This paper describes a 4T4R ultra-wideband transceiver (UWB TRX) with compact baseband shifter and digital phase interpolar (DPI) for beamforming to alleviate the contradiction between power consumption and performance. A complementary stacked multi-supply switched-capacitor power amplifier (SCPA) is introduced for efficiency. It allows PA work in both high output and low output mode, which makes the proposed transceiver could work as traditional short-ranging communication and ranging UWB TRX or as a 4 elements beamforming TRX for better system efficiency and sensitivity. A bounding wire based in-chip inductor less matching network is adopted for wide band and farther reducing the chip area. Implemented in 22nm CMOS technology, the proposed TRX works from 3GHz to 10GHz, achieve 3.7–4.2 dB NF and 57.1%@11.8dBm / 48%@-0.23dBm drain efficiency, occupies 8.72mW for RX and 31.9mW / 9.6mW for TX per channel.

Backscatter transceivers are often used in ultra-low-power Internet of Things (IoT) applications. However traditional backscatter transceiver (TRX) cannot actively control the transmitted power, which greatly limits the communication distance. This paper introduces a novel backscatter TRX operating in the ultra-high frequency (UHF) band, with a low power consumption of only 136μW and an impressive communication range surpassing 800 meters. Unlike the backscatter, the received continuous wave (CW) is not reflected via impedance modulating at the antenna but is directed into the TRX to be modulated and amplified. This technique significantly extends the communication range at a low power consumption. A coupler serves to prevent the direct entry of transmitted signals into the receiving path, ensuring the received CW remains unaffected to be modulated. Implemented in TSMC 40nm CMOS, the proposed TRX core occupies 0.7 mm2and works under a 0.7V supply voltage with the -54.6dBm input power and -20dBm output power.

A 2-T Antifuse cell with only thin-oxide transistors is proposed in this work, which is completely compatible with standard CMOS process. Its layout area is only as 0.5 μm2(1×0.5 μm2) in 40nm CMOS process, representing a 67% reduction in size compared with previous work at the same thickness. Considering the bitcell trade-off between area and reliability, the reliability is enhanced by an auto shut-off program logic and its feasibility is proven. Moreover, based on the cell, a 4Kb OTP array simulation shows that the program current is only 7 μA and read current is 5 μA. The characteristics of the memory array demonstrate its suitability for low-power applications in systems like RFID.

This paper presents a design of 250MHz single-ended digital transmitter (DTX) with switched-capacitor power amplifier (SCPA) for communication between mobile phones and satellites. The implementation of SCPA enhances linearity and efficiency. For compact die area and high efficiency, 50%-duty-cycled clocks are used in the DTX eliminating second-order harmonic without differential architecture. Aiming at higher efficiency compared to conventional quadrature DTX, the technique of digital-domain in-phase (I) and quadrature phase (Q) cell sharing is applied in this work. Moreover, the combination of three signals with specific amplitude and phase eliminates third-order harmonic, improving the output spectrum significantly. The DTX is designed in 22nm standard CMOS process and reaches a peak output power of 8.87dBm at 250MHz and power-added efficiencies (PAE) of 57.4%. When modulating a 4 MHz 64-QAM signal, the error vector magnitude (EVM) is 0.61%, while the average output power and PAE are 1.93dBm and 32.9%, respectively.

Automatic epilepsy detection is of great significance for the diagnosis and treatment of patients. Most detection methods are based on patient-specific models and have achieved good results. However, in practice, new patients do not have their own previous EEG data and therefore cannot be initially diagnosed. If the EEG data of other patients can be used to achieve cross-patient detection, and cross-patient and patient-specific experiments can be combined at the same time, this method will be more widely used. In this work, an EEG classification model based on a self-organizing fuzzy logic (SOF) classifier is proposed for both cross-patient and patient-specific seizure detection. After preprocessing, the features of the original EEG signal are extracted and sent to the SOF classifier. This classification model is free from predefined parameters or a prior assumption regarding the EEG data generation model and only stores the key meta-parameters in memory. Therefore, it is very suitable for large-scale EEG signals in cross-patient detection. Selecting different granularity and classification distance in two different experiments after post-processing will achieve the best results. Experiments were conducted using a long-term continuous scalp EEG database and the [Formula: see text]-mean of cross-patient and patient-specific detection reached 83.35% and 92.04%, respectively. A comparison with other methods shows that there is greater performance and generalizability with this method.

With the need of data storage increases tremendously nowadays, distributed file system becomes the most important data storage system in cloud computing. In distributed file system development, there are many researchers work hard to refine the architecture to provide scalability and reliability. In our work, we propose a distributed metaserver system including metaserver scale-out, metadata replication, metaserver recovery, and metaserver management recovery mechanisms. In our experiments, the proposed system can increase the capacity of metadata and increase the reliability by fault tolerance mechanism. The overhead of read/write data is very little in the proposed system as well.

Communication-aware task mapping algorithms, which map parallel tasks onto processing nodes according to the communication patterns of applications, are essential to reduce the communication time in modern high performance computing. In this paper, we design algorithms specifically for interconnected multicore systems, whose architectural property, namely small number of cores per node, large number of nodes, and large performance gap between the communication within a multicore and among multicores, had brought new challenges and opportunities to the mapping problem. Let k be the number of cores per multicore and n be the number of tasks. We consider the practical case that k ≪ n for k = 2,4, and 6. The designed algorithms are optimal for the mapping measurement, called Maximum Interconnective Message Size (MIMS), and of time complexity merely O(m log m) for m communication pairs. Thus, they are highly scalable for large applications. We had experimented the algorithms on the IBM Blue Gene/P system for two synthetic benchmarks and two applications. The results show good communication performance improvement.

In this paper, we propose a general turn model, Tree-turn model, for irregular topology. In Tree-turn model, links are classified as either tree or cross and six directions are associated with channels of links. From these six directions, we prohibit some turns such that an efficient deadlock-free routing algorithm, Tree-turn routing, can be derived. There are three phases to construct the Tree-turn routing. First, build up a coordinated tree for a given topology. Second, construct a communication graph of the topology and the corresponding coordinated tree. Third, set up the forwarding table by using the all-pairs shortest path algorithm according to the prohibited turns derived from the Tree-turn model and the directions of the channels in communication graph. To evaluate the performance, we implement the Tree-turn routing algorithm along with the up*/down* routing algorithm and the L-turn routing algorithm on a software simulator. The simulation results show that Tree-turn routing outperforms other two routing algorithms for all test cases

The multicast operation is a very commonly used operation in parallel applications. With the hardware supported multicast of the InfiniBand architecture (IBA), we propose a cyclic multicast scheme for fat-tree-based (m-port n-tree) InfiniBand networks. The basic concept of the proposed cyclic multicast scheme is to find the union sets of the output ports of switches in the paths between the source processing node and each destination processing node in a multicast group. Based on the union sets and the path selection scheme, the forwarding table for a given multicast group can be constructed. We implement the proposed multicast scheme along with the OpenSM multicast scheme and the unicast scheme on an m-port n-tree InfiniBand network simulator. The simulation results show that the proposed multicast scheme outperforms the unicast scheme for all simulated cases. For many-to-many and all-to-many cases, the cyclic multicast scheme outperforms the OpenSM multicast scheme. For many-to-all case, the performance of the cyclic multicast scheme is a little better than that of the OpenSM multicast scheme