This paper presents a 79 GHz ultra-wideband sensor monitoring the instantaneous heart-rate (HR) of moving persons. The sensor uses three approaches for the instantaneous HR monitoring: block-based motion/movement compensation of multiple persons, multiresolution analysis and Burg method for instantaneous HR analysis. The first approach normalizes and/or compensates for motion/movement of moving persons where the consecutive received signal, called radar range-profile, is stored on a block-by-block basis and the motion/movement within each block is then normalized as stationary. The second approach uses multi-resolution analysis (MRA) in order to remove most of the breathing signal from the received vital-sign waveform (HR and breathing). And the third approach estimates the instantaneous HR using Burg method. Measurement was conducted in order to investigate the usefulness of our suggested HR monitoring system including the above three approaches. The estimated HR is also compared with an optical pulse wave sensor (finger PPG) in order to confirm the accuracy.
This paper proposes an adaptive bandwidth control method in a transmitter for multi-band OFDM transmission with spectrum sharing. The proposed method controls the bandwidth used by a multi-band system to reduce out-of-band distortion noise which interferes to other spectrum sharing systems. In addition, the method uses clipping followed by in-band and out-of-band filtering to satisfy required interference power conditions on other system bands. The evaluation results by computer simulations show that adaptive band selection in the proposed bandwidth control can reduce out-of-band distortion noise power so that the required conditions can be satisfied in other spectrum sharing systems.
We propose an acoustic communication system using parametric loudspeaker that emits a communication signal into a limited area. We found that the use of minimum shift keying is suitable, since it has the potential and second harmonic signal that occur when the emit signal is distorted during propagation due to the effect of air. Experiments revealed that the proposed system emits an audible signal to a limited area, achieves a BER of 10−3 at Eb/N0 of 10 dB. Thus, it outperforms benchmarks using other modulation schemes.
This paper describes a method of process migration of PCs by FPGA-based ring networks. Here the original system configuration is given on the premise that the proposed hybrid cluster control circuit is used, and the communication protocol used on them is determined. The experiment results show that this system has the capability to perform PC process migration with FPGAs. The primary advantage of this system is that it is suitable for low-cost operations in which the PC is shut down after the process is entrusted to the FPGAs, and the result is obtained later.
Multiuser multiple-input multiple-output (MU-MIMO) downlink technology over massive MIMO is a key enabler for 5G systems and beyond. However, its performance may deteriorate when users are spatially correlated. Distributed antenna deployment (DAD) and nonlinear precoding (NLP) have been studied as countermeasures for this issue. In this paper, through simulations of 28 GHz-band massive MIMO downlink transmission in an ultra-dense urban scenario, it is revealed that, rather than DAD, concentrated antenna deployment (CAD) is more robust against channel transition issues up to walking speed. It is also found that combining CAD with NLP provided the best throughput performance in the evaluated scenario.