• Journal of the Institute of Electronics Engineers of Korea TC
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• v.42 no.1
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• pp.9-15
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• 2005

Most of location systems use RF signal. Because multipath is too severe at indoor environment, RF signal are usually used in outdoor positioning such as GPS. To overcome the difficulty at indoor positioning, m positioning is recently developed and is being vigorously studied. Some standardizations on UWB are in progress at IEEE 802.15 committee. In developing UWB positioning system, we should consider the synchronization of sensor network, positioning algorithm, sensor allocation, and so on. This paper presents a comparison of TDOA positioning algorithms that are widely used in location systems. Two algorithms are compared; one is derived by linearization, and the other is by analytic solution(CH algorithm). Simulation results show that the CH algorithm is superior to the linearized least square at indoor environment in that CH algorithm shows consistent positioning performance regardless of the visibility and geometry of basestations.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.10C
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• pp.992-998
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• 2005

In this paper, An Ultra Fast Acquisition Algorithm of low transmission rate ultra-wideband(UWB) systems for car positioning and traffic light controling is proposed. Since the acquisition algorithms for CDMA system are not fast enough to access the low transmission rate UWB systems, the new ultra fast acquisition scheme which can be implemented with low cost and simplified circuit is required. The proposed algorithm adopted the Recurrent Sequential Estimation scheme and trinomial M-sequence. Therefore, The proposed scheme can reduce the average acquisition time in $1\~3{\mu}sec$ with simple circuit, even for the UWB systems which use long pseudo-noise(PN) sequence and transmit low power below the FCC EIRP emission limits. The simulation results for the average acquisition time of the proposed scheme are compared with the ones of the existing acquisition schemes.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.44 no.7 s.361
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• pp.88-95
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• 2007

In this paper, we suggest the novel MIMO-UWB transceiver structure which can easily be adapted for various MIMO schemes and presents MIMO channel model for obtaining correlation characteristics among channels to analyze the performance. From the indoor channel modeling, we obtain the interferences among antennas due to the MIMO channel formation through numerical simulation and analyze the performance of MIMO-UWB system under frequency selective fading. Especially, to reduce the excessive computational complexity due to the inverse matrix computation of channel transfer function, we take the scheme combining the transmitting signals estimated from each receiving antenna after recovering each transmitting antenna signal from a receiving antenna.

• Proceedings of the IEEK Conference
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• 2005.11a
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• pp.241-244
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• 2005

In this paper, we construct UWB system formed by MIMO(Multi-input Multi-output) antennas using indoor WPAN(Wireless Personal Area Network) channel modeling and analyze the interference among these channels.

• Proceedings of the IEEK Conference
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• 2003.07a
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• pp.250-253
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• 2003

In this paper, a characteristics and points of Guassian pulse using UWB system is analyzed, the TDMG pulse is proposed that originated ultra wide band signal without pulse width reduction. It is showed that TDMG pulse character compare with Gaussian pulse through computer simulation. And it is verified that decreased a interference of other communication systems

• Journal of information and communication convergence engineering
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• v.7 no.3
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• pp.286-291
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• 2009

In this paper, the performance of ultra-wideband (UWB) single input multiple output (SIMO) systems to achieve high data rate communications is studied in dense multipath environments. The effects of spatial and temporal diversities on the performance of multi-user time-hopping UWB systems using binary pulse position modulation (2PPM) are analyzed. The reduced-complexity Rake receivers based on the selective combining (called SRake) and partial combining (called PRake) are considered. The theoretical and simulation results show that the BER performance of the UWB system can be enhanced as the number of array elements and/or Rake fingers increases. Moreover, we observe that SRake is more effective for the IR-UWB systems to achieve a good BER performance, as compared with PRake.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.10 no.3
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• pp.153-158
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• 2010

In this paper, we propose and analyze the positioning technique using TH-PPM ultra wideband for indoor environment. We employed AWGN and IEEE 802.15.3a channel as a simulation environment and used to TDOA algorithm. Positioning technique using ultra wideband has high accuracy in indoor environment. From the simulation results, it is analyzed the probability of error and positioning performance for channel effects and confirmed usefulness of the proposed scheme.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.41 no.8
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• pp.125-130
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• 2004

Various antennas have been developed to be used for UWB systems, However, Simultaneously meet omni-directional and low-VSWR requirements, essential for some applications such as UWB channel sounding. In this paper, we propose a novel wide band printed elliptic monopole antenna for UWB(Ultra wide Band). Wideband planar monopole disc antenna have been recently studied. The proposed antenna can cover m frequencies from 3.5GHz to 12GHz. it is determined from 10dB return loss. Antenna radiation pattern is omnidirectional at 3.5GHz - 10GHz. The antenna consists of the printed elliptical monopole disc with microstrip-line feed. Elliptic disc of antenna and ground height operate important to matching. The proposed antenna easy to construct UWB system.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.14 no.3
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• pp.587-594
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• 2010

In this paper, we propose an asynchronous IR-UWB ranging system based on the two-way ranging protocol. The periodic pulse sequence is used to measure a distance between two devices. At the receiver, a received signal is first transformed into a frequency-domain signal using an analog correlator bank and digital signal processing is followed in the frequency-domain. This make it possible for the system to use an ADC with a conversion speed of pulse rate. The proposed algorithm at the receiver side includes a peak detection procedure using mutipath channel compensation and matched filtering, and retransmits a pulse sequence synchronized with the detected peak. The validity of the proposed algorithm is verified from simulation results where the CM1 channel is assumed.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.11 no.1
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• pp.53-65
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• 2012

Recently wireless intra-vehicle communication has received a great interest from the automotive industry and ultra wideband (UWB) technology is considered as one of the potential candidate for this system. Many research works have been done on the measurement and modeling of intra-vehicle communication channel. However, very little work has been reported for the performance analysis of various PHY layer methods under the intra-vehicle communication environment. This paper is to study IEEE 802.15.4a standard in intra-vehicle channel and to evaluate its performance. Channel model in chassis and engine compartment is considered for evaluation. Through simulation BER performance of system with different receiver structures is analyzed.