Jinzhao Lin

Positive Davio-based synthesis algorithm for reversible logic

Reversible logic is a key technique for quantum computing so leading to low-power designs. However, current synthesis algorithms for reversible circuits are low efficiency and do not obtain optimized reversible circuits, so they are only applied to small logic functions. In this paper, we propose a new method based on positive Davio expansion to synthesize reversible circuits, which generates a positive Davio decision diagram for a logic function and transfers diagram nodes to reversible circuits. The algorithm has advantages of optimizing area and fast synthesis speed compared to BDD (Binary decision diagram) based and RM (Reed-Muller) based synthesis method, so it can be adapted for large functions.

A novel method of synthesizing reversible logic

As a new technique for low-power design and quantum computing, reversible logic has been paid much attention. A significant part of research lies in synthesizing a reversible network from non-reversible specification. However, current synthesis algorithms for reversible circuits suffer low efficiency and do not reach area optimization, so they are only applicable to small logic functions. In this paper, we propose a new method based on positive Davio expansion to synthesize reversible circuits, which generates a positive Davio decision diagram for a logic function and transfers diagram nodes to reversible circuits. Compared to BDD-based and Reed-Muller (RM) based synthesis methods, our algorithm can optimize area and have fast synthesis speed, so it is suitable for large functions.

Capsule Design for Blue Light Therapy against Helicobacter pylori

A photo-medical capsule that emits blue light for Helicobacter pylori treatment was described in this paper. The system consists of modules for pH sensing and measuring, light-emitting diode driver circuit, radio communication and microcontroller, and power management. The system can differentiate locations by monitoring the pH values of the gastrointestinal tract, and turn on and off the blue light according to the preset range of pH values. Our experimental tests show that the capsule can operate in the effective light therapy mode for more than 32 minutes and the wireless communication module can reliably transmit the measured pH value to a receiver located outside the body.

A lightweight method of data encryption in BANs using electrocardiogram signal

Abstract Body area network (BAN) is a key technology of solving telemedicine, where protecting security of vital signs information becomes a very important technique requirement. The traditional encryption methods are not suitable for BANs due to the complex algorithm and the large consumption. This paper proposes a new encryption method based on the QRS complex of the ECG signal, which adopts the vital signs from the BAN system to form the initial key, utilizes the LFSR (Linear Feedback Shift Register) circuit to generate the key stream, and then encrypts the data in the BANs. This new encryption method has the advantages of low energy consumption, simple hardware implementation, and dynamic key updating.

A PPG Signal De-Noising Method Based on the DTCWT and the Morphological Filtering

The pulse wave signal contains a variety of noises and has strong nonlinear and non-stationary. According to the previous wavelet transformation method, this paper proposes a PPG signal de-noising algorithm based on dual-tree complex wavelet transform (DTCWT) and morphological filtering. With the advantage of simple construction, clear mathematical implications and low computational complexity, this method overcomes the shift sensitive and the frequency aliasing in the discrete wavelet transform. The simulation results show that this algorithm could remove the power line interference and EMG interference, and the quantitative index of SNR and mean square error is superior to the traditional threshold de-noising algorithm. Therefore, the DTCWT and morphological filtering de-noising algorithm would obtain a clear pulse wave signal.

Channel models of body area networks for human motion

The channel characteristics of the body area network are important to transmission rate and transmission robustness. Current explorations mainly concern the channel characteristics in static state of the human body. In this paper, we establish human motion models of sitting to standing, walking and running postures, and calculate the path loss values in 2.4GHz for the models. The experimental results show that the path loss values vary sharply in the process of human movement, which is very helpful to determine the transmission power and design BAN sensor nodes.

A Sub-1V High-PSRR Piecewise-Linear Bandgap Reference

A piecewise-linear bandagp reference (BGR) with high power supply rejection ratio (PSRR) and low temperature coefficient is designed for analogue and mixed signal systems in this paper. By adopting LDO regulator, the designed high PSRR piecewise-linear BGR achieves well performances and has a simple architecture. Simulation results show that the PSRR of the designed piecewise-linear BGR with LDO regulator at 10Hz, 1kHz and 100kHz achieves, respectively, -110.42dB, -109.18dB and -64.51dB. Compared to the designed BGR without LDO regulator, the PSRR of the designed high PSRR piecewise-linear BGR with LDO regulator has the improvements of about 35dB, 36.9dB and 29.28dB at 10Hz, 1kHz and 100kHz respectively. The designed piecewise-linear BGR with LDO regulator generates an output voltage of 0.68V with 1.65ppm/oC temperature coefficient in the range from -50 oC to 125 oC. The deviation of the output voltage is within 98.23μV when the power supply voltage V DD changes from 1.2V to 7V.

A low-power circuit for BPSK and QPSK demodulation for body area networks applications

Body area networks (BANs) are of importance for telemedicine and telehealth services, so they have caught many engineers attention. A coordinator in a BAN plays a significant role to collect signals from sensors and interface with telecommunication networks. Since the wireless channel of BAN is very complicated and changeable, the modulation is not fixed. As a result, the coordinator must have different demodulators. In this paper, we propose a method to design a low-power circuit which can both demodulate BPSK and QPSK by using the technique of datapath merging. The results of the experiments show that the proposed demodulator implementation can reduce around 23% hardware area compared with the traditional implementation.

Indoor Positioning Algorithm Based on the Improved RSSI Distance Model

The Global Navigation Satellite System (GNSS) cannot achieve accurate positioning and navigation in the indoor environment. Therefore, efficient indoor positioning technology has become a very active research topic. Bluetooth beacon positioning is one of the most widely used technologies. Because of the time-varying characteristics of the Bluetooth received signal strength indication (RSSI), traditional positioning algorithms have large ranging errors because they use fixed path loss models. In this paper, we propose an RSSI real-time correction method based on Bluetooth gateway which is used to detect the RSSI fluctuations of surrounding Bluetooth nodes and upload them to the cloud server. The terminal to be located collects the RSSIs of surrounding Bluetooth nodes, and then adjusts them by the RSSI fluctuation information stored on the server in real-time. The adjusted RSSIs can be used for calculation and achieve smaller positioning error. Moreover, it is difficult to accurately fit the RSSI distance model with the logarithmic distance loss model due to the complex electromagnetic environment in the room. Therefore, the back propagation neural network optimized by particle swarm optimization (PSO-BPNN) is used to train the RSSI distance model to reduce the positioning error. The experiment shows that the proposed method has better positioning accuracy than the traditional method.

A Protocol with Self-adaptive Guard Band for Body Area Networks

Body area networks (BANs) are systems of wearable computing devices for long-term monitoring of personal health care. BAN is an emerging technology for the worldwide ageing population. In the BAN system, the transceiver is the most energy-consuming part of a sensor node and radio transmission in the vicinity of the human body is highly lossy and inefficient. Therefore, the energy of the sensor node constraints the life cycle and quality of service of the network; consequently, low-cost protocol shaves attracted wide interest. This study proposes a frame structure model of a self-adaptive guard band protocol, which introduces a GB in each time slot according to the allowed maximum time drift of the crystal, adaptively adjusts the value of the GB based on the actual time drift, and then ensures that the node simultaneously maintains the sleeping state and synchronisation with the coordinator during beacon transmission, thus reducing the energy consumption.