• Journal of Navigation and Port Research
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• v.31 no.2
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• pp.159-163
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• 2007

In this paper, we mainly analyze the performance of two ultra wideband communication systems, the classical Time Hopping Binary Pulse Position Modulation (TH-BPPM) UWB system and the Time Hopping Bipolar Pulse Amplitude Modulation (TH-BPAM) UWB system. The performance of TH-BPPM and TH-BPAM is analyzed in detail under an ideal AWGN channel and a correlation receiver. We use the power spectral density function to get the expression of BER of these two UWB systems. It yields simple and exact formulas relating the performance to the system parameters. The analysis shows that TH-BPPM suffers performance degradation with respect to TH-BPAM. Furthermore, we give the computer simulation of both data and image transmission and our simulation results also prove our theoretical analysis.

• Journal of electromagnetic engineering and science
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• v.8 no.1
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• pp.34-39
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• 2008

An RF front-end dual-conversion receiver for $3{\sim}5\;GHz$ MB-OFDM UWB systems is implemented in $0.18\;{\mu}m$ CMOS technology. The receiver includes a two-stage UWB LNA, an RF mixer, an IF I/Q mixer, and a frequency synthesizer. The proposed receiver adopts the dual-conversion architecture to mitigate the burden of design of the frequency synthesizer. Accordingly, the proposed frequency synthesizer generates four LO tones from only one VCO. The receiver front-end achieves power gain of 16.3 to 21 dB, NF of 7 to 7.6 dB over $3{\sim}5\;GHz$, and IIP3 of -21 dBm, while consuming 190 mW from a 1.8 V supply.

• The Bulletin of The Korean Astronomical Society
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• v.35 no.2
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• pp.36.1-36.1
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• 2010

The Redshift Search Receiver (RSR) is a sensitive, ultra-wideband spectrometer that is being built at the University of Massachusetts as one of the facility instruments for the 50-m Large Millimeter Telescope (LMT). It consists of four receivers each covering the entire 3 mm window from 74 to 111 GHz instantaneously. The primary goal of the receiver is to detect multiple molecular lines in galaxies at any distance and uniquely determine the redshift, in particular dust-obscured star forming systems at high-z which are not easily accessible. I will present some results from commissioning of the RSR on the Five College Radio Astronomy Observatory 14-m telescope, and discuss the future of the receiver.

• Journal of Communications and Networks
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• v.14 no.5
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• pp.518-523
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• 2012

This paper presents new coherent and non-coherent detection methods for the IEEE 802.15.4a low-rate ultra-wideband physical layer with forward error correction (FEC) coding techniques. The coherent detection method involving channel estimation is based on the correlation characteristics of the preamble signal. A coherent receiver uses novel iterated selective-rake (IT-SRAKE) to detect 2-bit data in a non-line-of-sight channel. The non-coherent detection method that does not involve channel estimation employs a 2-bit data detection scheme using modified transmitted reference pulse cluster (M-TRPC) methods. To compare the two schemes, we have designed an IT-SRAKE receiver and a MTRPC receiver using an IEEE 802.15.4a physical layer. Simulation results show the performance of IT-SRAKE is better than that of the M-TRPC by 3-9 dB.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.19 no.11
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• pp.2238-2248
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• 1994

In this paper, we analyze a Microwave Amplifier Ultra-Wideband charateristic to apply Multi-Giga b/s optical receiver preamplifier in high speed optical communication system. To obtain frequency expanding effect. we analyze the frequency gain degradation effects of capacitances in the GaAs MESFET small-signal equivalent circuit and design Feedback amplifier Module(FAM) which has inductor peaking elements to compensate its effects and to expand frequency band. We derive optimum inductor peaking values in order to get flat gain in frequency band. The input and the output impedances of FAM are matched by Real Frequency Method and we design one and two stage ultra wideband microwave amplifier. With simulation results, it show $6.36\sim6.86dB$ and $9.1\sim10.3dB$ gains and execllent gain flatness in $0.5\sim12GHz$ respectively.

• IEIE Transactions on Smart Processing and Computing
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• v.4 no.5
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• pp.354-365
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• 2015

This work presents an Internet of Things (IoT) system for home energy management based on a custom-designed Impulse Radio Ultra-Wideband (IR-UWB) transceiver that targets a generic and multi-standard control system. This control system enables the interoperability of heterogeneous devices: it integrates various sensor nodes based on ZigBee, EnOcean and UWB in the same middleware by utilizing an ad-hoc layer as an interface between the hardware and software. The paper presents as a first the design of the IR-UWB transceiver for a portable sensor node integrated with the middleware layer, and also describes the receiver connected to the control system. The custom-designed low-power transmitter on the sensor node is fabricated with 130 nm CMOS technology. It generates a signal with a 1.1 ns pulse width while consuming $39{\mu}W$ at 1 Mbps. The UWB sensor node with a temperature measurement capability consumes 5.31 mW, which is lower than the power level of state-of-the-art solutions for smart-home applications. The UWB hardware and software layers necessary to interface with the control system are verified in over-the-air measurements in an actual office environment. With the implementation of the presented sensor node and its integration in the energy management system, we demonstrate achievement of the broad flexibility demanded for IoT.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.23 no.10
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• pp.1290-1297
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• 2019

The paper proposes a distance estimation technique for ultra-wideband (UWB) systems using convolutional neural network (CNN). To estimate the distance from the transmitter and the receiver in the proposed method, 1 dimensional vector consisted of the magnitudes of the received samples is reshaped into a 2 dimensional matrix, and by using this matrix, the distance is estimated through the CNN regressor. The received signal for CNN training is generated by the UWB channel model in the IEEE 802.15.4a, and the CNN model is trained. Next, the received signal for CNN test is generated by filed experiments in indoor environments, and the distance estimation performance is verified. The proposed technique is also compared with the existing threshold based method. According to the results, the proposed CNN based technique is superior to the conventional method and specifically, the proposed method shows 0.6 m root mean square error (RMSE) at distance 10 m while the conventional technique shows much worse 1.6 m RMSE.

• Proceedings of the KSRS Conference
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• 2003.11a
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• pp.1421-1423
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• 2003

Ultra Wideband is a new technology from commercial or civilian application viewpoint. It uses already allocated radio spectrum without causing significant interference to other users. It uses very low power, which is below the thermal noise of the receiver and is inherently difficult to detect by un-intentional users. Since, FCC approved the regulation for the commercial use of UWB in February 2002, the development of UWB technology is drastically gaining momentum. However, the technology itself is not new. It has already been used in military applications. UWB has three basic areas of applications, which are communication, positioning and imaging (UWB Microwave). The main commercial application will be for communication since it has very high data transfer rate for short distance. It can also be used for both indoor and outdoor 3-D positioning. Another important application is imaging like microwave remote sensing. An UWB sensor can pass through doors and walls and hence detect the objects inside the room. In this paper, we will introduce about UWB technology along with it’s various possible applications. We will also present some models to generate UWB signal and it’s analysis using signal-processing tools.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.5C
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• pp.555-560
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• 2009

A vehicle radar has been studied to avoid the collision of vehicles. A vehicle radar using direct sequence-ultra wideband (DS-UWB) measures the distance between a vehicle and an objective with a sufficient time margin. Therefore, the receiver should estimate the distance by processing the short UWB pulse rapidly. There have been several investigations for distance measuring based on DS-UWB signals. In this paper, we propose a novel method for rapid measuring processing time. Simulation results show that the proposed method has a shorter processing time than the conventional method.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.3A
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• pp.205-212
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• 2009

A novel channel estimation scheme is proposed for coherent Impulse Radio Ultra Wideband (IR-UWB) system based on IEEE 802.15.4a specification. By extracting and utilizing the information on the frequency synchronization, the proposed channel estimation algorithm improves the receiver performance even under the restricted number of preamble symbols in IEEE 802.15.4a signal format. Simulation results over the IEEE 802.15.4a channel models show the performance gain with the proposed algorithm compared to ordinary channel estimation method.