Wireless access chips: In the 1 to 2 GHz range, scaled silicon technology such as bipolar and BiCMOS has been found capable of replacing existing GaAs RF circuits for the goal of high-level integration. A 1.9-GHz single-chip transceiver for PHS has been implemented by using BiCMOS [Sato et al., 1996]. To raise transmission rates above than 10 Mbps, higher frequency bands have been exploited in high-speed wireless access systems. A 5-GHz-band BiCMOS RF transceiver chip for HIPERLAN, which features up/down-conversion for GMSK modulation systems, has been developed [Madihian et al., 1998]. Moreover, a GHz-band bipolar IF limiting amplifier with a signal strength indicator for high-speed wireless access systems has been reported [Tsukahara et al.,1997].
Gb/s transmission chips: Test chips using InP HEMTs were reported for 40-Git/s optical fiber transmission [Otsuji et al., 1996], InP HBTs [Suzuki et al., 1997], and GaAs HBTs [Suzuki et al., 1997]. By using HEMT IC modules, electrically multiplexed and demultiplexed 40-Gbit/s transmission was realized [Yoneyama et al., 1997]. A 20-Gbit/s compact, low-power 3R receiver IC using InP HBTs was also reported [Sano etal.,1997]. To reduce the power dissipation and cost of low-Gb/s optical transceiver chip, a 4.25Gb/s Transceiver chip with PLL and MUX/DEMUX circuit were developed by using CMOS technology for Gb/s LAN applications[ M. Fukaishi et al., 1998].
ATM Switch LSIs: ATM switch LSI throughput has been quadrupled. By using the CMOS/SIMOX technologies, several tens of Gb/s-interface pins were realized on the same chip; the supply voltage was quite low at 2 V. This increased the link speed and switching capacity at the same time without increasing the power consumption. A 40-Gb/s 8x8 ATM switch LSI [Ohtomo et al., 1997] and an ATM switch LSI with a scaleable architecture [Oki et al., 1999] were developed using the CMOS/SIMOX technologies. The highest throughput ATM switch LSIs were used to implement a 640-Gb/s ATM switching system [Yamanaka et al., 1997] with 40-layer ceramic MCMs.
Low voltage LSI technology: The 1 V supply circuit techniques are being put into use. The variable supply voltage technique with on-chip voltage converter has been proposed to realize both high speed and low power supply levels [Sakiyama et al., 1997]. In analog circuits, the 1-V A/D and D/A converter was improved for adoption in audio equipment [Matsuya 1997]. Furthermore, ultra-low-voltage circuit techniques have been developed using SOI devices. One proposal is the multi-threshold CMOS/SIMOX (MTCMOS/SIMOX) technology, which uses three threshold-voltage levels and can achieve both high-speed and low-power operation at the supply voltage of 0.5 V [Fuji et al., 1998]. The DTMOS technology was used together with the variable threshold-voltage scheme to realize a 0.5 V, 320 MHz multiplexer and demultiplexer [Hirota et al., 1998].
Fujii, K., , "A sub-1V triple-threshold CMOS/SIMOX circuit for active power reduction," ISSCC'98, pp. 190-191.
Fukaishi, M., , "A 4.25Gb/s CMOS Fiber Channel Transceiver with Asynchronous Binary Tree-Type Demultiplexer and Frequency Convertion Architechcher," ISSCC'98, pp. 306-307.
Hirota, T.,, "0.5V 320MHz 8b multiplexer/demultiplexer chips based on a gate array with regular-structured DTMOS/SOI," ISSCC'98, pp. 188-189.
Madihian, M., , "A 5GHz-band BiCMOS up/down-converter for GMSK modulation wireless systems," ISSCC'98, pp.374-375.
Matsuya, Y., ,"1.2V, 16-bit audio A/D converter with suppressed latch error noise," 1997 Symp. On VLSI Circuits Digest of Technical Papers, pp. 19-20.
Minami, T., , "A single-chip MPEG2 MP@ML video encoder LSI with multi-chip configuration for a single-board MP@HL encoder," HOT Chips 10, Session 7
Mizuno, M., , "A 1.5-W single-chip MPEG2 MP@ML video encoder with low power motion estimation and clocking," ISSCC'97, pp.256-257
Ogura, E., , "A 1.2W single-chip MPEG2 MP@ML video encoder LSI including wide search range motion estimation and 81MOPS cotroller," ISSCC'98, pp.32-33
Ohtomo, Y., , "A 40Gb/s 8x8 ATM Switch LSI Chip using 0.25mm CMOS/SIMOX , " ISSCC'97, pp. 154-155.
Oki, E., , "A 10Gb/s (1.25Gb/s x 8) 4x2 CMOS/SIMOX ATM Switch," ISSCC'99, pp. 172-173.
Otsuji, T. , "40-Gbit/s ICs for future lightwave communicationsystems," Proc. 1996 IEEE GaAs IC Symposium, pp. 3-6.
Sakiyama, S., ,"A lean power management technique," 1997 Symp. On VLSI Circuits Digest of Technical Papers, pp. 99-100.
Sano, E. , "20 Gbit/s regenerative receiver IC using InP/InGaAs double- heterostructure bipolar transistors," Electron. Lett., vol. 33, 2, pp. 159-160.
Sato, H., , "A 1.9GHz single-chip IF transceiver for digital cordless phones," ISSCC'96, pp.342-343.
Suzuki, H. , "InP/InGaAs HBT ICs for 40 Gbit/s optical transmission systems, " Proc. 1997 IEEE GaAs IC Symposium, pp. 215-218.
Suzuki, Y. , "50-GHz bandwidth base-band amplifiers using GaAs-based HBTs, "Proc. 1997 IEEE GaAs IC Symposium, pp. 143-146.
Takahashi, M., , "A 60mW MPEG4 video codec using Clustered voltage scaling with variable supply-voltage scheme," ISSCC'98, pp. 36-37
Tsukahara, T., , "A 2GHz 60dB dynamic-range Si logarithmic/limiting amplifier with low phase deviations," ISSCC'97, pp. 82-83.
Yamanaka, N.,  , "OPTIMA: Tb/s ATM Switching System Architecture Based on Highly Statistical Optical WDM Interconnection," ISS'97, pp. 255-260.
Yoneyama, M. , "A 40-Gbit/s optical repeater circuits using InAlAs/InGaAs HEMT digital IC chip set," 1997 IEEE MTT-S Dig., pp. 461-464.
Perfect reconstruction of filter banks in conjunction with decimation technique has been an active research area. For example, cosine-modulated 2-Dimensional perfect reconstruction FIR filter bank [Nagai et al., 1996], oversampled DFT filter bank [Kobayashi et al., 1996], two channel stable IIR perfect reconstruction filter banks [Zhang et al., 1998] were proposed.
In filter banks using polyphase submatrices [Kiya et al., 1996] and parallel module decomposition [Murakami, 1997], decimation technique was utilized.
MDMR(multidimensional multirate) filters have been continuously studied. The checkerboard distortion caused by the periodic time-variant property of multirate filters was removed in the frequency domain [Tamura et al., 1998]. Simulation examples of MDMR filter banks without checkerboard distortion were also shown [Harada et al., 1998].
The digital signal processing based on wavelet transform was applied to wide areas. For example, noise reduction of ECG signals [Inoue et al., 1998] and AR spectral analysis [Resende et al., 1996] were investigated.
In the research area of nonlinear signal processing, recurrent neural networks for parallel nonlinear filters were proposed [Cao et al., 1996], and memoryless nonlinear gradient algorithm for a adaptive IIR filter [Xiao et al., 1998] was analyzed.
The spectral estimation by using time variation in analysis intervals [Nakagaki et al., 1996], multi-band decomposition of the linear prediction error [Resende et al., 1997], and robustness of an AR model [Sanubari et al., 1998] were studied.
In the fields of fundamental theory of digital signal processing, eigenvalue problem was used to d design IIR digital filters [Zang et al., 1996]. The algebraic phase unwrapping algorithm which can determine the exact zero distribution of complex polynomials was proposed [Yamada et al., 1998]. Two new filters were proposed. One was with log magnitude and phase response [Okuda et al., 1996], the other was with adaptation of nonuniformly spaced samples [Sakai et al., 1995].
Improvement of the performance of digital signal processor has been also investigating. In order to avoid the overhead in updating address registers, address allocation method based on the graph linearization algorithm was proposed [Sugino et al., 1997].
Cao, J. and T.Yahagi , "Parallel Nonlinear Adaptive Digital Filters Using Recurrent Neural Networks", Trans. IEICE, vol.J79-A, 4, pp.868-877 (in Japanese)
Harada, Y., S.Muramatsu and H.Kiya , "Multidimensional Multirate Filter and Filter Bank without Checkerboard Effect", IEICE Trans. Fundamentals, vol.E81-A, 8, pp.1607-1615
Inoue, H. and A.Miyazaki , "A Noise Reduction Method for ECG Signals Using the Dyadic Wavelet Transform", IEICE Trans. Fundamentals, vol.E81-A, 6, pp.1001-1007
Kiya, H. and H.Kobayashi , "Oversampled Filter Banks Based on Polyphase Submatrices", Trans. IEICE, vol.J79-A, 9, pp.1525-1534 (in Japanese)
Kobayashi, H. and H.Kiya , "A Design Method for Oversampled DFT Filter Banks with the Minimum Delay", Trans. IEICE, vol.J79-A, 11, pp.1801-1807 (in Japanese)
Kobayashi, M., Y.Takagi, J.Okello and T.Itoh , "An IIR Adaptive Filter Based on Estimation of All-Pass System", IEEE trans. on CAS-II, vol.45, 6, pp.676-684
Matsubara, K., K.Nishikawa and H.Kiya , "Pipelined Adaptive Filters Based on Delayed LMS Algorithm", Trans. IEICE, vol.J79-A, 5, pp.1050-1057 (in Japanese)
Murakami, H. , "Implementation and Perfect Reconstruction of a Maximally Decimated FIR Filter Bank Using Parallel Module Decomposition", IEEE Trans. on SP, vol.45, 2, pp.328-332
Nagai, T. and M.Ikehara , "Cosine-Modulated 2-Dimensional Perfect Reconstruction FIR Filter Bank with Linear Phase", Trans. IEICE, vol.J79-A, 3, pp.590-598 (in Japanese)
Nakagaki, A., Y.Miyanaga, K.Tochinai and K.Shibata , "Adaptive Spectrum Estimation Considering the Time-Variation in Analysis Intervals", Trans. IEICE, vol.J79-A, 3, pp.599-607 (in Japanese)
Okuda, M., M.Ikehara and S.Takahashi , "Simultaneous Approximation for IIR Digital Filters with Log Magnitude and Phase Response", IEICE Trans. Fundamentals, vol.E79-A, 11, pp.1879-1885
Okuda, M., M.Ikehara and S.Takahashi , "Fast and Stable Least-Squares Approach for the Design of Linear Phase FIR Filters", IEEE Trans. on SP, vol.46, 6, pp.1485-1493
Resende Jr., F.G.V, K.Tokuda and M.Kaneko , "Adaptive AR Spectral Estimation Based on Wavelet Decomposition of the Linear Prediction Error", IEICE Trans. Fundamentals, vol.E79-A, 5, pp.665-673
Resende Jr., F.G.V, K.Tokuda, M.Kaneko and A.Nishihara, "Multi-Band Decomposition of the Linear Prediction Error Applied to Adaptive AR Spectral Estimation", IEICE Trans. Fundamentals, vol.E80-A, 2, pp.365-376
Sakai, M., K.Aizawa and M.Hatori , "An Adaptive Filter with Adaptation of Nonuniformly Spaced Samples", Trans. IEICE, vol.J78-A, 11, pp.1429-1439 (in Japanese)
Sanubari, J., K.Tokuda and M.Onoda , "Robust Recursive Time Series Modeling Based on an AR Model Excited by a t-Distribution Process, IEEE trans. on SP, vol.46, 1, pp.218-222
Sugino, N., H.Miyazaki and A.Nishihara , "DSP Code Optimization Methods Utilizing Addressing Operations at the Codes without Memory Accesses", IEICE Trans. Fundamentals, vol.E80-A, 12, pp.2562-2571
Tamura, T., M.Kato, T.Yoshida and A.Nishihara , "Design of Checkerboard-Distortion-Free Multidimensional Multirate Filters", IEICE Trans. Fundamentals, vol.E81-A, 8, pp.1598-1606
Xiao, Y., Y.Tadokoro and Y.Kobayashi, "A New Memoryless Nonlinear Gradient Algorithm for a Second-Order Adaptive IIR Notch Filter and Its Performance Analysis", IEEE Trans. on CAS-II, vol.45, 4, pp.462-472
Yamada, I., K.Kurosawa, H.Hasegawa and K.Sakaniwa , "Algebraic Multidimensional Phase Unwrapping and Zero Distribution of Complex Polynomials - Characterization of Multivariate Stable Polynomials", IEEE trans. on SP, vol.46, 6, pp.1639-1657
Zang, X. and H.Iwakura , "Design of IIR Digital Filters Based on Eigenvalue Problem", IEEE trans. on SP, vol.44, 6, pp.1325-1333
Zhang, X. and T.Yoshikawa , "Design of Two Channel Stable IIR Perfect Reconstruction Filter Banks", IEICE Trans. Fundamentals, vol.E81-A, 8, pp.1592-1597
In the research of optical interconnection, synchronized parallel optical data transmission of 600MBytes/s throughput was demonstrated [Nishimura et al., 1998]. For optical correlation systems, the 2-dimensional phase modulator was developed by combining a parallel-aligned nematic liquid-crystal spatial light modulator (PAL-SLM) with an LCD [Mukohzaka etal., 1998]. The optical network unit for WDM transmission using a planar micro lens array was also proposed [Kato et al., 1998].
In order to realize high-speed optical signal processing, optical 2D-space to time to 2D-space conversion technique by using an ultra short pulse laser was proposed [Konishi et al., 1998]. Spectral filtering method was also used for expanding femto second light pulse into space domain [Mori et al., 1998].
Awatsuji, Y., N. Sakamoto, H. Utsuro, J. Tanida, Y. Ichioka , "Optical array logic network computing: design of a prototype system", Optical Review , Vol.4, 1B, pp.199-202
Ishikawa, M., N. McArdle , "Optically interconnected parallel computing systems", IEEE Computer Magazine, Vol.31, 2, pp.61-68
Kato, T., R. J. Mizuno, Y. Aoki, K. Iga , "A microoptic network unit using planar microlens array", Optical Review , Vol.5, 1, pp.1-3
Konishi, T., Y. Ichioka , "Ultra-fast space to time to space optical information processing and transmission", Optics in Computing '98, O21, pp.269-272
Kurokawa, T., T. Nakahara, S. Matsuo, K. Tateno, Y. Ohiso, A. Wakatsuki, H. Tsuda , "Design approaches for VCSEL's and VCSEL-based smart pixels toward parallel optoelectronic processing systems", Appl. Opt., Vol.37, 2, pp.1-11
Mori, M., Y. Yasuno, M. Watanabe, T. Yatagai, , "Differentiation images on spatio-temporal plane with femto second light pulses", Optics in Computing '98, P82
Mukohzaka, N., F. Li, N. Yoshida, Y. Igasaki, H. Toyoda, T. Inoue, Y. Kobayashi, T. Hara , "Phase Modulation Characteristics of LCD-coupled PAL-SLM (Parallel-Aligned nematic Liquid crystal Spatial Light Modulator)", Optics in Computing '98, P84
Nakahara, T., H. Tsuda, K. Tateno, S. Matsuo, T. Kurokawa , "Hybrid integration of GaAs pin-photodiodes with CMOS transimpedance amplifier circuits", Electron. Lett., Vol.34, 13 , pp.1352-1353
Nishimura, S., H. Inoue, H. Matsuoka, T. Yokota , "Synchronized parallel optical interconnection for the massively parallel computer RWC-1", Optics in Computing '98, I13, pp.536-539
Sakata, H., Y. Nagao, Y. Matsushima , "Optoelectronic memory characteristics by symmetric triangular-barrier optoelectronic switch (S-TOPS)", Optics in Computing '98, P45, pp.358-361
Toyoda, T., Y. Nitta, E. Funatsu, Y. Miyake, W. T. Freeman, J. Ohta, K. Kyuma , "Artificial retina chip as image input interfaces for multimedia systems", OECC'96, 19A2-2, pp.516-517
One of the most remarkable advances on circuits and systems was seen in the field of circuit simulation. Bipolar analog integrated circuits with more than 10,000 elements were solved efficiently with the theoretical guarantee of global convergence [Inoue and Yamamura, 1995]. This is an epoch-making result both in theory and in application, which gives a great breakthrough to the design of analog integrated circuits. A new algorithm using the homotopy method was proposed whose global convergence property was proved for modified nodal equations that are used in SPICE [Yamamura, Sekiguchi and Inoue, 1998c]. A precise event-driven MOS circuit simulator was also developed which was 5-7 times faster than a SPICE-like circuit simulator, while maintaining the less than 1% error accuracy [Kage, Fujisawa, Kawafuji and Kitaura, 1996].
Studies on chaos and bifurcations have been also very active. Bifurcation of one-dimensional maps using the renormarization technique in a parameter space was analized [Matsuba, 1997], and bifurcation phenomena in the Josephson junction circuit coupled by a resistor were investigated [Ueta and Kawakami, 1996]. A numerical method for calculating homoclinic points of a two-dimensional noninvertible map was proposed [Yoshinaga, Kitajima, Kawakami and Mira, 1997], and methods of automatically adjusting delay time and feedback gain in controlling chaos by delayed feedback control were proposed [Nakajima, Ito and Ueda, 1997]. Pecora-Carroll chaotic synchronization in R-L-diode circuit was observed by both experiments and computer simulation [Nishi and Matsumoto, 1997].
Transient response of Colpitts-voltage-controlled oscillator and its effect on performance of phase-locked loop (PLL) system was investigated [Shibutani, Saba, Moro and Mori, 1998]. Geometric structure of mutually coupled PLLs was studied [Tanaka, Oishi and Horiuchi, 1996], and a new type of intermittency from a ring of four coupled PLLs was investigated [Hasegawa, Komuro, Endo and Igarashi, 1998]. Furthermore, statistics of chaotic binary sequences were studied [Kohda and Tsuneda, 1997], and chaotic behavior in an autonomous flip-flop circuit was investigated [Okazaki, Nakano and Kawase, 1998].
Studies on neural networks have been also very active. Geometry of admissible parameter region in neural learning was studied [Ikeda and Amari, 1996], and an asynchronous pulse neural network model which is suitable for VLSI implementation was proposed [Hanagata, Horio and Aihara, 1998]. Design of nonlinear cellular neural network filters for detecting linear trajectory signals was studied [Muikaichi, Kondo and Hamada, 1997], and a hysterisis quantizer based on a simple hysterisis neural network was proposed [Jinno and Tanaka, 1998].
Related to nonlinear circuit analysis, the stability of operating points of nonlinear resistive circuits including transistors was studied, and a set of conditions for the operating points to be unstable were proposed [Nishi and Ogata, 1997]. An algorithm which converges to a stable operating point with high possibility from any initial point was also proposed [Yamamura, Sekiguchi and Inoue, 1998c]. The stability of characteristic curves of nonlinear resistive circuits was also investigated [Jiang, Nishio and Ushida, 1998]. An efficient algorithm for finding all solutions of piecewise-linear resistive circuits was proposed, which could find all solutions of a piecewise-linear resistive circuit where the number of variables is 200 and the number of linear regions is 10200 in practical computation time [Yamamura and Ohshima, 1998b]. An efficient algorithm for analzing nonuniform transmission lines was also proposed by using the Chebyshev expansion method and moment techniques [Tanji, Nishio and Ushida, 1997].
Related to the numerical computation with guaranteed accuracy, a method of verifying existence of connecting orbits of continuous dynamical systems described by parameterized nonlinear ordinary differential equations was proposed [Oishi, 1997], and a method of proving existence of simple turning points of two-point boundary value problems was proposed [Soma, Oishi, Kanzawa and Horiuchi, 1998]. Both methods are based on the numerical computation with guaranteed accuracy and interval analysis. It was also shown that all solutions of systems of nonlinear equations can be found very efficiently by introducing linear programming to the interval analysis [Yamamura, Kawata and Tokue, 1998a]. Using this idea, all solutions of systems of 100 nonlinear equations could be found with mathematical certainty. This idea was further extended to evaluating sharp ranges of functions [Kashiwagi, 1996]
The study on nonlinear system analysis by fixed point theorems for set-valued mappings has been extensively developed [Horiuchi, 1995]. This theory was further extended to the fluctuation analysis of information-transfer systems with uncertain feedback confirmation loops [Horiuchi, 1998]. Several researchers are now trying to develop this theory (termed Horiuchi theory) from the viewpoint of application. A numerical method to compute the number, location, and stability of fixed points of Poincare maps was also proposed [Fujisaka and Sato, 1997].
Related to graphs and networks, a new algorithm for the p-collection problem (which is known to be an NP-hard problem) on a tree-type flow network was proposed [Tsukiyama, 1998], and the complexity of the covering problems corresponding to the p-collection problem was discussed [Watanabe, Sengoku, Tamura and Shinoda, 1998]. A covering problem called single cover on undirected flow networks was generalized and an algorithm for solving the single covering problem was also proposed [Tamura, Sugawara, Sengoku and Shinoda, 1997].
(K. Horiuchi and K. Yamamura)
Fujisaka, H. and C. Sato , "Computing the number, location, and stability of fixed points of Poincare maps," IEEE Trans. Circuits and Systems-I, vol.44, 4, pp.303-311
Hanagata, M., Y. Horio and K. Aihara , "Asynchronous pulse neural network model for VLSI implementation,"IEICE Trans. Fundamentals, vol.E81-A, 9, pp.1853-1859
Hasegawa, A., M. Komuro, T. Endo and R. Igarashi , "A new type of intermittency from a ring of four coupled phase-locked loops,"IEEE Trans. Circuits and Systems-I, vol.45, 6, pp.623-633
Horiuchi, K. , "Nonlinear system analysis by fixed point theorems for set-valued mappings, " Proc. Int. Symp. Nonlinear Theory and its Applications, Las Vegas, Nevada, 2, pp.769-774
Horiuchi, K. , "Fluctuation analysis of information-transfer systems with uncertain feedback confirmation loops, by means of set-valued concept," Trans. IEICE, vol.J81-A, 1, pp.62-68
Ikeda, K. and S. Amari , "Geometry of admissible parameter region in neural learning," IEICE Trans. Fundamentals, vol.E79-A, 6, pp.938-943
Inoue, Y. and K. Yamamura , "Practical algorithms for dc operating-point analysis of large-scale circuits," Proc. Int. Symp. Nonlinear Theory and its Applications, Las Vegas, Nevada, 2, pp.1153-1158
Jiang, L., Y. Nishio and A. Ushida , "Stability of characteristic curves of nonlinear resistive circuits," IEEE Trans. Circuits and Systems-I, vol.45, 6, pp.634-643
Jinno, K. and M. Tanaka , "Hysterisis quantizer," Trans. IEICE, vol.J81-A, 6, pp.980-987
Kage, T., H. Fujisawa, F. Kawafuji and T. Kitaura , "A precise event-driven MOS circuit simulators," IEICE Trans. Fundamentals, vol.E79-A, 3, pp.339-346
Kashiwagi K. , "Interval arithmetic with linear programming - Extension of Yamamura's idea -," Proc. Int. Symp. Nonlinear Theory and its Applications, Kochi, Japan, pp.61-64.
Kohda, T. and A. Tsuneda , "Statistics of chaotic binary sequences," IEEE Trans. Information Theory, vol.43, 1, pp.104-112.
Matsuba, I. , "Bifurcation analysis of one-dimensional maps using the renormarization technique in a parameter space," Trans. IEICE, vol.J80-A, 4, pp.653-662
Muikaichi, M., K. Kondo and N. Hamada , "Design of nonlinear cellular neural network filters for detecting linear trajectory signals," IEICE Trans. Fundamentals, vol.E80-A, 9, pp.1655-1661
Nakajima, H., H. Ito and Y. Ueda , "Automatic adjustment of delay time and feedback gain in delayed feedback control of chaos," IEICE Trans. Fundamentals, vol.E80-A, 9, pp.1554-1559
Nishi, M. and T. Matsumoto , "Pecora-Carroll chaotic synchronization and masking in R-L-diode circuit," Trans. IEICE, vol.J80-A, 9, pp.1421--1430
Nishi, T. and M. Ogata , "On the stability of operating points of transistor circuits," IEICE Trans. Fundamentals, vol.E80-A, 9, pp.1540-1547
Oishi, S. , "Numerical verification method of existence of connecting orbits for continuous dynamical systems," J. Universal Computer Science, vol.4, 2, pp.171-177, http://www.iicm.edu/jucs_4_2
Okazaki, H., H. Nakano and T. Kawase , "Chaotic and bifurcation behavior in an autonomous flip-flop circuit used by piecewise linear tunnel diodes," Proc. Int. Symp. Circuits and Systems, Monterey, California, 3, pp.291-297.
Shibutani, A., T. Saba, S. Moro and S. Mori , "Transient response of Colpitts-VCO and its effect on performance of PLL system," IEEE Trans. Circuits and Systems-I, vol.45, 7, pp.717-725
Soma, T., S. Oishi, Y. Kanzawa and K. Horiuchi , "A method of proving the existence of simple turning points of two-point boundary value problems based on the numerical computation with guaranteed accuracy," IEICE Trans. Fundamentals, vol.E81-A, 9, pp.1892-1897
Tamura, H., H. Sugawara, M. Sengoku and S. Shinoda , "On a generalization of a covering problem called single cover on undirected networks," IEICE Trans. Fundamentals, vol.E80-A, 3, pp.544-550
Tanaka, H., S. Oishi and K. Horiuchi , "Geometric structure of mutually coupled phase-locked loops," IEEE Trans. Circuits and Systems-I, vol.43, 6, pp.438-443
Tanji, Y., Y. Nishio and A. Ushida , "Analysis of nonuniform transmission lines using Chebyshev expansion method and moment techniques," IEICE Trans. Fundamentals, vol.E80-A, 10, pp.1955-1960
Tsukiyama, S. , "A new algorithm for p-collection problems on a tree-type flow network," IEICE Trans. Fundamentals, vol.E81-A, 1, pp.139-146
Ueta, T. and H. Kawakami , "Bifurcation phenomena in the Josephson junction circuit coupled by a resistor," IEICE Trans. Fundamentals, vol.E79-A, 10, pp.1546-1550
Watanabe, K., M. Sengoku, H. Tamura and S. Shinoda , "Covering problems in the p-collection problems," IEICE Trans. Fundamentals, vol.E81-A, 3, pp.470-477
Yamamura, K., H. Kawata and A. Tokue [1998a], "Interval solution of nonlinear equations using linear programming," BIT, vol.38, 1, pp.186-199
Yamamura, K. and T. Ohshima [1998b], "Finding all solutions of piecewise-linear resistive circuits using linear programming," IEEE Trans. Circuits and Systems-I, vol.45, 4, pp.434-445
Yamamura, K., T. Sekiguchi and Y. Inoue [1998c], "A fixed-point homotopy method for solving modified nodal equations," IEEE Trans. Circuits and Systems-I, vol.45
Yoshinaga, T., H. Kitajima, H. Kawakami and C. Mira , "A method to calculate homoclinic points of a two-dimensional noninvertible map," IEICE Trans. Fundamentals, vol.E80-A, 9, pp.1560-1566
In the area of cryptography there has been a great progress in elliptic curve crypto-systems. The following two results are obtained on the elliptic curve discrete logarithm problem. One is that the elliptic curve discrete logarithm problem over anomalous curves can be reduced into the discrete logarithm problem of the additive group of the ground field in a probabilistic polynomial time [Satoh et al., 1997]. The other is that the natural generalization of the index calculus to the elliptic curve discrete logarithm problem yields an algorithm with is less efficient than a brute-force search algorithm [Silverman et al., 1998].
Some new cryptosystems are proposed. One is an RSA-type cryptosystem modulo n=pkq [Takagi, 1997] [Takagi, 1998] which resists two of the fastest factoring algorithms, the number field sieve and the elliptic curve method. Moreover its decryption process is faster than the RSA cryptosystem using Chinese reminder theorem. Another cryptosystem is based on logarithmic function, a Fp valued function on p-Sylow subgroup of (Z/p2Z)* [Okamoto et al., 1998]. The original version is not secure against active attacks, but its improved version called EPOC (Efficient Probabilistic Public-Key Encryption) is secure against active attacks.
In the area of data compression, two interesting algorithms have been introduced. One is a universal data compression algorithm based on context sorting [Yokoo,et al. 1996]. The other is the "interval algorithm" for random number generation [Han, et al. 1997], which is closely related to the arithmetic coding algorithm for data compression.
An efficient algorithm for successive errata decoding of BCH codes has been derived based on testing the candidate codeword generated by the most appropriate error locator polynomial and errata evaluator polynomial by a developed acceptance criterion [Kamiya, 1997]. Computationally efficient maximum-likelihood decoding algorithms for binary linear block codes based on trellis diagram was proposed [Fujiwara et al., 1998].
An algorithm for calculating the weight distribution of a linear block code by trellis diagram has been refined and that of a primitive BCH codes of length 128 was shown in [Desaki et al., 1997]. A fast erasure-and-error decoding method for any one-point Algebraic Geometric codes up to the Feng-Rao bound has been introduced by modifying Berlekamp-Massey-Sakata algorithm in [Sakata, 1997]. Generalized Hamming weights for the codes constructed on affine algebraic sets as a generalization of algebraic geometric codes has been investigated, especially by evaluating their lower bounds [Shibuya et al., 1997]. An explicit construction of codes achieving capacity for arbitrary discrete memoryless channels has been introduced [Uyematsu et al., 1997].
Multilevel coded modulation and multistage decoding with unequal error protection capability has been proposed and analyzed [Morelos-Zaragoza et al., 1998] and it was generalized to obtain more freedom in code constructions [Isaka et al., 1998]. A class of strictly geometrically uniform codes has been investigated and new codes were constructed in [Takeshita et al., 1997].
(H. Imai and H. Yamamo)
Desaki Y., T.Fujiwara, and T.Kasami , The weight distributions of extended binary primitive BCH codes of length 128, IEEE Trans. Info. Theory, 43, 4, 1364-1371.
Fujiwara T., H. Yamamoto, T. Kasami, and S. Lin , A trellis-based recursive maximum- likelihood decoding algorithm for binary linear block codes, IEEE Trans. Info. Theory, 44, 2, 714-729.
Han, Te Sun and H.Amari , Statistical inference under multi-terminal data compression, IEEE Trans. Info. Theory, 44, 6, 2300-2324.
Han, Te Sun and M.Hoshi , Interval algorithm for random number generation, IEEE Trans.Info. Theory, 43, 2, 599-611.
Isaka M., R.H.Morelos-Zaragoza, M.P.C.Fossorier, S.Lin, and H.Imai , Coded modulation for satellite broadcasting based on unconventional partitionings, IEICE Transactions on Fundamentals and Electronics, E81A, 10, 2055-2063.
Kamiya, N., ,On acceptance criterion for efficient successive errors-and-erasures decoding of Reed-Solomon and BCH codes, IEEE Trans. Info. Theory, 43, 5, 1477-1488.
Morelos-Zaragoza, R.H., T. Kasami, S. Lin and H. Imai , On block-coded modulation using unequal error protection codes over Rayleigh-fading channels, IEEE Trans.Commun., 46, 1, 1-4.
Okamoto, T. and S. Uchiyama , A new public-key cryptosystem as secure as factoring, Advances in Cryptology-Eurocrypt'98, Lecture Notes in Computer Science, Springer-Verlag, .1403, 308-318.
Oohama, Y., , Gaussian multiterminal source coding, IEEE Trans. Info. Theory, 43, 6,1912-1923 .
Sakata S., , A vector version of the BMS algorithm for implementing fast erasure-and-error decoding of one-point AG codes, Applied Algebra, Algebraic Algorithms and Error-Correcting Codes, in Lecture Notes in Computer Science, Springer-Verlag, 1255,291-310.
Satoh, T. and K. Araki , Fermat quotients and the polynomial time discrete log algorithm for anomalous elliptic curves, Commentarii Math, Univ, Saniti Pauli, 47, 1, 88-92.
Shibuya T., J. Mizutani and K. Sakaniwa , On generalized Hamming weights of Codes constructed on affine algebraic sets, Applied Algebra, Algebraic Algorithms and Error-Correcting Codes, in Lecture Notes in Computer Science, Springer-Verlag, 1255, 311-320.
Silverman, J. H. and J.Suzuki , Elliptic curve discrete logarithm and the index calculus, Advances in Cryptology-Asiacrypt'98, Lecture Notes in Computer
Takagi, T. , Fast RSA-type cryptosystem using n-adic expansion, Advances in Cryptology-Crypto'98, Lecture Notes in Computer Science, Springer-Verlag, 1294, 372-384
Takagi, T. , Fast RSA-type cryptosystem modulo pkq", Advances in Cryptology- Crypto'98, Lecture Notes in Computer Science, Springer-Verlag, 1462, 318-326.
Takeshita O.Y., and H. Imai , On strictly geometrically uniform codes: construction and new codes, IEICE Transactions on Fundamentals and Electronics, E80A, 3, 590-597.
Uyematsu T., and E. Okamoto , A construction of codes with exponential error bounds on arbitrary discrete memoryless channels, IEEE Trans. Info. Theory, 43, 3, 992-996.
Watanabe, Y. , The total capacity of two-user multiple-access channel with binary output, IEEE Trans. Info. Theory, 42, 5, 1453-1465.
Yamamoto, H., Rate-distortion theory for the Shannon cipher system, IEEE Trans. Info. Theory, 43, 3, 826-835.
Yokoo, H. and M. Takahashi , Data compression by context sorting, IEICE Trans. on Fundamentals, E79-A, 5, 681-186.
The active research topic for DS-CDMA is categorized into 8 topics: (1) Access scheme (2) Coherent Rake combining and diversity techniques with pilot channel, (3) Power control, (4) Handover technique, (5) Packet data transmission, (6) Canceller of co-channel interference, (7) Antenna diversity technique and (8) Experimental study by using prototype.
As for (1), CDMA/FDD (Frequency Division Duplex) [Adachi, 1996] and CDMA/TDD (Time Division Duplex) [Miya, 1997] for Wideband CDMA were proposed respectively. For (2), Rake diversity technique using channel estimation method by weighted multi-slot pilot sequence [Andoh, 1998], and experiments on path search performance of coherent RAKE Receiver [Fukumoto, 1998] for Wideband CDMA were studied. Moreover, as for (3), SIR -based transmission power control of reverse link for wideband CDMA [Seo, 1998] and the lower bound of open loop Transmission Power Control error in DS-CDMA system[Kudoh, 1997] were studied. For (4), a decision-avoided handover algorithm was studied on indoor communications [Kinoshita, 1998].
As for (5), a study of the throughput of multi-code CDMA ALOHA system with modified channel load sensing protocol [Sandouk, 1998], the throughput analysis of DS/SSMA unslotted Aloha with fixed packet length [Sato, 1996], capacity Evaluation of media access control method in DS-CDMA Packet Mobile Communications [Nagatsuka, 1998] and coherent block demodulation of W-CDMA packet in frequency selective multipath channels [Abeta, 1998] were proposed respectively.
As for (6), pilot symbol-assisted coherent multistage interference canceller for Wideband CDMA [Sawahashi, 1996], and adaptive multi-user equalizer using multi-dimensional lattice filters [Jitsukawa, 1996], were reported. As for (7), pilot symbol-assisted decision-directed coherent adaptive array diversity for Wideband CDMA [Tanaka, 1997] was proposed. As for (9), 1.92 Mbps data transmission experiments over coherent W-CDMA Radio Link [Okawa, 1998], and coherent DS-CDMA with TDD Scheme[Kato, 1998] reported the experimental study and the results of field trial.
For the other spread spectrum communication systems, double M-ary/ spread spectrum communication system [Takeuchi, 1998], cyclic extended modified M-sequence based spread spectrum communication system [Harada, 1997], differential parallel combinatorial CDMA systems [Kon 1997] and spread spectrum radar application [Hanada 1997] were proposed.
Abeta S., M. Sawahashi and F. Adachi ,"Coherent block demodulation of W-CDMA packet in frequency selective multipath channels," Technical report of IEICE, RCS98-66, 7, 55.
Adachi F., K. Ohno, A. Higashi, T. Dohi and Y. Okumura , "Coherent multi-code DS-CDMA mobile radio access," IEICE Trans Commun., E79-B, 9, 1316-1325.
Andoh H., M. Sawahashi and F. Adachi , "Channel estimation using time-multiplexed pilot symbols for coherent RAKE combining for DS-CDMA mobile radio," IEICE Trans. Commun., E81-B, 7, 1517-1526.
Fukumoto S., K. Okawa, H. Andoh, M. Sawahashi and F. Adachi , "Experiments on Path Search Performance of Coherent RAKE Receiver for W-CDMA Mobile Radio," Technical reprot of IEICE, RCS98-30, 5, 41-48 (in Japanese)
Harada H. , "Multicode CDM Radio Transmission Demonstrator Based on Cyclic Extended and Shifted M-sequences for Microwave-Band Mobile Communications," in Proc. WPMC'98, 11, 393-398.
Hanada H. and R. Kohno , "Vehicular Spread Spectrum Radar Using Multi-beam Antenna," in Proc. VTC'97, 5, 116-120.
Jitsukawa D. and R. Kohno , "Adaptive multi-user equalizer using multi-dimensional lattice filters for DS-CDMA," IEEE ISSSTA'96, 536-540.
Kato O., K. Miya, K. Homma, T. Kitade, M. Hayashi and M.Watanabe , "Experimental Performance Results of Coherent Wideband DS-CDMA with TDD Scheme," IEICE Trans. Commun., E81-B, 7, 1337-1343.
Kinoshita Y., H. Ohno and D.K. Asano , "Performance Analysis of a New Decision-Avoided Handover Algorithm for DS-CDMA Indoor Pico-cellular Systems," IEEE VTC'98,1044-1048.
Kon T., S. Sasaki, H. Kikuchi and G. Marubayashi , "A Study of Differential Parallel Combinatorial CDMA Systems in Multipath Fading Channel," Technical report of IEICE, RCS97-113, 10, 1.
Kudoh E., I. Okazaki and S. Ogose , "The Lower Bound of Open Loop Transmission Power Control Error in DS-CDMA System," IEICE Trans. Commun., E80-B, 12, 1805-1811.
Miya K., M. Watanabe, M. Hayashi, T. Kitade, O. Kato and K. Homma , "CDMA/TDD cellular systems for the 3rd generation mobile communication," IEEE VTC'97, 820-824.
Nagatsuka M., Y. Ishikawa, J. Hagiwara, T. Nakamura and S. Onoe , "Capacity Evaluation of Media Access Control Method in DS-CDMA Packet Mobile Communications," Technical report of IEICE, RCS97-195, 1, 23.
Okawa K., M. Sawahashi and F. Adachi , "2Mbps data transmission experiments over coherent W-CDMA radio channel," IEICE Trans. Commun. E81-B, 7,1330-1336.
Sandouk A., T. Yamazato, M. Katayama and A. Ogawa , "A Study on the Throughput of Multi-code CDMA ALOHA System with Modified Channel Load Sensing Protocol," Technical report of IEICE, SST 98-40, 10, 61-68
Sato T., H. Okada, T. Yamazato, M. Katayama and A. Ogawa , "Throughput analysis of DS/SSMA Unslotted Aloha with Fixed Packet length," IEEE J-SAC, Vol.14 No.4, 5, 750-756.
Sawahashi M., Y. Miki, H. Andoh and K. Higuchi , "Pilot symbolaided coherent multistage interference canceller using recursive channel estimation for DS-CDMA mobile radio," IEICE Trans. Commun., E79-B, 9, 1262-1270.
Seo S., T. Dohi and F. Adachi , "SIR-based transmit power control of reverse link for coherent DS-CDMA mobile radio," IEICE Trans. Commun., E81-13, 7,1508-1516.
Takeuchi K., M. Hamamura and S. Tachikawa , "Double M-ary/Spread Spectrum Communication Systems," IEICE Trans. Funcamentals, E81-A, 10, 2064-2077.
Tanaka S., M. Sawahashi and F. Adachi , "Pilot symbol-assisted decision-directed coherent adaptive array diversity for DS-CDMA mobile radio reverse link," IEICE Trans. Fundamentals, E80-A, 12, 2445-2454.
<Experiments> A 156Mbps ATM transmission experiment was carried out using the N-STAR multibeam transponder [Yoshimura et al.,1998]. A new system that enables interactive multimedia communication with portable terminals (A4 size) was proposed and its feasibility has been investigated [Kazama et al., 1998], [Nakayama et al., 1998]. The experimental satellite ETS-VIII (Engineering Test Satellite-VIII) is scheduled to be launched in 2002 with aim of establishing future technologies. It will use 13m aperture reflectors and offer packet switching [Kitahara et al., 1996]. The concept of the gigabit communication satellite was proposed to satisfy the demands placed on satellite systems by the future multimedia applications in the optical fiber era[Imai et al.,1998]. A new satellite orbit, the inclined geosynchronous orbit, should overcome the drawbacks of low elevation angle for high latitude areas and propellant consumption for station-keeping [Kanai et al., 1998]
<Key Technologies> On-board components are being investigated for new services and future satellite communication systems. A microwave signal processing device has been developed for active phased array beam forming and steering. A large scale network, comprising 63 power dividers and 32 pairs of phase/amplitude controllers, was realized using GaAs MMIC [Ohira et al., 1997]. A high-efficiency Ka-band transponder for data relay satellites has been developed and qualified by ground testing [Suzuki et al., 1998]. A Ka band active phased array antenna is being researched to achieve high EIRP and the beam scanning requirement for gigabit satellite is being considered [Kitao et al., 1998]. The modular type mesh antenna reflector has been investigated to make mobile terminals smaller. The feature of this reflector is that several nearly identical modules are combined to achieve the required aperture size. This structure has many advantages including easier ground testing, manufacture and aperture expansion [Watanabe et al.,1998].
Imai R., A. Saifudin, H. Okazawa, N. Kadowaki, M. Yamamoto , "System study on the experimental gigabit communications satellite," 17th AIAA International Communications Satellite Systems Conference, pp.265-269
Kanai H., S. Urasaki, I. Chiba, A. Iso, T. Katagi , "Inclined geosynchronous (I-GEO) communications satellite for Asia pacific region," 17th AIAA International Communications Satellite Systems Conference, pp.762-766
Kazama H., K. Kobayashi, T. Otsu, K. Araki , "Spread spectrum FDMA over high speed TDM transmission system for multimedia satellite communications," IEEE Fifth International Symposium on Spread Spectrum Techniques & Applications, pp.714-718
Kitahara H., A. Tsujihata, H. Tanaka, H. Kohata , "Japan's geostationary mobile communication test satellite (Phase A Study)", Second Ka Band Utilization Conference, pp.77-82
Kitao S., H. Nakaguro, R. Yonezawa, H. Mizutamari, A. Akaishi , "A consideration on Ka-band active phased array antenna for gigabit satellite," 17th AIAA International Communications Satellite Systems Conference, pp.270-278
Kobayashi M., K. Araki, M. Nakayama, K. Nidaira, H. Nakashima , "Satellite communication system for interactive multimedia network and its performance," 17th AIAA International Communications Satellite Systems Conference, pp.368-375
Murase K., M. Doi, K. Fukuda, A. Okuyama, N. Hosono , "Superbird-C communications satellite system," 17th AIAA International Communications Satellite Systems Conference, pp.209-215
Nakayama M., K. Ohata, T. Otsu, H. Kazama, K. Araki , "Portable interactive multimedia satellite communication system," 49th International Astronautical Congress, IAF-98-M.2.07
Ohira T., Y. Suzuki, H. Ogawa, H. Kamitsuna , "Megalithic microwave signal processing for phased-array beamforming and steering," IEEE Transactions on Microwave Theory and Techniques, Vol.45, No.12, pp.2324-2332
Otsu T., K. Okada, Y. Furuno, M. Minomo , "Ka band satellite communication systems operating through NTT's communication satellite N-STAR," Third Ka Band Utilization Conference, pp.75-82
Suzuki S., M. Amano, M. Nakazawa , "Ka-band transponder engineering model development result for DRTS ," Fourth Ka Band Utilization Conference, pp.531-538
Yoshimura N., T. Takahashi, A. Saifuddin, N. Kadowaki , "156 Mbps ATM transmission experiment using N-STAR" 17th AIAA International Communications Satellite Systems Conference, pp.288-293
Watanabe M., J. Mitsugi, A. Miyasaka, M. Shimizu , "Large Space Antenna Structural Design Technology Status," 49th International Astronautical Congress, IAF-98-I.1.01
Araki, N. and H. Shinonaga , "Time-dependent GES assignment method for non-GSO satellite systems", Trans. IEICE Commun., vol.E80-B, 1, pp.87-92
Araki, N., H. Ishikawa, Y. Mizuguchi and H. Kobayashi [1998 a], "Application of Ku-band USAT system to interactive multimedia services", Proceedings of 17th AIAA, pp.557-563
Araki, N., K. Minamisono and H. Shinonaga [1998b], "Interference simulation tool for non-GSO/MSS systems", Proceedings of 49th IAF Congress, p.41
Ishikawa, H., H. Shinonaga and H. Kobayashi , "Position determination method for personal satellite communication systems using non-geostationary satellites", 2nd APCC, vol.2, pp.838-842
Ishikawa, H., H. Shinonaga and H. Kobayashi , "Ambiguity removal technique for user position determination method in non-geostationary satellite system", IEE 5th International Conference on Satellite for Mobile Communications and Navigation (SSMCN), No.424, pp.160-163
Ishikawa, H., H. Shinonaga and H. Kobayashi , "Ambiguity removal technique for user position determination in non-geostationary satellite communications systems", Trans. IEICE B-II, vol.J81-B-II, 8, pp.773-780 (in Japanese)
Konishi, S., T. Mizuike, Y. Kishi and Y. Watanabe [1997a], "Flexible transmission bandwidth management with effective channel reservation techniques for NGSO MSS networks", IEEE JSAC, vol.15, 7, pp.1197-1207
Konishi, S., T. Mizuike and Y. Kishi [1997b], "A flexible channel assignment method and effective GOS control techniques for NGSO MSS systems", IEEE ICUPC, vol.1, pp.326-331
Aikawa, S., S. Uwano, Y. Nakayama, S. Kurosaki, H.Matsue , "Desing and performance of TDMA based radio component for ATM wireless access (AWA) prototype", IEEE ICC98, pp 2229-2233
Kagami,O., K. Watanabe, T. Yoshida , "Broadband space diversity for digital microwave radio systems" IEICE Trans. Commun., vol.E81-B, no.1, pp82-88
Mochizuki et. Al , "A High Performance Frequency and Timing Synchronization Technique for OFDM", IEEE Globecom 98
Matusmoto et.al , "OFDM Subchannel Space-Combining Transmission Diversity for Broadband Wireless Communication Systems"ICUPC'98
Takanashi et. al., "Enhanced capture effect for slotted ALDHA employing Transmission power control corresponding to offered traffic", IEEE ICC'98
Umehira,M, A.Hashimoto, H.Matsue, M.Nakura , "A proposal of an ATM wireless access system for tetherless multimedia services", Mobile Networks and Applications, pp.335-347
Watanabe, K , "Estimation Method of route outage probability in non-regenerative repeater digital microwave radio systems", IEICE Trans. Commun., vol E81-B, no.1, pp89-95
Co-channel interference is one of the dominant factors for restricting the system capacity. Interference detection [Iochi, H. et al 1997] and interference cancellers [Murata, H.et al 1997] [Yoshino, H. et al 1997] were developed for improving the capacity.
Dynamic channel assignment (DCA) is also effective for efficient spectrum utilization. Reuse partitioning [Furukawa, H.et al 1996] and DCA with adaptive modulation [Ikeda, T. et al 1997]were proposed and evaluated. The number of the papers for adaptive phased array antenna is increasing. Examples are evaluation of CMA adaptive array [Nishimori, K.et al 1996] and array with co-channel interference canceller [Furukawa, H.et al 1998]. Investigations for CDMA technology are also increasing. Capacity was estimated [Ohno, K.et al 1996] and dynamic cell layout was proposed under non-uniform traffic distribution [Takeo, K. et al 1997]. As for baseband technologies, coherent demodulation IC was developed [Matsumoto, Y. et al 1996] and the quality of ADPCM speech CODEC algorithm was improved [Kubota, S.et al 1997].
Adachi, F. , "Error rate analysis of differentially encoded and detected 16APSK under Rician fading", IEEE Tran. on Veh. Tech., vol.45, 1, pp.1-11
Arai, H., N. Igi and H. Hanaoka , "Antenna-gain measurement of handheld terminals at 900 MHz", IEEE Trans. on Veh. Tech., vol.46, 3, pp.537-543
Denno, S. and Y. Saito , "High speed QVLMS(Quantized Variable-gain Least Mean Square)-MLSE(Maximum Likelihood Sequence Estimation) equalizer for mobile communications---", Trans. of IEICE, vol.J80-B-II, 1, pp.10-18
Furukawa, H. and Y. Akaiwa , "Self-organized reuse partitioning, a distributed dynamic channel assignment method in cellular system", Trans. of IEICE, vol.J79-B-II, 7, pp.363-370
Furukawa, H., Y. Kamio and H. Sasaoka , "Co-channel interference canceller using a CMA adaptive array antenna", Trans. of IEICE, vol.J81-B-II, 6, pp.565-574
Hamazumi, H., Y. Ito and H. Miyazawa , "Performance of frequency domain sub-band diversity combination technique for wide-band mobile radio reception---an application to OFDM (Orthogonal Frequency Division Multiplexing) reception---", Trans. of IEICE, vol.J80-B-II, 6, pp.466-474
Ikeda, T., S. Sampei and N. Morinaga , "Adaptive modulation with dynamic channel assignment (AMDCA) for TDMA microcellular systems", Trans. of IEICE, vol.J-80-B-II, pp.162-170
Iochi, H. and Y. Akaiwa , "Co-channel interference measuring methods for digital mobile communications", Trans. of IEICE, vol.J80-B-II, 1, pp.10-17
Karasawa, Y., T. Kuroda and H. Iwai , "Cycle slip in clock recovery on frequency-selective fading channels", IEEE Trans. on Com. Soc., vol.45, 3, pp.376-383
Kubota, S., A. Dobashi, M. Suzuki, T.Hasumi and S. Kato , "Improved ADPCM voice signal transmission employing click-noise detection scheme for TDMA-TDD personal communication systems", IEEE Trans. on Veh. Tech., vol.46, 1, pp.108-113
Matsumoto, Y., S. Kubota and S. Kato , "High-performance coherent demodulator LSIC for wireless personal communications", IEEE Trans. on Veh. Tech., vol.45, 3, pp.475-483
Murata, H. and S. Yoshida , "Trellis-coded cochannel interference canceller for microcellular radio", IEEE Trans. on Com. Soc., vol.45, 9, pp.1088-1094
Nakamura, S. , "A study for errors caused by impulsive noise and a simple estimation method for digital mobile communications", IEEE Trans. on Veh. Tech., vol.45, 2, pp.310-317
Nishimori, K., N. Kikuma and N. Inagaki , "Performance analysis of CMA adaptive array for QAM signals", Trans. of IEICE, vol.J79-B-II, 12, pp.984-993
Ohno, K. and F. Adachi , "Reverse-link capacity and transmit power in a power-controlled cellular DS-CDMA system", Trans. of IEICE B-II, vol.J79-B-II, 1, pp17-25
Sakaida, H., F. Maehara and F. Takahata , "A demodulator for broad-band land mobile communications adopting 16 QAM modulation scheme", Trans of IEICE, vol.J79-B-II, 8, pp.431-440
Sawahashi, M. and F. Adachi , "Experimental evaluation of 96 multicarrier 16 QAM radio transmission using pilot symbol-assisted coherent detection", Trans. of IEICE, vol.J80-B-II, 8, pp.663-674
Shimizu, M., N. Aoki, K. Shirakawa, Y. Tozawa, N. Okubo and Y. Daido , "New method of analyzing BER performance of GFSK with postdetection filtering", IEEE Trans. on Com. Soc., vol.45, 4, pp.429-436
Takeo, K. and S. Sato , "Dynamic cell configuration for CDMA microcell mobile radio communication systems considering non-uniform traffic distribution", Trans. of IEICE, vol.J80-B-II, 7, pp.565-577
Taromaru, M, T. Konishi and H. Koga , "A diversity combining system with phase- baseband signals using maximum likelihood decision", Trans. of IEICE, vol.J80-B-II, 4, pp.307-313
Yoshino, H., K. Fukawa and H. Suzuki , "Interference canceling equalizer (ICE) for mobile radio communication", IEEE Trans. on Veh. Tech., vol.46, 4, pp.849-861
Other very high-speed or large capacity transmission experiments were successfully performed and the technical feasibility was tested. 1.04-Tbit/s DWDM transmission experiment based on alternative-polarization 80-Gbit/s OTDM signals was successfully performed [Y. Miyamoto et al., 1998]. The highest rate optical time-division multiplexing (200 Gbit/s/ch) being combined with a wideband wavelength-division multiplexing (30 nm) was tested to show the availability of terabit transmission capacity through a 50 km of dispersion-shifted fiber [S. Kawanishi et al., 1998].
The architecture of the future photonic network that is bandwidth abundant and enables reliable communication has been elucidated [M. Koga, et al., 1998] [K. Sato, 1998]. Network Node Interface technologies and network protection and restoration strategies have been developed [S. Okamoto, et al., 1998]. The IP backbone network based on optical path technologies is demonstrated and necessary technologies have been developed.
A novel dispersion slope compensating fiber was proposed [T. Tsuda et al., 1998]. A novel bi-directional optical amplifier was developed and a dense-WDM optically repeated transmission experiment was demonstrated in the zero-dispersion region employing the bi-directional optical amplifiers. These techniques are very useful to up-grade the existing optical transmission systems by applying broadband WDM or high bit-rate TDM schemes [T. Sato et al., 1998a,b].
Hagimoto, K., M. Yoneyama, A. Sano, A. Hirano, T. Kataoka, T. Otsuji, K. Sato, and K. Imajuku, W., and A. Takada , "Error-free operation of in-line phase-sensitive amplifier," Electron. Lett., vol.34, no.17, pp.1673-1674.
Kawanishi, S., H. Takara, K. Uchiyama, I. Shake, O. Kamatani, and H. Takahashi , "1.4Tbit/s (200Gbit/s x 7ch) 50 km optical transmission experiment," Electron. Lett., vol.33, no.20, pp.1716-1717.
Koga, M., A. Watanabe, T. Kawai, K. Sato and Y. Ohmori , "Large-capacity optical path cross-connect system for WDM photonic transport network," J-SAC, vol.16, No.7, pp.1260-1269.
Noguchi , "Limitations and challenges of single-carrier full40-Gbit/s repeater system based on optical equalization and new circuit design", OFC'97 Technical digest, ThC1, pp.242-243.
Miyamoto, Y., K. Yonenaga, A. Hirano, N. Shimizu, M. Yoneyama, H. Takara, K. Noguchi, and K. Tsuzuki , "1.04-Tbit/s DWDM transmission experiment based on alternative-polarization 80-Gbit/s OTDM signals", ECOC'98, Post deadline paper, vol.3, pp.55-57.
Mori, K., H. Takara, S. Kawanishi, M. Saruwatari , and T. Morioka: "Flatly broadened supercontinuum spectrum generated in a dispersion decreasing fiber with convex dispersion profile," Electron. Lett., vol.33, no.21, pp.1806-1808.
Okamoto, S. , "Photonic transport network architecture and OA&M technologies to create large-scale robust networks," J-SAC, vol.16, No.7, pp.995-1007.
Sato, K. , "Introduction strategy of photonic network technologies to create bandwidth abundant multimedia networks," Trends in Optics and Photonics; Optical Society of America, vol.20, pp.9-17.
Sato, T., and T. Horiguchi [1998a], "A novel bi-directional optical amplifier using AWGs for dense-WDM systems", Proceeding of ECOC'98, vol.1, pp.635-636.
Sato, T., and T. Horiguchi [1998b], "A novel dense-WDM optically repeated transmission system in the zero-dispersion region employing bi-directional USCA, FWM induced conjugate light filtering and a bi-directional optical Amplifier", Proceeding of ECOC'98, vol.3, pp.151-153.
Takara, H., S. Kawanishi, A. Yokoo, S. Tomaru, T. Kitoh, M. Saruwatari , "100 Gbit/s optical signal eye-diagram measurement with optical sampling using organic nonlinear optical crystal," Electron. Lett., vol.32, no.24, pp.2256-2258.
Tsuda, T., Y. Akasaka, S. Sentsui, K. Aiso, Y. Suzuki and T. Kamiya , "Broad band dispersion slope compensation of dispersion shifted fiber using negative slope fiber", Proceeding of ECOC'98, vol.1, pp.233-234.
Yonenaga, K., A. Hirano, M. Yoneyama, Y. Miyamoto, K. Hagimoto, and K. Noguchi, "Expansion of tolerable dispersion range in a 40 Gbit/s optical transmission system using an optical duobianry signal", Electron. Lett. Vol.34, pp.385-386.
In anticipation of these trends, technologies necessary for the 21st century have been analyzed [Aoki, 1997; Okada, 1998; Kano, 1998], and a new type of multimedia society, called the Electrum Cyber Society (ECS), has been proposed [Yamashita, M., 1998]. It will allow people to obtain instantaneously any information from around the world and immediately communicate and perform most human activities including social and business ones. To support the creation of ECS or multimedia applications, studies have been made from the following viewpoints.
Network middleware has been established for easier development of new advanced multimedia/ECS services and easier porting of existing IP-based applications over high-speed broadband networks [Koyanagi, 1997a; Koyanagi, 1997b, Kondo, 1997, Yamaguchi, H., 1997; Ushijima, 1998; Watanabe, 1998]. Also, a multimedia solution business environment using high-speed photonic networks has been established [Ono, 1998]. Several large-scale open IP networks have begun commercial services and obtained a larger number of customers [Matsuki, 1998]. For the efficient use of the multimedia network, traffic control schemes appropriate for multimedia communication have been studied [Mase, 1997; Mase, 1998].
ATM technology is still playing an important role in forming the network infrastructure, and a wide variety of ATM studies have been reported concerning the construction and deployment of a large-scale ATM network [Asano, 1997; Ohnishi, 1998], ATM-based application trials [Tsuboi, 1996; Yamaguchi, R., 1998], larger-scale ATM switches using advanced electronic or photonic elements [Yamanaka, 1997; Genda, 1997; Oki, 1998; Urushidani, 1998; Urushidani, 1999], traffic evaluation [Kamado, 1998], bandwidth management [Shiomoto, 1998], ATM signalling [Sunaga, 1998a], voice handling over an ATM network [Sunaga, 1999a], and a future ATM switching architecture [Yamanaka, 1998].
To convey such various traffic, there have been advances in xDSL access methods [Narumiya, 1999], optical access networks [Yamashita, I., 1996; Harikae, 1998], ATM-based radio access networks [Umehira, 1996; Umehira, 1998], and the transmission network [Matsuoka, 1999; Toba, 1999; Kawanishi, 1999]. A new node architecture appropriate for handling various kinds of media has been developed [Suzuki, 1996; Suzuki, 1997a], and advanced software technologies [Sunaga, 1997; Sunaga, 1998b; Sunaga, 1998c; Sunaga, 1999] and systems management [Sato, 1996; Kaihara, 1998] have beenreported. Also, advanced intelligent network (AIN) technologies, which are indispensable for service enhancement, have been actively studied, developed, and deployed into the commercial network [Sakurai, 1996; Kawarasaki, 1997; Hanazawa, 1998a; Hirano, 1998; Hanazawa, 1998b].
Based on the above technologies, a new network architecture appropriate for the future multimedia communication network has been studied [Suzuki, 1997b; Inoue, 1998].
Aoki, T ., "Innovative research and development towards the 21st century", ITU Telecom Interactive 97
Asano, S., S. Abe, S. Suzuki, and K. Miyake , "High-speed ATM backbone for academic information network in Japan", IEEE, ISS'97
Genda, K., N. Yamanaka , "TORAS : Terabit-per-second ATM switching system architecture based on distributed internal speed-up ATM switch", IEEE Jornal of Selected Areas in Communications, SAC-15, No.5, pp. 817-829
Hanazawa, T. [1998a], "NTT's intelligent network today and tomorrow", ICIN'98
Hanazawa T., A.Miura, E.Takemori, N.Takahashi, H.Imagawa [1998b], "Implementation of advanced intelligent network system at NTT and its future development", IEEE, GLOBECOM'98
Harikae, K., and Y. Shibata ,"New optical access system (pai-system)", NTT Review, Vol.10, No.2, pp. 69-76
Hirano, M., H. Sakurai, H. Imagawa, and Y. Kinouchi , "Inter-module connection of the distributed processing service control nodes in the advanced intelligent network", Trans. of IEICE, vol.J81-B-I, no.8, pp519-530 (In Japanese)
Inoue, Y., D. Chuha, H. Berndt ,"The TINA consortium", IEEE Communication Magazine, Vol.36. No.9, PP.130-136
Ito, N., and K. Yoshimura , "Trends of iInterconnection business in Japan and interface technology", NTT Review, Vol.10, No.4, pp.80-84
Kaihara. M., N. Ikeuchi, M. Makino and T. Adachi , "An operation system strategy for next-generation computer networks & services", NTT Review, Vol.10, No.4, pp.132-139
Kamado, Y., and K. Miyake 1998],"A measured-traffic-based bandwidth dimensioning method for Internet ATM backbone networks", IEICE, Trans., vol. E81-B, no.2, pp.449 - 458
Kano, S. , "The telecommunications market in Japan: entering the digital era and the second phase of competition", IEEE Communication Magazine, Vol 36, No.11, pp.38-44
Kawanishi, S., Y. Miyamoto, M. Asobe, and A. Takada , "Trends of terabit/s optical transmission Technology", NTT R&D, Vol.48, No.1, pp.81-88
Kawarasaki, K, T. Kishida, J. Akiba, A. Miura , "Issues of advanced intelligent network in ATM network," IEEE, ISS'97
Kondo, H., K. Hagishima, H. Hamada, and M. Kihara , "Proposal of GMN-2 (global mega-media network-2) for guaranteeing QoS on multimedia applications", IEICE, APCC '97, Sydney
Koyanagi, K., T. Saito, T. Kanada, K. Kitami[1997a], "Technology initiatives for the near future in internetworking" , IEEE Communication Magazine, Vol 35, No.5, PP 108-113
Koyanagi, K., T. Terayama, T. Adachi, and H. Sugioka [1997b], "Interworking technologies for GMN-1 (global mega-media network-1)", IEICE, APCC '97, Sydney
Koyanagi, K., H. Sunaga, T.Yamada, and M.Ikeda , "Applicability Evaluation of Service feature Enhancement Using Plug-in Modification Technique", IEICE, Trans. Commun., vol. E81-B, no.1, pp.58-65
Mase, K., and H. Kimura , "Quality of service issues in communication networks", Trans. of IEICE, Vol. J80-B-1, No.6, pp. 283-295, (In Japanese)
Mase, K., and H. Yamamoto, "Quality and traffic management in multimedia era", NTT Review, Vol.10, No.2
Matsuki, Y., "Actual operation state related to traffic and quality in OCN", NTT Review, Vol.10, No.2, pp.40-43
Matsuoka, S., and T. Yamamura , "Very-high-speed ring network in transmission networks: ADM 10G ring system", NTT R&D, Vol.48, No.1, pp.27-32
Narumiya, K , "Consideration of ADSL Service under NTT's Network", IEEE Communication Magazine, Vol.37, No.3
Ohnishi, H., and K. Miyake , "Issues in ATM network service development, standardization and deployment", IEICE, Trans., vol.E81-B, no.2, pp.152-163
Okada, T., and K. Narumiya , "From telecommunications to information distribution", NTT Review, Vol.10, No.5, pp.34-39
Oki, E., and N. Yamanaka , "A High-speed tandem-crosspoint ATM switch architecture with input and output buffers", IEICE Transactions on Communications, Vol.E81-B, No.2, pp.215-223
Ono, N. , "Overview of the PHOENIX project", NTT Review, Vol. 10, No. 4, pp.42-46
Sakai, N., and F. Endo, "Development of new service in telecommunication and ISDN for a new era", NTT Review, Vol.10, No.2, pp.10-13
Sakurai, H., M. Ito, M. Hirano, and H.Imagawa , "Inter-module connections in distributed-processing service control points in the advanced intelligent network and testing of associated hardware", ICIN '96
Sato, K. , "Photonic transport network OAM technologies", IEEE Communication Magazine, Vol.34, No.12, pp.86-94
Shiomoto, K., S. Chaki and N. Yamanaka , "A simple bandwidth management strategy based on measurements of instantaneous VP utilization in ATM network", IEEE/ACM Transactions on Networking, Vol.6, No.5, pp.625-634
Sunaga, H., M. Furukawa, and K. Nishikawara , "Increased software reusability in a communication switching platform based on object-oriented design", IEICE Trans., vol.E80-B, no.9, pp. 1300-1310
Sunaga, H., T. Ohba [1998a], "ATM internode signalling processing for a multimedia network", IEICE, Trans., vol.E81-B, no.3, pp.537-544
Sunaga, H., H. Matsumura, T. Hayashi, and K. Nishikawara [1998b], "Automatic code production of office data handling programs for switching systems", IEICE Trans., vol.E81-B, no.10, pp.1831-1839
Sunaga, H., T. Yamada, K. Nishikawara, and T. Murakami [1998c], "Evaluation of software development productivity and analysis of productivity improvement methods for switching systems", IEICE Trans., vol.E81-B, no.12, pp. 2519-2527
Sunaga, H., T. Okutani, K. Miyake [1999a], "Large-scale VTOA switching node architecture", IEICE, Trans., vol.E82-B, no.1, pp.70-80
Sunaga, H., R. Nakamura, and T. Yamada [1999b], "Evaluation of 'Plug-in' partial file modification mechanisms for node systems ", IEICE Trans., vol.E82-B, no.3
Suzuki, S. , "NS8000 series: The next-generation switching systems," NTT Review, Vol.8, No.3
Suzuki, S. [1997a], and H. Ishikawa, "The NS8000 series and multimedia-era networks", NTT Review, Vol.9, No.1
Suzuki, S., S. Yamada, M. Kubota, I. Kogiku and M. Matsuo [1997b], "DONA: distributed object-oriented network architecture for revolutionary network construction", IEEE, International Switching Symposium (ISS) '97, pp.459-465
Toba, H., Y. Miyamoto, M. Yoneyama, S. Kawanishi, Y. Yamabayashi , "Next-generation ultra-high-speed transmission technologies", NTT R&D, Vol.48, No.1, pp.33-42
Tsuboi, T., T.Fujii, S. Ono, H. Uematsu and T. Hoshino , "Super high definition-based on-line medical system over the ATM transport network", ISSLS '96, pp.62-67, Melbourne
Umehira, M., et al. , "ATM wireless access for mobile multimedia: concept and architecture", IEEE Personal Communications Magazine, Vol.3, No.5, pp.39-48
Umehira, M., Hideaki Matsue and Takehiro Murase, "Development of a prototype ATM wireless access system for nomadic multimedia services: concept and architecture", NTT Review, Vol.10, No.5, pp.34-39
Urushidani, S., S. Hino, Y. Ohtomo, and S. Yasuda , "A high-performance multicast switch and its feasibility study", IEICE, Trans., vol.E81-B, no.2, pp.284 -296
Urushidani, S., M. Yamaguchi, and T. Yamamoto , "A high-performance Switch architecture for free-space photonic switching systems", IEICE, Trans., vol.E82-B, no.2
Ushijima, S., H. Ichikawa, K. Noritake, and N. Watanabe , "Scalable Internet backbone using multi-gigabit ATM-based connectionless switching", IEICE Trans. Commun., vol.E81-B, No.2
Yamaguchi, H , "Strategy to global mega-media network (GMN)", IEICE, APCC '97, Sydney
Yamaguchi, R., N. Kondo, R. Nomura and S. Watanabe , "Asian multimedia forum trials", NTT Review, Vol.10, No.4, pp.38-41
Yamanaka, N, S. Yasukawa, E. Oki, T. Kurimoto , "OPTIMA: Tb/s ATM switching system architecture", IEEE, ISS'97, Session 16
Yamanaka, N , "Breakthrough technologies for the high-performance electrical ATM switching system", IEEE Journal of Lightwave Technology, Vol.16, No.12, pp.2181-2190
Yamashita, I , "The latest FTTH technologies for full service access networks", IEEE Asia Pacific Conference on Circuit and System, pp.263-268
Yamashita, M , "Multimedia technology", NTT Review, Vol.10, No.4, pp.66-72
Watanabe, N., H. Ichikawa, J. Aramomi, M. Tanikawa, H. Hara, S. Kato, H. Kitazume, and J. Maruyama , "Backbone network architecture for the next-generation computer networks", NTT Review, Vol.10, No.4, pp.121-131
Interference between conventional analogue FM signals and ISDB digital signals has been investigated to implement 12 GHz band ISDB system. The study proved to be in conformity with the criteria of the WARC-BS and it had compatible service continuity with the conventional FM television [Saito et al., 1996].
Multimedia broadcasting by ISDB has been expected to achieve interactive viewing and to raise individual viewer satisfaction. ISDB will also make it possible to set up multiple small-scale broadcasting stations and to provide a many-to-many information linking environment for transmitting information between an unspecified number of individuals [Kawai et al., 1996].
The transmission system for satellite ISDB must have high spectrum efficiency, continuous service availability and also superior flexibility in its transmission scheme. A hierarchical transmission technique and a newly proposed TMCC (Transmission and Multiplexing Configuration Control) signal have been employed [Katoh et al., 1996].
One requirement of a terrestrial ISDB system is the efficient allocation of frequencies using an SFN (Single Frequency Network). The SFN incorporates the great advantages of OFDM, which has excellent performance under multi-path conditions [Nakahara et al., 1996].
An interactive multimedia system consists of (1) a video server, to store the HDTV images of the fine arts, which have been shot from various paths around the fine arts at 0.2 degree intervals; (2) a specially designed manipulator to select a desired image from the server; and (3) an HDTV or stereoscopic HDTV display, and accompanying spectacles [Mitsumine et al., 1996].
Stable HDTV picture have been experimentally reproduced on a compact display using the new panel and pulse memory drive circuits. The peak white luminance is 150 cd/m2. The lifetime of 40-inch panel is expected to be over 30,000 hours, judging from the results obtained using a medium-sized panel under the same conditions [Seki et al.,1996].
The handy New Super-HARP color camera which uses this newly-developed pickup tube has higher sensitivity than human vision (11 lux,F8), negligibly low lag, and a limiting resolution of over 700 TV lines. It will be a powerful tool in emergency news gathering at night, the production of scientific programs, and other applications [Kubota et al., 1996].
A mobile SNG (Satellite News Gathering) RF terminal that transmits TV programs from a ship or a vehicle to a broadcasting center in real time via a communications satellite has been proposed. It consists of a transmitter using beam steering flat antenna with16 subarrays and of a turntable and pitch-roll stabilizer for mechanical tracking [Mitsumoto et al., 1996].
A prototype DVS system can realize virtual shooting where two prerecorded actors are performing in virtual sets generated by real-time computer graphics. The DVS system is applied to Desktop Program Production (DTPP) [Hayashi et al., 1996].
A portable real-time speech rate conversion system slows the input speech rate in order to compensate for the degeneration of hearing intelligibility of elder listeners. The portable system, which can be installed in a receiver, enables the listener to convert the speech rate directly as desired in real time with invariance in pitch as well as small impairments in quality [Nakamura et al., 1996].
A key technique of the system for a new digital satellite broadcasting service is hierarchical modulation, in which multiple modulation schemes can be applied simultaneously. The information bit rate of 52 Mbps is obtained in one satellite channel by applying TC8PSK (Trellis-Coded eight PSK) [Saito et al., 1996].
(T. Nomoto )
Hayashi, M., K. Enami et al. , Desktop virtual studio system, IEEE Trans. on broadcasting 42, 3, 278-284
Katoh, H., A. Hashimoto et al. , A flexible transmission technique for the satellite ISDB system, IEEE Trans. on broadcasting 42, 3, 159-166
Katoh, T., T. Yamamoto et al. , Improved 40-inch plasma display for wall-hanging HDTV Receiver, IEEE Trans. on broadcasting 42, 3, 208-214
Kawai, N., S. Namba et al. , Performance of multimedia broadcasting through ISDB transmission System, IEEE Trans. on broadcasting 42, 3, 151-158
Kubota, M., T. Kato et al. , Ultrahigh-sensitive new super-HARP camera, IEEE Trans. on broadcasting 42, 3, 251-258
Mitsumine, H., H. Noguchi et al. , Virtual Museum - 3-D fine art appreciation system, IEEE Trans. on broadcasting 42, 3, 200-207
Mitsumoto, H., T. Murata et al. , A mobile satellite news gathering system using a flat antenna, IEEE Trans. on broadcasting 42, 3, 272-277
Nakahara, S., S. Moriyama et al. , Efficient use of frequencies in terrestrial ISDB system, IEEE Trans. on broadcasting 42, 3, 173-178
Nakamura, A., N. Seiyama , A new approach to compensate degeneration speech intelligibility for elder listeners - Development of a portable real time speech rate conversion system, IEEE Trans. on broadcasting 42, 3, 285-293
Saito, T., A. Hashimoto et al. , Transmission system for satellite ISDB, 1998 IEEE Global Communications Conference Records,.5 of 6, 2942-2947
Saito, T., and H. Katoh , ISDB(Integrated Services Digital Broadcasting) transmission system based on protection ratio study, AIAA 16th ICSSC, AIAA-96-1083, 832-840