• Journal of the Institute of Convergence Signal Processing
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• v.2 no.4
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• pp.71-76
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• 2001

In this paper we propose the Digital Automatic Gain Controller for IEEE 802.11a-High-speed Physical Layer in the 5 GHz Band. The input gain it estimated by calculating the energy of the training symbol that it a synchronizing signal. The renewal gain is calculated by comparing the estimated gain with the ideal gain. The renewal gain is converted into the controlled voltage for GCA to reduce or amplify the input signals. We used a piecewise-linear approximation to reduce the hardware size. The gain control is performed seven times to provide more accurate gain control. The proposed automatic gain controller is designed with VHDL and verified by using the Xilinx FPGA.

• Journal of Life Science
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• v.5 no.3
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• pp.126-136
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• 1995

The studies had been conducted to evaluate the grain processing effects for ruminants on starch digestion, body weight gain and feed efficiency since 1970. This research deals with experimental results on chemical structure, gelatinization, microbial starch digestion in rumen, intestinal starch digestion in rumen, roles of protozoa, intestinal starch digestion of bypass starch, limits to starch digestion in small intestine. The grain processing has different effects on digestion, weight gain and feed efficiency when different grain sources and contents is used, and the quality and quantity of roughage is different. The economical and efficient method of grain processing should be selected considering weight gain and feed efficiency enhancement than digestibility.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.17 no.1
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• pp.68-79
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• 1992

In the high speed analog system satellite communication system, video signal processing and optical fiber interface circuits, GaAs high gain operational amplifier is advantageous due to obtain a high gain because of its low transconductance and other drawbacks, such as low frequency dispersion and process variation. Therefore in this paper, a circuit techniques for improving the voltage gain for GaAs MESFET amplifier is presented. Also, various types of existing current mirror and current mirror proposed are compared.To obtain the high differential gain, bootstrap gain enhancement technique is used and common mode feedback is employed in differential amplifier.The simulation results show that gain is higher than that of basic amplifier about 18.6dB, and stability and frequency performance of differential amplifier are much improved.

• Proceedings of the Korea Institute of Convergence Signal Processing
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• 2001.06a
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• pp.101-104
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• 2001

In this paper, we propose the Digital Automatic Gain Controller for IEEE 802.11a High-speed Physical Layer in the 5 GHz Band. The input gain is estimated by calculating the energy of the training symbol that is a synchronizing signal. The renewal gain is calculated by comparing the estimated gain with the ideal gain. The renewal gain is converted into the controlled voltage for GCA to reduce or amplify the input signals. We used a piecewise-linear approximation to reduce the hardware size. The gain control is performed seven times to provide more accurate gain control. The proposed automatic gain controller is designed with VHDL and verified by using the Xilinx FPGA.

• Proceedings of the KIEE Conference
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• 2006.04a
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• pp.27-29
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• 2006

In this paper, we propose a new method of automatic white balance which is one of the image signal processing techniques. Our method is conceptually based on gray world assumption. However, while previous methods generate linear results as multiplying pixel values by a gain, our method generates non-linear results using the feature of B-Spline curves. The two merits of deriving non-linear results are preventing AWB failure from transforming strong color of high level into wrong color and well preserving original contrast of an input image.

• Proceedings of the Korea Institute of Convergence Signal Processing
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• 2000.08a
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• pp.13-16
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• 2000

Since stimulated Brillouin scattering (SBS) impact wavelength division multiplexing (WDM) optical transmission systems, it is important to understand the implication of SBS in the design of such lightwave systems. Therefore, Brillouin gain spectrum (BGS) is measured to characterize the effect of SBS in optical fiber. The Brillouin gain coefficient is found to vary as the wavelength and linewidth of source. Theoretically measurement of BGS shows a dependence on wavelength(λ) and on linewidth(Δν), respectively.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.9B
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• pp.1579-1587
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• 2000

This paper presents the properties of the RF part in the receiving system based in IMT-2000 terminal technology. It mainly discuss the RF parameter performance of the receiving system for mobile telecommunication comparable to IS-98A and J-STD-018 specifications of commercially available CDMA and PCS, and is to anticipate the processing gain of the IMT-2000 receiving system, processing gain according to data processing rate, and terminal noise figure according to processing gain, relationship between noise figures according to Eb/Nt, Ioc. It is performed by such analysis method as CDMA and PCS receiving systems. Transmission bandwidth is n$\times$1.25 MHz(n=1, 3, 6, 9, 12) which is recommended by Qualcomm and NTT, the leading company in cdma 2000. Data transmission rate of IMT-2000 is classified into three cases as in moving vehicle environment of 144Kbps, outdoor pedestrian environment of 384Kbps, and indoor office environment of 2Mbps

• Proceedings of the IEEK Conference
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• 2003.07b
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• pp.1117-1120
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• 2003

In this paper, a 1.5V CMOS high frequency operational amplifier for high frequency signal processing systems is presented. For obtaining the high gain and the high unity gain frequency with the 1.5V supply voltage, the op-amp is designed with simple two stages which are consisting of the rail-to-rail differential input stage and the class-AB output stage. The designed op-amp operates with the 1.5V supply voltage, and shows well the push-pull class-AB operation. The simulation results show the DC open loop gain of 77dB and the unity gain frequency of 100MHz for the 1㏁ ┃ 10pF load. When the resistive load R$_1$. is varied from 1㏁ to 1 ㏀, the DC open loop gain decreases by only 4dB.

• Journal of Information Processing Systems
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• v.13 no.1
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• pp.83-94
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• 2017

Near-field source localization algorithms are very sensitive to sensor gain/phase response errors, and so it is important to calibrate the errors. We took into consideration the uniform linear array and are proposing a blind calibration algorithm that can estimate the directions-of-arrival and range parameters of incident signals and sensor gain/phase responses jointly, without the need for any reference source. They are estimated separately by using an iterative approach, but without the need for good initial guesses. The ambiguities in the estimations of 2-D electric angles and sensor gain/phase responses are also analyzed in this paper. We show that the ambiguities can be remedied by assuming that two sensor phase responses of the array have been previously calibrated. The behavior of the proposed method is illustrated through simulation experiments. The simulation results show that the convergent rate is fast and that the convergent precision is high.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.9C
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• pp.721-728
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• 2010

CAMC (constant amplitude multi-code) has a better performance of error correction in iterative decoding than SPCPC (single parity check product code). CAMC benefits from a processing gain since it belongs to a spread spectrum signal. We show that the processing gain enhances the performance of CAMC. Additional correction of bit errors is achieved in the de-spreading of iteratively decoded signal. If the number of errors which survived the iterative decoding is less than or equal to ($\sqrt{N}/2-1$), all of the bit errors are removed after the de-spreading. We also propose a stopping criterion in the iterative decoding, which is based on the histogram of EI (extrinsic information). The initial values of EI are randomly distributed, and then they converge to ($-E_{max}$) or ($+E_{max}$) over the iterations. The strength of the convergence reflects how successfully error correction process is performed. Experimental results show that the proposed method achieves a gain of 0.2 dB in Eb/No.