In this paper a different view on Viterbi's method for the estimation of the reverse link capacity of a single cell of CDMA based mobile communications systems is given. Viterbi's approach is well-known and of great importance for the capacity estimation. However, the interpretation of Viterbi's result on the system capacity is not that clear. Thus, we introduce a new approach giving accurate reasons for Viterbi's capacity estimation. When neglecting the noise power, both methods provide nearly the same result. We conclude that Viterbi's finding relates to the average capacity, which is an important statistical parameter. However, we should note that this average capacity will be not available all the time. The improvements discussed in this paper focus on the specification of a certain reliability about the availability of the average capacity.

This paper describes the wafer-level, three-dimensional packaging for MEMS in which sensors, actuators, electronic circuits and other functions are combined together in one integrated block. Si wafers with built-in MEMS functions were integrated with no change in thickness to ensure mechanical strength and improve heat dissipation. In the entire process of three-dimensional integration, Si wafers were processed at temperatures below 400C to prevent degradation of their built-in functions. A description is made of the low-temperature oxidation technology developed by us, which makes through-holes of high density and high aspect ratio in Si wafers with built-in functions by the Optical Excitation Electropolishing Method (OEEM) and forms an oxide film on the hole walls simply by replacing electrolyte. Next, a description is presented of the bumpless interconnection method which fills through-holes of stacked layers with metal by the molten metal suction method and of the electrocapillary effect as a countermeasure to prevent the filler metal from dropping out of holes under its own weight.

Future electronic systems can not be built only with System-on-a-Chip (SoC), since many SoC issues have become evident. Relatively low yield due to the larger die size and the huge investment in developing the process to embed different kinds of technologies are some of the issues. Instead, superconnect technology is getting more important as a viable solution in building electronic systems. The superconnect connects separately built and tested chips not by the printed circuit board but rather directly to construct high-performance yet low-cost electronic systems and may use around 10 micron level design rules. System-in-a-Package and stacked chips using interposers are some realization of the superconnect. The superconnect will also be used to mitigate IR-drop problems and RC delay problems in global on-chip interconnect.

Deterministic execution testing has been considered a promising way for concurrent program testing because of its ability to replay a program's execution. Since, however, deterministic execution requires that a synchronization event sequence to be replayed be feasible and valid, it is not directly applicable to a situation in which synchronization sequences, being valid but infeasible, are taken into account. Resolving this problem is very important because a program may still meet its specification although the feasibility of all valid sequences is not satisfied. In this paper, we present a new approach to deterministic execution for testing concurrent systems. The proposed approach makes use of the notion of event independence and constructs an automation which accepts all the sequences semantically equivalent to a given event sequence to be replayed. Consequently, we can allow a program to be executed according to event sequences other than the given (possible infeasible) sequence if they can be accepted by the automation.

As a new category of the optical application system integrated with electronics, the opto-electronic information system (OEIS) is presented. Combination of the different characteristic technologies, optics and electronics, is expected to be useful for development of an effective and high-performance information systems. The properties of the optical technologies such as parallelism, high-speed, and large information capacity can be utilized for information processing. Even if some of the functions are emulated by the electronics, the optics give more effective solutions. To implement the OEIS, various optoelectronic devices and fabrication technologies are available including vertical cavity surface emitting lasers and spatial light modulators. There are two forms of system construction for the OEIS: an application of optics to an electronic-based system and the reversed form. As examples of the OEIS, the parallel matching architecture (PMA) and the thin observation module by bound optics (TOMBO) are presented. The PMA is an architecture of parallel computing system specified for global processing. This architecture shows a typical strategy to utilize the optical interconnection capability with flexibility of the electronic technology. The TOMBO presents possibility of morphological conversion using combination of the optical and electronic technologies. A compound-eye imaging system and post digital processing enable us to realize a very thin image capturing system. The issues related on development of the OEIS are proper usage of optics, effective fusion of the optical and electronic technologies, methodologies for system construction, fabrication supporting tools, and development of attractive demonstrators other than communication and interconnection fields.

In this article, a hierarchical classifier is proposed for classification of ground-cover types of a satellite image of Kangaroo Island, South Australia. The image contains seven ground-cover types, which are categorized into three groups using principal component analysis. The first group contains clouds only, the second consists of sea and cloud shadow over land, and the third contains land and three types of forest. The sea and shadow over land classes are classified with 99% accuracy using a network of threshold logic units. The land and forest classes are classified by multilayer perceptrons (MLPs) using texture features and intensity values. The average performance achieved by six trained MLPs is 91%. In order to improve the classification accuracy even further, the outputs of the six MLPs were combined using several committee machines. All committee machines achieved significant improvement in performance over the multilayer perceptron classifiers, with the best machine achieving over 92% correct classification.

The smart vision chip has a large potential for application in general purpose high speed image processing systems. In order to fabricate smart vision chips including photo detector compactly, we have proposed the application of three dimensional LSI technology for smart vision chips. Three dimensional technology has great potential to realize new biologically inspired systems inspired by not only the biological function but also the biological structure. In this paper, we describe our three dimensional LSI technology for biologically inspired circuits and the design of smart vision chips.

A digital noncoherent demodulation scheme is presented for reception of Gaussian frequency shift keying (GFSK) signals with small modulation index. The proposed differential demodulator utilizes oversampled signals to estimate the symbol timing and to compensate the frequency offset. The performance of the proposed receiver is evaluated in terms of the bit-error rate (BER). Numerical results show that the proposed demodulator provides performance comparable to that of conventional baseband differential demodulator, while significantly reducing the implementation complexity suitable for single chip integration with direct conversion radio frequency module. Finally the performance of the proposed receiver is improved by adding a simple decision feedback module.

This paper describes the adaptability of communication software through a biologically-inspired policy coordination. Many research efforts have developed adaptable systems that allow various users or applications to meet their specific requirements by configuring different design and optimization policies. Navigating through many policies manually, however, is tedious and error-prone. Developers face the significant manual and ad-hoc work of engineering an system. In contrast, we propose to provide autonomous adaptability in communication endsystem with OpenWebServer/iNexus, which is both a web server and an object-oriented framework to tailer various web services and applications. The OpenWebServer's modular architecture allows to abstract and maintain a wide range of aspects in a HTTP server, and reconfigure the system by adding, deleting, changing, or replacing their policies. iNexus is a tool for automated policy-based management of OpenWebServer. Its design is inspired by the natural immune system, particularly immune network, a truly autonomous decentralized system. iNexus inspects the current system condition of OpenWebServer periodically, measures the delivered quality of service, and selects suitable set of policies to reconfigure the system dynamically by relaxing constraints between them. The policy coordination process is performed through decentralized interactions among policies without a single point of control, as the natural immune system does. This paper discusses communication software can evolve continuously in the piecemeal way with biological concepts and mechanisms, adapting itself to ever-changing environment.

Synthetic aperture radar interferometry have been established in the past two decades, and used extensively for many applications including topographic mapping of terrain and surface deformation. Vegetation analysis is also a growing area of its application. In this paper, we propose an polarimetric SAR interferometry technique for interferometric phase extraction of each local scatterer. The estimated position of local scattering centers has an important information for effective tree height estimation of forest. The proposed method formulated for local scattering center extraction is based on the ESPRIT algorithm which is known for high-resolution capability of closely located incident waves. The method shows high-resolution performance when local scattered waves are uncorrelated and have different polarization characteristics. Using the method, the number of dominant local scattering centers and interferometric phases in each image pixel can be estimated directly. Validity of the algorithm is demonstrated by using examples derived from SIR-C data.

We present iterative round-robin matching for an input and output buffered switch with multiple switching planes. The suggested algorithm is based on iSLIP and consists of request, grant and accept steps. The pointer update scheme of iSLIP is altered in the suggested algorithm to enhance the switch performance. Simulation results under Bernoulli traffic show the suggested algorithm is more appropriate than iSLIP for cell scheduling of input and output buffered switches.

This paper presents a novel approach to water pollution detection from remotely sensed low-platform mounted visible band camera images. We examine the feasibility of unsupervised segmentation for slick (oily spills on the water surface) region labelling. Adaptive and non adaptive filtering is combined with density modeling of the obtained textural features. A particular effort is concentrated on the textural feature extraction from raw intensity images using filter banks and adaptive feature extraction from the obtained output coefficients. Segmentation in the extracted feature space is achieved using Gaussian mixture models (GMM).

The reflection signal in the inverse synthetic aperture radar is measured in the polar coordinate defined by the object rotation angle and the frequency. The reconstruction of fixed scene images requires the coordinate transformation of the polar format data into the rectangular spatial frequency domain, which is then processed by the inverse Fourier transform. In this paper a fast and flexible method of coordinate transformation based on the nearest neighbor interpolation utilizing the Delauney triangulation is at first presented. Then, the induced errors in the transformed rectangular spatial frequency data and the resultant fixed scene images are investigated by simulation under the uniform plane wave transmit-receive mode over the swept frequency 120-160 GHz, and the results which demonstrate the validity of the current coordinate transformation are presented.

This paper presents methods for estimating the ocean wavelength in satellite altimetry and discusses the possibility of detecting the ocean wavelength. Numerical analyses show that there exists a relation between the significant wavelength and the pulse-to-pulse correlation coefficient. Presented methods are based on processing the data of existing satellite altimeters. Accordingly, we will be able to propose a method for measuring the wavelength without a large change in existing altimetry system.

A mesh-connected processor array consists of many similar processing elements (PEs), which can be executed in both parallel and pipeline processing. For the implementation of an array of large numbers of processors, it is necessary to consider some fault tolerant issues to enhance the (fabrication-time) yield and the (run-time) reliability. In this paper, we introduce the 1(1/2)-track switch torus array by changing the connections in 1(1/2)-track switch mesh array, and we apply our approximate reconfiguration algorithm to the torus array. We describe the reconfiguration strategy for the 1(1/2)-track switch torus array and its realization using WSI, especially 3-dimensional realization. A hardware realization of the algorithm is proposed and simulation results about the array reliability are shown. These imply that a self-reconfigurable system with no host computer can be realized using our method, hence our method is effective in enhancing the run-time reliability as well as the fabrication-time yield of processor arrays.

In this paper, the sequence interference suppression characteristics of code-diversity DS/CDMA over multipath fading channels are presented. In a code-diversity system, the data signal is modulated with several PN sequences, and using these sequences at the receiver, diversity reception of the signal is carried out to suppress the influence of multiple access interference (MAI) or sequence interference (SI) especially under a near-far problem. First, in a sequence interference and AWGN environment, the basic performance of code-diversity system is presented. Next, in single-path (flat-fading) and multipath fading channels, the average BER performance of the code-diversity system is shown and the observation that the performance of code-diversity system (combined with RAKE reception) is more effective over a multipath fading channel is clarified. Finally, it is presented that by implementing adaptive weight control (AWC) for the code-diversity system over fading channels, the BER performance can further be improved.

As the network speed becomes faster and requirements about various services are increased, a number of groups are currently developing technologies aimed at evolving and enhancing the capabilities of existing network. A Next-Generation Network (NGN) is defined as a hybrid telecommunications network that employs new distributed processing techniques to provide all types of services. By integrating the Intelligent Network (IN) technology and the Mobile Agent (MA) technology we can support service flexibility and service portability in NGN. In this paper, we propose a caching-based mobile agent model for NGN and analyze the performance of this model. The mobile agent technology increases the service portability and the caching strategy does the service reusability. Each Physical Entity (PE) has MAs within their repository through the caching strategy and processes service requests from users without the control of the central system such as Service Control Point (SCP). Therefore, we can decrease the total network load and the response time for user requests.

Antialiased is one of challenging problems to be solved for the high fidelity image synthesis in 3D graphics. In this paper a rasterization processor which is capable of single-pass full-screen antialiasing is presented. To implement a H/W accelerated single-pass antialiased rasterization processor at the reasonable H/W cost and minimized processing performance degradation, our work is mainly focused on the efficient H/W implementation of a modified version of the A-buffer algorithm. For the efficient handling of partial-pixel fragments of the rasterization phase, a new partial-pixel-merging scheme and a simple and efficient new dynamic memory management scheme are proposed. For the final blending of partial-pixels without loss of generality, a parallel subpixel blender is introduced. To study the feasibility of the proposed rasterization processor as a practical rasterization processor, a prototype processor has been designed using a 0.35 µm EML technology. It operates 100 MHz @3.3 V and has the rendering performance from 25M to 80M pixel-fragments/sec depending on the scene complexity.

This study is intended to realize an in-situ gas sensor based upon the principle of millimeter/submillimeter wave spectroscopy. In-situ gas sensor will be attractive because of gas selectivity, multiple parametric measurement such as gas temperature, pressure and density, and of the in-situ measurement capability. One of the major technical problem to be solved is to develop an instrument accurate enough to discern the spectrum change due to the variation of parameters such as temperature. In this paper a proposed gas absorption measurement system is investigated, which schematically consists of Fabry-Perot type gas cell for effective long path length, and vector signal processing to reject leak signal coupled between resonator input and output ports so as to achieve precise absorption measurement. Also included is an parametric study of oxygen absorption characteristics, which is served as the predicted value in the evaluation of the instrument. The experiment at 60 GHz and 120 GHz bands using oxygen demonstrates the effectiveness of the current system configuration.

This paper evaluates the effect of inter-sector diversity with maximal ratio combining (MRC) coupled with coherent Rake combining and 2-branch antenna diversity reception in the transmit-power-controlled wideband direct sequence code division multiple access (W-CDMA) reverse link. We first elucidate based on laboratory experiments that the required average transmit signal energy per bit-to-background noise spectrum density ratio (Eb/N0) at the average bit error rate (BER) of 10-3 with inter-sector diversity using two sectors is decreased by approximately 1.4, 1.0, and 0.2 dB compared to that with inter-cell site diversity using two cell sites with antenna diversity reception due to the superiority of MRC to selection combining (SC), when the difference in the average path loss between a base station (BS) and a mobile station (MS) is Δ12 = 0, 3, and 6 dB, respectively. We also clarify in actual field experiments that the inter-sector diversity associated with Rake time diversity and antenna diversity further decreases the required average transmit power of a MS if the number of resolved paths is small such as 1 or 2 in each sector reception, even when the fading correlation between sectors is relatively large. Furthermore, we show that the required average transmit power of a MS for satisfying the average BER of 10-3 with inter-sector diversity is decreased above approximately 2.0-2.5 dB compared to that with one-sector reception, owing to the significantly increased inter-sector diversity effect in addition to the Rake time diversity and antenna diversity, when the fading correlation averaged over the measurement course is approximately 0.7.