• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.32 no.11A
• /
• pp.1086-1095
• /
• 2007

This paper proposes a novel non-coherent TOA estimation scheme using multiple correlation process on the existence of multiple simultaneously operating piconets (SOPs). Impulse radio-ultra wideband (IR-UWB) based on direct sequence spread spectrum (DSSS) using Gold sequence is employed in order to discriminate each piconet. In order to enhance the characteristic of correlation, this paper presents the method of multiple mask operation (MMO). The time of arrival (TOA) of direct line of sight (DLOS) path is estimated via two step coarse/fine timing detection. To verify the performance of proposed scheme, two distinct channel models approved by IEEE 802.15.4a Task Group (TG) are considered. According to the simulation results, it could conclude that the proposed scheme have performed better performance than the conventional method well even in densed indoor multi-path environment as well as in the existence of multiple SOPs.

• Journal of the Institute of Electronics Engineers of Korea TC
• /
• v.45 no.7
• /
• pp.38-44
• /
• 2008

In this paper, we introduce an low complexity and low power IR-UWB (impulse radio ultra wideband) baseband transceiver for wireless sensor network. The proposed baseband, implemented by TSMC 0.18um CMOS technology, has a simple structure in which a simplified packet structure and a digital synchronizer with 1-bit sampler to detect incoming pulses are used. Besides, clock gating method using gated clock cell as well as customized clock domain division can reduce the total power consumption drastically. As a result, the proposed baseband has about 23K digital gates with an internal memory of 2Kbytes and achieves about 1.8mW@1Mbps power consumption.

• Proceedings of the IEEK Conference
• /
• 2000.09a
• /
• pp.589-592
• /
• 2000

무선 LAN은 유선 LAN을 대체하기 보다는 기간망과 이동(Mobile) 사용자간의 수십 미터 이내의 종단 연결점을 제공한다는 개념으로 구성되며, 이동성(Mobility)과 확장성(Scalability)을 발휘할 수 있다는 장점으로 많은 응용 분야에서 각광을 받고 있다. 초광대역 시간 도약(ultra wideband time hopping; UWB/TH) 임펄스 무선기술은 기존 시스템의 정상적인 동작에 거의 영향을 미치지 않기 때문에 별도의 주파수 할당이 필요치 않는 새로운 기술이다. 본 논문에서는 IEEE 802.11의 무선 LAN의 프로토콜을 기적으로 사용하고 전송 방식을 직접수열 확산 스펙트럼 방식을 사용하는 기존의 방법과 임펄스 라디오 방식을 사용하는 경우를 비교하였다.

• Journal of Advanced Navigation Technology
• /
• v.13 no.4
• /
• pp.515-522
• /
• 2009

In this paper, we have investigated the technology of location-aware applicable for ubiquitous environment and considered IEEE 802.15.4a IR UWB of location-aware WPAN specification which is capable of both communication of 1Mbps and wireless localization. We analyzed both system structure and the characteristic of transmission pulse as comprising of the transmitter for wireless localization of IR UWB.

• ETRI Journal
• /
• v.28 no.1
• /
• pp.91-94
• /
• 2006

Impulse radio (IR) is a competitive candidate for ultra-wideband (UWB) systems. In this letter, we evaluated the coexistence of an IR-UWB system based on an orthogonal sinusoidal correlation receiver (OSCR) with an IEEE 802.11a WLAN through a detailed simulation. The coexistence performance of the two systems is characterized in terms of the receiver's bit-error rates. Then, some approaches to interference mitigation are discussed.

• Journal of Digital Contents Society
• /
• v.5 no.3
• /
• pp.171-175
• /
• 2004

In this paper, We applied CCI canceller to remove multi-user interference in co-channel environment and improved performance of TH PPM UWB-IR system. As a result, We could get reception performance that data transmission of high speed is available in small reception power applying CCI canceller. Also, We could get permission available channel capacity to maximum access number 40 in high speed transmission environment more than 100Mbps.

• JSTS:Journal of Semiconductor Technology and Science
• /
• v.16 no.4
• /
• pp.415-424
• /
• 2016

This paper describes a high data rate proximity transmitter design for high resolution smartphone-mirrored display applications. A 2 Gb/s transmitter is designed with a low transmission power of -70 dBm/MHz and a wide bandwidth of nearly 3 GHz. A digital pre-correction method is employed in the transmitter to mitigate the inter-symbol interference problem. A carrier-based digital pulse shaping and a reconfigurable digital envelope generation methods are employed for robust operation by utilizing 20 phases from a 2 GHz phase-locked loop. A 6.5-9.5 GHz transmitter implemented in 65 nm CMOS achieves the maximum data rate of 2 Gb/s, consuming only 7.6 mW from a 1 V supply.

• Proceedings of the KIEE Conference
• /
• 2005.07c
• /
• pp.2339-2341
• /
• 2005

본 논문은 주파수 영역과 시간 영역에서 초광대역 (Ultra Wideband UWB) 안테나의 임펄스 응답 특성을 고려한 채널측정 연구에 대해 발표하고자 한다. 임펄스 전파 채널 측정을 위해 UWB conical monopole 안테나를 설계하였고, 설계한 안테나의 임펄스 응답을 도출하였다. 안테나의 특성이 임펄스 전파 채널측정에 주는 영향을 무반향 반사실에서 다중경로 환경과 무반사 환경을 구현하여 측정하였다. 측정을 통하여 안테나의 dispersive한 특성과 ringing이 임펄스 전파 채널에 영향을 미침을 확인했고, 이러한 결과를 바탕으로 정확한 임펄스 채널 측정을 위해 사용한 UWB 안테나의 특성을 고려해야 함을 확인하였다.

• Proceedings of the Korean Society of Broadcast Engineers Conference
• /
• 2018.11a
• /
• pp.29-32
• /
• 2018

본 논문에서는 IR-UWB(Impulse-Radio Ultra Wideband) 레이더와 서보 모터를 이용한 실내 환경의 물체 위치(거리, 각도) 탐지 방법을 제안한다. 기존의 카메라나 적외선을 사용한 기술은 비용이 비싸고 장애물이 있을 시 측정이 어려워 정확도가 떨어지는 단점을 가지고 있다. 반면 IR-UWB 레이더는 저 전력, 저 가격, 소형으로 구현이 가능하고 광대역을 사용하여 투과성이 좋다는 장점을 가져 실내 환경의 물체 움직임 탐지에 적합하다. 하지만 IR-UWB 레이더를 이용한 물체 탐지 시 각도 측정 없이 거리만을 측정하기 때문에 물체의 정확한 위치를 탐지할 수 없다. 이러한 점을 보완하고자 레이더를 모터 위에 설치하고 모터를 180 도 회전시키는 방법을 사용함으로써 넓은 측정 범위를 가짐과 동시에 물체의 위치를 보다 정확히 탐지해내는 결과를 보였다.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.35 no.11A
• /
• pp.1085-1090
• /
• 2010

Ultra wideband (UWB) technologies have been developed to exploit a new spectrum resource in substances and to realize ultra-high-speed communication, high precision geolocation, and other applications. The energy of UWB signal is extremely spread from near DC to a few GHz. This means that the interference between conventional narrowband systems and UWB systems is inevitable. However, the interference effects had not previously been studied from UWB wireless systems to conventional mobile wireless systems sharing the frequency bands such as Cellular CDMA and Korean PCS. This paper experimentally evaluates the interference from two kinds of UWB sources, namely a direct-sequence spread-spectrum UWB source and an impulse radio UWB source, to a Cellular CDMA and K-PCS digital transmission system. The average frame error rate degradation of each system arc presented. From these experimental results, we show that in all practical cases UWB system can coexist with Cellular CDMA and K-PCS terminal without causing any dangerous interference.