Toyota Central RandD Laboratories Inc.

Nagakute, Japan

Toyota Central RandD Laboratories Inc.

Nagakute, Japan
SEARCH FILTERS
Time filter
Source Type

Sugiura S.,Toyota Central R and D Laboratories Inc.
IEEE Communications Letters | Year: 2012

In this letter, we propose a novel decentralized-precoding aided rateless code, which is conceived for Wireless Sensor Networks (WSNs). More specifically, the proposed algorithm allows a collection of source nodes to precode their information symbols in an uncoordinated manner. The precoded symbols are then channel-encoded by a distributed rateless code at each sensor node. This architecture enables us to eliminate an error floor imposed on the conventional Luby Transform (LT)-code based WSNs, without requiring a central coordinator or any elaborate cooperations between the nodes. Our simulation results demonstrate that the proposed distributed rateless code is capable of attaining achievable BER performance comparable to that of a Raptor code coordinated by a central coordinator, while outperforming a distributed LT code. © 1997-2012 IEEE.


Sugiura S.,Toyota Central R and D Laboratories Inc. | Hanzo L.,University of Southampton
IEEE Signal Processing Letters | Year: 2012

In this letter, we investigate the effects of training-based channel estimation on the achievable performance of the recent spatial modulation (SM) based multiple-input multiple-output (MIMO) scheme. This is motivated by the fact that the SM transmitter is constituted by a single radio-frequency (RF) branch and multiple antenna elements (AEs), hence simultaneous pilot transmissions from the AEs are impossible, unlike in the classic multiple-RF MIMO transmitters. Our simulation results demonstrate that the SM scheme's BER curve exhibits a performance penalty, while relying on realistic imperfect channel-estimation. In order to combat these limitations, we propose two single-RF arrangements, namely a reduced-complexity joint channel estimation and data detection aided SM scheme as well as a non-coherently detected single-RF space-time shift keying scheme dispensing with channel estimation. © 1994-2012 IEEE.


Kayama T.,Toyota Central R and D Laboratories Inc. | Yamazaki K.,Toyota Central R and D Laboratories Inc. | Shinjoh H.,Toyota Central R and D Laboratories Inc.
Journal of the American Chemical Society | Year: 2010

We introduce a new concept for a nanomaterial in terms of both synthesis and properties. The nanomaterial, aggregates of ceria particles around central silver metal (CeO 2-Ag), was fabricated by a one-pot selective redox reaction using cerium(III) and silver(I) autocatalyzed by silver metal without the need for surfactants or organic compounds. This unique nanostructure is suitable as a catalyst, in contrast to core-shell materials wherein the shell deactivates the catalyst metal. The material was developed to be intimately related to catalytic carbon oxidation. © 2010 American Chemical Society.


Iwasaki M.,Toyota Central R and D Laboratories Inc. | Shinjoh H.,Toyota Central R and D Laboratories Inc.
Journal of Catalysis | Year: 2010

The evolution of NO following NO2 introduction onto various Fe/ZSM-5 catalysts was investigated. The activity depended on the method of catalyst preparation used. The most efficient method was CVD with high-Fe loading. Results from in situ FT-IR revealed that NO was initially generated on ion-exchanged Fe sites, temporarily adsorbed, and then desorbed. For the most active samples, the result of temperature-programmed desorption of NO 2, from which ion-exchanged sites may be estimated, indicated that the amount of NO evolution corresponded to nearly half the amount of exchanged Fe. Assuming that most of the exchange sites in these samples are binuclear structures, it may be postulated that one NO molecule evolves from each binuclear site. From this, we propose that NO2 is decomposed into NO and atomic oxygen at the binuclear Fe sites. The oxygen occupies a bridging vacancy site between Fe atoms. NO evolves and is replaced by follow-on NO 2. © 2010 Elsevier Inc.


Sugiura S.,Toyota Central R and D Laboratories Inc. | Chen S.,University of Southampton | Hanzo L.,University of Southampton
IEEE Communications Surveys and Tutorials | Year: 2012

In this tutorial, we first review the family of conventional multiple-antenna techniques, and then we provide a general overview of the recent concept of the powerful Multiple-Input Multiple-Output (MIMO) family based on a universal Space-Time Shift Keying (STSK) philosophy. When appropriately configured, the proposed STSK scheme has the potential of outperforming conventional MIMO arrangements. © 1998-2012 IEEE.


Sugiura S.,Toyota Central R and D Laboratories Inc. | Chen S.,University of Southampton | Hanzo L.,University of Southampton
IEEE Communications Surveys and Tutorials | Year: 2012

In this treatise, we firstly review the associated Multiple-Input Multiple-Output (MIMO) system theory and review the family of hard-decision and soft-decision based detection algorithms in the context of Spatial Division Multiplexing (SDM) systems. Our discussions culminate in the introduction of a range of powerful novel MIMO detectors, such as for example Markov Chain assisted Minimum Bit-Error Rate (MC-MBER) detectors, which are capable of reliably operating in the challenging high-importance rank-deficient scenarios, where there are more transmitters than receivers and hence the resultant channel-matrix becomes non-invertible. As a result, conventional detectors would exhibit a high residual error floor. We then invoke the Soft-Input Soft-Output (SISO) MIMO detectors for creating turbo-detected two- or three-stage concatenated SDM schemes and investigate their attainable performance in the light of their computational complexity. Finally, we introduce the powerful design tools of EXtrinsic Information Transfer (EXIT)-charts and characterize the achievable performance of the diverse near-capacity SISO detectors with the aid of EXIT charts. © 1998-2012 IEEE.


Sugiura S.,Toyota Central R and D Laboratories Inc.
IEEE Communications Letters | Year: 2011

In this Letter, we introduce an efficient dispersion-matrix optimization technique for the recent concept of Space-Time Shift Keying (STSK). By exploiting the STSK-specific signal structure relying on the dispersion-matrix activation, rather than the classic spatial multiplexing, computational complexity imposed by the system optimization is reduced by tens of times, in comparison to that of the conventional approach. Our simulation results reveal that the proposed technique substantially reduces computational cost and time required for the dispersion-matrix optimization, which is especially beneficial for large search-space scenarios, such as a high number of transmit antennas, symbols per space-time block and constellation points. © 2011 IEEE.


Iwasaki M.,Toyota Central R and D Laboratories Inc. | Shinjoh H.,Toyota Central R and D Laboratories Inc.
Chemical Communications | Year: 2011

An addition of rare earth metals with trivalent cation radii of 1.05-1.15 Å to Fe/BEA zeolites improves hydrothermal stability for selective catalytic reduction of NO by NH3. © The Royal Society of Chemistry.


Sugiura S.,Toyota Central RandD Laboratories Inc. | Hanzo L.,University of Southampton
IEEE Transactions on Wireless Communications | Year: 2013

Joint dispersion-matrix and constellation optimization algorithm is proposed, which is invoked for the recent space-time shift keying (STSK) scheme. More specifically, the theoretical gradients of the discrete-input continuous-output memoryless channel's (DCMC) capacity with respect to both a dispersion-matrix set and to the modem constellations are derived, which allows a substantial reduction in the computational complexity required for maximizing the system's capacity. Furthermore, we also conceive a near-capacity irregular-precoded STSK (IR-PSTSK) architecture, which is designed with the aid of extrinsic information transfer (EXIT) charts, while invoking STSK subcodes, which are optimized by using the proposed algorithm. © 2013 IEEE.


Yasuda T.,Toyota Central R and D Laboratories Inc. | Ogihara N.,Toyota Central R and D Laboratories Inc.
Chemical Communications | Year: 2014

We have found that the specific capacity of a Li-intercalated metal-organic framework (iMOF) electrode material, 2,6-naphthalene dicarboxylate dilithium, can be increased by narrowing the distance between naphthalene layers via ordering. The increase in specific capacity can be attributed to formation of more efficient electron and ion pathways in the framework. © The Partner Organisations 2014.

Loading Toyota Central RandD Laboratories Inc. collaborators
Loading Toyota Central RandD Laboratories Inc. collaborators