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A method for detecting human motion in complex scenarios based on Channel State Information (CSI) is presented. First, the sensitivity of CSI phase information to human motion is explored, especially to the strenuous motion. Through a large number of experiments, the influence of human motion on CSI phase is found out, and the characteristics of signal changes are extracted. The One-class Support...
For a given set of communication links whose senders transmit at a fixed power level, it is a hot problem to select a maximum set of links that can be transmitted simultaneously, which is known to be NP-hard. The existing algorithm only apply to the condition of omnidirectional transmission. This paper addresses the problem in a plane wireless network where the nodes use directional antennas under...
This paper presents a mostly digital IR UWB transceiver operating in 0∼960 MHz frequency range for low power wearable and implantable biomedical devices. The UWB transmitter adopts a carrier-less pulse generator with BPSK modulation, and achieves energy efficiency of 100 pJ/pulse. Intermittent operation is adopted by the receiver to save power which consumes about 600 μW at 1 Mbps. The timing window...
In this paper, we propose an adaptive tracking channel control mechanism for GNSS receivers in weak signal applications powered by renewable energy sources. The proposed technique dynamically adjusts tracking channels to get better time coverage and positioning availability under the desired accuracy requirement. A low-complexity hardware architecture is developed for power management and adaptive...
A compact 4-channel UWB beamforming receiver is proposed by employing low-Q LC delay with Q-compensation technique. The delay chain achieves 224 ps delay range with 7 ps delay resolution. It occupies area of 1.44 mm2, which is 7 times smaller than other UWB beamformer with LC delay. To compensate the losses generated by low Q inductors and minimize the power consumption, current reuse LNA and buffers...
Wireless communications employing 60 GHz millimeter wave are quite attractive recently due to the huge clean unlicensed bandwidth (up to 7 GHz) in this frequency band. In this paper, aiming at increasing channel capacity and improving the reliability of non-line-of-sight (NLOS) indoor wireless communications, we focus on a first-order-reflection multiple input multiple output (MIMO) model for 60 GHz...
Device-to-Device (D2D) communication has been proposed to be a promising data offloading solution in the coming big data age, with multimedia dominating the digital contents. As quality of experience (QoE) is the major determining factor in the success of new multimedia applications, we novelly propose a QoE-driven cooperative content dissemination (QeCS) scheme in the paper. Specifically, all the...
Ultrasound represents a very compact, low cost method that is non-invasive and does not involve ionizing radiation. A new A-mode ultrasound pulser-receiver system, which digital control module is based on FPGA chip, has been designed and implemented. The pulser-receiver system consists of three parts: digital signal processing module, high frequency pulser and receiver module. The pulser was programmed...
In this paper, we investigate the problem of jointly designing optimum linear precoder and decoder with secrecy constraints, where two legitimate parties communicate in the presence of an eavesdropper over multiple-input multiple-output (MIMO) Gaussian channels. In particular, we focus on optimizing the linear transceiver to guarantee a certain quality of service (QoS) level for the legitimate receiver...
A new link and energy adaptive UWB-based sensing system is proposed to maximize the detection time coverage of UWB-based pulse radar in embedded sensing applications powered by renewable energy. By jointly considering the link information between the transmitter and receiver of the UWB radar as well as the non-deterministic characteristics of the renewable energy, the proposed system dynamically adjusts...
This paper presents a mostly digital impulse radio (IR) UWB transceiver for low power wearable and implantable biomedical devices. The UWB transmitter adopts carrier-less pulse generator with on-off keying (OOK) modulation and uses an 11-bit Barker code for reliable communication in the frequency range of 0-960 MHz. The receiver is based on auto-threshold detection and operates intermittently for...
High sensitivity receivers and multiple satellite constellations have vastly improved GNSS signal availability in dense urban areas. However, accuracy remains a problem due to the blockage and reflection of many of the signals by buildings and other obstacles. Reliable metres-level positioning in dense urban areas is difficult to achieve cost-effectively using a single technology. The way forward...
Wide area measurements are becoming the basis of power system monitoring, protection and control. The frequency disturbance recorder (FDR) is actually a single-phase phasor measurement unit (PMU). It measures the voltage amplitude, angle and frequency from a single-phase 120-V wall outlet. Currently, the accuracy of synchrophasor measurements depends heavily on the precise time signal provided by...
We introduce a new Widely Linearly (WL) framework that combines the WL filter with the Auxiliary Vector Filtering (AVF) technique for non-circular signals. Moreover, an adaptive interference suppression algorithm is developed for a high data rate Direct Sequence Ultra Wideband (DS-UWB) system. The proposed algorithm exploits the second-order behavior of the received signal and takes full advantage...
Biomedical sensor research is moving towards portable, wearable and implantable designs. Human body communication (HBC) is a promising data transmission method for low-power and high-speed biomedical sensors. Using the conductive human body as transmission medium, HBC trials has significant potential applications for personal healthcare and sports performance. The human body channel investigation...
Orthogonal frequency division multiplexing (OFDM) is an attractive and effective technique for wireless communications. However, an OFDM signal has a large peak-to-average power ratio (PAPR), which will cause serious nonlinear distortion especially when the signal passes through a nonlinear system. Adaptive symbol selection scheme (ASSS) is used to reduce the unwanted PAPR by selecting the adaptive...
Key technology for physical layer (PHY) of worldwide interoperability for microwave access (WiMAX) which conforms to IEEE802.16e standard contains generalized multi-carrier (GMC), adaptive modulation and coding (AMC), etc. This paper firstly introduces orthogonal frequency division multiplexing (OFDM) in the application of WMAN in the broadband wireless access (BWA) protocol IEEE 802.16e, then we...
This paper presents a new energy-efficient cooperative sensor network scheme. Cooperative nodes shift the carrier frequency of the source node, and the destination node receives the signal from the source node and the cooperative nodes as a standard orthogonal frequency division multiplexing (OFDM) receiver. The maximal ratio combining (MRC) approach is applied to achieve full diversity with low complexity...
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