Interference Alignment Through User Cooperation for Two-cell MIMO Interfering Broadcast Channels

This paper focuses on two-cell multiple-input multiple-output (MIMO) Gaussian interfering broadcast channels (MIMO-IFBC) with $K$ cooperating users on the cell-boundary of each BS. It corresponds to a downlink scenario for cellular networks with two base stations (BSs), and $K$ users equipped with Wi-Fi interfaces enabling to cooperate among users on a peer-to-peer basis. In this scenario, we propose a novel interference alignment (IA) technique exploiting user cooperation. Our proposed algorithm obtains the achievable degrees of freedom (DoF) of 2K when each BS and user have $M=K+1$ transmit antennas and $N=K$ receive antennas, respectively. Furthermore, the algorithm requires only a small amount of channel feedback information with the aid of the user cooperation channels. The simulations demonstrate that not only are the analytical results valid, but the achievable DoF of our proposed algorithm also outperforms those of conventional techniques.Comment: This paper will appear in IEEE GLOBECOM 201

Omecamtiv mecarbil in chronic heart failure with reduced ejection fraction, GALACTIC‐HF: baseline characteristics and comparison with contemporary clinical trials

Aims: The safety and efficacy of the novel selective cardiac myosin activator, omecamtiv mecarbil, in patients with heart failure with reduced ejection fraction (HFrEF) is tested in the Global Approach to Lowering Adverse Cardiac outcomes Through Improving Contractility in Heart Failure (GALACTIC‐HF) trial. Here we describe the baseline characteristics of participants in GALACTIC‐HF and how these compare with other contemporary trials. Methods and Results: Adults with established HFrEF, New York Heart Association functional class (NYHA) ≥ II, EF ≤35%, elevated natriuretic peptides and either current hospitalization for HF or history of hospitalization/ emergency department visit for HF within a year were randomized to either placebo or omecamtiv mecarbil (pharmacokinetic‐guided dosing: 25, 37.5 or 50 mg bid). 8256 patients [male (79%), non‐white (22%), mean age 65 years] were enrolled with a mean EF 27%, ischemic etiology in 54%, NYHA II 53% and III/IV 47%, and median NT‐proBNP 1971 pg/mL. HF therapies at baseline were among the most effectively employed in contemporary HF trials. GALACTIC‐HF randomized patients representative of recent HF registries and trials with substantial numbers of patients also having characteristics understudied in previous trials including more from North America (n = 1386), enrolled as inpatients (n = 2084), systolic blood pressure < 100 mmHg (n = 1127), estimated glomerular filtration rate < 30 mL/min/1.73 m2 (n = 528), and treated with sacubitril‐valsartan at baseline (n = 1594). Conclusions: GALACTIC‐HF enrolled a well‐treated, high‐risk population from both inpatient and outpatient settings, which will provide a definitive evaluation of the efficacy and safety of this novel therapy, as well as informing its potential future implementation

Efficient channel estimation for block transmission systems

Block transmission systems have recently gained considerable interest as a promising method for high data rate communications. This is due to their uncomplicated implementation and simple equalization of frequency-selective fading channels. For coherent signal detection and channel equalization in block transmission systems, channel state information (CSI) should be known to, or estimated at, the receiver. In this dissertation, we present three approaches for efficient channel estimation in block transmission systems. First, to provide a bandwidth-efficient solution for multiple-input multiple-output (MIMO) orthogonal frequency division multiplexing (OFDM) channel estimation, we establish conditions for channel identifiability and propose a blind channel estimation method based on a subspace technique. Second, to relax existing strict conditions for blind MIMO channel identification without a sacrifice of data rates and to provide a bandwidth-efficient solution for channel estimation in MIMO block transmission systems with a cyclic prefix, we present a framework for blind channel estimation based on a general non-redundant precoding. Using this framework, we propose a blind channel estimator exploiting a simplified non-redundant precoding. To complete the channel estimation, we also develop a technique for resolving the channel ambiguity in the proposed method. Third, in rapid mobile environments where channels change very fast, blind channel estimation techniques may not be suitable to obtain CSI due to their relatively slow convergence. In this case, to achieve accurate estimation of doubly selective channels in OFDM systems, we propose an optimal (in the sense of mean square error) pilot tone placement applicable to OFDM systems regardless of the time variations of a channel. In addition, we present an accurate linear minimum mean square error (LMMSE) channel estimator that exploits a small number of pilot tones located according to the derived optimal placement. To achieve computationally efficient channel estimation with lower complexity than the LMMSE estimator and to obtain performance close to the LMMSE estimator, an approximate LMMSE (ALMMSE) channel estimator is also proposed. Finally, we propose a novel iterative ALMMSE channel estimator that achieves better performance than the LMMSE and ALMMSE estimators, while having complexity in between the two.Electrical and Computer Engineerin

Capacitor flipping ????????? ???????????? Relaxation oscillator??? ???????????? ??? CMOS ?????? ??????

Department of Electrical EngineeringTemperaturecan be a factor that affect anykind ofsystem so measuring and predicting temperature is necessaryfor stablesystem. In bio-signal acquisition or artificial viscera, body is vulnerable to heat, so monitoring temperature is necessary. Not only human???s body but also electronicdevice and chip are vulnerable to heat. For overheating protection applications, temperature must be monitored. In environmental and industrial system, temperature is important factor. For better performance and preventing accident, temperature must be adjusted stably. If temperature changes suddenly, we must observe it and adjust temperature properly. Method for measuring temperature is so various.In real life, people mostly use mercury thermometer.The characteristic of temperature dependence is utilized. However, it is hard to communicate with the electronic device. That???s why we need smart temperature sensor. Temperature sensor needs to be integrated in electronic device. Most of the passive devices show temperature dependency. Using that characteristic, electronic smart temperature sensor is invented. Resistors, BJTs, MOSFETs, diodes, are the examples. It has its pros and cons so selection should be considered smartly. Resistor is power effective, but it wastes area, and temperature dependency is poor so multi-point trimming is necessary. MOSFET is power effective, but its temperature dependency is poor, so we need additional technique that can compensate non-linearity. However, BJT still shows poor temperature dependency. If we observe the base-emittervoltage with change of temperature, curvature is observed. Nevertheless, it shows betterdependencythan othersGenerally, BJT is widely utilized as smart temperature sensor because of its linearity. However, it shows better performance relatively with other passive devices, but it still lacks accuracy and dependency. That???s why solution for reducing non-linearity is significant. Trimming or calibration technique is needed for that problem.In circuit, trimming can be done with adjusting biasing current or voltage. However, it can be a burden and the production cost increases. Today???s trend does calibration or trimming at the back stage digitally. It gives simplicity and cost effective. Not only the sensing type but also analog circuit itself can be errorsource. In the layout, mismatch of the devices and the parasitic capacitance can degrade the performance of circuit Amplifier and comparator can be affected by offset. Mismatch of the current mirror can give the incorrect bias current ratio. To reducethese errors, many efforts are done. Many techniques are utilized in the circuit. Chopping can mitigate the error caused by offset. DEM(Dynamic Element Matching) can reduce the error of current source mismatch. Various techniques are included in this CMOS smart temperature sensor. Readout circuit as well as bias circuit is significant. Input type can be current, voltage, time, frequency. Readout circuit can also be many kinds of circuits. ADC(Analog-to-digital converter), FDC(Frequency-to-digital converter), TDC(Time-to-digital converter) can be connected to get a output. Each readout circuits include their own pros and cons, so we must choose the readout circuit with our expected spec. Calibration and trimming can be important factor in CMOS temperature sensor. It has direct relationship with the production cost. The more calibration and trimming is needed, the much money is payed. Effort to reduce calibration point or simplifying trimming is in progress.clos

Novelty-focused patent mapping for technology opportunity analysis

Patent maps are an effective means of discovering potential technology opportunities. However, this method has been of limited use in practice since defining and interpreting patent vacancies, as surrogates for potential technology opportunities, tend to be intuitive and ambiguous. As a remedy, we propose an approach to detecting novel patents based on systematic processes and quantitative outcomes. At the heart of the proposed approach is the text mining to extract the patterns of word usage and the local outlier factor to measure the degree of novelty in a numerical scale. The meanings of potential technology opportunities become more explicit by identifying novel patents rather than patent vacancies that are usually represented as a simple set of keywords. Finally, a novelty-focused patent identification map is developed to explore the implications on novel patents. A case study of the patents about thermal management technology of light emitting diode (LED) is exemplified. We believe the proposed approach could be employed in various research areas, serving as a starting point for developing more general models.close0

Multicell coordination via joint scheduling, beamforming and power spectrum adaptation

Abstract—The mitigation of intercell interference is a central issue for future generation wireless cellular networks where frequencies are reused aggressively and where hierarchical cellular structures may heavily overlap. The paper examines the benefit of coordinating transmission strategies and resource allocation schemes across multiple cells for interference mitigation. For a multicell network serving multiple users per cell sectors and where both the base-stations and the remote users are equipped with multiple antennas, this paper proposes a joint proportionally fair scheduling, spatial multiplexing, and power spectrum adaptation method that coordinates multiple basestations with an objective of optimizing the overall network utility. The proposed scheme optimizes the user schedule, transmit and receive beamforming vectors, and transmit power spectra jointly, while taking into consideration both the intercell and intracell interference and the fairness among the users. The proposed system is shown to significantly improve the overall network throughput while maintaining fairness as compared to a conventional network with per-cell zero-forcing beamforming and with fixed transmit power spectrum. The proposed system goes toward the vision of a fully coordinated multicell network, whereby transmission strategies and resource allocation schemes (rather than transmit signals) are coordinated across the basestations as a first step. A