• Title/Summary/Keyword: High Rate UWB

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6Bit 2.704Gs/s DAC for DS-CDMA UWB (DS-CDMA UWB를 위한 6Bit 2.704Gs/s DAC)

  • Jung, Jae-Jin;Koo, Ja-Hyun;Lim, Shin-Il;Kim, Suki
    • Proceedings of the IEEK Conference
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    • 2006.06a
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    • pp.619-620
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    • 2006
  • This paper presents a design of a 6-bit 2.704Gsamples/s D/A converter (DAC) for DS-CDMA UWB transceivers. The proposed DAC was designed with a current steering segmented 4+2 architecture for high frequency sampling rate. For low glitches, optimized deglitch circuit is adopted for the selection of current sources. The measured integral nonlinearity (INL) is -0.081 LSB and the measured differential nonlinearity (DNL) is -0.065 LSB. The DAC implemented in a 0.13um CMOS technology shows s spurious free dynamic range (SFDR) of 50dB from dc to Nyquist frequency. The prototype DAC consumes 28mW for a Nyquist sinusoidal output signal at a 2.704Gsamples/s. The chip has an active area of $0.76mm^2$.

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Adaptive Dual-Hop Transmission Based On Hierarchical Modulation in UWB System (초광대역 시스템의 계층변조 기반 적응적 듀얼 홉 전송 기법)

  • Kim, Dae-Hwan;Song, Hyoung-Kyu;Cho, We-Duke
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.36 no.7C
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    • pp.443-450
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    • 2011
  • Recently, various transmission techniques for communication and broadcasting systems have been developed to meet the dramatically increasing requirement of consumers. Because UWB (Ultra-Wideband) is a wireless communication technique that supports high data rate with low power, it can satisfy the requirement and can be applied to various wireless communication services. The multi-band orthogonal frequency division multiplexing (MB-OFDM) system, one of UWB system, is the wireless communication system that satisfies the transmission characteristic for UWB and so it can be used for various wireless communication services. In this paper, we propose a scheme that uses hierarchical modulation which is applied in digital video broadcasting system at the source and adaptive modulation based on the channel quality at the relays. The simulation results have shown that the proposed scheme has both the advantages of the increased throughput by 33% and similar BER performance to conventional scheme.

Implementation of Uncompressed Video Transmission System for Wireless Video Mirroring Service in Portable Multimedia Devices (휴대용 멀티미디어 기기에서의 무선 영상 미러링 서비스를 위한 비압축 영상 전송 시스템의 구현)

  • Lee, Sangjae;Jeon, Youngae;Choi, Sangsung;Cho, Kyoung-Rok
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.38A no.4
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    • pp.381-391
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    • 2013
  • Wireless transmission of uncompressed video guarantees higher quality with lower latency than compressed video transmission. Although current wireless technologies cannot fully cover required data rates of about a few Gb/s for full high definition resolution, some wireless technologies such as ultra-wideband (UWB) provide 1 Gb/s data rate which is adequate for uncompressed video transmission in portable devices. In this paper, we propose an uncompressed video transmission system for wireless mirroring services in portable devices. We firstly simulated the performance of uncompressed video transmission using single or multiple 1 Gb/s UWB technology. Then we implemented hardware-based uncompressed video processing block and Gb/s wireless MAC accelerator. Finally, we show the implementation result and the demonstration of uncompressed HD video transmission using multiple 1 Gb/s UWB PHYs.

A Initial Channel Estimation Method Based on Extensive Preamble Utilization in MB-OFDM UWB System (프리엠블 확장 사용 기반 MB-OFDM UWB용 채널 추정 방식)

  • Jeong, Jin-Doo;Jin, Yong-Sun;Chong, Jong-Wha
    • 전자공학회논문지 IE
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    • v.48 no.1
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    • pp.30-35
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    • 2011
  • In this paper, we propose a method to improve the performance of initial channel estimation (CE) for the multiband-OFDM (MB-OFDM) UWB. The performance of the initial CE can be generally improved as increasing the number of the used preamble symbols. The MB-OFDM specification presents two CE symbols per band in preamble format. The performance of CE estimation with two CE symbols may be satisfied in relatively high sensitivity -77.5 and -72.5 dBm for 200 Mbps and 480 Mbps data rate, respectively, but can not be enough in the degraded 55 Mbps and 110 Mbps sensitivities such as -83.5 and -80.5 dBm, respectively. A method proposed in this paper achieves the performance improvement by extending CE estimation region to packet synchronization (PS) symbols and frame synchronization (FS) symbols including two CE symbols. This can improve the CE performance in the degraded SNR and increase the link-margin by reducing the error rate in physical-layer header. The link-margin improvement obtained by the proposed CE preamble can induce the decrease of error-rate in physical-layer header and increase of communication throughput. Simulation results for the proposed initial method show that the performance is improved by about 0.7 dB at 10-4 bit-error-rate using '4' symbols than initial method using only two CE symbols.

Transmitted Reference UWB Systems Based on Block-Coded Modulation (블럭부호변조 기반의 Transmitted Reference 광대역 통신 시스템)

  • Min, Seungwook
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.38A no.3
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    • pp.289-293
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    • 2013
  • In the noncoherent methods for UWB-IR (ultra-wideband impulse radio), block coded modulation (BCM) is better than the transmitted reference (TR) systems in terms of the energy efficiency and data rate. However, even BCM suffers from the performance degradation in the presence of strong inter-frame interference and inter symbol interference. We propose the transmitted reference based on the BCM (TR-BCM) which is the hybrid system of TR and BCM. Performance evaluation shows that the performance of TR-BCM is better than that of BCM in the high SNR range.

UWB RADAR based Modified Adaptive CFAR Algorithm for improved safety of Personal Rapid Transit (무인 궤도 차량의 안전성 제고를 위한 UWB 레이더 기반 적응형 CFAR 알고리즘)

  • Hong, Seok-Gon;Kim, Baek-Hyun;Jeong, Rag-Gyo;Kwak, Kyung-Sup
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.12 no.1
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    • pp.28-42
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    • 2013
  • Personal Rapid Transit(PRT) is a new unmanned transportation system using electricity. The purpose of the PRT is relieving the congestion of city traffic and connecting between inner city and airport, high-speed railroad. PRT requires to develop devices for the guarantee of safety and reliability. PRT as the mean of rail transportation must be equipped with control system for front rail sensing. Ultra Wide Band(UWB) radar system is suitable for PRT's detection because it has the advantage of low power consumption, low interference and high resolution. In this paper, an improved adaptive Constant False Alarm Rate(CFAR) algorithm is proposed and studied in various noise environments. The proposed algorithm improves performance in various noise environments compared to the Mean Level CFAR algorithms and other adaptive CFAR algorithms.

Performance Analysis of Noncoherent OOK UWB Transceiver for LR-WPAN (저속 WPAN용 비동기 OOK 방식 UWB 송수신기 성능 분석)

  • Ki Myoungoh;Choi Sungsoo;Oh Hui-Myoung;Kim Kwan-Ho
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.30 no.11A
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    • pp.1027-1034
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    • 2005
  • IEEE802.15.4a, which is started to realize the PHY layer including high precision ranging/positioning and low data rate communication functions, requires a simple and low power consumable transceiver architecture. To satisfy this requirements, the simple noncoherent on-off keying (OOK) UWB transceiver with the parallel energy window banks (PEWB) giving high precision signal processing interface is proposed. The flexibility of the proposed system in multipath fading channel environments is acquired with the pulse and bit repetition method. To analyze the bit error rate (BER) performance of this proposed system, a noise model in receiver is derived with commonly used random variable distribution, chi-square. BER of $10^{-5}$ under the line-of-sight (LOS) residential channel is achieved with the integration time of 32 ns and signal to noise ratio (SNR) of 15.3 dB. For the non-line-of-sight (NLOS) outdoor channel, the integration time of 72 ns and SNR of 16.2 dB are needed. The integrated energy to total received energy (IRR) for the best BER performance is about $86\%$.

A MAC Design for Collision Avoidance in Wireless USB Home Networks (WUSB 홈네트워크에서의 충돌회피를 위한 MAC설계)

  • Sim, Jae-Hwan
    • The Journal of the Korea institute of electronic communication sciences
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    • v.8 no.1
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    • pp.55-64
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    • 2013
  • The USB-IF has specified a Wireless USB (WUSB) protocol based on UWB for high speed wireless home networks and WPANs. In this paper, firstly, performance degradation due to the Private Distributed Reservation Protocol (DRP) conflict problem caused by devices' mobility is analyzed. And a novel relay transmission protocol combined with Private DRP conflict resolution is proposed to overcome the performance degradation at Private DRP conflicts. In order to give the loser device due to Private DRP conflicts another chance to maintain resources, the proposed relay transmission protocol executed at each device helps the loser device reserve another indirect link maintaining the required resources via a relay node.

The Calculation of the Exact BER of UWB-TH BPSK Communication systems with the Multiple User Interference (다중 사용자 간섭을 고려한 TH-BPSK UWB 통신 시스템의 정확한 BER 계산)

  • Park, Jang-Woo;Choi, Yong-Seok;Cho, Kyung-Ryong
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.9 no.5
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    • pp.951-957
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    • 2005
  • The bit error probability of UWB Time-Hopping(TH) multiple access communication systems combined with BPSK is calculated with a high accuracy including the multiple user interference(MUI). This paper finds that with some manipulations, the TH-BPSK UWB signal can be modified to the similar form of the DS-CDMA signal. The MUI in the system is explained by the characteristic function technique. Above two descriptions have been bases on the derivation of the exact BER expression of the system. We also propose the approximate expression for the BER, which has enough accuracy compared with the expression from the Gaussian approximation of the MUI. The comparison of the results from the proposed expressions with the simulation results gives the confirmation for the validity and accuracy of the proposed expressions.

STCDD Cooperative Transmission Scheme for Improvement of Reliability in OFDM Based UWB System (OFDM 기반 UWB 시스템의 신뢰도 향상을 위한 STCDD 협력 전송 기법)

  • Song, Hyoung-Kyu;Song, Jin-Hyuk;Yoon, Jae-Seon
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.35 no.6A
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    • pp.547-554
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    • 2010
  • Recently, the multi-band orthogonal frequency division multiplexing(MB-OFDM) system, one of UWB system, can satisfy the requirement and can be applied to various wireless communication services because ultra-wideband(UWB) is a wireless communication technique that supports high data rate with low power. In this paper, the method applying Alamouti's space time block code(STBC) and cyclic delay diversity(CDD) is proposed. The proposed method can be easily applied with arbitrary number of relays and only needs two time slots of quasi stationary assumption. And it is applied to the MB-OFDM system. Second, an optimal relaying scheme based on decode-and-forward(DF) method is proposed which is provides good error performance compared to conventional schemes.