This paper introduces a block-based motion estimation algorithm based on projection with adaptive window size selection. By using one-dimensional (1-D) projection the original two-dimensional (2-D) block-matching problem is translated to a simpler 1D matching, which eliminates majority of potential pixel participation. In this paper, we propose an efficient fast motion estimation method by using region similarity detection (RSD) algorithm to reduce the encoding time. The proposed RSD algorithm effectively estimates the texture direction of the block to find the direction and then horizontal, vertical or diagonal projection is employed for SAD calculation. Experimental results show that the proposed algorithm achieves more than a 60% time reduction with negligible PSNR loss and bitrate increments.
DCH was solely used to convey data and voice traffic in the first releases of UMTS mobile systems. Apart from the properties of the traffic services, one OVSF code was permanently assigned to this channel. Then, to improve the system performance, DSCH and HS-DSCH channels were used in the next releases of the mobile systems for bursty traffic services. OVSF codes were only assigned to the channel in the data transfer time in these releases. In this paper by a multiplexer/scheduler, queue and a buffer we introduce a Traffic Model Scheduler (TMS) in layer two/RLC of HSDPA to reduce the OVSF code usage more in HS-DSCH.
Several practical criteria to improve the performance of a mixed FDTD-MoL method of electromagnetic analysis are proposed. Concepts as the properly dimension selection of the waveguide “containing” the microstrip geometry, the true propagation speed on the microstrip, the suitability of the excitation pulse spread and the relation between the reflected and incident waveforms, the preservation of both, the time and space derivatives for the FDTD segmentation-discretization part, and the analytical incorporation of the boundary conditions are all discussed.
A new type of millimeter-wave quasi-optical variable phase shifter which exploits the dielectric anisotropy of liquid crystal (LC) materials is presented. The device is operated in transmission mode and consists of inductive and capacitive metal grids, each patterned on a dielectric substrate, which are separated by a thin layer of LC. The grids together with the LC form a parallel resonant circuit. Prototype devices with a 25-µm-thick LC layer for use at a millimeter-wave frequency of 50GHz were designed and fabricated. Experiments performed at U-band frequencies show that a phase shift of 7.8° is obtained with a low insertion loss of ∼ 0.6dB at the resonant frequency by applying a control signal of 20V. Good time response for the device is demonstrated. It is suggested that the phase shift attainable with the device can be further enhanced by using LC materials with larger dielectric anisotropy and/or thinner dielectric substrates.
Nowadays, with technology shrinking and the huge demand for supporting multiple applications has led designers to use multiple IP cores within a single chip. Therefore, the designers have proposed Networks-on-chip to overcome the problems of future complex systems. Mapping IPs directly affects NoC design parameters such as latency and power consumption. In this paper we present a power and performance aware mapping technique based on the combination of both the bandwidth-constrained and branch and bound concepts. Results have shown improvements of the latency and power consumption of our technique when compared to other popular NoC mappings.
A compact monolithic RF-MEMS switch (2mm × 4mm in area) with the dual single-pole-double-throw (SPDT) configuration was developed by using the SOI bulk micromachining technique. The electrostatic comb-drive actuators and the mechanically movable coplanar waveguides were implemented on the low-resistive active SOI layer and the high-resistive handle layer, respectively, to effectively allocate the device footprint. Electrical crosstalk between the waveguide and the electrostatic actuator was suppressed by using the buried silicon dioxide layer. At a driving voltage of 35V, the switch exhibits an insertion loss of 3dB and isolation of 30dB at 12GHz.
The far-field gain of a double-ridged guide horn antenna is determined by the three-antenna method by considering the phase center. The location of the phase center is calculated by the finite integration method. The experimental and theoretical results show the efficacy of using the phase center for antenna calibration.
A low-power wideband frequency synthesizer that generates multiple LO frequencies for mobile TV tuner ICs is presented. The synthesizer utilizes a single on-chip LC VCO and an odd-order frequency division technique to achieve both low power and small silicon area. The integrated LC VCO has a tuning range of 2.3 to 3.85GHz. With a division ratio of 2, 4, 6, 12, 16, 24, and 32, the LO generation block supports FM, VHF III, UHF, Europe-L, and USA-L bands. The measured LO phase noise for the L-band is under -79dBc/Hz at an offset of 10kHz. The synthesizer implemented in 0.18-µ m CMOS technology occupies an area of about 1.2mm2and dissipates up to 33.5mW from a 1.8-V supply.
Nowadays, power savings when designing a circuit become more important than area cost. Through duplicating a Functional Unit (FU)instead of sharing it, designers can archive more power efficient circuits. To prove the advantage of the FU duplication, we compared the power consumptions of circuits with shared FU and duplicated FUs. Experimental results on ISCAS '85 benchmarks showed great savings in dynamic power of interconnection circuits and fan-out buffers. The circuits with duplicated FUs consumed less power than the shared FU by average 28.4%.
We have evaluated the electric characteristics of an organic surfactant material, n-Cethyl-trimethyl-ammonium Bromide (C16TAB) to fabricate the p-n homo-junction. This C16TAB was dissolved in the pure water, where the potassium iodide (KI) was added. The impurities adaptation has been processed in this mixed solution with the application of voltage. The KI is ionized in the water and the potassium ion is moved to the negative electrode and the iodine ion to the positive electrode. We collected the solution in the vicinity of both electrodes separately, and dried it to fabricate the samples. We measured the resistivities of both samples which were in the range of 10+3Ωcm. Both materials were contacted, and we measured the current-voltage (I-V) characteristics. We have obtained the I-V characteristics similar to a p-n homo-junction.