Edited by Kazuhiro Miyauchi

C1. LSI for Telecommunications

[Chip Set for Gb/s Transmission] DC-10GHz mixer and amplifier for coherent optical heterodyne receiver using GaAs technology have been developed [Fujita et al., 1991]. In the following year, 10GHz mixer and amplifier ICs fabricated in silicon bipolar technology were reported [Okamura et al., 1992]. 10Gb/s Si Bipolar Chip Set for Intensity-Modulation has also been developed [Soda et al., 1992].

[ATM Switch] High speed ATM switch LSIs which used in B-ISDN have been developed. In 1990, 100Mbp/s BiCMOS ATM switch were reported [Kato et al., 1990]. And in 1991, a 400Mb/s 8X8 ATM switch has been developed. It realized total switch throughput of 3.2Gb/s with a 0.8mm BiCMOS technology [Tanaka et al., 1991]. A CMOS chip set for a 1.28Gb/s 16X16 output buffer ATM switch has been developed. This chip set consists of four Cell Aligner Chips, two Routing Control Chips, and nine Buffer Chips [Sugaya et al., 1992]. A 8X8 ATM switch LSI adopted Shared Multi-Buffer Architecture is proposed and implemented [Notani et al., 1992].

[High-Performance DSP] High-Performance Digital-Signal-Processor (DSP) LSIs have been developed for video and still-image processing. One of these has achieved a processing capability of 300-MOPS, which works four pipelined data-processing units at 25MHz [Minami et al., 1991]. Another has achieved a 500 MOPS by operating a single-pipelined data-processing unit at 250MHz [Goto et al., 1991]. Such high performance enabled implementation of a 64-kb/s video codec with 4 DSPs and 5 DSPs, respectively. Implementation was based on the international standard for the video-coding algorithm.

(H. Ikeda)


Fujita, S. [1991], "DC-10GHz Mixer and Amplifier GaAs ICs for Coherent Optical Heterodyne Receiver," ISSCC '91, 122-123.

Goto, J. [1991], "A 250MHz 16b 1-Million Transistor BiCOMS Super-High-Speed Video Signal Processor," ISSCC '91, 254-255.

Kato, Y. [1990], "A Development of A High-Speed ATM Switching LSIC," ICC '90, 1562-1566.

Minami, T. [1991], "A 300-MOPS Video Signal Processor with A parallel Archtecture," ISSCC '91, 252-253.

Notani, H. [1992], "An 8X8 ATM Switch LSI with Shared Multi-Buffer Archtecture," Symposium on VLSI Circuits, 74-75.

Okamura, T. [1992], "10GHz Si Bipolar Amplifier and Mixer ICs for Coherent Optical Systems," ISSCC '92, 202-203.

Soda, M. [1992], "A Si Bipolar Chip Set for 10Gb/s Optical Receiver," ISSCC '92, 100-101.

Sugaya, N. [1992], "A 1.28Gbps 16X16 CMOS Chip Set for an Output-Buffer ATM Switch," Symposium on VLSI Circuits, 76-77.

Tanaka S. [1991], "A 400Mb/s 8X8 BiCMOS ATM Switch LSI with 128kb On-Chip Shared Memory," ISSCC '91, 242-243.

C2. Digital Signal Processing

In the past three years, researches in the field of digital signal processing have been greatly developed with rapid advance of powerful VLSI techniques, especially of high performance processor chips. Digital filter design methodologies from one to three dimensions continued to be an active research area. A new approximation method was proposed for IIR filters with log magnitude and phase functions[Kobayashi et al.1990]. An effective design method was proposed for equiripple magnitude IIR filters [Nishikawa et al.1991]. An analytical least squares design method was proposed for 3-D linear phase FIR filters[Muneyasu et al.1991]. Decomposition of magnitude specifications was proved to be useful to decompose the 3-D filter design problems to 1-D ones[Kawamata et al.1992]. Besides, a design method was proposed for coherent optical fiber filters of direct form[Lee et al.]. Also arbitrary transfer function was proved to have a structually bounded wave digital filter[Ishiwata et al.1992].

In the fields of spectral estimation, an optimal smoothing estimator was directly derived from Wiener-Hopf's theorem[Omatsu 1990]. An estimation method of input pulse locations from the response of AR transfer function was proposed based on tapered rank reduction[Kanai et al. 1991]. Instantaneous maximum entropy method was proposed as a new spectral estimation technique for nonstationary process[Takizawa 1990]. As to the approximation problem of a nonstationary ARMA Gaussian process, a solution was obtained by solving a set of linear equations[Koga 1990].

Some major developments in adaptive signal processing were also observed. A new IIR adaptive algorithm was proposed based on orthogonalization method [Fukumi et al.1990]. A simple and fast ADF algorithm was found[Chao et al.1990]. Adaptive cepstral analysis was proposed for application to speech analysis [Tokuda et al. 1990].

Multirate signal processing techniques also continued to be an active research area.To reduce the computational complexity of filters with a large number of tap coefficients used for subband coding, a new structure of filter banks was proposed[Katto et al. 1990]. Some nonuniform perfect reconstruction QMF systems were proposed [Kurosawa et al. 1989]. A perfect reconstruction QMF was proposed by improving Vitterli's design method[Ikehara 1992].

In the fields of nonlinear signal processing, a theoretically clear homomorphic operator was found, which transforms a finite sequence into another finite sequence[Yamada et al.1989]. This operator was generalized in multi-dimensional case[Yamada et al.1990]. To eliminate non-gaussian noises in picture signals, order statistic filter was extended[Fujii et al. 1990]. Fuzzy filtering was proposed for estimating nonstationary signals[Arakawa et al.1991].

It should be emphasized that numerous works have been intended to improve software development environment for signal processor[Ito et al. 1991]. Another notable new trend was development of new signal processor chips with real time processing ability for video signals [Tamitani et al. 1989, Kawamata et al.1992]. Specially for super high definition image processing, a very powerful digital signal processor was also developed[Sawabe et al. 1991].

(S. Tsujii)


Arakawa,K. et al.,Digital Signal Processing using Fuzzy Clustering, IEICE Trans., Vol.E74, No.11, pp.3554-3558(Nov. 1991)

Chao,J. et al.],A Fast Adaptive Filter Algorithm Using Eigenvalue Reciprocals as Stepsizes, IEEE Trans. ASSP., Vol.38, No.8, pp.1343-1352(Aug. 1990)

Fujii,T. et al., Extended Order Statistic Filter and Evaluation of Noise ReductionPerformance, Trans.IEICE, Vol.J73-A, No.7, pp.1216-1224(July 1990)

Fukumi,M. et al., New IIR-Adaptive Algorithms Based on Orthogonalization Method, Trans. IEICE, Vol.73-A, No.1, pp.44-50(Jan.1990)

Ikehara,M. et al., Design of Two-channel Perfect Reconstruction QMF, Trans. IEICE, Vol.75-A, No.8, pp.1333-1340(Aug.1992)

Ishiwata,S. et al., Existence of Structually Bounded Wave Digital Filters for Arbitrary Transfer Functions,Trans.IEICE, Vol.75-A, No.1, pp.10-17(Jan. 1992)

Ito,K. and Kunieda,H., VLSI System Compiler for Digital Signal Processing: Modularization and Synchronization, IEEE Trans. on CAS Vol.38, No.4, pp.423-433(April 1991)

Kanai,H. et al.], Estimation of Input Pulse Locations From the Response of an All-pole Transfer System Using Tapered Rank Reduction, IEEE Trans. ASSP., Vol.39, No.1, pp.148-159(Jan. 1990)

Katto.J et al.], A New Structure of the Perfect Reconstruction Filter Banks for Subband Coding, Trans.IEICE, Vol.E73, No.10, pp.1616-1624(Oct.1990)

Kawamata,M et al., Design of Three-Dimensional Digital Filters for Video Signal Processing via Decomposition of Magnitude Specifications, IEICETrans. Funda-mentals, Vol.E75-A, No.7, pp.821-832(July 1992)

Kawamata,M et al., Design and Evaluation of Highly Parallel VLSI Processors for 2-D State-Space Digital Filters Using Hierarchical Behavioral Description Language and Synthesizer, IEICE Trans.Fundamentals, Vol.E75-A, No.7, pp.837-845(July 1992)

Kobayashi,T. et al., Design of IIR Digital Filters with Arbitrary Log Magnitude Function by WLS Techniques1, IEEE Trans.ASSP., Vol.38, No.2, pp.247-252(Feb. 1990)

Koga.T], A Consideration on Modeling of Nonstationary ARMA Process, Trans.IEICE, Vol.E73, No.11,pp.1800-1801(Nov.1990)

Kurosawa,K. et al., Nonuniform Perfect-Reconstruction Systems for Quadrature Mirror Filter Banks, Trans.IEICE, Vol.72-A, No.10, pp.1510-1340(Oct.1989)

Lee,C. et al., A Design Method for Coherent Optical Fiber Filters of Direct Form,Trans.IEICE, Vol.72-A, No.11, pp.1894-1901(Nov. 1990)

Muneyasu,M. et al., Analytical Least Squares Design of Three-Dimensional Linear-Phase FIR Digital Filters, Trans.IEICE, Vol.74-A, No.4, pp.654-661(April 1991)

Nishikawa,K. et al., Z-Domain Design of Equripple Magnitude IIR Digital Filters, Trans.IEICE, Vol.74-A, No.6, pp.857-864(Jun. 1991)

Omatu,S., Optimal Smoothing Estimator for Time-Averaged Measurement, Trans.IEICE, Vol.73-A, No.3, pp.456-461(March 1990)

Sawabe,T. et al., A 15 GFLOPS Parallel DSP System for Super High Definition Image Processing, IEICE Trans., Fundamentals, Vol.E75-A, No.7, pp.786-793(July 1992)

Takizawa,Y., Spectral Estimation of Nonstationary Process Based on Instantaneous Maximum Entropy Method, Trans.IEICE, Vol.73-A, No.6, pp.1083-1093(June 1990)

Tamitani,I. etal., A Real-Time Video Signal Processor Suitable for Motion Picture Coding Applications, IEEE Trans. on CAS Vol.36, No.10, pp.1259-1266(Oct.1989)

Tokuda,K. et al., Adaptive Cepstral Analysis-Adaptive Filtering Based on Cepstral Representation-, Trans.IEICE, Vol.73-A, No.7, pp.1207-1215(July 1990)

Yamada,I. et al., A New Homomorphic Operator and Its Application to DeconvolutionProblems, Trans.IEICE, Vol.72-A, No.10, pp.1528-1546(Oct.1989)

Yamada,I. et al., New Multi-dimensional Homomorphic Operator and Its Properties, Proc. of JC-CNSS 1990, pp.259-263(1990)

C3. Optical Signal Processing

In the recent three years, studies on non-guidedwave photonic switching devices for optical interconnections and optical signal processings have made great progress. In the field of photonic switching system, efforts have been concentrated mainly on capacity expansion.

An experimental free-space optical bus, which utilized 4 cascaded 8x2 pnpn-switch arrays based on surface emitting lasers, was demonstrated. Each switch provides an optical output, and can operate up to 20 MHz. [Yamanaka et. al., 1992]. An all optical XOR logic gate for bit-pattern matching, which consists of two vertical stacks of an HPT, a DBR mirror and a MQW modulator, was developed. The logic gate has 20 dB contrast ratio and 300 ns switching time. [Matsuo et. al., 1992]. An 256 bits array of all optical XOR logic gates which can emit light as outputs was also developed. A logic unit of the array consists of two LEDs and two HPTs, and has 10 ns switching time and 5 pJ switching energy. [Adachi et. al., 1991].

A dynamic optical neurochip with 8 neurons and 64 synapse, which is composed of an 8x8 metal-semiconductor-metal variable sensitivity photodetector (VSPD) array and an 8 line-shaped LED array, was fabricated. The VSPD array provides this neurochip variable synaptic interconnections, which is must for realizing learning capability. [Nitta et. al., 1992].

An experimental photonic ATM switching system, which utilized a space division 4x4 InP photonic switch, was developed. The system has 4 optical highways each of which has 2.4 Gb/s capacity consisted of two wavelength division multiplexed 1.2 Gb/s signals, and can exchange HDTV signals in STM-1 format. [Takahashi et al., 1990]. Experimental photonic space-division switching system was also developed using an integrated 8x8 silica-based guided-wave crossbar switch. The system has 8 subscriber lines, and can identify four terminal types such as G4 facsimile, CSMA/CD LAN, NTSC TV, and HDTV. [Yamaguchi et. al., 1990]. Semiconductor optical amplifiers with 12 dB module gain were fabricated to expand line capacity in space-division photonic switching system by compensating insertion loss of switch matrix. [Fujiwara et. al., 1991].

(K. Amano)


Adachi, H., K. Matsuda, T. Chino, and J. Shibata [1991], "InGaAsP/InP Optoelectronic Exclusive-OR(XOR) Gate Operating with Optical Inputs and Outputs." IEEE Photon. Technol. Lett., vol. 3, 11, 1013-1015.

Fujiwara, M., H. Nishimoto, T. Kajitani, M. Itoh, and S. Suzuki [1991], "Studies on Semiconductor Optical Amplifiers for Line Capacity Expansion in Photonic Space-Division Switching System," IEEE J. Lightwave Technol., vol. 9, 2, 155-160.

Matsuo, S., T. Kurokawa, T. Tsuda, and C. Amano [1992], "All-Optical Bit-Pattern Matching with Photonic Switching Arrays, " IEEE Photon. Technol. Lett., vol. 4, 3, 267-269.

Nitta, Y., J. Ohta, M. Takahashi, S. Tai, and K. Kyuma [1992], "Optical Neurochip with Learning Capability," IEEE Photon. Technol. Lett., vol. 4, 3, 247-249.

Takahashi, Y., K. Ando, H. Inoue, and E. Amada [1990], "An Experimental Photonic ATM Switching System Using An InP Semiconductor Optical Switch, "Globcom '90, 805.1, 1586-1589.

Yamaguchi, M., T. Matsunaga, and M. Okuno [1990], "Experimental Photonic Multimedia Switching System Using Integrated 8X8 Silica-Based Guided-Wave Crossbar Switch," Globcom '90, 706B.2, 1301-1305.

Yamanaka, Y., K. Yoshihara, I. Ogura, T. Numai, K. Kasahara, and Y. Ono [1992], "Free-Space Optical Bus Using Cascaded Vertical-to-Surface Transmission Electrophotonic Devices." appl. Opt., vol. 31, 23, 4676-4681.

C4. Circuit and Systems

In the recent three years, studies on circuits and systems have been very active in Japan. The Joint Technical Conference on Circuits andSystems was held once a year in Japan and Korea, alternately. The Karuizawa Workshop on Circuits and Systems continued to be held annually. Since 1990, the Symposium on Nonlinear Theory and its Applications was held annually. Among these conferences, many excellent papers in various fields of circuits and systems were presented and a lot of fruitful discussions were made.

It is also worth noting here that the rapid advance of CAD research has made progress in Japan in both theory and application[Kang et al.,1991] and [Takizawa et al.,1991]. Related graph theoritical problems to CAD researches such as [Maruyama et al.,1990],[Isomoto et al.,1992] and [Matsunaga et al.,1991] have been discussed.

Graph theory and its applications to circuits and systems have continued to be active research field. Some prominent results are related to connectivity augmentation problem[Watanabe et al.,1990], location problem[Tamura et al.,1990], fault diagnosis of analog circuits[Yamaguchi et al.,1990] and channel assignment problem [Tamura et al.,1991].

Petri Net theory and its applications to discrete event system has become a big research area in Japan. Many fruitful results, for example, [Lee et al.,1991], [Matsumoto et al.,1991] and [Watanabe et al.,1992] have been obtained. Studies on the analysis of nonlinear systems have been very active and successive. For example, the number of solutions of nonlinear resistive circuits was discussed [Nishi et al.,1991]. A new idea of computational graph was proposed for partial differentiation [Iri et al.,1991] and was applied to detect separability of nonlinear mappings [Yamamura et al.,1991]. By the use of the notion of set-valued mappingsnew concept of quasitolera-bility of system fluctuations was proposed and the related fale-safe principle in wide sense was discussed [Horiuchi,1991].

It is remarkable that researches by homotopy method were vigorousand efficient to solving nonlinear equations. It is shown that the samemethod could also be applied to solve functional equation [Makino M. and Oishi,S.,1989 and 1990]. Also, a posteriori method was proposed for estimating the error between the exact solution and an approximate solution [Makino M., Oishi,S.and,1991].

Many Japanese researchers attended the IEEE International Symposium on Circuits and Systems (ISCAS). Hence considerably large part of the recent activities concerning circuits and systems can be reviewed in the Proceedings of 1990,1991 and 1992 ISCAS,too.

(K. Horiuchi)


Amamura, K.and Kiyoi, M., Algorithms for Detecting Separability of Nonlinear Mappings Using Computational Graphs, Trans.IEICE,Vol.J74-A,12,pp.1755-1765(Dec.1991)

Horiuchi, K., Functional Analysis of Nonlinear System Fluctuations, IEICE Trans., Vol. E-74,6, pp.1353-1367(Jun.1991)

Iri, M. and Kubota, K., Norms, Rounding Errors, Partial Derivatives and Fast Automatic Differentiation,IEICE Trans.,Vol.E-74,3, pp.463-471(Mar.1991)

Isomoto, K., Wakabayashi, S., Miyao, J. and Yoshida, N., A Parallel Algorithm for k-Way Graph Partitioning, Trans. IEICE, Vol.J75-A,6, pp.1064-1071(Jun.1992)

Kang, M. S., Iwashita, H. and Shirakawa, I., An Extended Digital Fault Simulator for VLSI Circuits, IEICE Trans., Vol.E-74, 10, pp.3051-3056(Oct.1991)

Kotani, K., Masuda, S., and Kashiwabara, T., An Algorithm for Embedding a Biconnected Planar Graph to Maximize the Total Sum of Vertex- and Edge-Weights on the Exterior Window, Trans. IEICE, Vol.J74-A, 7, pp.1041-1052(Jul.1991)

Lee, D., Kumagai, S. and Kodama, S., Complete Structural Characterization of State Machine Allocatable Nets, IEICE Trans., Vol.E-74, 10, pp.3115-3123(Oct.1991)

Makino, M. and Oishi, S., A Homotopy Method for Numerically Solving Infinite Dimensional Convex Optimization Problems,Trans. IEICE, Vol.E-72, 12, pp.1307-1316(Dec.1989)

Makino, M., Oishi, S., Kashiwagi, M. and Horiuchi, K., An Urabe Type A Posteriori Stopping Criterion and a Globally Convergent Property of the Simplicial Approximate Homotopy Method, IEICE Trans., Vol.E-74,6, pp.1440-1446(Jun.1991)

Maruyama, T., Tsukiyama, S. and Shinoda, S., An Acceleration of an Algorithm to Enumerate All Rectangular Dual Graphs, Trans. IEICE, Vol.J73-A,4, pp.818-828(Apr.1990)

Matsumoto, T. and Tsuji, K., A Useful Necessary condition and a Simple Sufficient Condition for Liveness of General Petri Nets,IEICE Trans.,Vol.E-74,10, pp.3124-3132(Oct.1991)

Matsunaga, Y. and Fujita, M., Multi-Level Logic Optimization Using Ordered Binary Decision Diagrams and Permissible Functions,Trans.IEICE,Vol.J74-A,2, pp.196-205(Feb.1991)

Nishi, T. and Kawane, Y., On the Number of Solutions of Nonlinear Resisitive Circuits, IEICE Trans., Vol.E-74, 3, pp.479-487(Mar.1991)

Takizawa, T., Kubota, K., Sato, M. and Ohtsuki, T., A VLSI Geometrical Design Rule Verification Accelerated by CAM-Based Hardware Engine, IEICE Trans., Vol.E-74,10, pp.3072-3077 (Oct.1991)

Tamura, H., Sengoku, M., Shinoda, S. and Abe, T., Location Problems on Undirected Flow Networks, Trans. IEICE, Vol.E-73,12, pp.1989-1993(Dec.1990)

Tamura, H., Sengoku, M., Shinoda, S. and Abe,T.,Channel Assignment Problem in a Cellular Mobile System and a New Coloring Problem of Networks, IEICE Trans., Vol.E-74,10, pp.2983-2989(Oct.1991)

Taoka, S., Watanabe, T. and Onaga, K., A Linear-Time Algorithm for Computing All 3-Edge- Connected Components of a Multigraph, IEICE Trans., Vol.E-75,3, pp.410-424(Mar.1992)

Watanabe, T., Higashi, Y. and Nakamura, A., Constructing Robust Networks by means of Graph Augmentation Problems, Trans. IEICE, Vol.J73-A, 7, pp.1242-1254(Jul.1990)

Yamaguchi, I. and Shinoda, S., A Sufficient Condition for the Unique Restorability of Circuits and its Related Graph-Theoretic Problems, Trans. IEICE, Vol.J73-A, 4, pp.839-855(Apr.1990)

Watanabe, T., Kato, N. and Onaga, K., Proof Procedures and Axiom Sets in Petri Net Models of Horn Clause Propositional Logic -Minimum Modification for Provability-, IEICE Trans., Vol.E-75, 4, pp.478-491(Apr.1992)

Makino, M. and Oishi, S., Constructive Analysis for Infinite Dimensional Nonlinear Systems, Trans. IEICE, Vol.J73-A,3, pp.470-477(Mar.1990)

C5. Information Theory

Shannon theory is being extended to cover various communication models. A remarkable result in past three years is that of identification via channels. It is shown that efficient coding is possible for multi-user communication by combining identification and transmission [Han et al. 1992].

In the area of source coding, universal coding is still one of the most popular research subjects and considerable improvements have been made [Yokoo, 1992].

In the area of error-control coding, algebraic-geometry codes and coded modulation are most actively studied. The award-winning paper [Kamiya et al., 1991] has established a construction method for algebraic-geometry codes on plane curves having singular points. Berlekamp-Massey algorithm has been extended to n dimensions [Sakata, 1990]. The extended algorithm, which is called Sakata algorithm, gives a powerful technique for fast decoding of algebraic-geometry codes. Imai-Hirakawa's multilevel block coded modulation has been generalized and its error performance has been analyzed [Kasami et al., 1991]. Another important aspect of the theory of error-control coding is its practical applications. From this aspect Japan is one of the most active countries as is summarized in [Imai, 1990].

Cryptography and its applications to information security are active research areas in information theory. There has been a great progress in cryptanalytic methods for des-like block ciphers. In particular powerful methods for known-plaintext attack of FEAL has been presented [Matsui et al., 1992]. A new electronic version of cash has been proposed [Okamoto et al., 1991]. This electronic cash firstly attains good dividability in the class based on the "digital signature = money" notion. The implicit asking protocols, which were originated from Japan, are actively studied. It is shown that these protocols are actually useful to enhance computational power of IC cards in case of RSA digital signatures[Kawamura et al., 1990]. A novel human identification problem of how to construct dynamic password schemes requiring no auxiliary devices has been presented and some solutions have been given [Matsumoto et al., 1992]

(H. Imai)


Han, T. S., and S. Verdu[1992], "New Resuts on The Theory of Identification via-Channels," IEEE Trans. Inform. Theory, vol. 38, 1, 14-25.

Imai, H.[1990], Essentials of Error-Control Coding Techniques, San Diego, Academic Press.

Kamiya, N., S. Miura, and H. Imai[1991], "Construction of Codes on Arbitrary Plane Curves," Trans. IEICE Japan, vol. J74-A, 7, 1067-1074.

Kasami, T., T. Takata, T. Fujiwara, and S. Lin[1991], "On multilevel Block Modulation Codes," IEEE Trans. Inform. Theory, vol. 37, 4, 965-975.

Kawamura, S., and A. Shimbo[1990], "Performance Analysis of Server-Aided Secret Computation Protocols for The RSA Cryptosystem," Trans IEICE Japan, vol. E73, 7, 1073-1080.

Matsui, M., and A. Yamagishi[1992], "A new Method for Known Plaintext Attack of FEAL Cipher," Eurocrypt'92, Extended Abstracts, 77-78.

Matsumoto, T., and H. Imai[1991], "Human Identification Through Insecure Channels," Advances in Cryptology-Eurocrypt'91, Lecture Notes in Computer Science, Springer-Verlag, no. 547, 409-421.

Okamoto, T. , and K. Ohta[1991], "Universal Electronic Cash," Advances in Cryptology-Crypto'91, Lecture Notes in Computer Science, Springer-Verlag, no. 576, 324-337.

Sakata, S.[1990], "Extension of Berlekamp-Massey Algorithm to N Dimensions,"Information and Computation, vol. 84, 2, 207-239.

Yokoo, H.[1992], "Improved Variations Relating The Ziv-Lempel and Welch-Type Algorithms for Sequential Data Compression," IEEE Trans. Inform. Theory, vol. 38, 1, 73-81.

C6. Spread Spectrum Technology

In a Spread Spectrum (SS) communication system, interference rejection techniques bring a better performance. Many techniques were proposed ; SAW progra mmable notch filters [Sugai et al., 1989], adaptive canceller [Kohno et al., 1990], adaptive array antenna and a canceller [Kohno et al., 1990], a new delay lock loop [Suzuki et al., 1991] and an elimination filter [Suehiro, 1992].

SS modem implementation and proposal for simplicity, efficiency and multipurpose were reported ; transceiver using a SAW convolver [Tsubouchi et al., 1989], modem using soft decision digital matched filter [Miyake et al., 1990. Kataoka et al., 1991], heterodyne-type autocorrelator [Kajiwara et al., 1991], demodulator using block processing [kajiwara et al., 1991] and coherent matched filter receiver[Ikegami et al., 1991].

Other results were reported on properties of a truncated sequence [Fukumasa et al., 1991], performance of an FH system in fading [Yamamura et al., 1991] and an SS signal transmission over a QPSK signal [Enomoto et al., 1991].

(M. Yokoyama)


Enomoto, K., M.Morikura, S.Kubota, and S.Kato[1991],"Common Transmission of High Speed QPSK Signals over Nonlinearly Amplified Transponder," IEICE Japan, Trans. Comm., vol.E74, 5, 1155-1163.

Fukumasa, H., R.Kohno, and H.Imai[1991],"Pseudo-Noise Sequence for Tracking and Data Relay Satellite and Related Systems," IEICE Japan, Trans. Comm., vol.E74, 5,1137-1144.

Ikegami, T., R.Suzuki, N.Hamamoto, and N.Sato[1991],"Experiments on Coherent Matched Filter Receiver for Spread-Spectrum Mobile Satellite Communications," IEICE Japan, Trans. Comm., vol.E74, 5, 1130-1136.

Kajiwara, A., and M.Nakagawa[1991], "Heterodyne-Type Autocorrelator for SS-DS Communications," IEICE Japan, Trans.Comm., vol.E74, 5, 1103-1107.

Kajiwara, A., M.Nakagawa, and M.Hagiwara[1991], "Direct-Sequence Spread-Spectrum Demodulator Using Block Processing," IEICE Japan, Trans.Comm., vol.E74, 5, 1108-1114.

Kataoka, N., T.Kojima, M.Miyake, and T.Fujino[1991], "Performance of Soft Decision Digital Matched Filter in Direct-Sequence Spread-Spectrum Communication System," IEICE Japan, Trans.Comm., vol.E74, 5, 1115-1122.

Kohno, R., H.Imai, M.Hatori, and S.Pasupathy[1990], "Combination of An Adaptive Array Antenna and A Canceller of Interference for Direct-Sequence Spread-Spectrum Multi-Access System," IEEE J. Sel. Areas Comm., vol.8, 4, 663-674.

Kohno, R., H.Imai, M.Hatori, and S.Pasupathy[1990],"An Adaptive Canceller of Cochannel Interference for Spread-Spectrum Multiple-Access Communication Systems in A Power Line," IEEE J. Sel. Areas Comm., vol.8, 4, 691-699.

Miyake, M., T.Kojima, N.Kataoka, and T.Fujino[1990],"Design and Performance of Direct-Sequence Spread-Spectrum Modem Using Soft Decision Digital Matched Filter," IEEE Int.Symp.Spread Spectrum Tech. & Application'90, 135-139.

Suehiro, N.[1991],"Elimination Filter for Cochannel Interference in Asynchronous SSMA Systems Using Polyphase Modulatable Orthogonal Sequences," IEICE Japan, Trans. Comm., vol.E75-B, 6, 494-498.

Sugai, K., H.Takakuni, O.Noguchi, and K.Omori[1989],"SAW Programmable Notch Filters for Adaptive Interference Suppression," 1989 Ultrasonic Symposium Proceedings, IEEE89CH2791-2, 201-206.

Suzuki, S., M.Sato, and N.Morinaga[1991],"A New Delay Lock Loop Capable of Rejecting the Interference due to the Other Users in SSMA," IEICE Japan, Trans. Comm., vol.E74, 5, 1123-1129.

Tsubouchi, K., N.Mikoshiba[1989], "An Asynchronous Multichannel Spread SpectrumTransceiver Using SAW Convolver," 1989 Ultrasonic Symposium Proceedings, IEEE89C, H2791-2, 165-172.

Yamamura, H., R.Kohno, and H.Imai[1991],"Performance of Multihop Fast Frequency Hopping/Spread Spectrum Multiple Access System in a Selective Fading Channel," I.

C7. Radio Communications

C7.1. Satellite Communmications

(1) Domestic Satellite Communication

The dynamic channel assigning and routing satellite aided digital network Dyanet has been expanded from switcher lines to subscriber lines [Kato et al, 1992] using Ku-band domestic commercial communication satellite JC-SAT.

The state-of-the-art engineering test satellite ETS-VI has been developed and is waiting for launch by Japan's first 2-ton class rocket H-2. The ETS-VI employs advanced onboard equipment [Tanaka et al,1992] including deployable 3.5- and 2.5-meter reflector antennas [Ohtomo et al, 1990], 30-GHz band full-MMIC ultra lightweight transponder [Ohira et al, 1989 ; Kato et al, 1990], 2.5GHz-band multi-port transponder [Horikawa et al, 1990], which are all developed by NTT to pursue experimental missions of multi-beam satellite communications covering Japan with 13/5 beams.

(S. Samejima)


Horikawa, K., M.Tanaka and K.Yamamoto: "A highly flexible and highly efficient 100 W S-band transponder for multibeam mobile satellite communications", AIAA 14th International Communication Satellite systems Conference, AIAA-92, 1823, pp.148-154, March 1992.

Kato, S., M.Morikura, S.Kubota, H.Kazama, K.Enomoto and M.Umehira: "A TDMA satellite communication system for ISDN services", IEEE Journal on selected areas in communications, J-SAC-10, 2, pp.456-464, Feb.1992.

Kato, H., T.Ohira, F.Ishitsuka, T.Tokumitsu, Y.Kihata and N.Imai: "A 30 GHz MMIC receiver for satellite transponder", IEEE Trans. Microwave Theory Tech., MTT-38, 7, pp.896-903, July 1990.

Ohtomo, I., H.Kumazawa, Y.Kawakami and T.Yasaka: "Development of the on-board fixed and mobile multi-beam antenna for ETS-VI satellite", 13th ICSSC, 90-0805, March 1990.

Ohira, T., K.Araki, H.Kato and F.Ishituska: "A compact full-MMIC module for Ku-band phase locked oscillators", IEEE Trans. Microwave Theory Tech., MTT-37, 4, pp.723-728, April 1989.

Tanaka, M., K.Yamamoto and K.Horikawa: "Ka-band and S-band transponder technologies for satellite on-board multibeam communication system", 4th Asia Pacific Microwave Conference Proceedings , APMC '92, 1, pp.261-264, Aug.1992.

(2) International Satellite Communications

Studies on sub-channel switched frequency-division multiple access (SS/FDMA) system have been continued to realize efficient and flexisible multibeam satellite communications network. A proof of concept model of an SS/FDMA on board equipment (called SS/FDMA router) were developed and evaluated through experiments, and a redundant configuration of the SS/FDMA router was proposed for sufficiently reliable system operation. The development and the evaluation of sharp and stable Surface Acoustic Wave (SAW) filters which are the most suitable for the on board filter matrices in the SS/FDMA system have also been continued [Shinonaga et al., 1992]

A narrow band interference exciser (NBIE) was developed to eliminate the adverse effects of the interference on TDMA carrier. A field experiment confirmed the good interference elimination performance of a prototype NBIE equipment against narrow band CW and swept CW interference [Satoh et al., 1992]

Novel carrier synchronization algorithms were developed to make the PSK demodulator operable under severe circumstances of low C/N, large frequency offset, multipath fading, and no or short preamble in the signalling and the communication systems such as INMARSAT C and M system [Takeuchi et al., 1990 and 1992]

A powerful error correction codec, which is suitable for the application to some VSAT systems or other ssystems requiring the high coding gain, was developed by employing a stack algorithm type sequential decoder. This codec can transmit up to 1Mb/s information at coding rates of 1/2, 3/4 and 7/8, enjoys coding gain higher than usually emplyed Viterbi decoder, and shows good performance even in a very noisy channel [Ohashi et al., 1992]

(K. Amano)


Shinonaga, H., Ito, Y., SS/FDMA router for flexible satellite communication network, IEEE J. Select Areas Commun.,Vol. 10, No. 2, pp. 391-400, (Feb. 1992)

Shinonaga, H., Ito, Y., 250MHz SAW filters for SS/FDMA system employing ST-cut quartz substrates, 9-th Int. Conf. on Digital Satellite Commun., B, pp.197-203, (May 1992)

Shinonaga, H., Ito, Y., Microwave SAW bandpass filters for space applications, IEEE Trans. Microwave Theory, Vol. 40, No. 6, pp. 1110-1116, (June 1992)

Satoh, G., Inoue, T., Method of hardening TDMA system by eliminating a narrow band

Honda, T., Takeuchi, Y., Kobayashi, Y., Mizuno, T., A novel carrier recovery method for preambleless demodulation, Trans. IEICE, Vol. E73, No. 10, (Oct. 1990)

C7.2. Terrestrial Radio Communication

Synchronous Digital Hierarchy (SDH) compatible digital radio systems were commercialized during these three years. NTT has developed a series of SDH-based digital radio systems; (4.5.6G-300M and 4.5.6G-150M) for long haul transmission links, and (11G-150M, 11G-50M and 4G-50M) for short haul transmission links [Murase,1991]. SDH compatible digital radio systems have been introduced in 2700km long haul transmission links and 2500km short haul transmission links.

Studies on non-regenerative repeating digital microwave radio systems are being carried out to reduce equipment cost, response quickly to network construction and long MTBF [Watanabe,1991].

For access links, 26 GHz microwave systems have been introduced to provide broadband video, high-speed digital and ISDN services [Inoue,1990]. The high reliability of the 26 GHz microwave system has been proven through field trial tests [Manabe,1991].

Non-regenerative radio transmission systems are also being studied for personal communications base station links [Fujimoto,1991]. The SCM/concentrating method is compared to the conventional multiplexing/distri-buting method from the viewpoints of network structure and cost effectiveness.

(K. Morita)


Fujimoto,N., Kuroda,T., Hoshino,H., Segawa,J. and Hashimoto,A., "Non-regenerative Radio Transmission Systems for personal Communications Base Station Links," GLOBECOM'91, 29.2.2-29.2.7,(Dec. 1991)

Inoue, K. and Furuta,Y.[1990], "26GHz-band Subscriber Radio System for Various Services," NTT Review, vol.2, No.5, 59-65,(Sept. 1990)

Manabe,T., Yoshida,T. and Hashimoto,A., "High-speed, Broadband Microwave Access Networks," ICC'91, 37.3.1-37.3.5,(June 1991)

Murase.T., Hashimoto.A. and Segawa.J, "Design and Performance of the SDH based Microwave Digital Radio Systems," 3rd ECRR, pp.48-55,(Dec. 1991)

Watanabe.K, Ohtsuka.H and Kagami.O, "A Non-regenerative Repeating Digital Microwave Radio System," GLOBECOM'91, 51.5.1-51.5.5,(Dec.1991)

C7.3. Mobile Communication

Land Mobile Communications In land mobile communications, digital cellular system, personal communication system, and mobile packet communication system have been very actively studied and many papers are presented. Especially, in personal communication system, new system concept are proposed and it is sure that new era of land mobile communications has come.

In the research field, there are many kind of items investigated, that are System, Channel Assignment, FEC, Hardware, Antennas & Propagation, Equalizer, Diversity, Modem, Multiple Access, Switching, Voice Codec, Control, Equipment.

The typical papers for system proposal are personal communication concept developed from cordless telephone system (Hattori '90) and (Nakajima '92) from digital cellular system.

In control techniques, the featured papers are autonomous decentralized microcellular systems (Akaiwa '91, Kanai '92, and Yasuda '92) and handoff (Kinoshita '92). The papers of Dynamic Channel Assignment in Channel Assignment are shown by (Furuya '91 and Akaiwa '92).

Many papers are presented for Antenna & propagation. The papers concerned with Adaptive antenna (Ogawa '92 and Kohno '92) are interesting theme and show new trend to study.

There are many papers of Equalizers which are effectively applied by classical method. i.e. RLS (Ueda '90), DFE (Kamio '92) etc.. In voice coding, low delay codec (Ono '91) and half rate codec (Kataoka '91) are mainly investigated.

(T. Hattori)


Akaiwa, Y., Andoh, H. and Kohama, T.[1991],"Autonomous decentralized inter-base-station synchronization for TDMA microcellular systems", IEEE Vehicular Tech-nology Conference, St. Louis, U.S.A., 257-262

Akaiwa.Y.[1992],"The Channel Segregation, a Self-Organized Dynamic Channel Allocation Method Application to TDMA/FDMA Microcellular System,"Proc. of ICUPC,1992,pp.345-349.

Furuya, Y., Akaiwa, Y.[1991],"Channel Segregation, a Distributed Adaptive Channel Allocation Scheme for Mobile Communication Systems," Trans. IEICE Japan,

Hattori,T. Sekiguchi,H. Kohiyama,K. Yamamoto,H . [1990], "Personal Communication -Concept and Architecture," IEEE ICC'90, 335.4

Kamio, Y. and Sampei, S.[1992],"Performance of reduced complexity DFE using bidirectional equalizing in land mobile communications", IEEE Vehicular Technology Conference, Denver, U.S.A., 372-374

Kanai, T.[1992],"Autonomous reuse partitioning in cellular systems", IEEE Vehicular Technology Conference, Denver, U.S.A., 782-784

Kataoka,A. Moriya,T. [1991], "A Backward Adaptive 8kbit/s Speech Coder Using Conditional Pitch Predictor," IEEE Globecom'91, 53.6

Kohno.R.[1991],"Array Antenna Beamforming based on Estimation of Arrival Angles using DFT on Spatial Domain,"Proc. of PIMRC,1991, pp.38-43.

Kohno.R.[1992],"Adaptive Array Antenna Combined with Tapped Delay Line using Processing Gain for Spread-Spectrum CDMA Systems,"Proc. of PIMRC,1992,pp.634-638.

Nakajima.A.[1992],"Intelligent Network Architecture for Personal Mobile Telecom-munication,"Proc. of ICUPC,1992, pp.339-344.

Ogawa, Y., Nagashima, Y. and Itoh, K.[1992], "An Adaptive Antenna System for Mobile Communication," Trans.IEICE Japan, vol.E75-B, 05, 413-421

Ono,S.[1991], "8kbps Low Delay CELP with Feedback Vector Quantization," IEEE Globecom'91, 21.2

Ueda, T. and Suzuki, H.[1990],"Performance of equalizers employing a re-training RLS algorithm for digital mobile radio communications", IEEE Vehicular Technology Conference, Orland, U.S.A., 553-558

Yasuda, S. and Onoe, S.[1992],"Autonomous channel assignment control for flexible reuse in mobile radio systems", IEEE Vehicular Technology Conference, Denver, U.S.A., 798-801

C8. Optical Fiber Communication

Optical fiber amplifiers will play a important role in future optical communication systems. High-bit-rate and long-haul optical transmission experiments using optical fiber amplifiers were reported [ Hagimoto et al., 1992 and Imai et al., 1992 ]. Performance of optical time-domain reflectometers (OTDRs) is improved by adopting optical fiber amplifiers [ Sato et al., 1991]. 10 Gbit/s, 1200 km error-free soliton data transmission was carried out using the amplifiers [ Nakazawa et al., 1992]

Coherent transmission technique has the potential for long-span signal transmission. Fiber chromatic dispersion was compensated using an electronic technique [ Iwashita et al, 1990]. Polarization diversity technique was experimentally confirmed to be practical for the compensation of signal polarization fluctuation [ Ryu et al, 1991].

Optics is suited for ultrafast signal processing in communication systems. Trasform-limited 7.6 ps optical pulses with a repetition rate of 30 GHz were generated [ Takada et al., 1990]. A phase-locked-loop type clock generator was proposed and operated at 14 GHz [ Takayama et al., 1992]. Optical tank circuits were used for all optical timing recovery [ Jinno et al., 1992]

Optical wavelength-division-multiplexing (WDM) is a technique to implement multiple channels in a single optical fiber. A 100-channel, 622 Mb/s transmission/distribution experiment with a channel spacing of 10 GHz was carried out over a 50 km-long fiber [ Toba et al., 1990]. Multichannel amplification utilizing an optical fiber amplifier was demonstrated [ Inoue et al., 1991]

Optical switches are indispensable for the control of optical fiber networks. A wavelength-division switching system using tunable laser-diode filters is proposed [ Suzuki et al., 1990] A 8 x 8 waveguide matrix switch utilizing thermo-optic effect having an insertion loss of 11 dB was reported [ Sugita et al., 1990]. A 128 x 128 rearrangeable free-space optical switch using liquid crystal modulators was demonstrated [ Noguchi et al., 1991]

Optical subscriber loop system is one of the important systems of the B-ISDN. A subcarrier multiplexing (SCM) system which can simultaneously distribute 11 AM-TV channels and 50 FM-TV channels was demonstrated [ Yoneda et al., 1992].

Cable design and fiber connection are fundamental technologies for optical fiber communication systems. A 1000-fiber cable including 8-fiber ribbons was developed [ Kawase et al., 1989]. SC-type single-mode optical fiber connectors were developed for subscriber loop networks [ Sugita et al., 1989].

(H. Ishio)


Hagimoto, K., Miyamoto, Y., Kataoka, T., Ichino, H., and Nakajima, O., Twenty-Gbit/s Signal Transmission Using a Simple High-Sensitivity Optical Receiver, Conf. Rec. Optical Fiber Communication, OFC'92, Tul.3 (1992)

Imai, T., Murakami, M., Fukuda, Y., Aiki, M., and Ito, T., 2.5 Gbit/s, 10073 km Straight Line Transmission System Experiment Using 199 Er-Doped Fiber Amplifiers, Electron. Lett., 28, 16, pp.1484-1485 (1992)

Inoue, K., Toba, H., and Nosu, K., Multichannel Amplification Utilizing an Er3+doped Fiber Amplifier, IEEE J. Light. Tech., 9, 3, pp.368-374 (1991)

Iwashita, K. and Takachio, N.,Chromatic Dispersion Compensation in CoherentOptical Communications, IEEE J. Lightwave Tech., 8, 3, pp.367- 375 (1990)

Jinno, M. and Matsumoto, T., Optical Tank Circuits Used for All-Optical Timing Recovery, IEEE J. of Quantum Electron., 28, 4, pp. 895-900 (1992)

Kawase, M., Fuchigami, T., Matsumoto, M., Nagasawa, S., Tomita, S., and Takashima, S., Subscriber Sigle-Mode Optical Fiber Ribbon Cable Technologies Suitable for Midspan Access, IEEE J Light. Tech.,7, 11, pp.1675-1681 (1989)

Nakazawa, M., Suzuki, K., Yamada, E., Kubota, H., and Kimura, Y.,10 Gbit/s, 1200 km Error-Free Soliton Data Transmission Using Erbium-Doped Fibre Amplifiers, Electron. Lett.,28, 9, pp. 817-818 (1992)

Noguchi, K., Sakano, T., and Matsumoto, T., A Rearrangeable Multichannel Free-Space Optical Switch Based on Multistage Network Configuration, IEEE J. Lightwave Technol., 9, 12, pp.1726-1732 (1991)

Ryu, S., Yamamoto, S., Namihira, Y., Mochizuki, K., and Wakabayashi, H., Polarization Diversity Techniques for the Use of Coherent Optical Fiber Submarine Cable Systems, IEEE J. Lightwave Tech., 9, 5, pp.675-682 (1991)

Sato, Y. and Aoyama, K., OTDR in Optical Transmission Systems Using Er-Doped Fiber Amplifiers Containing Optical Circulators, IEEE Trans. Photonics Technol. Lett.,3, 11, pp.1001-1003 (1991)

Sugita A., Okuno, M., Matsunaga, T., Kawachi, M., and Ohmori, Y., Strictly Nonblocking 8 x 8 Integrated Optical Matrix Switch with Silica-Based Waveguides on Silicon Substrate, Proc. ECOC'90, WeG4.1 (1990)

Sugita, E., Nagase, R., Kanayama, K., and Shintaku, T., SC-Type Single-Mode Optical Fiber Connectors, IEEE J. Light. Tech.,7, 11, pp.1689- 1696 (1989)

Suzuki, S., Nishio, M., Numai T., Fujiwara, M., Itoh, M., Murata, S., and Shimaoka, N., A Photonic Wavelength Division Switching System Using Tunable Laser Diode Filters, IEEE J. Light. Tech., 8, 5, pp.660-666 (1990)

Takada, A. and Miyazawa, H.,30 GHz Picosecond Pulse Generation from Actively Mode-Locked Erbium-Doped Fibre Laser, Electron. Lett.,26, 3, pp.216-217 (1990)

Takayama, K., Habara, K., Miyazawa, H., and Himeno, A., High-Frequency Operation of a Phase-Locked Loop-Type Clock Regenerator Using a 1 x 2 Optical Switch as a Phase-Comparator, IEEE Photonics Technol. Lett., 4, 1, pp.99-101(1992)

Toba, H., Oda, K., Nakanishi, K., Shibata, N., Nosu, K., Takato, N., and Fukada, M., A 100-Channel Optical FDM Transmission/Distribution at 622 Mb/s over 50 km, IEEE J. Light. Tech., 8, 9, pp.1396-1401(1990)

Yoneda, E., Suto, K., Kikushima, K., and Yoshinaga, H., Erbium-Doped Fiber Amplifiers for All-Fiber Video Distribution (AFVD) Systems, IEICE Trans. Commun., E75-B, 9, pp.850-861 (1992)

C9. Communication Networks

Narrow-band ISDN services were introduced in 1988 and now there is a great variety of telecommunication services. Furthermore visual, intelligent and personal will be the key requirements for 21st century telecommunication services. In order to realize these services, two key specific-technologies are reqired. These are network architecture and broad-band ISDN (B-ISDN) [Terada,1991, Inoue,1992].

There are various requirements for future networks, such as easy integration of multiproviders networks, easy introduction of new services, and easy operation of network management and maintenance. The concept of network architecture technology was proposed for network planning and construction in order to realize these demands easily and systematically [Kano et al.,1990]. Intelligent Network (IN) has been studied to achieve rapid introduction of services [CCITT Recommendations, 1990]. As communications software has become more important, the number of papers has increased. Software interfaces for information communications [Ishino,1990] and specification description [Ichikawa et al.,1991] have been studied.

Asynchronous Transfer Mode (ATM) technology is necessary in order to realize B-ISDN [Inoue et al.,1991]. Many studies have been reported concerning this technology, for example, ATM switching technology [Takeuchi et al.,1991], traffic control technology on ATM networks [Saito et al.,1991], multimedia telecommu-nication services quality technology [Tachi et al.,1992] and ATM network planning and constructing technology [Murakami et al.,1992]. In advanced private network services, future concepts and their realization methodology based on ATM have been presented [Yamagata et al.,1991].

Concerning the network operation technology, dynamic-routing schemes especially have been studied for advanced traffic control. NTT has carried out field tests of a dynamic-routing scheme called STR (State- and Time-dependent Routing) on a real network and proved its effectiveness [Yamamoto et al.,1991]. For restoration control, self-healing algorithms have been presented for use in digital cross-connect systems that makes it possible to reconfigure the network dynamically [Sakauchi H. et al.,1990].

Optical fiber techniques have been gradually introduced and the conversion to optical fibers is nearly finished for the transit network. However subscriber networks opticalization is progressing more slowly and strategies for FTTH (fiber to the home) have yet to be studied [Miki,1991].

(T. Aoki)


CCITT [1990], "Report of SG X1/4," SGXI-R30,R31.

Ichikawa H.,Itoh M.,Kato J.,Takura A. and Shibasaki M.[1991],"SDE: Incremental Specification and Development of Communications software,"IEEE Trans. Computers, vol.40, no.4, 553-561.

Inoue Y.[1992], "Network Evolution toward the VI&P Era," NTT REVIEW, vol.4,4, 23-29.

Inoue Y., and Tokizawa I. [1991], "Transport Network Evolution toward ATMized B-ISDN," IEICE Trans., vol.E74, 4, 780-786.

Ishino F.[1990], "Multivendor Oriented Software Architecture," TINA 90 Workshop.

Kano S., Tomita S., Sato F.[1990], "Network Architecture and Switch Interface Scenarios," ICC '90, 366.2.

Miki T.[1991], "Fiber-Optic Subscriber Networks and Systems Developement,"IEICE Trans. vol.E74,1, 93-100.

Murakami H., Yokoi T., Taka M. [1992], "Considerations on ATM Network Performance Planning," IEICE Trans. vol.E75-B,7, 563-571.

Saito H., Kawashima K. and Sato K. [1991],"Traffic Control Technologies in ATM Networks," IEICE Trans., vol.E74,4, 761-771.

Sakauchi H., Nishimura Y. and Hasegawa H.[1990], "A Self-healing network with an economical spare-channel assignment", Globecom'90, 403.1.1,438-443.

Tachi T.,Iai S.,Kitawaki N.[1992],"Proposal of Selection Method of Test Pictures in HDTV Subjective Quality Assessments,"4th IEEE Comsoc International Workshop in Multimedia Communication Session : VIDEO CODING AND SYSTEMS.

Takeuchi T., Suzuki H., and Aramaki T. [1991], "Switch Architecture and Technologies for Asynchronous Transfar Mode," IEICE Tranc., vol.J74-B-I,4, 752-760.

Terada Y.[1991], "Evolution of ISDN towards B-ISDN," NTT REVIEW, vol.3,3, 25-33.

Yamagata J.,Kumon S. [1991],"Technologies for Broadband and Multimedia Private Network with Aspects of Next-Generation LAN Trend,"IEICE Trans. vol.E74,9, 2671-2676.

Yamamoto H., Mase K., Inoue A., Suyama M.[1991], "Dynamic Routing Schemes for Advanced Network Manegement," IEICE Trans., vol.E74,12, 3981-3991.

C10. Broadcasting

For more improved future broadcasting satellites, NHK has developed onboard key components such as 12GHz 200W helix TWT's with high reliability and high efficiency [Y. Morishita et al, 1991], and shaped reflector antennas whose radiation pattern fits the geographical shape of Japan [K. Shogen et al,1992].

An active flat plate antenna with high efficiency for Japanese DBS has been developed [T. Murata et al, 1991]. By using the above antenna it has also developed compact mobile receivers for buses and small cars. They have been already put into practical use since the end of 1991.

The developement of ISDB(Integrated Services Digital Broadcasting), which can broadcast several few number of television programs and various kinds of data services on one broadcasting channel, such as 12GHz satellite broadcasting, is being carried out [T. Yoshimura et al, 1992].

A new 16kbps FM multiplex broadcasting system for mobile reception hasbeen realized with LMSK(Level controlled Minimum Shift Keying), which can maintain the constant quality of the multiplexed signals and suppress audible interference from multiplexed signals to stereo sound signals by controlling the injection level in proportion to the modulation level of L-R signals [T. Komoto et al, 1992].

A 120/140Mbits/s HDTV digital transmission system for contribution usehas been developed [K. Seo et al, 1992], where the codec based on Hybrid DCTcoding scheme provides a good performance with little perceptible degradation. The system was used for HDTV program transmission via an optical fiber at the Barcelona Olympics.

NHK has developed an ultra-high sensitive camera tube for HDTV combining an avalanche-mode photoconductive target with 1-inch SS-type electron optics. The camera tube, called the Super-HARP tube, have a sensitivity about 80 times as great as conventional tubes. It was confirmed that the maximum sensitivity of the HDTV camera equipped with the tubes was 2000 1x, f/36 [M. Nanba et al, 1992].

In 1990, partial pictures of Hi-Vision was reproduded on a 33-inch diagonal planar pulse memory panel [H. Murakami et al.]. Recently, we have succeeded in developing a 40-inch panel with 16 60 9 aspect ratio and display-ing Hi-Vision pictures. Also, High contrast TV pictures was displayed on the new 25-inch panel where each display cell had a color filter.

The Picot which is a real-time video signal processing system for video production has been developed [N. Yagi et al, 1991]. This system can replace various video equipment such as video switcher, video effector, and diting system.

A new method of the distance control system for a sound image using a multi-loudspeaker array has been developed [SMDTE TV Conf. 1991]. This arraysimulates a prabolic antenna in audio by means of digital delay lines. An audio signal is fed to the loudspeakers with appropriatc delay time in order that the sound waves from the loudspeakers focus at the point where the sound image is to be localized.

D-3 the new format for composite digital VTRs using a 1/2-in. tape cassette, whose format was developed by NHK [Y. Ohba, 1991], is now commercially available. 1/2-in. tape cassette enable a single format operationfrom a studio VTR to a camera-integrated VTR for ENG/EFP use. In order to achieve such a small format, advanced technologies such as the new 8-14 modulation and high-performance error correction techniqe have been developed.

A demand-access optical fiber CATV system which enables to distribute 80 HDTV MUSE-FM and NTSC signals by means of the frequency multiplexing selection performed at the HUBs has been developed [Y. Utsumi et al, 1992]. An experimental transmission revealed that the CN ratio of more than 17.5dB can be obtained after the optical-fiber transmission of 40km.

Research on the mechanism of seeing shapes and depth of objects was conducted as a basis for future three-dimensional(3-D) picture system, and 3-D television display systems have been developed to study the effects of stereoscopic images [H. Isono et al, 1991].

NHK has developed a new type of spatial light modulator (SLM) using a Bi12SiO20 crystal and a polymer-dispersed liquid crystal. The deveice is usable in image conversion, large area display, and optical computing [K. Takizawa et al, 1990].

(Y. Utsumi)


Isono, H., M. Yasuda, Autostereoscopic 3-D Television Display, NHK LaboratoriesNote, No. 398, pp. 1-12(Dec. 1991)

Komoto, T., O. Yamada, T. Isobe, T. Kuroda, M. Takada, An FM Multiplex Broadcasting System for Mobiles Having a Large Transmission Capacity, NAB Radio Symposium Record(June 1992)

Morishita, Y., H. Hoshino, H. Nakakita et al, A 12GHz, 200W TWT for Broadcasting Satellites, Proc. of ESA Workshop on Space TWTAs,(May 1991)

Murakami, H. et al., A 33-inch diagonal HDTV display using gas-discharge pulse memory technology, SID Int. Symp., Dig. Tech. Papers, pp. 713-716 (May 1991)

Murata, T., M. Fujita, An Electromagneticlly Coupled Active Flat Panel Antenna for DBS Reception, 21st European Microwave Conference Proceedings, Vol. 2(Sept. 1991)

Nanba et al., M., HDTV 1-inch All-electrostatic Super-HARP Tube,1992 ITE Annual Convention, 22-5, pp. 423-424(1992)

Oba, Y., A 1/2 Composite Digital VTR Format, Proc. NAB'91 Conf., pp. 350-358

Seo, K., E. Nakasu, H. Fujio, M. Enari, M. Owada, M. Katou, 120/140Mbps codec for HDTV studio signal transmission, ITEJ Technical Report, No.52, pp. 25-30(1992)

Shogen, K., H. Nishida, N. Toyama, Single Shaped Reflector Antennas forBroadcasting Satellites, IEEE Trans. Antennas and Propagation, Vol. AP-40, No.2(Feb. 1992)

Takizawa, K., H. Kikuchi, H. Fujikake, M. Okada, Transmission Mode Spatial Light Modulator using a Bi12SiO20 Crystal and Polymer-Disperesed Liquid- Crystal Layers, Appl. Phys. Lett., Vol. 56, No.11, pp. 9991-1001(1990)

Utsumi, Y., S. Fujisawa, M. Maeda, K. Murakami, Optical Fiber Broadcasting System, 1992 NAB HDTV World Conference Proceedings, pp. 233-240(April, 1992)

Yagi, N., K. Fukui, K. Enami et al, A programmable real-time video signal processing system, SMPTE Journal, Vol. 100, No.11, pp. 860-868(1991),The 25th Annual SMPTE TV Conference(Feb. 1991)

Yoshimura, T., N. Kawai, E. Nakasu, T. Isobe, Integrated Services Digital Broadcasting (ISDB), International Broadcasting Convention Conference Publication, pp. 350-354 (July 1992)