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In this paper, the location estimation of the human body with UWB radar is studied by the computer simulation with real measurements of channel response, and dependence of antenna height of the UWB radar on the detection capability is evaluated. Also, in order to improve detection accuracy, the use of pre-measured ambient response without human body is evaluated. As a result, effectiveness of using...
The detector proposed in this paper tries to address the challenge of low signal-to-noise ratio signal detection in low-complexity MB-OFDM UWB receivers. The idea is to exploit the 128-point FFT of the UWB receiver to carry out frequency-domain energy detection. The main advantage of the proposed detector is that it only requires a memory buffer the size of the UWB receiver FFT, which makes it lighter...
The present article describes the experimental result of victim system detection by UWB wireless system to contribute for Japanese UWB regulatory discussion, in which a mitigation, including detect-and-avoid (DAA), technology implementation in the frequency range of 3.4 to 4.8 GHz is a major technical topic. A FPGA based MB-OFDM UWB receiver with 528 MHz sampling rate and 128 points FFT capability...
In most Asian and European countries, detect-and-avoid (DAA) is required at UWB low band (3.1-4.8 GHz). In Japan, we conducted evaluation experiments on the performance of DAA until March of 2010, which was a part of a three-year campaign to provide results of literature review and technical evaluation for the purpose of accomplishing Japanese UWB regulation. In this paper, experiment results on the...
This paper presents evaluation on avoidance capability of a tunable notch filter (TNF) in IR-UWB systems. The TNF enables to control the frequency where a single frequency notch is generated by changing the DC voltage into the capacitance in the TNF. We showed test results on coexistence between QPSK and IR-UWB systems. The results show that the TNF successfully avoids the interference from the UWB-IR...
This paper proposes a new method based on the combination of a soft-decision ranging and Maximum A Posteriori (MAP) estimation for Impulse Radio type Ultra Wide Band (UWB-IR) Time of Arrival (TOA) localization. The soft-decision ranging assigns the probability of being generated by a signal to each component in the observed instantaneous power delay profile (the probability density function (pdf)...
A measurement campaign has been carried out in Japan to evaluate UWB technology for both aggregation characteristics and coexistence performance. Different from other previous studies, our evaluation is based on measurements with real devices. We examined both UWB low band and UWB high band, the latter has rarely been investigated by others. UWB aggregation results with real measurements are also...
This paper provides channel models for wireless body area network (WBAN) in UWB frequency band, and also presents performance evaluation using the derived channel models. The channel model is given by a statistical model in which parameters are derived from actually measured channel transfer function in a hospital room environment. These models enable us to evaluate performance of UWB-based WBAN....
This paper presents two tunable notch filters (TNFs) for detect-and-avoid (DAA) implementation in an ultra-wideband (UWB) radio system. The developed filters have relatively wide- and narrow-stopband, respectively, using two different resonant structures. A system experiment has been carried out to evaluate the influence of bandwidth of notch band on the system performance when the two different filters...
In 2007, IEEE802.15.4a was standardized as a low-rate and low-power UWB system for sensor networks. In general, detection of the IEEE802.15.4a signal is considered to be difficult because of its low transmitting power density and low duty cycle. However, if detecting of the IEEE802.15.4a signal is available, it is possible to avoid interference issues both among the 15.4a systems and between the 15...
A new major application of UWB is medical healthcare using advantages of low power spectrum density, high capacity of transmission and accurate ranging. As a core network of medical healthcare based on ICT, i.e. medical ICT, a body area network (BAN) has been researched and developed. BAN can provide a wide range of applications in primary for medical healthcare such as tele-metering vital sign, e...
We developed a detect-and-avoid (DAA) method for single-carrier ultra wideband (SC-UWB) systems. The method is simple and pragmatic. It uses frequency domain equalization (FDE) and incorporates a tunable notch Alter. Using computer simulations, we evaluated both the probability of detecting a narrow band (NB) signal and the reduction of interference level caused by a UWB system to an NB system. The...
This paper presents a wireless vital sign monitoring system using IEEE802.15.4a standard based on ultra wideband (UWB) wireless communications. The vital signs are categorized into continuous and routine vital signs; the continuous signs include electrocardiogram (ECG), and the routine ones cover blood pressure, oxygen saturation, and body temperature. To conduct both tasks simultaneously, a superframe...
Modelling of path loss behaviour in ultra wideband radio channels was revisited. Although simple but realistic standardized channel models have already been established, this paper attempts to provide detailed insights about the precision of the standardized model based on an extensive measurement campaign which covered whole areas inside an office room. Attention was paid to the frequency and distance...
This paper presents a performance evaluation in terms of bit error rate (BER) of a 26 GHz-band ultra-wideband (UWB) communication system through measurement-based simulation. We measured real channel responses in an office to obtain responses for use in simulations. The simulation results demonstrate that the 26-GHz-band UWB system can achieve high-speed data transmission of 500 Mbps or more, in and...
This paper presents a precise leading edge detection using a forward error correction (FEC) coding, for providing accurate ranging results in multipath fading channels. Highly dispersive nature of ultra-wideband (UWB) channels make time-of-arrival (TOA) estimation extremely challenging, where the leading-edge path is not necessarily the strongest path (peak path). In this paper, we consider a leading...
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