Wireless access chips: There are strong movements toward compact and low-power dissipation handsets for digital cellular and personal handy-phone system. A 1.9 GHz Si-bipolar receiver with no intermediate frequency (direct conversion), which is suitable for compact handsets, has been developed [Takahashi et al., 1995]. To achieve low power dissipation, very low power supply voltage of 2 V for 2 GHz quadrature modulator IC has also been reported [Tsukahara et al., 1994]. In order to integrate bypass capacitors in the GaAs RF-IC, on-chip ferroelectric capacitors of barium strontium titanate (e=300) were used [Nagata et al., 1993].

Gb/s transmission chips: Compact 10-Gb/s optical transmitter and receiver circuit packs were developed using GaAs MESFET ICs [Kobayashi et al., 1994] and Si bipolar ICs [Noda et al., 1995]. Test chips for 40-GHz baseband amplifier [Sano et al., 1994] and 40-Gb/s D-F/F [Kuriyama et al., 1994] using AlGaAs/GaAs HBTs were reported. A 60-GHz-bandwidth distributed baseband amplifier module [Shibata et al., 1994] and 90-GHz amplifier IC [Kimura et al., 1995] using InP HEMTs were reported.

ATM switch LSIs: A 320 Gb/s ATM switching system using multilayer copper-polyimide MCM and Si bipolar LSI technologies were developed [Yamanaka et al., 1995]. A 5.6 Gb/s 2x2 BiCMOS ATM switch LSI [Nishikido et al., 1993] and a 20 Gb/s 2x2 GaAs MESFET chip set [Hino et al., 1995] using optical interconnection were reported.

Low voltage LSI technology: Multi-threshold CMOS (MTCMOS) technique, which use two sets of threshold-voltage levels, has been proposed for low voltage baseband LSI's [Mutoh et al. 1993]. Using this technique and an embedded processor for efficient power management, a 1 V DSP LSI achieved 26 MOPS and 1.1 mW/MOPS performance in battery-driven mobile phone equipment [Mutoh et al., 1996]. Instead of additional threshold-voltage process, another concept, called variable-threshold-voltage scheme, has been proposed. This concept is that a substrate bias is variable during stand-by and in active mode [Kuroda et al., 1996]. A/D and D/A converters using swing-suppression noise-shaping scheme performed very well to improve the S/N ratio when operating with a 1-V power supply [Matsuya et al., 1994].

(Y. Sakai)

References

Hino, S., Asynchronous transfer mode switching LSIs with 10 Gbit/s serial inputs and outputs, 94 VLSI Circuit Symposium, 73-74 (1994)

Kimura, S., 0-90 GHz InAlAs/InGaAs/InP HEMT distributed baseband amplifier IC, Electron. Lett., 1430-1431 (1995)

Kobayashi, Y., Compact 10-Gbit/s optical transmitter and receiver circuit packs, 1994 IEEE MTT-S, 73-76 (1994)

Kuriyama, Y., A 40 GHz D-type flip-flop using AlGaAs/GaAs HBT's, 1994 IEEE GaAs IC Symposium, 189-192 (1994)

Kuroda, T., A 0.9 V 150 MHz 10 mW 4 mm^{2} 2-D discrete
cosine transform core processor with variable-threshold-voltage scheme,
ISSCC '96, 166-167 (1996)

Matsumura, T., A chip set architecture for programmable real-time MPEG2 encoder, CICC'95, 17.1.1-17.1.4 (1995)

Matsuya, Y., 1 V power supply, 384 Ks/s 10 bit A/D and D/A converters with swing-suppression noise-shaping, ISSCC '94, 152-153 (1994)

Mutoh, S., 1-V high-speed digital circuit technology with 0.5 mm multi-threshold CMOS, Int. ASIC Conf. '93 (1993)

Mutoh, S., A 1 V multi-threshold voltage CMOS DSP with an efficient power management technique for mobile phone application, ISSCC '96, 168-169 (1996)

Nagata, S., A GaAs MMIC chip-set for mobile communications using on-chip ferroelectric capacitors, ISSCC'93, 127-128 (1993)

Nishikido, J., Demonstration of optically interconnected asynchronous transfer mode switching fabric, GLOBECOM'93, 1187 (1993)

Noda, A., Fully integrated 10 Gb/s optical transmitter module and receiver module, ECOC'95, 669-672 (1995)

Sano, E., 40 GHz bandwidth amplifier IC using AlGaAs/GaAs ballistic collection transistors with carbon-doped bases, Electron. Lett., 635-636 (1994)

Shibata, T., 60 GHz-bandwidth distributed baseband amplifier IC in a package optimized for isolation, ISSCC'94, 180-181 (1994)

Suguri, K., A real-time motion estimation and compensation LSI with wide-search range for MPEG2 video encoding, ISSCC'96, 242-243 (1996)

Takahashi, C., A 1.9 GHz Si direct conversion receiver IC for QPSK modulation systems, ISSCC'95, 138-139 (1995)

Tsukahara, T., A 2 V 2 GHz Si-bipolar quadrature modulator, ISSCC'94, 40-41 (1994)

Yamanaka, N., 320 Gb/s high-speed ATM switching system hardware technologies based on copper-polyimide MCM, IEEE Trans. Components, Packaging and Manufacturing Technology, 83-91 (1995)

In the fields of spectral estimation, an adaptive ARMA four-line lattice filter was proposed for spectral estimation with frequency weighting [Haseyama et al. 1993]. A two dimensional line spectrum estimator by polar coordinate AR models was derived [Sakurai et al., 1993].

Some major developments in adaptive signal processing have been also observed. A fast convergent algorithm for adaptive FIR filters with sparse taps was proposed [Sugiyama et al., 1994]. A unifying treatment of general gradient ADF and convergent analysis was given [Chao et al., 1995a] and a stable and globally convergent IIR ADF was also proposed [Chao et al., 1995b]. An adaptive algorithm based on nonuniform resolution filter was proposed [Naito et al., 1995].

Multirate signal processing techniques also continued to be an active research area. A design of 2-dimensional perfect reconstruction filter banks for arbitrary sampling lattice was proposed [Ikehara et al., 1993]. A simple design method of Perfect Reconstruction QMF banks was proposed [Kurosawa et al., 1994]. An over sampling subband adaptive digital filter with rational decimation ratios was proposed [Kiya et al., 1994].

Some real valued decimation in time and decimation in frequency algorithms were proposed and sampling rate conversion systems was proposed by using a new generalized form of DFT [Murakami 1994,1995]. A design method of nonuniform division multirate FIR filter banks was proposed [Wada 1995].

In the fields of nonlinear signal processing, a median type fuzzy filter and its optimum design were proposed [Arakawa et al., 1992]. A 2-dimensional neural hybrid filter was proposed for image processing [Muneyasu et al., 1993]. A multidimensional isomorphic operator was proposed, which exactly relates two multidimensional signal spaces of finite support where finite convolution and and usual addition, respectively, are defined as binomial operations [Yamada et al., 1994].

In the fields of fundamental theory of digital signal processing, the optimum approximation of multidimensional signals was proposed based on the quantized sample values of transformed signals [Kida, 1995]. A multidimensional phase unwrapping algorithm that computes zero distribution of complex polynomials was proposed [Yamada et al., 1995a]. A global optimization technique was proposed based on excluding hyperspheres [Yamada et al., 1995b].

It should be emphasized that numerous works have been intended to improve soft ware environment for signal processor. A new DSP compiler was proposed for matrix and vector expressions with automatic computational ordering [Sugino et al., 1995].

(S. Tsujii)

References

Arakawa, K. et al., Proposal of median type fuzzy filters and its optimum design, Trans. IEICE, J75-A, 12, 1792-1799 (in Japanese) (Dec.1992)

Chao, J. et al., A unifying treatment of general gradient ADF and convergence analysis with arbitrary inputs, Trans. IEICE, J78-A, 1, 21-29 (in Japanese) (Jan.1995a)

Chao, J. et al., A stable and globally convergent IIR adaptive filters of output error formulation, Trans. IEICE, J78-A, 2, 227-235 (in Japanese) (Feb.1995b)

Haseyama, M. et al., An adaptive ARMA four line lattice filter for spectral estimation with frequency weighting, IEEE Trans. on SP, 41, 6, 2193-2207 (Jun.1993)

Hinamoto, T. et al., Design of 3-D separable denominator digital filters using minimal decomposition and balanced realization, Trans. IEICE, J77-A, 6, 837-843 (in Japanese) (Jun.1994)

Ikehara, M. et al., Design of 2-D perfect reconstruction filter banks for arbitrary sampling lattices--Design of 2-D Nth band digital filters--, Trans. IEICE, J76-A, 7, 933-941 (in Japanese) (Jul.1993)

Ikehara, M. et al., Design of IIR digital filters using all-pass networks, IEEE Trans. on CAS, 41, 3, 231-235 (Mar.1994)

Inui, K. et al., Design of maximally flat diamond shaped half-band FIR filters with rectangular supports of impulse response, Trans. IEICE, J77-A, 8, 1336-1345 (in Japanese) (Aug.1994)

Kawamata, M. et al., Optimal design method of separable denominator two dimensional digital filters based on a genetic algorithm, Trans. IEICE, J78-A, 2, 132-140 (in Japanese) (Feb.1995)

Kida, T. et al., The optimum approximation of multidimensional signals based on the quantized sample values of transformed signals, IEICE Trans. Fundamentals, E78-A, 2, 208-234 (Feb.1995)

Kiya, H. et al., An over sampling subband adaptive digital filter with rational decimation ratios, Trans. IEICE, J77-A, 8, 1129-1136 (in Japanese) (Aug.1994)

Kurosawa, K. et al., A simple design method of perfect reconstruction QMF banks, IEEE Trans. on CAS, 41, 3, 243-245 (Mar.1994)

Muneyasu, M. et al., A 2-D IIR neural hybrid filter for image processing, Trans. IEICE, J76-A, 10, 1440-1449 (in Japanese) (Oct.1993)

Murakami, H., Real valued decimation in time and decimation in frequency, Algorithms, IEEE Trans. on CAS, 41, 12, 808-816 (Dec.1994)

Murakami, H., Sampling rate conversion systems using a new generalized form of the discrete Fourier transform, IEEE Trans. on SP, 43, 9, 2095-2102 (Sep.1995)

Naito, Y. et al., An adaptive algorithm based on nonuniform resolution filter, Trans. IEICE, J78-A, 9, 1092-1102 (in Japanese) (Sep.1995)

Sakurai, M. et al., Two dimensional line spectrum estimation by polar coordinate AR models, Trans. IEICE, J76-A, 10, 1431-1439 (in Japanese) (Oct.1993)

Sugino, N. et al., DSP compiler for matrix and vector expressions with automatic computational ordering, IEICE Trans. Fundamentals, E78-A, 8, 989-995 (Aug.1995)

Sugiyama, A., Stochastic gradient algorithms with a gradient adaptive and limited step size, IEICE Trans. Fundamentals, E77-A, 3, 534-538 (Mar.1994)

Wada, S, Design of nonuniform division multirate FIR filter banks, IEEE Trans. on CAS, 42, 2, 115-121 (Feb.1995)

Yamada, I. et al., A multidimensional isomorphic operator and its properties --A proposal of finite extent multidimensional cepstrum--, IEEE Trans. on SP, 42, 7, 1766-1785 (Jul.1994)

Yamada, I. et al., A multidimensional phase unwrapping algorithm and zero distribution of complex polynomials, Proceeding of European Conference on Circuit Theory and Design'95, 491-495 (1995a)

Yamada, I. et al., A global optimization based on excluding hyperspheres, Proceeding of European Conference on Circuit Theory and Design'95, 947-950 (1995b)

Yoshida, T. et al., A design method for 3-dimensional band limiting FIR filters using McClellan transformation, IEICE Trans. Fundamentals, E76-A, 8, 1283-1292 (Oct.1993)

Optical TDM is also an important optical signal processing technology as well as frequency- or wavelength-division multiplexing (FDM or WDM) in cross-connecting systems for optical network. Demultiplexing and routing of a 5.24 Gbit/s 2 channel TDM signal has been achieved by using FWM in a dispersion-sifted fiber and a wavelength router consisting of optical circulators and fiber gratings [Yamamoto et al., 1995]. Optical FDM technologies have been studied for cross-connects [Sato, 1994] and add/drop multiplexing (ADM) [Oda et al., 1993], both of which are key technologies to site and to distribute the optical paths between access nodes in optical network.

In switching systems, photonics may not be able to replace electronics within one or two decades. As an approach to utilize the advantage of photonics, space-division switching networks can be used for rearranging optical interconnections among the electronic function blocks. A strictly nonblocking 16x16 matrix switch using silica based planar waveguides have been developed for such switching networks [Okuno et al., 1994]. Many studies to develop all-optical switching devices have been continuing for approaching to future photonic switching. Recently, all-optical picosecond full switching has been achieved with the use of spin relaxation in a quantum well etalon [Nishikawa et al., 1995].

In the field of optical computing, massively parallel processing (MPP) technologies have been extensively studied because of recent needs for image processing. Massive optical interconnections with 64 optical channels for interconnecting 64 processing elements has been developed as an approach to MPP [Araki et al., 1995]. A new type of reconfigurable space-variant interconnections between arbitrary processors using binary computer-generated hologram has been proposed and experimentally investigated [Ishida et al., 1995]. Optical neural computing is also of great interest in terms of MPP for image processors. An optical learning neurochip with internal analog memory, consisting of 2-D variable-sensitivity photodiodes array vertically integrated on a one-dimensional LED array, has been fabricated and its capability of parallel processing in vector-matrix-operations has been demonstrated [Nitta et al., 1993]. An artificial retina chip has also been made of a 128x128 array of variable-sensitivity photodetectors and its application for image processing with arbitrary two-dimensional filters has been demonstrated [Funatsu et al., 1995].

(K. Amano)

References

Araki, S., M. Kajita, K. Kasahara, K. Kubota, K. Kurihara, I. Redmond, E. Schenfeld, and T. Suzaki, Massive optical interconnections (MOI): interconnections for massively parallel processing systems, Optical Computing'95, Postconference Edition, OMA3-1, 8-10 (Mar.1995)

Funatsu, E., K. Hara, T. Toyoda, Y. Miyake, J. Ohta, S. Tai, and K. Kyuma, An artificial retina chip made of a 128x128 pn-np variable-sensitivity photodetector array, IEEE Photonics Technol. Lett., 7, 2, 188-190 (Feb.1995)

Ishida, T., and M. Ishikawa, Reconfigurable space-variant optical interconnection using binary CGH, Optical Computing'95, Postconference Edition, PD-1, 296-298 (Mar.1995)

Kamatani, T., S. Kawanishi, and M. Saruwatari, Prescaled 6.3 GHz clock recovery from 50 Gbit/s TDM optical signal with 50 GHz PLL using four-wave mixing in a traveling-wave laser diode optical amplifier, Electron. Lett., 30, 10, 807-809 (May.1994)

Kawanishi, S., H. Takara, O. Kamatani, and T. Morioka, 100-Gbit/s 500-km optical transmission experiment, OFC'95 Technical Digest, ThL2, 287-288 (Feb.1995)

Morioka, T., S. Kawanishi, K. Uchiyama, H. Takara, and M. Saruwatari, Polarization-independent 100 Gb/s all-optical demultiplexer using four-wave mixing in a polarization-maintaining fibre loop, Electron. Lett., 30, 7, 591-592 (Mar.1994)

Nishikawa, Y., A. Takeuchi, S. Nakamura, S. Muto, and N. Yokoyama, All-optical picosecond switching of a quantum well etalon using spin-polarization relaxation, Appl. Phys. Lett., 66, 7, 839-841 (Feb.1995)

Nitta, Y., J. Ohta, S. Tai, and K. Kyuma, Optical learning neurochip with internal analog memory, Appl. Opt., 32, 8, 1264-1274 (Aug.1993)

Oda, K., and H. Toba, An optical FDM-add/drop multiplexing ring network utilizing fiber Fabry-Perot filters and optical circulators, Photonic Technol. Lett., 5, 7, 825-828 (Jul.1993)

Okuno, M., K. Katoh, S. Suzuki, Y. Ohmori, and A. Himeno, Strictly nonblocking 16x16 matrix switch using silica-based planar lightwave circuits, Proc. ECOC'94, 4 Post-deadline Papers, 83-86 (Sep.1994)

Sato, K., Transport network evolution with optical paths, Globecom'94, 919-926 (Nov.1994)

Suzuki, M., N. Edagawa, H. Taga, H. Tanaka, S. Yamamoto, and S. Akiba, Feasibility demonstration of 20 Gbit/s single channel soliton transmission over 11500 km using alternating-amplitude solitons, Electron. Lett., 30, 1083-1084 (Jun.1994)

Yamamoto, T., T. Imai, T. Komukai, Y. Miyajima, and M. Nakazawa, Optical demultiplexing and routing of TDM signal by using four-wave mixing and a novel wavelength router with optical circulators and fiber grating, IOOC-95 Technical Digest, 2, WB3-2, 60-61 (Jun.1995)

Related to nonlinear circuits, the study on chaos and periodic oscillation has been very active, and many researchers have studied this problem. It is known that asymmetric Lienard's equation can have more than one periodic solution. The problem of finding the maximum number of such solutions is known as a special case of Hilbert's sixteenth problem. This important problem was solved by T. Koga [Koga et al., 1993]. Also, chaotic dynamics observed from a widely used second-order phase-locked loops was studied [Endo et al., 1993], and some qualitative properties of an inductively coupled circuit containing two Josephson junction elements with a dc source were investigated [Ueta and Kawakami, 1994]. Statistical properties of chaotic binary sequences generated by Chebyshev maps was discussed, and an important role of the Perron-Frobenius operator in evaluating statistics of chaos by means of the ensemble-average technique was confirmed [Kohda et al., 1994]. A simple algorithm for the deterministic nonlinear prediction of chaotic time series with noise was proposed [Ikeguchi and Aihara, 1995]. Also, synchronization phenomena in oscillators coupled by one resistor was discussed [Moro et al., 1995].

The study on self-validating numerical methods and interval analysis is one of the most remarkable topics in the past three years. A numerical validation method for nonlinear equations using interval analysis was proposed, and a practical system for finding solutions with guaranteed accuracy was developed [Kashiwagi and Oishi, 1994]. It was shown that the nondeterministic operator theory developed by K. Horiuchi and the theory for nonlinear boundary value problems developed by M. Urabe have deep relationship with the interval analysis, and these theories suggest future directions of the interval analysis and the self-validating numerics [Oishi, 1994]. Also, based on the Horiuchi's theory, a mathematical theory of system fluctuations using a new concept of the fuzzy mapping was developed, and some applications including the generalization of the fail-safe principle and the sensitivity analysis were shown [Horiuchi and Endo, 1993, 1994].

In relation to LSI simulation, the study on the homotopy method has been developed remarkably in Japan, both in theory and in application. A simple algorithm using hyperspheres was proposed, which is easily implemented on the current circuit simulators such as SPICE [Yamamura, 1993a]. Using this algorithm, the homotopy method was realized in practical LSI simulation, and more than 20,000-dimensional modified nodal equations describing a bipolar analog circuit have been solved efficiently by the spherical-type homotopy method [Inoue, 1994]. Also, a priori estimation was presented for a computational complexity of the homotopy method applying to a certain class of strongly monotone nonlinear equations [Makino et al., 1993].

The study on the number of solutions of nonlinear resistive circuits and the algorithms for finding all the solutions is a very important problem in circuits and systems. Related to this problem, the necessary and sufficient conditions were given for the basic equation of nonlinear resistive circuits containing ideal diodes to have a unique solution [Nishi and Kawane, 1993], and the number of solutions of a class of nonlinear equations related to neural networks with tapered connections was discussed [Nishi et al., 1995]. Also, efficient algorithms have been developed for finding all solutions of piecewise-linear resistive circuits [Yamamura, 1993b].

The study on neural networks have also been very active. A middle-mapping learning algorithm for cellular neural networks was proposed [Ushida et al., 1994], and highly parallel analog image coding and decoding by cellular neural networks was described [Tanaka et al., 1994]. A systematic synthesizing method to realize the parallel binary image-thinning algorithm by a discrete-time cellular neural network was proposed [Mori et al., 1994]. The mathematical programming formulation for neural combinatorial optimization algorithms was studied [Urahama, 1995]. Also, fully connected recurrent neural networks were investigated for blind separation of sources [Amari et al., 1995].

In relation to the problem of diagnosis of deviation faults in linear analog circuits, it is an important problem to check the unique determinability of the element-values in a given linear analog circuit from the node-voltage measurements at its accessible nodes. For this problem, many excellent results have been derived [Shinoda et al., 1994]. Also, the problem of obtaining an optimal file transfer on a file transmission net is discussed [Kaneko et al., 1995], and the universal graphs for graphs with bounded path-width is considered [Takahashi et al., 1995].

(K. Horiuchi and K. Yamamura)

References

Amari, S., A. Cichocki, and H. H. Yang, Recurrent neural networks for blind separation of sources, Proc. 1995 Int. Symp. on Nonlinear Theory and its Applications, 1C-1, 37-42 (1995)

Endo, T., and L. O. Chua, Piecewise-linear analysis of high-damping chaotic phase-locked loops using Melnikov's method, IEEE Trans., Circuits and Systems, 40, 11, 801-807 (Nov.1993)

He, C., and A. Ushida, Iterative middle mapping learning algorithm for cellular neural networks, IEICE Trans. Fundamentals, E77-A, 4, 706-715 (Apr.1994)

Ho, C.-Y., and S. Mori, An optimized synthesis of a discrete-time cellular neural network for parallel thinning, Int. J. of Circuit Theory and Applications, 22, 5, 363-375 (Sep.1994)

Horiuchi, K., and Y. Endo, A mathematical theory of system fluctuations using fuzzy mapping, IEICE Trans. Fundamentals, E76-A, 5, 678-682 (May.1993)

Horiuchi, K., and Y. Endo, A fluctuation theory of systems by fuzzy mapping concept and its applications, IEICE Trans. Fundamentals, E77-A, 11, 1728-1735 (Nov.1994)

Ikeguchi, T., and K. Aihara, Prediction of chaotic time series with noise, IEICE Trans. Fundamentals, E78-A, 10, 1291-1298 (Oct.1995)

Inoue, Y., A practical algorithm for DC operating-point analysis of large scale circuits, Trans. IEICE, J77-A, 3, 388-398 (in Japanese) (Mar.1994)

Kaneko, Y., S. Shinoda, and K. Horiuchi, On an optimal file transfer on an arborescence-net with constraints on copying numbers, IEICE Trans. Fundamentals, E78-A, 4, 517-528 (Apr.1995)

Kashiwagi, M., and S. Oishi, Numerical validation method for nonlinear equations using interval analysis, Trans. IEICE, J77-A, 10, 1372-1382 (in Japanese) (Oct.1994)

Koga, T., M. Shinagawa, and S. Hasako, Synthesis of Lienard's equations having more than one periodic solutions, IEICE Trans. Fundamentals, E76-A, 6, 848-857 (Jun.1993)

Kohda, T., and A. Tsuneda, Explicit evaluations of correlation functions of Chebyshev binary and bit sequences based on Perron-Frobenius operator, IEICE Trans. Fundamentals, E77-A, 11, 1794-1800 (Nov.1994)

Makino, M., M. Kashiwagi, S. Oishi, and K. Horiuchi, A sufficient condition of a priori estimation for computational complexity of the homotopy method, IEICE Trans. Fundamentals, E76-A, 5, 786-794 (May.1993)

Moro, S., Y. Nishio, and S. Mori, Synchronization phenomena in oscillators coupled by one resistor, IEICE Trans. Fundamentals, E78-A, 2, 244-253 (Feb.1995)

Nishi, T., and Y. Kawane, Necessary and sufficient conditions for the basic equation of nonlinear resistive circuits containing ideal diodes to have a unique solution, IEICE Trans. Fundamentals, E76-A, 6, 858-866 (Jun.1993)

Nishi, T., and N. Takahashi, On the number of solutions of a class of nonlinear equations related to neural networks with tapered connections, IEICE Trans. Fundamentals, E78-A, 10, 1299-1305 (Oct.1995)

Oishi, S., Two topics in nonlinear system analysis through fixed point theorems, IEICE Trans. Fundamentals, E77-A, 7, 1144-1153 (Jul.1994)

Shinoda, S., and K. Okada, On solutions of the element-value determinability problem of linear analog circuits, IEICE Trans. Fundamentals, E77-A, 7, 1132-1143 (Jul.1994)

Takahashi, A., S. Ueno, and Y. Kajitani, Universal graphs for graphs with bounded path-width, IEICE Trans. Fundamentals, E78-A, 4, 458-462 (Apr.1995)

Tanaka, M., K. R. Crounse, and T. Roska, Parallel analog image coding and decoding by using cellular neural networks, IEICE Trans. Fundamentals, E77-A, 8, 1387-1395 (Aug.1994)

Ueta, T., and H. Kawakami, Bifurcation of an inductively coupled Josephson junction circuit, IEICE Trans. Fundamentals, E77-A, 11, 1758-1763 (Nov.1994)

Urahama, K., Mathematical programming formulation for neural combinatorial optimization algorithms, Trans. IEICE, J78-A, 1, 47-53 (in Japanese) (Jan.1995)

Yamamura, K., Simple algorithms for tracing solution curves, IEEE Trans. Circuits and Systems, 40, 8, 537-541 (Aug.1993a)

Yamamura, K., Finding all solutions of piecewise-linear resistive circuits using simple sign tests, IEEE Trans., Circuits and Systems, 40, 8, 546-551 (Aug.1993b)

Research in source coding and universal coding are very much active. Research work on Lempel-Ziv codes, as well as on universal coding [Oohama, 1994] has been reported. Data compression for fractal sets is a new and promising area.

Error control coding is still one of the most active research areas in information theory. Code constructions for channels with unidirectional errors [Saitoh et al., 1993] and byte-oriented memory systems [Fujiwara at al., 1994] have been accomplished. A general decoding algorithm for Reed-Solomon (RS) codes was presented in Morii et al. [1992], which may be useful in implementing fast decoders for RS codes. A new Viterbi algorithm for efficient implementation of convolutional coded ARQ systems has been introduced [Hashimoto, 1993]. A new construction of orthogonal sequences, reported in Kirimoto et al. [1994], may have important consequences in designing spread spectrum systems. A new fast algorithm for joint equalization and channel estimation was introduced. The milestone paper [Kamabe, 1994] presents new theoretical results for designing good spectral null codes, which are useful for digital recording on constrained channels. The trellis structure of linear block codes is now very well understood [Kasami et al., 1993], and relatively low complexity soft-decision decoding algorithms for linear block codes have been introduced [Takata et al., 1993].

Cryptography and its applications to information security are active research areas in information theory. There has been a great deal of progress in linear cryptanalytic methods for DES-like block ciphers. In particular, powerful methods for known-plaintext attack of DES have been presented [Matsui, 1993]. And the first experimental attack using twelve computers was carried out. As a result, the full 16-round DES was broken in fifty days based on the condition that random plaintexts and their ciphertexts must be available [Matsui, 1994]. Search algorithms for the best linear expression on the linear cryptanalysis were improved [Ohta et al., 1995]. The required time was decreased from over three months to only about two and a half days. Fast RSA-type public-key schemes were also proposed [Koyama, 1995]. Their decryption speed is about 2.0 times faster than the RSA scheme. The author claims that breaking the proposed schemes is computationally equivalent to breaking the RSA scheme.

(H. Imai)

References

Fujiwara, E., and M. Kitakami, A class of error-locating codes for byte-oriented memory systems, IEEE Trans. Info. Theory, 40, 6, 1857-1865 (Nov.1994)

Hashimoto, T., A coded ARQ scheme with the generalized Viterbi algorithm, IEEE Trans. Info. Theory, 39, 2, 423-432 (Mar.1993)

Kamabe, H., Irreducible components of canonical diagrams for spectral nulls, IEEE Trans. Info. Theory, 40, 5, 1375-1391 (Sep.1994)

Kasami, T., T. Takata, T. Fujiwara, and S. Lin, On the optimum bit orders with respect to the state complexity of trellis diagrams for binary linear codes, IEEE Trans. Info. Theory, 39, 1, 242-245 (Jan.1993)

Kirimoto, T., and Y. Ohashi, Orthogonal periodic sequences derived from M-sequences on GF(q), IEEE Trans. Info. Theory, 40, 2, 526-532 (Mar.1994)

Koyama, K., Fast RSA-type schemes based on singular cubic curves, Advances in Cryptology-Eurocrypt'95, in Lecture Notes in Computer Science, Springer-Verlag, 921, 329-340 (1995)

Matsui, M., Linear cryptanalysis method for DES cipher, Advances in Cryptology-Eurocrypt'93, in Lecture Notes in Computer Science, Springer-Verlag, 765, 386-397 (1993)

Matsui, M., The first experimental cryptanalysis of the data encryption standard, Advances in Cryptology-Crypto'94, in Lecture Notes in Computer Science, Springer-Verlag, 839, 1-11 (1994)

Morii, M., and M. Kasahara, Generalized key-equation of remainder decoding algorithm for Reed-Solomon codes," IEEE Trans. Info. Theory, 38, 6, 1801-1807 (Nov.1992)

Ohta, K., S. Moriai, and K. Aoki, Improving the search algorithm for the best linear expression, Advances in Cryptology-Crypto'95, in Lecture Notes in Computer Science, Springer-Verlag, 963, 157-170 (1995)

Oohama, Y., and T. S. Han, Universal coding for the Slepian-Wolf data compression system and the strong converse theorem, IEEE Trans. Info. Theory, 40, 6, 1908-1919 (Nov.1994)

Saitoh, Y., and H. Imai, Generalized concatenated codes for channels where unidirectional errors are predominant, IEEE Trans. Info. Theory, 39, 3, 1014-1022 (Mar.1993)

Takata, T., U. Satoshi, T. Kasami, and S. Lin, Multistage decoding of multilevel block M-PSK modulation codes and its performance analysis, IEEE Trans. Info. Theory, 39, 4, 1204-1228 (Jan.1993)

Verdu, S., and T. S. Han, A general formula for channel capacity, IEEE Trans. Info. Theory, 40, 4, 1147-1158 (Jul.1994)

Yanagi, K., On the capacity of the discrete-time Gaussian channel with delay feedback, IEEE Trans. Info. Theory, 41, 4, 1051-1059 (Jul.1995)

Most actively studied are co-channel interference cancellation techniques because they can greatly increase the channel capacity of a CDMA system. Many techniques have been proposed that use, among others, an DS/CDMA adaptive interference canceller [Yoshida, 1994], interference cancellation using radio channel estimation [Fukasawa, 1994], orthogonalizing matched filter detection [Fukawa, 1994], a DS-FH CDMA with interference cancelling [Tomisato, 1994] and M-ary SS with interference cancellation techniques [Tachikawa, 1993].

Multiuser detection techniques for removing co-channel interference are also active research subjects for the DS/CDMA system. The many studies encompass joint decorrelating multiuser detection [Kawahara, 1995], multiuser detection using a neural network [Miyajima, 1993] and multi-user receiver with an array antenna [Kohno, 1995].

Active study is under way on RAKE combining and diversity techniques to improve BER performance over land mobile radio channels. Papers cover such topics as coherent detection and RAKE [Higashi, 1995], path diversity based on path selection [Moriyama, 1994] and coherent detection with a pilot channel [Abeta, 1994].

Other techniques relating to SS such as synchronization, FH (frequency hopping), and modulation/demodulation schemes, are still very popular research subjects. Various kinds of interesting papers have been presented. Among them are discussions of a delay lock loop for mobile communications [Takeuchi, 1993], an MFSK/FH-SSMA system [Mabuchi, 1993], an SS system for selective fading [Miyatani, 1994], and SS pulse position modulation [Okazaki, 1993]. In addition, a variety of subjects were studied as basic research.

For the practical use of SS systems, studies about CDMA cellular systems, SS modem implementation, and field experimentation on SS systems are very important. Great progress has been made in CDMA cellular systems shown in studies on wideband coherent DS-CDMA [Ohno, 1995] and CDMA/TDD cellular systems [Hayashi, 1995]. The many papers relating to implementation and experimentation of a demodulator that uses a SAW correlator [Nakase, 1994], and field testing of an SS land mobile satellite [Ikegami, 1993].

(S. Sasaoka)

References

Abeta, S., S. Sampei, and N. Morinaga, A coherent detection system with a suppressed pilot channel for DS/CDMA system, Trans. IEICE, J77-B-II, 11, 641-648 (in Japanese) (1994)

Fukasawa, A., T. Sato, M. Kawabe, S. Sato, and H. Sugimoto, Configuration and its performance of an interference cancellation system using pilot signal for radio channel estimation, Trans. IEICE, J77-B-II, 11, 628-640 (in Japanese) (1994)

Fukawa, K., and H. Suzuki, Orthogonalizing matched filter (OMF) detection for DS-CDMA mobile radio systems, IEEE Globcom'94, 11.3, 385-389 (1994)

Hayashi, M., K. Miya, O. Kato, and K. Homma, CDMA/TDD cellular systems using a base-station-based diversity scheme, IEEE VTC'95, 799-803 (1995)

Higashi, A., T. Taguchi, and K. Ohno, Performance of coherent detection and RAKE for DS/CDMA uplink channel, Proc. of PIMRC'95, B3.3, 436-440 (1995)

Ikegami, T., S. Taira, and Y. Araki, Field tests of a spread spectrum land mobile satellite communication system, IEICE Trans. Commun., E76-B, 8, 996-1001 (1993)

Kawahara, T., and T. Matsumoto, Joint decorrelating multiuser detection and channel estimation in asynchronous CDMA mobile communications channel, IEEE Trans., Veh. Technol., 44, 3, 506-515 (1995)

Kohno, R., N. Ishii, and M. Nagastuka, A spatially and temporally optimal multi-user receiver using an array antenna for DS/CDMA, Proc. of PIMRC'95, A5.7, 950-954 (1995)

Mabuchi, T., R. Kohno, and H. Imai, Multihopping and decoding of error-correcting code for MFSK/FH-SSMA systems, IEICE Trans. Commun., E76-B, 8, 874-885 (1993)

Miyajima, T., T. Hasegawa, and M. Haneishi, On the multiuser detection using a neural network in code-division multiple-access communications, IEICE Trans. Commun., E76-B, 8, 961-968 (1993)

Miyatani, T., and Y. Akaiwa, A spread spectrum communication system without reference signal for frequency-selective fading channel, Trans. IEICE, J77-B-II, 11, 649-954 (in Japanese) (1994)

Moriyama, E., Path-diversity technology based on multiple path selection for a spread spectrum communication system, Trans. IEICE, J77-B-II, 11, 599-607 (in Japanese) (1994)

Nakase, H., T. Kasai, Y. Nakamura, K. Masu, and K. Tsubouchi, One chip demodulator using RF front-end SAW correlator for 2.4 GHz asynchronous spread spectrum modem, Proc. of PIMRC'94, E3.3, 374-378 (1994)

Ohno, K., M. Sawahashi, and F. Adachi, Wideband coherent DS-CDMA, IEEE VTC'95, 779-783 (1995)

Okazaki, I., and T. Hasegawa, Spread spectrum pulse position modulation--A simple approach for Shannon's limit--, IEICE Trans. Commun., E76-B, 8, 929-940 (1993)

Tachikawa, S., Characteristics of M-ary/spread spectrum multiple access communication system using co-channel interference cancellation techniques, IEICE Trans. Commun., E76-B, 8, 941-946 (1993)

Takeuchi, M., A. Kajiwara, and M. Nakagawa, A delay lock loop for mobile communications in the presence of multipath fading, IEICE Trans. Commun., E76-B, 8, 1039-1046 (1993)

Tomisato, S., K. Fukawa, and H. Suzuki, Coherent hybrid DS/FFH CDMA with adaptive interference cancelling for cellular mobile communications, IEICE Trans. Commun., E77-B, 5, 589-597 (1994)

Yoshida, S., A. Ushirokawa, S. Yanagi, and Y. Furuya, DS/CDMA adaptive interference canceller on differential detection for fast fading channel, Trans. IEICE, J77-B-II, 11, 618-627 (in Japanese) (1994)

(S. Samejima)

Network architectures, and location determination and registration methods for handheld terminals of communications systems with medium earth orbit (MEO) satellites are investigated [Araki et al., 1993]. A gateway earth station (GES) assignment method, which is one of important networking issues associated with ICO (Intermediate Circular Orbit) and LEO (Low Earth Orbit) systems is described. One is the "time-independent service area", and the other is the "time-dependent service area". A GES assignment method making use of advantageous features obtained by adopting the time-dependent service areas are proposed [Araki and Shinonaga, 1994, 1995]. Interference characteristics between a non-GSO MSS gateway station and a GSO FSS earth station, under the implementation of reverse band operation is described [Kobayashi et al., 1995a]. The present and future mobile satellite communications focusing on Inmarsat standard systems as existing systems and Inmarsat-P personal satellite system using non-geostationary orbiting satellites as the future systems are reviewed [Kobayashi et al., 1995b]. A novel position determination method suitable for personal satellite communication systems using non-GSO orbiting satellites is proposed. The proposed method has a capability to provide the higher position accuracy by using one non-GSO satellite [Ishikawa et al., 1995].

A Ku-band Ultra Small Aperture Terminal (USAT) network offering various kinds of multi-media communications services are considered. As the key technologies for the realization of the USAT system, low sidelobe simple antenna which meets ITU-R recommendations, carrier power spectrum density reduction technique for suppressing interference level toward the adjacent satellite systems, and an efficient multiple access method are proposed [Inoue et al., 1995].

The use of enhanced digital video coding and FEC technique is an effective way to reduce the size of transportable terminal for satellite news gathering (SNG) transmission services. To achieve a high link availability, an information and FEC coding rate control scheme is proposed. This scheme selects an appropriate information and FEC coding rates, referring to the monitored link condition. An outline of the developed SNG transmission system and its experimental results by using existing domestic Ku-band satellite transponder is described [Inoue et al., 1994].

A hierarchical network architecture is proposed to perform a satellite-based data distribution to a vast number of receive-only user stations reliably and effectively. The network consists of one hub station and several regional host stations each of which manages data transmission and user information, respectively. The network also employs terrestrial lines for a receipt acknowledgment procedure between the user and regional host stations, and the regional host and the hub [Nohara et al., 1995].

A new type of optically controlled BFN (beam forming network) is proposed. The experimental results show the feasibility of utilizing an electro-optic BFN in future advanced microwave and millimeter-wave array systems [Kamiya et al., 1995].

(T. Shiokawa)

References

(1) Domestic Satellite Communication

Nakagawa et al., N-STAR: communication satellite for Japanese domestic use, 1994 International Communication Satellite Systems Conference, AIAA-94-1078-CP, 1129-1134 (1994)

Otsu et al., An advanced satellite communication system for ISDN services and a transportable earth stations for subscribers, 1995 Asia-Pacific Communication Conference, 588-592 (1995)

Sakamoto et al., Experimental in-orbit test of multibeam communication systems on Kiku-6, to be published in 20th International Symposium on Space Technology and Science (1996)

Takei et al., Damage from the great Hanshin-Awaji earthquake and NTT's efforts to recover from it, NTT Review, 7, 5, 9-16 (Sep.1995)

(2) International Satellite Communications

Araki, N., and H. Shinonaga, Time-dependent service area definition for gateway earth stations in medium earth orbiting satellite systems, 19th International Symposium on Space Technology and Science (19th ISTS) (May.1994)

Araki, N., and H. Shinonaga, Call by call basis GES assignment method for ICO systems adopting time-dependent service areas, 10th International Conference on Digital Satellite Communications (ICDSC-10) (May.1995)

Araki, N., and H. Shinonaga, GES assignment method for ICO systems employing time-dependent service area, 2nd Asia-Pacific Conference on Communications (APCC '95) (Jun.1995)

Araki, N., H. Shinonaga, and Y. Ito, Study on networking issues of medium earth orbit satellite communications systems, 3rd International Mobile Satellite Conference and Exhibition (IMSC'93) (Jun.1993)

Inoue, T., M. Nohara, and G. Satoh, A study of international digital SNG transmission systems, 19th International Symposium on Space Technology and Science (19th ISTS) (May.1994)

Inoue, T., M. Nohara, and G. Satoh, An international digital SNG transmission system with variable information/FEC coding rate control, 1994 IEEE GLOBCOM (Nov.1994)

Inoue, T., H. Ishikawa, Y. Mizuguchi, and H. Kobayashi, Low sidelobe simple antenna and efficient multiple access method for realization of USAT system, 10th International Conference on Digital Satellite Communications (ICDSC-10) (May.1995)

Ishikawa, H., H. Shinonaga, and H. Kobayashi, Position determination method for personal satellite communication systems using non-geostationary satellites, 2nd Asia-Pacific Conference on Communications (APCC '95) (Jun.1995)

Kamiya, Y., Y. Murakami, W. Chujo, and M. Fujise, An electro-optic BFN for array antenna beam forming, IEICE Trans. Electron., E78-C, 8, 1090-1094 (Aug.1995)

Kobayashi, H., H. Shinonaga, N. Araki, and Y. Ito, Study on interference between non-GSO MSS gateway station and GSO FSS earth station under reverse band operation, 10th International Conference on Digital Satellite Communications (ICDSC-10) (May.1995a)

Kobayashi, H., H. Shinonaga, and Y. Ito, Inauguration of global personal satellite communications, 1995 Microwave Workshops and Exhibition (MWE'95) (Dec.1995b)

Nohara, M., T. Inoue, G. Satoh, and H. Hara, Satellite-based data distribution system with receipt acknowledgment, 2nd Asia-Pacific Conference on Communications (APCC '95) (Jun.1995)

Based on the results of field trials over a four-year period, a new 26 GHz microwave system with an increased rain attenuation margin was developed in order to realize almost outage-free access links [Manabe et al., 1993].

Recently in the field of modulation techniques, a fully digitized modulator for multi-level modulation up to 256 QAM has been applied to high capacity transmission over 10 Mbaud [Shirato et al., 1992]. Also attractive techniques have been reported on a new digitized group modulator for handling multi-carriers [Yamada et al., 1994] or modified symbol-rate-increased trellis coded modulation [Tanaka et al., 1993].

(A. Hashimoto)

References

Kagami, O., K. Watanabe, A. Satoh, and T. Yoshida, A common control broadband combiner for full band non-regenerative repeating digital microwave radio systems, GLOBECOM'94, 405-409 (1994)

Manabe, T., and T. Yoshido, Digital transmission characteristics on millimeter waves, ICC'93, 1602-1605 (1993)

Shirato, T., and T. Okada, A high capacity fully digitalized modulator for digital radios, GLOBECOM'92, 1870-1874 (1992)

Tanaka, H., and T. K. Matsushima, An application of trellis coded modulation to digital microwave radio and its performance, ICC'93, 128-132 (1993)

Watanabe, K., T. Shirato, and O. Kagami, Coherent non-regenerative repeater digital microwave radio system field test, GLOBECOM'92, 1846-1850 (1992)

Yamada, Y., and T. Shirato, A digitized group modulator using simple fractional sampling, GLOBECOM'94, 420-424 (1994)

CDMA system is very hot research field. For example, wideband system [Ohno et al., 1995], transmitter power control [Kudoh, 1993], path diversity [Esmailzadeh et al., 1993], interference canceller [Yoshida et al., 1994] are explored. There are many papers of equalizers which are mainly based on both DFE [Ishikawa, 1994] and MLSE [Kubo, 1994] schemes. In their application, interference cancellers [Yoshino, 1994] are investigated.

In control techniques, the papers concerned with dynamic channel assignment method [Furukawa et al., 1993], handoff algorithm [Kinoshita et al., 1993] and signaling protocol [Hirata et al., 1993] are mainly investigated.

In propagation and antennas, propagation loss and delay characteristics for digital mobile systems and personal communication systems have been very actively studied. Especially, in microcellular systems, many papers concerned with delay spread characteristics [Taga et al., 1995] and bidirectional base station antennas [Hori et al., 1995] are presented. Wideband propagation models [Iwai et al., 1993; Kozono, 1994; Yamaguchi et al., 1995] for the next generation multi-media personal communication systems are also actively discussed.

Mobile and personal terminals including modems, synchronization controllers, voice codecs and LSI implementation are actively studied and developed. Typical topics are the one-chip baseband LSI for PHS terminals [Kato, 1994] and the half-rate PDC system [Satoh, 1995].

(T. Hattori)

References

Esmailzadeh, R., and M. Nakagawa, Pre-RAKE diversity combination for direct sequence spread spectrum communications systems, IEEE ICC'93, 463-467 (1993)

Furukawa, H., and Y. Akaiwa, Self-organized reuse partitioning, a dynamic channel assignment method in cellular system, IEEE VTC'93, 524-527 (1993)

Hattori, T., Personal communications system and wireless technology, NTT Review, 7, 56-65 (1995)

Hirata, S., Y. Uchiyama, and M. Yabusaki, Signaling protocol for personal mobile telecommunications, IEEE ICUPC '93, 163-167 (1993)

Hori, T., K. Cho, and K. Kagoshima, Bidirectional base station antenna illuminating a street microcell for personal communication system, 9th International Conf. on Antennas and Propagation, 419-422 (1995)

Ishikawa, H., Personal communications system--System overview and outlook for future development--, NTT Review, 7, 37-47 (1995)

Ishikawa, H., and H. Kobayashi, A novel selection diversity method with decision feedback equalizer, IEICE Trans. Commun., E77-B, 5, 566-572 (1994)

Iwai, H., and Y. Karasawa, Wideband propagation model for the analysis of the effect of the multipath fading on the near-far problem in CDMA mobile radio systems, IEICE Trans. Commun., E76-B, 103-112 (1993)

Kato, S., S. Kubota, K. Seki, K. Enomoto, K. Kawazoe, T. Sakata, K. Kobayashi, and Y. Matsumoto, A very low power and high-quality signal transmission baseband LSIC for personal communications, IEEE Globecom'94, 1019-1023 (1994)

Kinoshita, Y., and T. Itoh, Performance analysis of a new fuzzy handoff algorithm by an indoor propagation simulator, IEEE VTC'93, 241-245 (1993)

Kozono, S., Received signal level characteristics in a wideband mobile radio channel, IEEE Trans. Veh. Technol., VT-43, 480-486 (1994)

Kubo, H., K. Murakami, and T. Fujno, An adaptive maximum-likelihood sequence estimator for fast time-varying intersymbol interference channels, IEEE Trans. Commun., COM-42, 1872-1881 (1994)

Kudoh, E., On the capacity of DS/CDMA cellular mobile radios under imperfect power control, IEICE Trans. Commun., E76-B, 886-893 (1993)

Ohno, K., M. Sawahashi, and F. Adachi, Wideband coherent DS-CDMA, IEEE VTC'95, 779-783 (1995)

Satoh, T., Y. Ohto, and A. Murase, TDMA half-rate digital cellular system based on PDC standard in Japan, IEEE VTC'95, 301-305 (1995)

Taga, T., T. Furuno, and K. Suwa, Channel modeling for 2 GHz band urban line-of-sight street microcells, IEEE VTC'95, 246-251 (1995)

Takanashi, H., T. Tanaka, and T. Hattori, High-quality and high-speed wireless multimedia transmission technology for personal handy phone systems, Proc. of Telecom '95 Technical Forum, 669-673 (1995)

Yamaguchi, A., K. Suwa, and R. Kawasaki, Received signal level characteristics for wideband radio channel in microcells, IEEE PIMRC'95, 1367-1371 (1995)

Yoshida, S., A. Ushirokawa, S. Yanagi, and Y. Furuya, DS/CDMA adaptive interference canceller on differential detection in fast fading channel, IEEE VTC'94, 780-784 (1994)

Yoshino, H., K. Fukawa, and H. Suzuki, Interference canceling equalizer (ICE) for mobile radio communications, IEEE ICC'94, 1427-1432 (1994)

The high-bitrate transmission experiments were conducted in another method of WDM technology for 16 wavelengths [Oda et al., 1995], and 128 wavelengths [Oda et al., 1995]. Non-linear technologies were on trial introduced into submarine system experiments [Edagawa et al., 1995].

For the higher bitrate, sub-terabit transmission experiments were reported for 200 Gbps [Kawanishi et al., 1995], and 400 Gbps [Morioka et al., 1995a]. The systems were composed of some new key-elements cleverly adopting nonlinear effects. Light source [Takara et al., 1995], pulse generator [Morioka et al., 1994], optical DEMUX [Morioka et al., 1995b], clock recovery circuit [Kawanishi et al., 1993], and optical sampling [Takara et al., 1994] were reported.

Path layer technologies will play a key role in future B-ISDN. A new technology, optical paths, was proposed [Sato et al., 1993]. The optical path concept exploits and consolidates the layered transport network architecture, WDM transmission and wavelength routing technologies. A new optical path cross-connect system architecture was proposed [Watanabe et al., 1994]. The architecture has various advantages like the maximum commonality with WP and VWP (Wavelength/Virtual Wavelength Path). A very effective novel WP/VWP accommodation design algorithms were proposed [Nagatsu et al., 1995].

Network reliability is a basic requirement for high-speed optical fiber communication systems. An ATM VP-based Self-Healing Ring (VP-SHR) of 2.4 Gbps optical access networks was developed [Kajiyama et al., 1994]. An Optical Path based Self-Healing Ring (OP-SHR) was proposed [Tokura et al., 1995].

Many other experiments were attempted for pulsed lightwave frequency supply [Nakagawa et al., 1994], optical ADM filter [Toba et al., 1994], photonic cross-connect system [Matsumoto et al., 1994], and optical duobinary transmission for dispersion/scattering tolerance [Yonenaga et al., 1995]

In an access network, many experiments and introduction trials have led the systems to modernization based on fiber and photonic technologies. The compendium were reported [Miki et al., 1994]. One of the most important technologies in the field may be an ATM-PON [Kanada et al., 1993].

(I. Kobayashi)

References

Edagawa, N., I. Morita, M. Suzuki, S. Yamamoto, H. Taga, and S. Akiba, 20 Gbit/s, 8100 km straight-line single-channel soliton-based RZ transmission experiment using periodic dispersion compensation, Proc. ECOC'95, ThA. 3.5 (1995)

Hagimoto, K., Y. Miyamoto, T. Kataoka, T. Ono, and K. Nakagawa, Ultra-high speed optical modulation and detection for long haul transmission, presented at ICC'92, 326.1 (Jun.1992)

Kajiyama, Y., N. Tokura, and K. Kikuchi, An ATM VP-based self-healing ring, IEEE JSAC, 12, 1, 171-178 (1994)

Kanada, T., N. Terada, T. Nakashima, K. Sano, and K. Kikuchi, Outline and introduction scenarios of an ATM based optical access network as a service platform, ISSLS'93, Vancouver, Canada (Sep.1993)

Kawanishi, S., and M. Saruwatari, Ultrahigh-speed PLL-type clock recovery circuit based on all-optical gain modulation in travelling-wave laser diode amplifier, IEEE J. Lightwave Technol., 11, 12, 2123-2129 (1993)

Kawanishi, S., H. Takara, T. Morioka, and M. Saruwatari, 200 Gbit/s, 100 km time-division-multiplexed optical transmission using supercontinuum pulses with prescaled PLL timing extraction and all optical demultiplexing, Electron. Lett., 31, 10, 816-817 (1995)

Kobayashi, Y., Y. Sato, K. Aida, K. Hagimoto, and K. Nakagawa, SDH-based 10 Gbit/s optical transmission system, presented at GLOBECOM'94, 34.2 (Dec.1994)

Matsumoto, T., M. Jinno, K. Kimura, and K. Noguchi, Studies on optical digital cross-connect systems for very-high-speed optical communications networks, Proc. ICC'94, 1060-1065 (1994)

Miki, T., Toward the service-rich era, IEEE Comm. Mag. 32 2, 34-39 (1994)

Morioka, T., S. Kawanishi, K. Mori, and M. Saruwatari, Transform-limited, femtosecond WDM pulse generation by spectral filtering of gigahertz supercontinuum, Electron. Lett., 30, 1166-1168 (1994)

Morioka, T., S. Kawanishi, H. Takara, O. Kamatani, M. Yamada, T. Kanamori, K. Uchiyama, and M. Saruwatari, 100 Gbit/s x 4 ch, 100 km repeaterless TDM-WDM transmission using a single supercontinuum source, European Conferences on Optical Communications(ECOC'96), PD.ThA3.4 (1995a)

Morioka, T., S. Kawanishi, H. Takara, and M. Saruwatari, Multiple-output, 100 Gbit/s all-optical demultiplexer based on multi-channel four-wave mixing pumped by a linearly-chirped square pulse, Elect. Lett., 30, 23, 1959-1960 (1995b)

Murakami, M., T. Takahashi, M. Aoyama, M. Amemiya, M. Sumida, N. Ohkawa, Y. Fukada, T. Imai, and M. Aiki, 2.5 Gbit/s-9720 km, 10 Gbit/s-6480 km transmission in the FSA commercial system with 90 km spaced optical amplifier and dispersion-managed cables, Electron. Lett., 30, 10, 814-815 (1995)

Nagatsu, N., and K. Sato, Optical path accommodation design enabling cross-connect system scale evaluation, IEICE Trans. Commun., E78-B, 9, 1339-1343 (1995)

Nakagawa, K., and K. Hagimoto, Very high speed FA-10G optical fiber transmission system, NTT R&D, 44, 3, 241-246 (1995)

Nakagawa, K., K. Aida, Y. Yamabayashi, Photonic networks with pulsed lightwave frequency supply module, 1994 IEEE International Conference on Communications, ICC'94, 116-120 (1994)

Oda, K., M. Fukutoku, H. Toba, and T. Kominato, 128 Channel, 480 km FSK-DD transmission experiment using 0.98 mm pumped erbium-doped fibre amplifiers and tunable gain equaliser, Electron. Lett., 30, 12, 982-983 (1994)

Oda, K., M. Fukutoku, M. Fukui, T. Kitoh, and H. Toba, 16-channel x 10 Gbit/s optical FDM transmission over a 1000 km conventional single-mode fiber employing dispersion compensating fiber and gain equalization, Conf. Rec. Optical Fiber Communication, OFC'95, PD22 (1995)

Sato, K., S. Okamoto, and H. Hadama, Network integrity enhancement with optical path layer technologies, IEEE Journal of Selected Areas in Communications, 12, 1, 159-170 (1994)

Takara, H., S. Kawanishi, S. Morioka, K. Mori, and M. Saruwatari, 100 Gbit/s optical waveform measurement with 0.6 ps resolution optical sampling using subpicosecond supercontinuum pulses, Elect. Lett., 30, 14, 1152-1153 (1994)

Takara, H., S. Kawanishi, and M. Saruwatari, Stabilisation of a mode-locked Er-doped fibre laser by suppressing the relaxation oscillation frequency component, Electron. Lett., 31, 4, 292-293 (1995)

Toba, H., K. Oda, K. Inoue, K. Nosu, and T. Kitoh, Demonstration of optical FDM based self-healing ring network employing arrayed-waveguide-grating ADM filters and EDFAs, Proc. ECOC'94, 263-266 (1994)

Tokura, N., and Y. Kajiyama, An optical path based self-healing ring system, Proc. ECOC'95, TuP25 (1995)

Watanabe, A., S. Okamoto, and K. Sato, Optical path cross-connect node architecture with high modularity for photonic transport network, IEICE Trans. Commun., E77-B, 10, 1220-1229 (1994)

Yonenaga, K., S. Kuwano, S. Norimatsu, and N. Shibata, Optical duobinary transmission system with no receiver sensitivity degradation, Electron. Lett., 31, 302-303 (1995)

- Asynchronous transfer mode (ATM) specifications for network elements

- Network architecture

- Network integration

- Network and service management

- Evolution strategy towards multimedia networks

ATM technology is an intrinsic part of B-ISDN, and a wide variety of ATM studies have been reported: network planning [Yoshida and Okazaki, 1993], ATM node and link systems [Aoyama et al., 1993; Koinuma and Takahashi, 1994; Tokizawa and Kikuchi, 1994], photonic technology [Matsunaga et al., 1993; Saruwatari, 1994; Miki, 1994], traffic control schemes [Yamanaka et al., 1993; Esaki et al., 1994; Saito, 1994], self-healing virtual path architecture [Kawamura and Tokizawa, 1995], performance evaluation of ATM connections [Taka and Murakami, 1994; Murakami et al., 1995], and ATM-LAN internetworking [Kinoshita and Saito, 1994; Murata and Miyahara, 1995].

While both studies and applications of network architectures have made steady progress [Kano, 1993; Suzuki, 1993; Ishihara, 1994], there have been significant advances in the Telecommunications Information Networking Architecture (TINA) [Iizuka et al., 1994; Dupuy et al., 1995; Yagi et al., 1995].

Network integration [Aoki, 1993b; Kinoshita et al., 1995] is a synthetic technology developed for creating information services in multimedia networks, which imply both connection-oriented and connectionless networks. Network and service management are indispensable for network users to enjoy sophisticated services at a preferable level of "Quality of Service"; an approach to this via operations systems has been reported [Yoshida, 1994; Ejiri and Yoshida, 1995; Matsushita et al., 1995].

Based on the above technologies, requirements for future switching system [Aoki, 1993a] and several possible migration scenarios from existing networks into multimedia ones have been studied [Fukuda et al., 1993; Aoki and Makino, 1994; Inoue and Terada, 1994; Kinoshita et al., 1994]; open telecommunications management [Matsushita et al., 1994; Miyagishi et al., 1994] has also been studied.

(T. Aoki)

References

Aoki, T., Future switching system requirements, IEEE Commun. Mag., 31, 1, 34-38 (1993a)

Aoki, T., Network architecture--Present and future, NTT Review, 5, 3, 17-23 (1993b)

Aoki, T., and S. Makino, Future prospects for telecommunications networks, NTT Review, 6, 1, 20-25 (1994)

Aoyama, T., I. Tokizawa, and K. Sato, ATM VP-based broadband networks for multimedia services, IEEE Commun. Mag., 31, 4, 30-39 (1993)

Dupuy, F., G. Nilsson, and Y. Inoue, The TINA consortium: towards networking telecommunications information services, Proc. of ISS'95, 2, 207-211 (1995)

Ejiri, M., and M. Yoshida, Progress in telecommunications services and management, IEICE Trans. Commun., E78-B, 1, 5-10 (1995)

Esaki, H., K. Iwamura, T. Kodama, and T. Fukuda, Connection admission control in ATM networks, IEICE Trans. Commun., E77-B, 1, 15-27 (1994)

Fukuda, T., T. Kodama, and Y. Katsube, Considerations on future customer premises network, IEICE Trans. Commun., E76-B, 3, 213-219 (1993)

Iizuka, H., K. Suda, Y. Inoue, and C. Hishinuma, Efforts to develop a next-generation telecommunications information networking architecture, NTT Review, 6, 1, 10-13 (1994)

Inoue, Y., and N. Terada, Granulated broadband networks, IEEE Commun. Mag., 32, 4, 56-62 (1994)

Ishihara, H., Plans for an optical access network, NTT Review, 6, 4, 11-18 (1994)

Kano, S., Network architecture applications in NTT networks, NTT Review, 5, 4, 65-71 (1993)

Kawamura, R., and I. Tokizawa, Self-healing virtual path architecture in ATM networks, IEEE Commun. Mag., 33, 9, 72-79 (1995)

Kinoshita, K., and T. Saito, ATM LAN technologies for integrated business communication services, NTT Review, 6, 1, 32-37 (1994)

Kinoshita, K., T. Wakahara, K. Haruta, and S. Kumon, Service aspects of future private network, IEICE Trans. Commun., E77-B, 3, 306-313 (1994)

Kinoshita, K., T. Saito, and E. Doi, Concept and services of network integration, NTT Review, 7, 2, 49-57 (1995)

Koinuma, T., and T. Takahashi, ATM node system technologies, NTT Review, 6, 1, 43-48 (1994)

Matsunaga, T., M. Tsukada, J. Nishikado, K. Takayama, and H. Nakano, Photonic ATM switching technologies, NTT Review, 5, 1, 46-54 (1993)

Matsushita, M., O. Miyagishi, and M. Yoshida, NTT's approach to open telecommunications management, part-1: fundamental concept, NTT Review, 6, 2, 94-98 (1994)

Matsushita, M., T. Okazaki, and M. Yoshida, A telecommunications management integration network, IEICE Trans. Commun., E78-B, 1, 17-23 (1995)

Miki, T., The potential of photonic networks, IEEE Commun. Mag., 32, 12, 23-27 (1994)

Miyagishi, O., M. Matsushita, and M. Yoshida, NTT's approach to open telecommunications management, part-2: current activities and future plans, NTT Review, 6, 3, 88-94 (1994)

Murakami, H., T. Abe, and K. Mase, Performance design and control for B-ISDN, IEICE Trans. Commun., E78-B, 4, 439-446 (1995)

Murata, M., and H. Miyahara, LAN internetworking through broadband ISDN, IEICE Trans. Commun., E77-B, 3, 294-305 (1994)

Saito, H., Teletraffic technologies in ATM networks, Boston, Artech House (1994)

Saruwatari, M., All-optical signal processing in ultrahigh-speed optical transmission, IEEE Commun. Mag., 32, 9, 98-105 (1994)

Suzuki, S., IN rollout in Japan, IEEE Commun. Mag., 31, 3, 48-55 (1993)

Taka, M., and H. Murakami, Performance design and monitoring techniques for multimedia services, NTT Review, 6, 1, 56-59 (1994)

Tokizawa, I., and K. Kikuchi, ATM link system technologies, NTT Review, 6, 1, 49-55 (1994)

Yagi, H., K. Ohtsu, M. Wakano, H. Kobayashi, and R. Minerva, TINA-C service components, in Proc. of TINA 95, 113-124 (1995)

Yamanaka, N., Y. Sato, and K. Sato, Usage parameter control and bandwidth allocation methods considering cell delay variation in ATM networks, IEICE Trans. Commun., E76-B, 3, 270-278 (1993)

Yoshida, M., An overview of next-generation operations systems, NTT Review, 6, 3, 59-65 (1994)

Yoshida, M., and H. Okazaki, A study on ATM network planning based on evaluation of design items, IEICE Trans. Commun., E76-B, 11, 1333-1340 (1993)

The large screen and flat TV receiver are also indispensable if Hi-Vision is to penetrate the homes. Research on a large plasma display has made it possible to increase the area of the panel display to 40 inches [Yamamoto et al., 1995a].

Luminance has been further improved to build a large plasma display that promises to make wall Hi-Vision a practical proposition. A long-life 40-inch fluorescent wall screen panel has been developed, the quality of motion pictures improved, and a signal processor LSI and transparent electrode also developed [Yoshikawa et al., 1995].

Research on digital broadcasting technology is being conducted for broadcasting in the multimedia era. The focus is on ISDB, an audio and video encoding and multiplexing systems, transmission systems, satellite and terrestrial ISDB, and service and application technologies [Kawai et al., 1994].

In the area of satellite ISDB, an information bit rate and a system for 21 GHz-band satellite broadcasting have been studied; basic data to counter rain attenuation has been obtained; the channel plan for the 12 GHz-band satellite broadcasting system reviewed to meet WRC'97 requirements [Katoh et al., 1993].

Research and development on FM multiplex broadcasting systems (DARC: Data Radio Channel) has been carried out. The chosen modulation is Level-controlled Minimum Shift Keying (LMSK) [Kuroda et al., 1992].

Requirements for improving mobile reception, the single frequency network (SFN), and protection ratio were selected for terrestrial ISDB. A multicarrier modulation scheme and band split transmission (BST) system were studied [Saito et al., 1994].

Analog/digital hybrid optical broadcasting, demand-access digital optical broadcasting system, optical CATV digital transmission technology and ultra-wideband optical transmission have been studied for CATV and optical fiber broadcasting, which will allow the digital transmission of large capacity interactive services [Yamamoto et al., 1995b].

The D-3 VTRs have been installed in the NHK Broadcasting Center and other major local stations. The cart machines have also started operation. In June, 1993, the D-3 was standardized as SMPTE 263M for tape cassette, SMPTE 264M for 525/60 system and SMPTE 265M for 625/50 system. All the documents were approved as ANSI standards in January, 1994 [Uehara et al., 1993].

Studies have been carried out to develop a commercial speech-speed conversion hearing-aid system to compensate for hearing impairments due to aging. The system has been miniaturized for use by the rising population of the elderly [Nakamura et al., 1994].

Research has been conducted on 3D Hi-Vision without use of goggles, photographic conditions and screen effects with 3D images and 3D image information processing, which will be indispensable when the 3D image system is developed [Isono et al., 1993].

(T. Yoshino)

References

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Katoh, H., T. Saito et al., A digital modulation scheme for digital satellite broadcasting for J. Inst. TV Engineers. Japan, 47, 10, 1358-1366 (1993)

Kawai, N., K. Ohsaki, T. Kimura et al., Transport structure for Integrated Services Digital Broadcasting, IEICE Trans. Commun., E77-B, 12, 1474-1479 (1994)

Kuroda, T., T. Saito, M. Takada et al., A digital modulation scheme of FM multiplex broadcasting for mobile reception, Trans. IEICE, J75-B-II, 9, 613-621 (in Japanese) (1992)

Nakamura, A., N. Seiyama, R. Ikezawa et al., Real time voice speed converting system with small impairments, The Journal of the Acoustical Society of Japan, 50, 7, 509-520 (1994)

Saito, M., S. Moriyama, S. Nakahara et al., Transmission characteristics of DQPSK-OFDM for terrestrial digital broadcasting systems, IEICE Trans. Commun., E77-B, 12, 1451-1460 (1994)

Uehara, T., Y. Oba et al., A new 8-14 channel coding for D-3 format VTR, IEEE Trans. Broadcasting, 39, 2, 265-272 (1993)

Yamamoto, T., T. Kuriyama, M. Seki, T. Katoh, T. Takei, T. Kawai, H. Murayama, K. Shimada et al., A 40-inch-diagonal HDTV DC plasma display, IEEE Transactions on Electron Devices, 42, 5 (May.1995a)

Yamamoto, M., N. Nakamura, M. Maeda et al., The digital transmission on demand-access optical CATV, Proceedings 4th International Symposium on Broadcasting Technology (ISBT'95, Beijing) (1995b)

Yoshikawa, S., M. Kurashige, H. Murakami, M. Seki et al., A 40-inch HDTV plasma displays montreux (Jun.1995)