• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.19 no.3
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• pp.384-390
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• 2008

Chaotic OOK modulation method can be used in LDR(Low Data Rate) UWB systems. In this paper, UWB chaotic-OOK transmitter system is designed and verified using TSMC 0.18 um CMOS process. A transmitter system is composed of Quasi-chaotic signal generator, OOK Modulator, and driving amplifier. The traditional chaotic signal generators using analog feedback method is weak to process variation. In order to solve this problem, a quasi-chaotic signal generator using digital feedback technique is get wide band signal and OOK Modulator using T-type switching structure is used to enhance the isolation characteristic. A driving amplifier has differential to single structure to avoid an external balun for low cost communication. The measured output power spectrum of the transmitter meet the FCC regulation and the result of the modulation test at data rate of 20 Kbps, 200 Kbps, 2 Mbps, and 10 Mbps is conformed to LDR UWB system. It is shown that the transmitter in this paper can be used for the UWB chaotic-OOK system.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.18 no.1 s.116
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• pp.90-95
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• 2007

Chaotic OOK(On-Off Keying) modulation method can be used in LDR(Low Data Rate) UWB systems. The chaotic generator in one of the most important circuit in this system. The traditional chaotic generator circuits using analog feed back technique have low yield characteristic due to the process variation. A novel quasi-chaotic signal generator using digital PN-sequence in proposed in this paper and verified in 0.18um CMOS teleology.

• Journal of Broadcast Engineering
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• v.12 no.2
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• pp.148-158
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• 2007

Recently, IEEE 802.15.4a(low-rate UWB) technique has been paid much attention to the LR-UWB communication system for WPAN. However, there are various interferences such as MPI(Multi Path Interference) or IPI(Inter Piconet Interference) in IEEE 802.15.4a wireless channel. In order to cancel various interferences occurred to WPAN environment, in this paper, we propose a UWB wireless communication system with high QoS(Quality of Service) which is a chaotic-OOK(On-Off Keying) system using unipolar ZCD(Zero Correlation Duration) spreading code in physical layer level. Furthermore, we analyze its performance via simulations and verify the availability of proposed system with prototype implementation.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• v.2
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• pp.311-315
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• 2006

Precision location and positioning of Asset within a network is an attractive feature with various applications, especially in indoor environments. Such a demand is met by the standard task group, IEEE 802.15.4a. Several methods, that is, pulse, chirp and chaotic communications have been proposed so far to satisfy the requirements of the standard. Among them, ultra wideband direct chaotic communications has advantageous features such as low hardware complexity, low cost, lower power consumption and flexible frequency band plan. In this paper, the feasibility of the ranging system using non-coherent chaotic transceiver is investigated by designing and implementing the system and the performance is proved by conducting location experiments in real indoor environments.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2006.11a
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• pp.179-183
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• 2006

현재 WPAN(Wireless Personal Area Network) 전송기술의 하나인 IEEE 802.15.4a의 저속형 UWB(Ultra Wide Band) 기술이 활발하게 연구되어지고 있다. 하지만 IEEE 802.15.4a에서 제시된 WPAN 전송채널의 경우에는 심각한 멀티패스 간섭성분이 존재하여 이에 대한 해결방안이 절실히 요구되어지고 있다. 따라서 본 논문에서는, WPAN환경에서 전송채널의 심각한 멀티패스 성분을 물리계층(Physical layer) 레벨에서 근원적으로 해결하여 높은 QoS(Quality of Service)를 확보하게 해줄 수 있는 단극형 ZCD(are Correlation Duration)확산코드 기반의 Chaotic-OOK (On-Off Keying) 무선통신기술을 제안하고 IEEE 802.15.4a 채널 환경하에서의 모의실험을 통한 성능평가를 통해 제안한 무선통신기술의 유용성을 입증하였다.