Date applied：2007.4

Announcement no：特開2008-262040  Date announced：2008.10

Patent/Registration no：特許第5134281号  Date issued：2012.11

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Applicant：KDDI株式会社

Application no：特願2007-041954  Date applied：2007.2

Announcement no：特開2008-203720  Date announced：2008.9

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Applicant：KDDI株式会社

Application no：特願2007-041954  Date applied：2007.2

Announcement no：特開2008-203720  Date announced：2008.9

Patent/Registration no：特許第4917453号  Date issued：2012.2

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Applicant：KDDI株式会社

Application no：特願2006-335421  Date applied：2006.12

Announcement no：特開2008-145917  Date announced：2008.6

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Applicant：KDDI株式会社

Application no：特願2006-335421  Date applied：2006.12

Announcement no：特開2008-145917  Date announced：2008.6

Patent/Registration no：特許第4933241号  Date issued：2012.2

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Applicant：KDDI株式会社

Application no：特願2006-279653  Date applied：2006.10

Announcement no：特開2008-099068  Date announced：2008.4

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Applicant：KDDI株式会社

Application no：特願2006-279653  Date applied：2006.10

Announcement no：特開2008-099068  Date announced：2008.4

Patent/Registration no：特許第4938409号  Date issued：2012.3

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Applicant：KDDI株式会社

Application no：特願2006-277477  Date applied：2006.10

Announcement no：特開2008-098894  Date announced：2008.4

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Applicant：KDDI株式会社

Application no：特願2006-277478  Date applied：2006.10

Announcement no：特開2008-096644  Date announced：2008.4

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