• Title/Summary/Keyword: ultra wideband signal

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Novel UWB Transceiver for WBAN Networks: A Study on AWGN Channels

  • Zhao, Chengshi;Zhou, Zheng;Kwak, Kyung-Sup
    • ETRI Journal
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    • v.32 no.1
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    • pp.11-21
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    • 2010
  • A novel ultra-wideband (UWB) transceiver structure is presented to be used in wireless body area networks (WBANs). In the proposed structure, a data channel and a control channel are combined into a single transmission signal. In the signal, a modulation method mixing pulse position modulation and pulse amplitude modulation is proposed. A mathematical framework calculating the power spectrum density of the proposed pulse-based signal evaluates its coexistence with conventional radio systems. The transceiver structure is discussed, and the receiving performance is investigated in the additive white Gaussian noise channel. It is demonstrated that the proposed scheme is easier to match to the UWB emission mask than conventional UWB systems. The proposed scheme achieves the data rate requirement of WBAN; the logical control channel achieves better receiving performance than the logical data channel, which is useful for controlling and maintaining networks. The proposed scheme is also easy to implement.

A Joint Timing Synchronization, Channel Estimation, and SFD Detection for IR-UWB Systems

  • Kwon, Soonkoo;Lee, Seongjoo;Kim, Jaeseok
    • Journal of Communications and Networks
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    • v.14 no.5
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    • pp.501-509
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    • 2012
  • This paper proposes a joint timing synchronization, channel estimation, and data detection for the impulse radio ultra-wideband systems. The proposed timing synchronizer consists of coarse and fine timing estimation. The synchronizer discovers synchronization points in two stages and performs adaptive threshold based on the maximum pulse averaging and maximum (MAX-PA) method for more precise synchronization. Then, iterative channel estimation is performed based on the discovered synchronization points, and data are detected using the selective rake (S-RAKE) detector employing maximal ratio combining. The proposed synchronizer produces two signals-the start signal for channel estimation and the start signal for start frame delimiter (SFD) detection that detects the packet synchronization signal. With the proposed synchronization, channel estimation, and SFD detection, an S-RAKE receiver with binary pulse position modulation binary phase-shift keying modulation was constructed. In addition, an IEEE 802.15.4a channel model was used for performance comparison. The comparison results show that the constructed receiver yields high performance close to perfect synchronization.

Distance Estimation Using Convolutional Neural Network in UWB Systems (UWB 시스템에서 합성곱 신경망을 이용한 거리 추정)

  • Nam, Gyeong-Mo;Jung, Tae-Yun;Jung, Sunghun;Jeong, Eui-Rim
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.23 no.10
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    • pp.1290-1297
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    • 2019
  • The paper proposes a distance estimation technique for ultra-wideband (UWB) systems using convolutional neural network (CNN). To estimate the distance from the transmitter and the receiver in the proposed method, 1 dimensional vector consisted of the magnitudes of the received samples is reshaped into a 2 dimensional matrix, and by using this matrix, the distance is estimated through the CNN regressor. The received signal for CNN training is generated by the UWB channel model in the IEEE 802.15.4a, and the CNN model is trained. Next, the received signal for CNN test is generated by filed experiments in indoor environments, and the distance estimation performance is verified. The proposed technique is also compared with the existing threshold based method. According to the results, the proposed CNN based technique is superior to the conventional method and specifically, the proposed method shows 0.6 m root mean square error (RMSE) at distance 10 m while the conventional technique shows much worse 1.6 m RMSE.

Performance of M-ary PPM UWB Radio in Fading Channels

  • Mohammed, Abdel-Hafez;Alagoz, Fatih;Hamalainen, Matti
    • Journal of Communications and Networks
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    • v.5 no.4
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    • pp.365-373
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    • 2003
  • This paper investigates the performance of M-ary pulse position modulation (PPM) multiuser ultra-wideband (UWB) communication systems in terms of symbol error rate (SER) over fading and additive white Gaussian noise (AWGN) channel. Based on Gaussian approximation for the multiple access interference, an expression for the signal-to-noise ratio (SNR) is derived for the UWB system. This expression is used to derive exact SER expressions for coherent UWB receivers. The effect of pulse selection on the SER of multiuser UWB system is studied. In addition to rectangular pulse, the 2nd derivative Gaussian waveform and Rayleigh pulses were considered. We show that the system capacity and/or SER performance can be significantly increased by using the monocycle pulse in fading channels.

Secret Key Generation Using Reciprocity in Ultra-wideband Outdoor Wireless Channels

  • Huang, Jing Jing;Jiang, Ting
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.8 no.2
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    • pp.524-539
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    • 2014
  • To investigate schemes of secret key generation from Ultra-wideband (UWB) channel, we study a statistical characterization of UWB outdoor channel for a campus playground scenario based on extensive measurements. Moreover, an efficient secret key generation mechanism exploiting multipath relative delay is developed, and verification of this algorithm is conducted in UWB Line-of-sight (LOS) outdoor channels. For the first time, we compare key-mismatch probability of UWB indoor and outdoor environments. Simulation results demonstrate that the number of multipath proportionally affects key generation rate and key-mismatch probability. In comparison to the conventional method using received signal strength (RSS) as a common random source, our mechanism achieves better performance in terms of common secret bit generation. Simultaneously, security analysis indicates that the proposed scheme can still guarantee security even in the sparse outdoor physical environment free of many reflectors.

Study on the Ultra-Wideband Microwave Amplifier Design for MMIC (MMIC용 초광대역 마이크로파 증폭기설계에 관한 연구)

  • 이영철;신철재
    • The Proceeding of the Korean Institute of Electromagnetic Engineering and Science
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    • v.3 no.1
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    • pp.11-19
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    • 1992
  • To design of Ultra-wideband amplifier, we analyzed the inductor peaking to reduce the capacitance effect of GaAs MESFET in upper frequency edge. And we deduced an optimun inductor peaking element from transfer function of GaAs MESFET small-signal equivalent circut and realized the Feedback Amplifier Module (FAM) having flat gain. We design the imput and output impe dance matching networks by Real-Frequency Method. It show that the gain of designed amplifier has a 6.38dB with gain variation 0.56 at 0.1~12 GHz frequency gand by computer simu-lation.

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Multi-Antenna Noncoherent ML Synchronization for UWB-IR Faded Channels

  • Baccarelli Enzo;Biagi Mauro;Pelizzoni Cristian;Cordeschi Nicola
    • Journal of Communications and Networks
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    • v.8 no.2
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    • pp.194-204
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    • 2006
  • This contribution focuses on the maximum likelihood (ML) noncoherent synchronization of multi-antenna transceivers working in faded environments and employing ultra-wideband impulse radio (UWB-IR) transmit technology. In particular, the Cramer-Rao bound (CRB) is derived for the general case of multiple input multiple output (MIMO) UWB-IR systems and used to compare the ultimate performance of three basic transmit schemes, thereinafter referred to as single input multiple output (SIMO), MIMO equal signaling (MIMO-ES), and MIMO orthogonal signaling (MIMO-OS) ones. Thus, the noncoherent ML synchronizer is developed for the better performing transmit scheme (i.e., the SIMO one) and its performance is evaluated under both signal acquisition and tracking operating conditions. The performance gain in the synchronization of UWB- IR signals arising by the utilization of the multi-antenna technology is also evaluated.

Performance Analysis of M-ayy PPM Ultra-wideband Multiple Access Systems Using Gaussian Monopulse (가우시안 모노펄스를 이용하는 M-ary PPM 초광대역 다중접속시스템의 성능해석)

  • Kwak, Jae-Min;Lee, Sung-Chul;Cho, Sarm-Goo;Cho, Sung-Joon
    • Proceedings of the Korea Electromagnetic Engineering Society Conference
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    • 2003.11a
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    • pp.229-233
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    • 2003
  • In this paper we theoretically analyze the probability of error for M-ary pulse position modulation (PPM) ultra-wideband (UWB) multiple access system using Gaussian monopulse. The optimum detection of UWB signals using M-ary orthogonal PPM in additive white Gaussian noise (AWGN) and multiple access interference (MAI) is considered, then receiver signal to noise power ratio (SNR) and upper bound fur the bit error rate (BER) are derived. Numerical results considering some practical parameters are presented.

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Performance Analysis of Ultra Wideband Communication System in Fading Environment using Nakagami m-distribution Model (나카가미 m-분포 모델을 이용한 페이딩 환경에서 초광대역 통신 시스템의 성능 해석)

  • 이양선;김지웅;강희조
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.8 no.1
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    • pp.41-48
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    • 2004
  • In this paper, we analyzed channel performance of PPM modulated UWB communication system in indoor radio fading environment that consider amplitude characteristic of channel. Fading channel considered various channel environments by fading index m utilizing Nakagami-m distribution model with data through an UBW radio signal experiment that announced in existing. Also, we improved performance of system that it is decreased in fading environment employing convolution encoding techniques.

Non-Data-Aided Weighted Non-Coherent Receiver for IR-UWB PPM Signals

  • Shen, Bin;Yang, Rumin;Cui, Taiping;Kwak, Kyung-Sup
    • ETRI Journal
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    • v.32 no.3
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    • pp.460-463
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    • 2010
  • This letter proposes an energy-detection-based non-data-aided weighted non-coherent receiver (NDA-WNCR) scheme for impulse radio ultra-wideband (IR-UWB) pulse-position modulated signals. Compared to the conventional WNCR, the optimal weights of the proposed NDA-WNCR are tremendously simplified as the maximum eigenvector of the IR-UWB signal energy sample autocorrelation matrix. The NDA-WNCR serves to blindly obtain the optimal weights and entirely circumvent the transmission of training symbols or channel estimation in practice. Analysis and simulation results verify that the bit error rate (BER) performance of the NDA-WNCR closely approaches the ideal BER of the conventional WNCRs.