Hiroshi Kamabe | Gifu University (original) (raw)
Papers by Hiroshi Kamabe
ArXiv, 2017
The 10th Asia-Europe workshop in "Concepts in Information Theory and Communications" AE... more The 10th Asia-Europe workshop in "Concepts in Information Theory and Communications" AEW10 was held in Boppard, Germany on June 21-23, 2017. It is based on a longstanding cooperation between Asian and European scientists. The first workshop was held in Eindhoven, the Netherlands in 1989. The idea of the workshop is threefold: 1) to improve the communication between the scientist in the different parts of the world; 2) to exchange knowledge and ideas; and 3) to pay a tribute to a well respected and special scientist.
IEICE technical report. Information theory, 1999
Memory devices on which data can be written only once are called write ollce memories (WOM) ． A I... more Memory devices on which data can be written only once are called write ollce memories (WOM) ． A IVOM code is a code which allows us to rewrite the W ］ OM at least ・ t times for a predetermined t by sacrificing the storage capacity ．" ， Te propose a Inultiple error correcting WOM code which is sinlpler than error correctiIlg 、 VOM codes previously proposed ． Furthermore our scheme allows us to construct a 且) merror correcting WOM code for eVery Positive rn ．
Information Technology, 2006
IEICE ESS Fundamentals Review
2018 International Symposium on Information Theory and Its Applications (ISITA), 2018
Permutation codes with various metrics have recently been studied for flash memory applications. ... more Permutation codes with various metrics have recently been studied for flash memory applications. In this work, we derive a tighter upper bound on the generalized Cayley distance using the block permutation distance proposed by Yang, Schoeny, and Dolecek. Furthermore, we employ our upper bound to derive a tighter upper bound on the optimal rate for codes with the generalized Cayley distance when the code length is relatively small.
2018 International Symposium on Information Theory and Its Applications (ISITA), 2018
A recursive construction of k-ary uniquely decodable multiuser codes is proposed for use in a noi... more A recursive construction of k-ary uniquely decodable multiuser codes is proposed for use in a noiseless multiple-access adder channel. The code rates of the proposed codes are higher than those of previous uniquely decodable multiuser codes. A recursive decoding algorithm is also proposed.
IEICE Transactions on Fundamentals of Electronics, Communications and Computer Sciences, 2021
In the user identification (UI) scheme for a multiple-access fading channel based on a randomly g... more In the user identification (UI) scheme for a multiple-access fading channel based on a randomly generated (0,1,-1)-signature code, previous studies used the signature code over a noisy multiple-access adder channel, and only the user state information (USI) was decoded by the signature decoder. However, by considering the communication model as a compressed sensing process, it is possible to estimate the channel coefficients while identifying users. In this study, to improve the efficiency of the decoding process, we propose an iterative deep neural network (DNN)based decoder. Simulation results show that for the randomly generated (0,1,-1)-signature code, the proposed DNN-based decoder requires less computing time than the classical signal recovery algorithm used in compressed sensing while achieving higher UI and channel estimation (CE) accuracies.
IEICE technical report. Information theory, 2002
Tw ｛ ト Dimensional Magnetic Recording (TDMR) is one of architectures that can achieve the recordi... more Tw ｛ ト Dimensional Magnetic Recording (TDMR) is one of architectures that can achieve the recording density higher than that of current magnetic recording technology ． Coding techniques and signal processing methods are important parts of TDMR ． Cha皿 nel models for TDMR are also important because channels of TDMR must be very different from channels implemented by other magnetic recording architec − tures． The Vbronoi model is a good model for medium of TDMR but it is very time − consuming ， Thus ， we try to propose simple channel models which have similar properties on error rate ． Key words Magnetic recoding ， TDMR ， Vbronoi model
IEICE technical report. Information theory, 2011
2016 International Symposium on Information Theory and Its Applications (ISITA), 2016
The Index-less Indexed Flash Code (ILIFC) is a coding scheme for flash memories, in which one bit... more The Index-less Indexed Flash Code (ILIFC) is a coding scheme for flash memories, in which one bit of a data sequence is stored in a slice consisting of several cells but the index of the bit is stored implicitly. Although the code rate of the scheme is not good, the scheme uses the cell state space very efficiently. Many modified ILIFC schemes have been proposed. One of them is an ILIFC with inversion operation. The scheme reduces an increase of the sum of changes of cell levels at each rewriting request. In this paper we analyze the scheme and show that the analytic results coincide with simulation results for many cases.
2020 International Symposium on Information Theory and Its Applications (ISITA), 2020
The fountain code is an erasure correcting code used for the packet erasure channel. ZDF codes (Z... more The fountain code is an erasure correcting code used for the packet erasure channel. ZDF codes (Zigzag Decodable Fountain codes) are a kind of fountain codes which are generalizations of Raptor codes. The distinguishing characteristic of ZDF codes is to apply bit shift operation to generate the encoded packets. The bit-wise peeling decoding (PA) is used based on the difference bit shift of the precoded packets to the encoded packets. To provide more start of bit-wise PA, we investigate the enumerator of the encoded packets’ shift combinations. We found that the shift combination of all the degree of the encoded packet has the uniform enumerator, the packets can have an effective start for bit-wise PA. Thus, we propose a ZDF code with variable shift distribution based on shift combinations with a uniform enumerator. From the simulation results, we have shown that the decoding erasure rate per received packet is decreased compared with other methods by limiting the number of selection...
2014 International Symposium on Information Theory and its Applications, 2014
Non-volatile memories, e.g., flash memories and phase change memories (PCM), have been widely use... more Non-volatile memories, e.g., flash memories and phase change memories (PCM), have been widely used in computers and especially mobile computing devices because they have no mechanical components, they consume less power, and the access speeds of them are very high in comparison with hard disc drives. In magnetic recording systems, constrained codes are used so that stored data sequences are easily and correctly retrieved. In storage systems using non-volatile solid state memory, the constrained codes may also be employed but for different input constraints, e.g., (α, β, p)-constraints introduced by A. Jiang et al. [4]. In this paper, two code construction methods for the (α, β, p)-constraints for PCM are given. Next, a new constraint for PCM is introduced so that a constrained code with a higher code rate can be constructed from the constraint.
2017 IEEE International Symposium on Information Theory (ISIT), 2017
Index-less indexed flash code (ILIFC) is a coding scheme for flash memories in which one bit of a... more Index-less indexed flash code (ILIFC) is a coding scheme for flash memories in which one bit of a data sequence is stored in a slice consisting of several cells but the index of the bit is stored implicitly. Although several modified ILIFC schemes have been proposed, in this study we consider an ILIFC with inversion cells (I-ILIFC). The I-ILIFC reduces the total number of cell level changes at each write request. Computer simulation is used to show that the I-ILIFC improves the average performance of ILIFC in many cases. This paper presents our derivation of the lower bound on the number of write operations by I-ILIFC. Additionally, we consider another lower bound thereon and show that the threshold of the code length that determines whether the I-ILIFC improves the worst-case performance of the ILIFC is smaller than that in the first lower bound. Lastly, we analyze the asymptotic performance of the I-ILIFC in the worst case.
ArXiv, 2019
In this paper, we proposed a construction of a UD kkk-ary TTT-user coding scheme for MAAC. We fir... more In this paper, we proposed a construction of a UD kkk-ary TTT-user coding scheme for MAAC. We first give a construction of kkk-ary Tf+gT^{f+g}Tf+g-user UD code from a kkk-ary TfT^{f}Tf-user UD code and a kpmk^{\pm}kpm-ary TgT^{g}Tg-user difference set with its two component sets mathcalD+\mathcal{D}^{+}mathcalD+ and mathcalD−\mathcal{D}^{-}mathcalD− {\em a priori}. Based on the kpmk^{\pm}kpm-ary TgT^{g}Tg-user difference set constructed from a (2k−1)(2k-1)(2k−1)-ary UD code, we recursively construct a UD kkk-ary TTT-user codes with code length of 2m2^m2m from initial multi-user codes of kkk-ary, 2(k−1)+12(k-1)+12(k−1)+1-ary, \dots, (2m(k−1)+1)(2^m(k-1)+1)(2m(k−1)+1)-ary. Introducing multi-user codes with higer-ary makes the total rate of generated code mathcalA\mathcal{A}mathcalA higher than that of conventional code.
ArXiv, 2017
The 10th Asia-Europe workshop in "Concepts in Information Theory and Communications" AE... more The 10th Asia-Europe workshop in "Concepts in Information Theory and Communications" AEW10 was held in Boppard, Germany on June 21-23, 2017. It is based on a longstanding cooperation between Asian and European scientists. The first workshop was held in Eindhoven, the Netherlands in 1989. The idea of the workshop is threefold: 1) to improve the communication between the scientist in the different parts of the world; 2) to exchange knowledge and ideas; and 3) to pay a tribute to a well respected and special scientist.
IEICE technical report. Information theory, 1999
Memory devices on which data can be written only once are called write ollce memories (WOM) ． A I... more Memory devices on which data can be written only once are called write ollce memories (WOM) ． A IVOM code is a code which allows us to rewrite the W ］ OM at least ・ t times for a predetermined t by sacrificing the storage capacity ．" ， Te propose a Inultiple error correcting WOM code which is sinlpler than error correctiIlg 、 VOM codes previously proposed ． Furthermore our scheme allows us to construct a 且) merror correcting WOM code for eVery Positive rn ．
Information Technology, 2006
IEICE ESS Fundamentals Review
2018 International Symposium on Information Theory and Its Applications (ISITA), 2018
Permutation codes with various metrics have recently been studied for flash memory applications. ... more Permutation codes with various metrics have recently been studied for flash memory applications. In this work, we derive a tighter upper bound on the generalized Cayley distance using the block permutation distance proposed by Yang, Schoeny, and Dolecek. Furthermore, we employ our upper bound to derive a tighter upper bound on the optimal rate for codes with the generalized Cayley distance when the code length is relatively small.
2018 International Symposium on Information Theory and Its Applications (ISITA), 2018
A recursive construction of k-ary uniquely decodable multiuser codes is proposed for use in a noi... more A recursive construction of k-ary uniquely decodable multiuser codes is proposed for use in a noiseless multiple-access adder channel. The code rates of the proposed codes are higher than those of previous uniquely decodable multiuser codes. A recursive decoding algorithm is also proposed.
IEICE Transactions on Fundamentals of Electronics, Communications and Computer Sciences, 2021
In the user identification (UI) scheme for a multiple-access fading channel based on a randomly g... more In the user identification (UI) scheme for a multiple-access fading channel based on a randomly generated (0,1,-1)-signature code, previous studies used the signature code over a noisy multiple-access adder channel, and only the user state information (USI) was decoded by the signature decoder. However, by considering the communication model as a compressed sensing process, it is possible to estimate the channel coefficients while identifying users. In this study, to improve the efficiency of the decoding process, we propose an iterative deep neural network (DNN)based decoder. Simulation results show that for the randomly generated (0,1,-1)-signature code, the proposed DNN-based decoder requires less computing time than the classical signal recovery algorithm used in compressed sensing while achieving higher UI and channel estimation (CE) accuracies.
IEICE technical report. Information theory, 2002
Tw ｛ ト Dimensional Magnetic Recording (TDMR) is one of architectures that can achieve the recordi... more Tw ｛ ト Dimensional Magnetic Recording (TDMR) is one of architectures that can achieve the recording density higher than that of current magnetic recording technology ． Coding techniques and signal processing methods are important parts of TDMR ． Cha皿 nel models for TDMR are also important because channels of TDMR must be very different from channels implemented by other magnetic recording architec − tures． The Vbronoi model is a good model for medium of TDMR but it is very time − consuming ， Thus ， we try to propose simple channel models which have similar properties on error rate ． Key words Magnetic recoding ， TDMR ， Vbronoi model
IEICE technical report. Information theory, 2011
2016 International Symposium on Information Theory and Its Applications (ISITA), 2016
The Index-less Indexed Flash Code (ILIFC) is a coding scheme for flash memories, in which one bit... more The Index-less Indexed Flash Code (ILIFC) is a coding scheme for flash memories, in which one bit of a data sequence is stored in a slice consisting of several cells but the index of the bit is stored implicitly. Although the code rate of the scheme is not good, the scheme uses the cell state space very efficiently. Many modified ILIFC schemes have been proposed. One of them is an ILIFC with inversion operation. The scheme reduces an increase of the sum of changes of cell levels at each rewriting request. In this paper we analyze the scheme and show that the analytic results coincide with simulation results for many cases.
2020 International Symposium on Information Theory and Its Applications (ISITA), 2020
The fountain code is an erasure correcting code used for the packet erasure channel. ZDF codes (Z... more The fountain code is an erasure correcting code used for the packet erasure channel. ZDF codes (Zigzag Decodable Fountain codes) are a kind of fountain codes which are generalizations of Raptor codes. The distinguishing characteristic of ZDF codes is to apply bit shift operation to generate the encoded packets. The bit-wise peeling decoding (PA) is used based on the difference bit shift of the precoded packets to the encoded packets. To provide more start of bit-wise PA, we investigate the enumerator of the encoded packets’ shift combinations. We found that the shift combination of all the degree of the encoded packet has the uniform enumerator, the packets can have an effective start for bit-wise PA. Thus, we propose a ZDF code with variable shift distribution based on shift combinations with a uniform enumerator. From the simulation results, we have shown that the decoding erasure rate per received packet is decreased compared with other methods by limiting the number of selection...
2014 International Symposium on Information Theory and its Applications, 2014
Non-volatile memories, e.g., flash memories and phase change memories (PCM), have been widely use... more Non-volatile memories, e.g., flash memories and phase change memories (PCM), have been widely used in computers and especially mobile computing devices because they have no mechanical components, they consume less power, and the access speeds of them are very high in comparison with hard disc drives. In magnetic recording systems, constrained codes are used so that stored data sequences are easily and correctly retrieved. In storage systems using non-volatile solid state memory, the constrained codes may also be employed but for different input constraints, e.g., (α, β, p)-constraints introduced by A. Jiang et al. [4]. In this paper, two code construction methods for the (α, β, p)-constraints for PCM are given. Next, a new constraint for PCM is introduced so that a constrained code with a higher code rate can be constructed from the constraint.
2017 IEEE International Symposium on Information Theory (ISIT), 2017
Index-less indexed flash code (ILIFC) is a coding scheme for flash memories in which one bit of a... more Index-less indexed flash code (ILIFC) is a coding scheme for flash memories in which one bit of a data sequence is stored in a slice consisting of several cells but the index of the bit is stored implicitly. Although several modified ILIFC schemes have been proposed, in this study we consider an ILIFC with inversion cells (I-ILIFC). The I-ILIFC reduces the total number of cell level changes at each write request. Computer simulation is used to show that the I-ILIFC improves the average performance of ILIFC in many cases. This paper presents our derivation of the lower bound on the number of write operations by I-ILIFC. Additionally, we consider another lower bound thereon and show that the threshold of the code length that determines whether the I-ILIFC improves the worst-case performance of the ILIFC is smaller than that in the first lower bound. Lastly, we analyze the asymptotic performance of the I-ILIFC in the worst case.
ArXiv, 2019
In this paper, we proposed a construction of a UD kkk-ary TTT-user coding scheme for MAAC. We fir... more In this paper, we proposed a construction of a UD kkk-ary TTT-user coding scheme for MAAC. We first give a construction of kkk-ary Tf+gT^{f+g}Tf+g-user UD code from a kkk-ary TfT^{f}Tf-user UD code and a kpmk^{\pm}kpm-ary TgT^{g}Tg-user difference set with its two component sets mathcalD+\mathcal{D}^{+}mathcalD+ and mathcalD−\mathcal{D}^{-}mathcalD− {\em a priori}. Based on the kpmk^{\pm}kpm-ary TgT^{g}Tg-user difference set constructed from a (2k−1)(2k-1)(2k−1)-ary UD code, we recursively construct a UD kkk-ary TTT-user codes with code length of 2m2^m2m from initial multi-user codes of kkk-ary, 2(k−1)+12(k-1)+12(k−1)+1-ary, \dots, (2m(k−1)+1)(2^m(k-1)+1)(2m(k−1)+1)-ary. Introducing multi-user codes with higer-ary makes the total rate of generated code mathcalA\mathcal{A}mathcalA higher than that of conventional code.