UWB Through-the-wall Detection and Communication System Demonstration
Overview of IR-UWB
- Low energy level, High bandwidth, Short-range high-speed communications.
- FCC definition: bandwidth exceeds 500MHz or 20% of the center frequency.
- Unlicensed use of UWB in 3.1 to 10.6GHz, power spectral density emission limit for UWB is -41.3dBm/MHz.
- IR-UWB, DS-UWB, OFDM-UWB.
Impulse-Radio Ultra-wideband (IR-UWB)
- Short duration pulse(ns), no carrier wave.
- Higher range measurement accuracy and resolution.
- Increased immunity to RFI.
- Low energy consumption, and potential for simple and real-time implementations
- Can easily pass through obstacles.
- Demonstrate the UWB technology can be used in detection and positioning
- Research on UWB radar and communication system design;
- Localizing authorized persons;
- Security and military applications;
- Search and rescue victims after avalanche or earthquake;
- Medical applications;
Outcome and Performance
- UWB device for Through-the-wall communication and detection;
- More than 5 sensor nodes deployed;
- Penetrating ability>30cm thickness wall;
- Detection range>15m, communication range>20m;
- 30cm position accuracy;
- Data rate>10Mbps;
- Battery powered and hand-held.
- Radio propagation and channel modeling, radar scattering.
- UWB RF front-end and antenna design, compatible to Radar and Communication;
- High-speed sampling and signal processing baseband design;
- Radar detection and clutter-reduction algorithm;
- TOA ranging and NLOS mitigation;
- Data Fusion, matching and positioning;
- Communication algorithm: modulation, demodulation, coding;
- Network protocol design.
My Project Work
I have had the opportunity to lead the team for this 863 national project: “UWB Through-the-wall Detection and Communication System Demonstration, ” No.2009AA011204. I hosted the weekly meeting and pushed the team forward-moving. My contribution to this project is significant. I designed the high-speed realtime sampling and processing platform (32Gbps), designed and implemented parallel radar detection, communication transceiver, parameter estimation algorithms in FPGA (1517 pins). I cooperated with the RF team for clock synchronization, adaptive gain control, power management, and IQ dual channel sampling; I teamed with networking labs for protocol design and upper layer data traffic. This project in particular allowed me to experience teamwork and cross-layer collaboration. In addition, it was gratifying and stimulating, because the project was reported on National news, and my designed hardware platform serves followup projects for many years.
My Thesis Work
I proposed a new UWB receiver architecture for compact, hybrid communication and radar devices that could move forward the estimation into the digital sampling stage (one first-author patent: CN102360070B, four published papers). This architecture aims to solve the bottleneck in UWB technique: digital sampling and processing poses stringent challenges to hardware complexity and power consumption. Compared with the state of the art systems, the experiment results of the developed prototype system demonstrates significant device power, size and cost reduction, at the same time realizes hybrid functionality for communication, detection and localization.
I built the whole system from scratch with compact RF module, low-complexity sampling and decision, FPGA and DSP processing. The receiver architecture is patented (first author).
- Liu, K., Yin, H., and Chen, W. (2011) “Low Complexity Tri-level Sampling Receiver Design for UWB Time-of-Arrival Estimation.” in Proc. Int. Conf. Communication(ICC2011), Kyoto, Japan. [IEEE Xplore] [pdf]
- Liu, K., Xu, H., et al, (2010) “Odd-Symmetry Template Based Three-Step Detector for IR-UWB Detection.” in Proc. Int. Conf. Ultra-Wideband(ICUWB2010), Nanjing, China, Sep. 2010, vol. 2, pp. 615-618. [IEEE Xplore] [pdf]
- Liu, K., Xu, H., Chen, W., “Finite-Resolution Receiver Performance for IR-UWB Target Detection.” in Proc. Int. Conf. Signal Processing and Communication Systems(ICSPCS2010), Gold Coast, Australia, Dec. 2010. [IEEE Xplore] [pdf]
- Liu, K., Ren, J, et al, (2010) “A Practical UWB TOA Estimator in the Presence of Interference and NLOS.” in Proc. Int. Conf. Signal Processing(ICSP2010), Beijing, China, Oct. 2010. [IEEE Xplore] [pdf]
- Xu Hao, Liu Kaikai, Ma Yunfei, Wang Dongjin, Chen Weidong, “An Improved IPCP Detector of UWB Radar Signals Based on Adaptive Searching Window,” in Proc. Int. Conf. Ultra-Wideband(ICUWB2010), Nanjing, China, Sep. 2010, vol. 2.
- Xu Hao, Liu Kaikai, Wang Dongjing, Chen Weidong, “The Effect of Timing Jitter to the Radar Detection Performance,” in Journal of Science and Technology of China (ISSN 0253-2778), 2011. (In Chinese)
- Jinshuang Hao, Kaikai Liu, Jingjing Ren, Guanghua Lu, Weidong Chen, “IR-UWB radar signal sampling and reconstruction based on step-delay pulses,” Electrical and Control Engineering (ICECE), 2011 International Conference on, vol., no., pp. 3505-3508, 16-18 Sept. 2011.
- Liu, K., et al,“Receiving apparatus for ultra wideband impulse signal and ultra wideband impulse radar system,”(CN 102360070 B). [Google Patent] [Chinese]
Room: Length:9m，width:6m，hight:2m; Mesh:0.1m mesh grid line; 5 detection node and 1 central node
Antenna and RF Module
Signal Processing Platform (My Project Work)
Evaluation by Experts