• Journal of the Institute of Electronics Engineers of Korea TE
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• v.42 no.2
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• pp.23-28
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• 2005

This study was to suggest the propagation path loss and predictive model of propagation path analysis in order to apply the frequency in the millimeter-wave band to the real time inter-vehicle communication system. This study was to suppose the case of inter-vehicle communication on the one-way two-lanes road in the big cites with a lot of traffic jams in order to analyze the effect by the reflected wave of multipath. As a simulation of suggested model, it found out that the propagation path by the reflected wave was about 0.1[m]$\sim$5.1[m] longer than the one by the direct wave during the transmission of 100[m] wave direct path. Also, as a result of comparing the propagation path loss, the loss would be about -0.8[dB]$\sim$-4.2[dB] larger in case of wall reflection and -0.8[dB]$\sim$-1[dB] vehicle reflection. From the result above, this researcher found out that the path loss of reflected wave produced by the walls was about -3.2[dB] larger than the path loss produced by the adjacent vehicles.

• Journal of Communications and Networks
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• v.18 no.6
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• pp.913-925
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• 2016

In-band wireless full-duplex is a promising technology that enables a wireless node to transmit and receive at the same time on the same frequency band. Due to the complexity of self-interference cancellation techniques, only base stations (BSs) are expected to be full-duplex capable while user terminals remain as legacy half-duplex nodes in the near future. In this case, two different nodes share a single subchannel, one for uplink and the other for downlink, which causes inter-node interference between them. In this paper, we investigate the joint problem of subchannel assignment and power allocation in a single-cell full-duplex orthogonal frequency division multiple access (OFDMA) network considering the inter-node interference. Specifically, we consider two different scenarios: i) The BS knows full channel state information (CSI), and ii) the BS obtains limited CSI through channel feedbacks from nodes. In the full CSI scenario, we design sequential resource allocation algorithms which assign subchannels first to uplink nodes and then to downlink nodes or vice versa. In the limited CSI scenario, we identify the overhead for channel measurement and feedback in full-duplex networks. Then we propose a novel resource allocation scheme where downlink nodes estimate inter-node interference with low complexity. Through simulation, we evaluate our approaches for full and limited CSIs under various scenarios and identify full-duplex gains in various practical scenarios.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.39B no.3
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• pp.151-161
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• 2014

3GPP LTE-Advanced (Release 10) system specifies carrier aggregation (CA) to enable high data rate on using multiple frequency bands, including the variout CA-specific deployment scenarios. Considering one of those scenarios in which the different directional sector antenna is employed by each frequency band, we propose a per-carrier cell selection scheme that can improve the average throughput of the cell-edge users by allowing each user equipment (UE) to select the frequency band of the adjacent cell. Furthermore, a distributed algorithm for inter-cell copperative scheduling in this scheme is proposed to support proportional fairness among the cells. It has been shown that the proposed scheduling algorithm for the per-carrier cell selection scheme improves the cell-edge user throughput roughly by 50% over that of the conventional scheme.

• JSTS:Journal of Semiconductor Technology and Science
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• v.10 no.4
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• pp.265-275
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• 2010

In this work, reliable methodology for device design is presented. Based on this method, the underlap length has been optimized for minimizing the gateinduced drain leakage (GIDL) in a 22-nm node 4-terminal (4-T) silicon-on-insulator (SOI) fin-shaped field effect transistor (FinFET) by TCAD simulation. In order to examine the effects of underlap length on GIDL more realistically, doping profile of the source and drain (S/D) junctions, carrier lifetimes, and the parameters for a band-to-band tunneling (BTBT) model have been experimentally extracted from the devices of 90-nm channel length as well as pnjunction test element groups (TEGs). It was confirmed that the underlap length should be near 15 nm to suppress GIDL effectively for reliable low standby power (LSTP) operation.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.11 no.3
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• pp.235-240
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• 2018

FTN method which transmits signals faster the Nyquist rate is representative method for improving throughput efficiency sacrificed performance due to inter-symbol interference. To compensate performance loss, in this paper, we propose a multiband FTN method which split the coded bits into several bands and transmits signals applying FTN method. As coded bits are being assigned different bands, number of samples per bit of each band is increased, it induced performance improvement by noise averaging effect. In the simulations, compared the performance of single band FTN method and multiband FTN method when the interference rate is 25%. The results of simulation show the performance of proposed method is better than that of single band FTN one by 0.3dB~0.5dB.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.16 no.11 s.102
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• pp.1164-1170
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• 2005

This paper presents a dual-band, dual-polarized microstrip patch antenna with simple dual-probe feed. The inter-port isolation and cross-polarization are greatly improved by designing feed structure with annular gap between patch and feed-probe. Measured results show that the antenna's inter-port isolation and cross-polarization in each -10 dB return loss bandwidth of $1.84\;GHz\~l.93\;GHz$ and $2.62\;GHz\~2.81\;GHz$ are greater than 21 dB, greater than 22.2 dB and greater than 27 dB, greater than 19 dB, respectively. The antenna gain is about 6.9 dBi in both frequency bands.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37 no.6C
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• pp.512-519
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• 2012

To design a new Navigation Satellite System signal, we should analyze the influence of inter-system interference to existing Global Navigation Satellite Systems(GNSS). Various GNSS systems such as GSP, GALILEO, Compass use same frequence band and incur inter-system interference due to the overlapping spectrums. In this paper, we consider L2 Band for new Navigation Satellite System and propose the BOCcos(15,2.5) signal what has least Spectral Separation Coefficient with GPS L2 system. Assuming 4 stationary satellite over Korea, we simulate the effect of interference. As a result, proposed system shows very small mutual interference effect and negligible effective signal to noise ratio(SNR) loss, compared to the interferences between GNSS systems in L1 Band.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.8 no.3
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• pp.686-693
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• 2004

We have studied a method to fabricated a Surface Acoustic Waves (SAW) filter for Wide band Codeless Division Multiple Access(WCDMA) was formed on the Langasite substrate and was evaporated by Aluminum-Copper alloy and then we developed a simulator using the mathematica package. And, we can design and fabricate the Slanted finger Inter-digital Transducer (SFIT) for the purpose to decreased the ultimate rejections on side of the electrodes, and performed computer-simulation by simulator. Also, we have employed that the block weighted type Inter-digital Transduce(IDT) as input transduce of the filter and the withdrawal weighted type IDT as an output transducer of the filter in order to minimize effect of diffractions. We have employed that the number of pairs of the input and output IDT are 50 pairs and the thickness and the width of reflector are $5000\AA$, and $1\lambda/4(\cong3.6{\mu}m)$, respectively. Also the width of IDT' finger and the space between IDT' finger and reflector are $1\lambda$/16 and 1\lambda$/8, respectively. Frequency response of the fabricated SAW bandpass filter has the property that center frequency is about 190MHz, bandwidth at the 3dB is probably 4MHz and out-band attenuation is -60dB approximately.

• The Korean Journal of Pain
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• v.36 no.2
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• pp.208-215
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• 2023

Background: To evaluate the feasibility, inter-reader reliability, and intra-reader reliability for various morphological features reported to be related to iliotibial band friction syndrome (ITBFS) on knee magnetic resonance imaging (MRI). Methods: A total of 145 patients with a clinical diagnosis and knee MRI findings consistent with ITBFS were included in the "study group" and 232 patients without knee pathology on both physical examination and MRI were included in the "control group". Various morphologic features on knee MRI were assessed including the patella shape, patella height, lateral epicondyle anterior-posterior (AP) width, lateral epicondyle height, ITB diameter (ITB-d), and ITB area (ITB-a). Results: Patients in the study group had significantly higher lateral epicondyle height (13.9 mm vs. 12.92 mm, P = 0.003), ITB-d (2.9 mm vs. 2.0 mm, P = 0.022), and ITB-a (38.5 mm² vs. 23.8 mm², P < 0.001) than the control group. ITB-a showed higher area under the curve index (0.849 with 74.1% sensitivity and 72.4% specificity at a 30.3 mm² cutoff) than ITB-d (0.710 with 70.8% sensitivity and 61.2% specificity at 2.4 mm cutoff) and lateral epicondyle height (0.776 with 72.4% sensitivity and 67.8% specificity at 13.4 mm cutoff). However, only the inter-reader agreement for ITB-a (intraclass correlation coefficient = 0.65) was moderate, while the agreements for other morphologic features were good or excellent. Conclusions: Lateral epicondyle height seems to be a reliable and feasible morphologic feature for diagnosis of ITBFS.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.22 no.12
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• pp.1684-1690
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• 2018

A new digital pre-distortion (DPD) technique for closely spaced dual-band signals is proposed. In the system under consideration, dual-band signals are amplified by a single broadband power amplifier (PA) at a transmitter. The PA output is distorted by cross-modulation between the two bands as well as their own inter-modulation distortion. Especially, if the two bands are placed in close proximity to each other, their spectral regrowths due to in-band intermodulation overlap with each other, which degrades DPD performance. To solve this problem, we propose a new DPD technique where the dual-band PA characteristics are estimated first, and then the DPD parameters are obtained from the estimated PA characteristics. By finding the DPD parameters through two steps, pre-distortion can perform well for the closely-spaced dual band signals. The proposed technique is verified through computer simulation. Simulation result shows that the proposed method performs better than the conventional method for closely-spaced dual band signals.