Several grammars of which generative power is between context-free grammar and context-sensitive grammar were proposed. Among them are macro grammar and tree adjoining grammar. Multiple context-free grammar is also a natural extension of context-free grammars, and is known to be stronger in its generative power than tree adjoining grammar and yet to be recognizable in polynomial time. In this paper, the generative power of several subclasses of variable-linear macro grammars and that of multiple context-free grammars are compared in details.

Accurate estimating or measuring the intake manifold absolute pressure plays an important role in automobile engine control. In order to achieve the real-time estimation of the absolute pressure, the high accuracy and high speed processing ability are required for automobile engine control systems. Therefore, in this paper, an analog method is discussed and a fully integrated analog circuit is proposed to simulate automobile intake systems. Furthermore, a novel behavioral macromodeling is proposed for the analog circuit design. With the analog circuit, the intake manifold absolute pressure, which plays an important role for the effective automobile engine control, can be accurately estimated or measured in real time.

The utilization of a high-Tc superconductor for implementing a superconducting qubit is to be expected. Recent researches on the quantum property of Josephson junctions in high-Tc superconductors indicate that the low energy quasiparticle excitation is weak enough to observe the macroscopic quantum tunneling. Therefore, a detailed study on the quantum property of high-Tc Josephson junctions becomes more important for applications. We show our experimental results of the macroscopic tunneling of current biased intrinsic Josephson junctions in Bi-2212 and its resonant activation in the presence of microwave radiation.

In CDMA cellular systems, the frequency reuse factor equals one. Therefore, the soft-handoff technology with combining macroscopic diversity was introduced to enhance the link performance. In this work, a novel macroscopic diversity combining scheme is proposed to enhance the link performance of the forward-link. The basic concept of this scheme is to integrate error correction coding into the soft-handoff technology. According to the number of soft-handoff channels, the source information is encoded by a convolutional code with a lower code rate. The coded symbols are then equally distributed to all channels from different BSs to the MS, and each channel carries a disjointed set of coded symbols. For this proposed scheme, no extra transmission power or bandwidth is required. The only cost is a slight increase of the encoding and decoding complexity of the convolutional codes. Numerical and simulation results show that a performance gain of 1 dB in bit energy-to-total noise power density ratio can be obtained as compared with the conventional scheme in the same conditions.

This paper presents a methodology based on congruent transformation for distributed interconnects described by state-space time-delays system. The proposed approach is to obtain the passive reduced order of linear time-delays system. The unified formulations are used to satisfy the passive preservation. The details of the mathematical proof and a couple of validation examples are given in this paper.

We describe a new characteristic of soft handoff, call failure when a mobile moves from the handoff region to the normal region, and introduce the metric of region-transition failure probability to more accurately assess the performance of CDMA systems that support real-time video streaming services. This characteristic has not been considered in previous research. Simulations show that this failure must be considered since it significantly degrades system performance.

Multiple-input multiple-output (MIMO) systems applying macroscopic selection diversity (MSD) are analyzed in composite fading channels through derived expressions of capacity outage probability. The MSD system uses a maximum capacity MIMO base station (BS) selection algorithm, where the results show a significant improvement in outage capacity.

This paper presents a systematic methodology for the system-level assessment of signal integrity and electromagnetic compatibility effects in high-speed communication and information systems. The proposed modeling strategy is illustrated via a case study consisting of a critical coupled net of a complex system. Three main methodologies are employed for the construction of accurate and efficient macromodels for each of the sub-structures typically found along the signal propagation paths, i.e. drivers/receivers, transmission-line interconnects, and interconnects with a complex 3D geometry such as vias and connectors. The resulting macromodels are cast in a common form, enabling the use of either SPICE-like circuit solvers or VHDL-AMS equation-based solvers for system-level EMC predictions.

The rapid growth of multimedia applications has increased interest in the compression of video data. This paper presents a new method for improving the compression ratio of video data, which can be easily used in a multilayer environment for error resilience applications as well. Data of four luminance blocks in a macroblock are processed and arranged in such a way that important macroblock data is compressed in one block(A), while the rest of the three remaining data blocks(H,V,D) are given difference values in the horizontal, vertical and diagonal directions. This results in a reduced bitstream size because of the low-valued data present in the three blocks(H,V,D), giving better compression at low bitrates. In an error resilient environment, the important data block in a macroblock is transmitted in a secure channel while the remaining three blocks with difference data are sent via a lossy channel. If error occurs in the lossy channel, picture can still be reconstructed with reasonably good quality using only the block data that is transmitted in the secure channel.

We present a new approach to the power modeling of synthesizable soft macros, which uses the characteristics of individual input signals for high accuracy. We also present the parameterized power model, developed using the proposed approach, which can relieve us from the power characterization for all possible macro sizes. Extensive experiments illustrate that the proposed approaches exhibit the overall modeling errors below 4.24% and 4.71% for benchmark macros before and after parameterization, when compared with the results of gate-level analysis.

This paper proposes an ROF ubiquitous antenna architecture for the wireless CDMA system. The proposed system separates each component of independent signals passing through the multipath in radio and optical links, which are gathered at passive double star link, by using RAKE reception and the macrodiversity effect is obtained. Theoretical analysis shows that the proposed system improves BER performance by 22 dB and reduces the transmission power and its control range by 19 dB.

Utilizing a macromodel which calculates the floating gate potential by combining resistances and dependent voltage and current sources, DC transfer characteristics for multi-input neuron MOS inverters and for those in the neuron MOS full adder circuit are simulated both at room temperature and at 77 K. Based on the simulated results, low temperature circuit failures are discussed. Furthermore, circuit design parameter optimization both for low and room temperature operations is described.

The demand for wireless mobile communications has grown at a very high rate, recently. In order to solve the non-uniform traffic rates, the use of cell splits is unavoidable for balancing the traffic rate and maximizing total system capacity. For cell planning, a DS-CDMA cellular system can be comprise of different cell sizes because of different demands and population density of the service area. In this paper, we develop a general model to study the forward link capacity and outage probability of a DS-CDMA cellular system with mixed cell sizes. The analysis of outage probability is carried out using the log-normal approximation. When a macrocell is split into the three microcells, as an example, we calculate the multi-cross interferences between macrocells and microcells, and the forward link capacities for the microcells and the neighboring macrocells. The maximum allowable capacity plane for macrocell and microcell is also investigated. The numerical results and discussions with previous published results of reverse link are summarized.

The forward link capacity plane of a hierarchically structured cellular CDMA system, in which a single frequency band is used for both macrocell and microcell layers, is obtained for isolated microcells (hotspots). The impact of each neighbour microcell and macrocell on the capacity plane, for a reference mobile station as the worst case, is also investigated. The results for the case of three microcells in each macrocell show that 69% of macrocell interference to microcell mobile stations comes from the closest macrocell. It is also found that 80% of macrocell interference to the reference macrocell mobile station comes from the central cell and the first cell tier around it.

This paper describes an Embedded DRAM Hybrid Macro, which supports various memory specifications. The eDRAM module generator with Hybrid Macro provides more than 120,000 eDRAM configurations. This eDRAM includes a new architecture called Auto Signal Management (ASM) architecture, which automatically adjusts the timing of the control signals for various eDRAM configurations, and reduces the design Turn Around Time. An Enhanced-on-chip Tester performs the maximum 512b I/O pass/fail simultaneous judgments and the real time repair analysis. The eDRAM testing time is reduced to about 1/64 of the time required using the conventional technique. A test chip is fabricated using a 0.18 µm 4-metal embedded DRAM technology, which utilizes the triple-well, dual-Tox, and Co salicide process technologies. This chip achieves a wide voltage range operation of 1.2 V at 100 MHz to 1.8 V at 200 MHz.

This paper presents a framework for modeling and mixed-mode simulation of circuits/interconnects and electromagnetic (EM-) radiations. The proposed framework investigates the signal integrity in VLSI chips, packages and wiring boards at the GHz-band level, and verifies the electromagnetic interference (EMI) and the electromagnetic compatibility (EMC) of high-speed systems. In our framework, the frequency characteristics of interconnects and EM-radiations are extracted by the full-wave FDTD simulation. The macromodels of interconnects are synthesized as SPICE subcircuits, and the impulse responses of EM-radiations are stored in the database. Once the macromodels are synthesized, the circuit simulation with the consideration of EM-effects can be performed by using SPICE. The EM-field distributions can be also easily calculated by taking convolutions of pre-simulated EM impulse responses and the SPICE results.

Both macrodiversity and microdiversity can effectively overcome the harmful effect of fading. Much of previous work focused on their benefits to the reverse link in CDMA systems. However, their effects on the forward link are less well understood. In this paper, we analyze the CDMA forward-link capacity with macrodiversity and microdiversity. It is shown that macrodiversity causes forward-link capacity loss since the extra forward-link channels supported by the involved base stations enhance not only the received signal power, but also the total interference. Unfortunately the latter gains more whatever power allocation scheme is adopted. Based on the analysis of the cause of capacity loss, we further present a new transmission scheme, in which some joint control among the involved base stations is made to assure that the signals arrived at the desired mobile in phase and simultaneously. The simulation results show that in the new transmission scheme much higher capacity can be achieved with macrodiversity and the capacity increases rapidly with the number of involved base stations. A comparison of the forward-link capacity with microdiversity and macrodiversity indicates that both types of diversity can bring benefits to the forward-link capacity. However, with macrodiversity higher capacity can be obtained at the cost of complexity.

In this work, teletraffic performance of a hierarchically overlaid microcell and macrocell structure in a PCS environment is presented. In this system, each group of N microcells is overlaid exclusively by one macrocell. The microcell tier is dedicated to low-mobility users and the macrocell tier is dedicated to both high-mobility users and overflowed low-mobility users from microcells. In general, forced termination is considerably undesirable from the user's viewpoint compared with the occurrence of call blocking. Therefore, handoff calls are given access priority to channels at the macrocell tier. As a priority scheme at the macrocell tier, a partial buffer sharing (PBS) scheme is proposed. As performance measures, call blocking probability, forced termination probability, and carried traffic are derived. Effects of the sizes of a macrocell and of hierarchical cell structure on system performance are discussed. The performance of the PBS scheme is also compared with those of the no priority scheme (NPS) and the first-come-first-service (FCFS) queueing scheme. Numerical results show that the PBS scheme gives the best performance for handoff traffic among the three schemes.

In this letter, we propose an efficient channel allocation scheme to provide multicast traffic in multitier cellular systems. Our proposed scheme allocates microcell/macrocell channels based on the 'microcell-group size' and probability. Also, we analyze the performance of the scheme in view of the call blocking probability in case of considering overflow traffic or not. Numerical results show that our proposed scheme exhibits a better performance than conventional schemes.

This report describes an acceleration technique to synthesize time-domain macromodels of interconnects using FDTD method. In FDTD calculation, the characteristic impedance of the interconnect is inserted into every terminal in order to damp quickly the transient waveforms. Additionally, an efficient technique for analyzing the macromodels is proposed. We demonstrate the efficiency of this method with examples.