• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.9 no.5
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• pp.133-138
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• 2009

In this paper, we propose a ZCD (Zero Correlation Duration) code based Ultra Wide Band(UWB) MODEM(modulation and demodulation) technique for WBAN as a hunman body wireless communication operating in WBAN (Wireless Body Area Network) environment. We certified ZCD code based UWB schemes are available for hunman body wireless communications by various simulation and performance analysis using WBAN transmission channels. Furthermore, we suggested some possibility of RFIC implementation related to human body based UWB communication module by presenting some related examples.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2003.10a
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• pp.133-136
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• 2003

UWB(Ultra-Wide Band) system is transmitted using Gaussian monocycle pulse of very short pulse duration less than 1 nsec. Therefore, transmission signal has ultra-wide band spectrum to GHz band of very low power and not interfere with the existing communication system. A collision of multipath waves in UWB system with tarrier frequency very different with general wireless communication system. In this paper, the BER(Bit Error Rate) performance of UWB system applying Binary Phase Shift Keying, Quadrature Phase Shift Keying, 16-Quadrature Amplitude Modulation method under multipath channel using computer simulation is compared and analyzed.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.3A
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• pp.157-165
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• 2003

The purpose of this paper is to analyze the performance requirements of wireless systems on ultra wide band, which is set by FCC(Federal Communications Commission). Normally the calculation of performance requirements is used in the standard form of each communication systems, but there is no standard in the wireless systems on Ultra WideBand. Therefore, I derive each system parameters through the analysis of new system performance on the basis of the method of Indoor Communication Systems. Additionally, I compare the conditions that are given by FCC with resolution of the performance by domestic law.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.12 no.6
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• pp.37-43
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• 2013

In this paper, an UWB (Ultra Wide Band) band-pass filter with open stubs using SIR (Stepped Impedance Resonator) structure is presented. The proposed band pass filter (BPF) has SIR structure instead of open stubs for UWB application with low insertion loss. The bandwidth of the proposed BPF is 103 % at the center frequency of 5.8GHz and the insertion and return losses are 0.17dB and 13.1dB, respectively. Also, the entire size of the proposed band-pass filter is $21.6{\times}17.8mm^2$.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2008.10a
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• pp.299-302
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• 2008

In this paper, A compact ultra-wideband(UWB) bandpass filter(BPF) with WLAN notched filter has been proposed. H-shaped slot is studied and adopted to tighten the coupling of inter-digital capacitor in order to improve the BPF's performance. Three pairs of tapered defected ground structures(DGS) are formed to assign their transmission zeros towards the out of band signal, thereby suppressing the spurious passband. Also Meander line slot is developed to reject the undesired wireless local-area network(WLAN) radio signals. That's combining these three structures we obtain a small sized UWB BPF.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.12 no.11
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• pp.1909-1913
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• 2008

In this paper, A compact ultra-wideband(UWB) bandpass filter(BPF) with WLAN notched filter has been proposed. H-shared slot is studied and adopted to tighten the coupling of inter-digital capacitor in order to improve the BPF's performance. Three pairs of tapered defected ground structures(DGS) are formed to assign their transmission zeros towards the out of band signal, thereby suppressing the spurious passband. Also Meander line slot is de#eloped to reject the undesired wireless local-area network(WLAN) radio signals. That's combining these three structures we obtain a small sized UWB BPF.

• Journal of Communications and Networks
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• v.5 no.2
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• pp.167-173
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• 2003

We treat the problem of channel estimation and interference cancellation in multiuser ultra-wide-band (UWB) communication systems over multipath fading channels. The UWB system under consideration employs a random time-hopping impulse radio format. We develop a channel estimation method based on linear weighted algorithm. An iterative channel estimation and interference cancellation scheme is proposed to successively improve the receiver performance. We also consider systems employing multiple transmit and/or receive antennas. For systems with multiple receive antennas, we develop a diversity receiver for the wellseparated antennas. For systems with multiple transmit antennas, we propose to make use of Alamouti’s space-time transmission scheme, and develop the corresponding channel estimation and interference cancellation receiver techniques. Simulation results are provided to demonstrate the performance of various UWB receiver techniques developed in this paper.

• 한국정보통신설비학회:학술대회논문집
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• 2008.08a
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• pp.39-42
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• 2008

In this paper, we analyze the performance of ultra wide band (UWB) systems in indoor wireless channel in accordance with the number of pulses per bit at transmit signals and the decision types of receiver. The indoor channel is modeled as the modified Saleh and Valenzuela (SV) model which has been proposed as a UWB channel model by the IEEE group, IEEE 802.15.SG3a. Two types of UWB signals are considered One is the pulse position modulation-time hopping (PPM-TH) signal. And the other is the pulse amplitude modulation-direct sequence (PAM-DS) signal. It is assumed that the receiver is an ideal receiver which can receive all signals of the multipath.

• Journal of electromagnetic engineering and science
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• v.9 no.3
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• pp.164-173
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• 2009

In this paper, two new circuit structures for European and U.S. ultra-wide band(UWB) bandpass filters(BPFs) with sharp roll-off characteristics are introduced. We show first that the ultra-wide bandpass property is obtained from a $\lambda$/4 open T resonator with a capacitively coupled $\lambda$/4 short-circuited line, which provides two attenuation poles at lower and upper cutoff frequencies. Then, two identical capacitively coupled input/output lines, which can be $\lambda$/4-length open ends or $\lambda$/2-length short ends, with the T-resonator, are adopted to suppress lower and higher frequency components outside of the pass band. There is coupling between the input and output lines providing two additional transmission zeros in the lower and upper transition bands of the filter. Since the coupling between the T-resonator with the $\lambda$/4 short-circuited line and the input/output lines limits the bandwidth of the filter to the European UWB band, both the $\lambda$/4 short-circuited line and the input/output lines are inserted between the two stacked T-resonators for the U.S. UWB band. The filter structures are simulated with ADS and HFSS and realized with low-temperature co-fired ceramic(LTCC) green tape which has the dielectric constant of 7.8. Measurement results agree well with HFSS simulation results.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.10C
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• pp.965-975
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• 2005

In this paper, we propose and evaluate joint carrier and sampling frequency offset estimation schemes based on the channel estimation sequences in PLCP (Physical Layer Convergence Procedure) preamble for the proper and effcient synchronization of the MB-OFDM WB (Multi-Band Orthogonal Frequency Division Multiplexing Ultra Wide Band) systems which have recently drawn explosive attention for future W-PAN (Wireless Personal Area Network) applications. In the joint estimation schemes, we first estimate the sampling frequency offset, and then estimate the carrier frequency offset using the estimated sampling frequency offset. Moreover, to improve the reliability of the estimated offset values, each process uses a combination scheme based on weighting factors. Simulation results using IEEE 802.15 Task Group 3a UWB channel models reveal that the estimation scheme using the simple weighting factors based on easily-measurable received signal power of each sub-channel shows favorably comparable performance to the ideal scheme using the weighting factors based on the perfectly-estimated frequency response of the channel.