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Showing papers on "Signal published in 2015"


Patent
26 Mar 2015
TL;DR: In this paper, a surgical instrument can comprise a handle, a shaft assembly, a first sensor configured to detect a condition of the surgical instrument, and a second sensor configurable to detect the condition.
Abstract: A surgical instrument can comprise a handle, a shaft assembly, a first sensor configured to detect a condition of the surgical instrument, and a second sensor configured to detect the condition of the surgical instrument. The surgical instrument can further comprise a processor, wherein the first sensor and the second sensor are in signal communication with the processor, wherein the processor receives a first signal from the first sensor, wherein the processor receives a second signal from the second sensor, wherein the processor is configured to utilize the first signal and the second signal to determine the condition, and wherein the processor is configured to communicate instructions to the surgical instrument in view of the condition.

785 citations


Patent
26 Mar 2015
TL;DR: In this article, a surgical system can include an electric motor, a sensor and a microcontroller in signal communication with the electric motor and the sensor, and the microcontroller can adjust the velocity of a firing element when the sensor detects a change in current drawn by the motor that exceeds a threshold amount.
Abstract: A surgical system can include an electric motor, a sensor and a microcontroller in signal communication with the electric motor and the sensor. In various instances, the microcontroller can adjust the velocity of a firing element when the sensor detects a change in current drawn by the electric motor that exceeds a threshold amount.

630 citations


Patent
06 Mar 2015
TL;DR: In this paper, a device including smart sensors with a local signal processor is disclosed, where the processed information is generated by the signal processing component at the end-effector based on data received from the at least one sensor.
Abstract: A device including smart sensors with a local signal processor is disclosed. The device includes an end-effector including at least one sensor and a signal processing component corresponding to the at least one sensor; and a handle configured to receive processed information from the signal processing component. The processed information is generated by the signal processing component at the end-effector based on data received from the at least one sensor at the end-effector.

541 citations



Patent
23 Mar 2015
TL;DR: In this article, a compensator compensates for a gamma value of a 3D image to be increased in response to a first mode signal when the 2D mode is converted to the 3D mode and decreases an increased gamma value to a gamma values for a 2D image in reaction to a second mode signal.
Abstract: In a display apparatus and a driving method thereof, a detector determines whether a timing controller is operated in a three-dimensional (3D) mode or a two-dimensional (2D) mode to output a first or second mode signal according to a result of the determination. A compensator compensates for a gamma value of a 3D image to be increased in response to a first mode signal when the 2D mode is converted to the 3D mode and decreases an increased gamma value to a gamma value for a 2D image in response to a second mode signal when the 3D mode is converted to the 2D mode.

372 citations


Proceedings ArticleDOI
01 Oct 2015
TL;DR: This work addresses narrow-linewidth tunable lasers as one of key components of low phase noise photonic microwave signal generators and shows the possibility of achieving sub-kHz linewidths by utilizing on-chip high-Q ring resonators.
Abstract: Microwave signal generation using the heterogeneous photonic integration platform is described. Preliminary results from a heterogeneously integrated photonic microwave signal generator are shown. Heterogeneous integration, as was recently demonstrated, allows for superior performance of certain devices compared to purely III-V devices and we outline the benefits it brings. Finally, we address narrow-linewidth tunable lasers as one of key components of low phase noise photonic microwave signal generators and show the possibility of achieving sub-kHz linewidths by utilizing on-chip high-Q ring resonators.

357 citations


Journal ArticleDOI
TL;DR: In this paper, the authors proposed a digital self-interference cancellation technique for full-duplex systems, which is shown to significantly mitigate the selfinterference signal as well as the associated transmitter and receiver impairments, more specifically, transceiver nonlinearities and phase noise.
Abstract: Full-duplex systems are expected to double the spectral efficiency compared to conventional half-duplex systems if the self-interference signal can be significantly mitigated. Digital cancellation is one of the lowest complexity self-interference cancellation techniques in full-duplex systems. However, its mitigation capability is very limited, mainly due to transmitter and receiver circuit's impairments (e.g., phase noise, nonlinear distortion, and quantization noise). In this paper, we propose a novel digital self-interference cancellation technique for full-duplex systems. The proposed technique is shown to significantly mitigate the self-interference signal as well as the associated transmitter and receiver impairments, more specifically, transceiver nonlinearities and phase noise. In the proposed technique, an auxiliary receiver chain is used to obtain a digital-domain copy of the transmitted Radio Frequency (RF) self-interference signal. The self-interference copy is then used in the digital-domain to cancel out both the self-interference signal and the associated transmitter impairments. Furthermore, to alleviate the receiver phase noise effect, a common oscillator is shared between the auxiliary and ordinary receiver chains. A thorough analytical and numerical analysis for the effect of the transmitter and receiver impairments on the cancellation capability of the proposed technique is presented. Finally, the overall performance is numerically investigated showing that using the proposed technique, the self-interference signal could be mitigated to $\sim$ 3 dB higher than the receiver noise floor, which results in up to 76% rate improvement compared to conventional half-duplex systems at 20 dBm transmit power values.

343 citations


Patent
02 Apr 2015
TL;DR: In this article, a navigation system can comprise a microprocessor, a memory, a navigational signal receiver configured to receive a radio signal from at least one external system, a motion sensing device, and a navigation program executable by the microprocessor.
Abstract: A navigation system can comprise a microprocessor, a memory, a navigational signal receiver configured to receive a radio signal from at least one external system, a motion sensing device, and a navigation program executable by the microprocessor. The navigational signal receiver can be communicatively coupled to the microprocessor via a communication port. The navigation program can be configured to receive messages from the navigational signal receiver by communicating to the driver of the communication port. The communication port driver can adjust the current position based on the data returned by the motion sensing device.

336 citations


Patent
28 Aug 2015
TL;DR: In this paper, the authors describe a system including a frequency mixer that combines a signal and a carrier wave to form a combined signal, and a transmitter that generates a transmission based on the combined signal.
Abstract: Aspects of the subject disclosure may include, for example, a system including a frequency mixer that combines a signal and a carrier wave to form a combined signal, and a transmitter that generates a transmission based on the combined signal. The system can also include a coupling device that emits the transmission as an electromagnetic wave guided by an outer surface of a transmission medium. The electromagnetic wave can propagate longitudinally along the surface of the transmission medium and at least partially around the surface of the transmission medium. Other embodiments are disclosed.

281 citations


Patent
27 May 2015
TL;DR: In this article, the authors describe a system for receiving a communication signal, generating an electromagnetic wave from the communication signal and inducing the electromagnetic wave on a portion of a transmission medium having an insulation layer with a tapered end covering at least part of a conductor.
Abstract: Aspects of the subject disclosure may include, for example, a system for receiving a communication signal, generating an electromagnetic wave from the communication signal, and inducing the electromagnetic wave on a portion of a transmission medium having an insulation layer with a tapered end covering at least part of a conductor Other embodiments are disclosed

260 citations


Patent
19 Mar 2015
TL;DR: In this article, a system including an input sensor, a summer, a controller, and a feedback sensor is used to detect a first amount of force or torque applied on a component of an x-ray scanner gantry in a direction; and generates a command signal.
Abstract: A system including an input sensor, a summer, a controller, and a feedback sensor. The input sensor: detects a first amount of force or torque applied on a component of an x-ray scanner gantry in a direction; and generates a command signal. The command signal indicates the first amount of force or torque. The summer generates an error signal based on the command signal and a feedback signal. The controller controls operation of a motor based on the error signal to: reduce the error signal; provide counterbalancing of the gantry in the direction; and provide a net force or torque on the gantry that is equal to a predetermined value or is within a predetermined range of the predetermined value. The feedback sensor detects a second amount of force or torque applied on the gantry in the direction as a result of the controlled operation and generates the feedback signal.

Patent
Sangwoo Seo1, Yoo Hyunsun1
24 Mar 2015
TL;DR: In this article, a mobile terminal including a display configured to display information; a short range communication module configured to exchange a signal with an external control device; and a controller configured to receive the signal from the external controller, determine a context at a timing point of receiving the signal, and control an operation corresponding to the signal to be performed in the determined context.
Abstract: A mobile terminal including a display configured to display information; a short range communication module configured to exchange a signal with an external control device; and a controller configured to receive the signal from the external control device, determine a context at a timing point of receiving the signal, and control an operation corresponding to the signal to be performed in the determined context. Further, the operation includes at least one of activation/deactivation of the display, an activation/deactivation of a lock mode of the mobile terminal, a volume operation and a camera operation.

Patent
22 Apr 2015
TL;DR: In this article, a circuit includes a light detector for generating a first electrical signal based on received light, and a switching circuit, having a first and a second configuration, configured to receive a first voltage signal and to switch among the first and second configurations.
Abstract: One innovative aspect is directed to heart rate data collection. In some implementations, a circuit includes a light detector for generating a first electrical signal based on received light. The circuit includes a switching circuit, having a first and a second configuration, configured to receive a first voltage signal based on the first electrical signal and to switch among the first and the second configurations. The circuit includes first and second sampling circuits for sampling a value of the first voltage signal when the switching circuit is in the first configuration and second configurations, respectively. The circuit includes an ambient light cancellation circuit for generating a current signal to counter a first component of the first electrical signal when the first switching circuit is in the first configuration.

Patent
14 Jul 2015
TL;DR: In this article, the authors describe a system that performs operations including detecting a signal degradation of guided electromagnetic waves bound to a transmission medium without utilizing an electrical return path, adjusting an alignment of at least a portion of fields of the guided electromagnetic wave to mitigate the signal degradation.
Abstract: Aspects of the subject disclosure may include, for example, a system that performs operations including detecting a signal degradation of guided electromagnetic waves bound to a transmission medium without utilizing an electrical return path, the guided electromagnetic waves having a non-optical frequency range, and adjusting an alignment of at least a portion of fields of the guided electromagnetic waves to mitigate the signal degradation. Other embodiments are disclosed.

Journal ArticleDOI
TL;DR: This paper introduces a novel virtual signal injection-based control method for maximum torque per ampere (MTPA) operation of interior permanent magnet synchronous machine (IPMSM) drives that is parameter independent in tracking the MTPA points and robust to current/voltage harmonics and motor torque disturbances.
Abstract: This paper introduces a novel virtual signal injection-based control method for maximum torque per ampere (MTPA) operation of interior permanent magnet synchronous machine (IPMSM) drives. The proposed method injects a small virtual current angle signal mathematically for tracking the MTPA operating point and generating d -axis current command by utilizing the inherent characteristic of the MTPA operation. This method is parameter independent in tracking the MTPA points, and it does not inject any real signal to current or voltage command. Consequently, the problems associated with real high-frequency signal injection, such as increases in copper and iron loss can be avoided. Moreover, it is robust to current/voltage harmonics and motor torque disturbances. The proposed method is verified by simulations and experiments under various operating conditions on a prototype IPMSM drive system.

Journal ArticleDOI
Jürgen Rahmer1, Aleksi Halkola1, Bernhard Gleich1, Ingo Schmale1, Jörn Borgert1 
TL;DR: Experimental evidence of the separability of signals from different particle types and aggregation states using a 'multi-color' reconstruction approach is presented and several mechanisms are discussed that may form the basis for successful signal separation.
Abstract: Magnetic particle imaging is a new approach to visualizing magnetic nanoparticles. It is capable of 3D real-time in vivo imaging of particles injected into the blood stream and is a candidate for medical imaging applications. To date, only one particle type has been imaged at a time, however, the ability to separate signals acquired simultaneously from different particle types or from particles in different environments would substantially increase the scope of the method. Different colors could be assigned to different signal sources to allow for visualization in a single image. Successful signal separation has been reported in spectroscopic experiments, but it was unclear how well separation would work in conjunction with spatial encoding in an imaging experiment. This work presents experimental evidence of the separability of signals from different particle types and aggregation states (fluid versus powder) using a 'multi-color' reconstruction approach. Several mechanisms are discussed that may form the basis for successful signal separation.

Journal ArticleDOI
Alon Kuperman1
TL;DR: In this article, a method for deriving proportional-resonant (PR) controller structure and coefficients according to desired transient behavior of ac signal amplitude, applied to typical power converter current loop, is proposed.
Abstract: Stationary reference frame proportional-resonant (PR) controllers have recently became a viable alternative to rotation reference frame proportional-integrative compensators in ac applications because of their ability of achieving zero steady-state error without the need for computational-intensive reference frame transformations. While extensive efforts have been put into performance comparison of the two control schemes, design of PR controllers according to desired closed-loop time-domain transient performance was barely investigated. This letter proposes a method for deriving PR controller structure and coefficients according to desired transient behavior of ac signal amplitude, applied to typical power converter current loop. The method is based on the fact that if ac signal envelope is perceived as dc signal, its transient behavior may be easily shaped utilizing well-known approaches employed in dc systems loop shaping while keeping zero phase tracking error at all times. On the other hand, while desired transient performance is easily achieved, the relation between crossover frequency and transient processes time constant is not as straightforward as in dc systems. The validity of the presented theoretical analysis is evaluated by simulations.

Patent
15 Jan 2015
TL;DR: In this paper, the authors describe a device for use in a power transmission system to sense GICs, which may be a part of a reactance-injecting device on a power line, a standalone device, or it may be part of another type of device.
Abstract: A device for use in a power transmission system to sense GICs. The device may be a part of a reactance-injecting device on a power line, it may be a standalone device, or it may be a part of another type of device. The device may include a sensor to sense magnetic fields (e.g., a Hall effect sensor). The sensor may be positioned in the air gap of a magnetic core formed concentrically around the power line. The signal from the sensor may be converted to a digital signal and separately processed to determine the magnitude of the AC current and the magnitude of the DC (or quasi-DC) current. If the output signal of another A/C current sensor is available, that output signal may be used to adjust/calibrate the determined magnitude of the DC current. The sensor may communicate with other devices in a network to provide GIC information.

Patent
10 Apr 2015
TL;DR: In this article, a proposed flight path of a UAV may be collected, and a communication signal distribution, such as a cellular signal distribution along the proposed flight of the UAV, may be determined, and relays may be provided to improve a quality of the communication signal.
Abstract: The systems and methods are provided to provide communication coverage to an unmanned aerial vehicle. A proposed flight path of a UAV may be collected, and a communication signal distribution, such as a cellular signal distribution, along the proposed flight of the UAV may be determined. At positions having low or no communication signal, relays may be provided to improve a quality of the communication signal. The relay may be a ground device or an aerial vehicle. A stable and continuous communication between the UAV and user terminals during the entire flight path of UAV may be provided, and a coverage of cellular signal may be expanded.

Patent
19 Jan 2015
TL;DR: In this paper, a charger receives a beacon signal from the receiver, and transmits power, and a control signal, to the device, and the receiver interprets and effectuates the commands.
Abstract: The present invention relates to systems and methods for a charger which interacts with devices equipped with receivers. The charger may likewise have access to a server via a network connection. The charger receives a beacon signal from the receiver, and transmits power, and a control signal, to the device. Applications enable proper communication between the charger and the receiver. The receiver interprets and effectuates the commands. The receiver also includes sensors which generate data regarding the device status and usage. This data is provided to the server, via the charger. The server maintains a database of all user data collected from the devices, as well as user configurations. The user and third parties may access this data.

PatentDOI
TL;DR: In this paper, a receiver on an optical transmission channel uses an oscillator signal generated by a light source at the receiver's location to perform interferometric detection on received signals.
Abstract: Various technologies for continuous-variable quantum key distribution without transmitting a transmitter's local oscillator are described herein. A receiver on an optical transmission channel uses an oscillator signal generated by a light source at the receiver's location to perform interferometric detection on received signals. An optical reference pulse is sent by the transmitter on the transmission channel and the receiver computes a phase offset of the transmission based on quadrature measurements of the reference pulse. The receiver can then compensate for the phase offset between the transmitter's reference and the receiver's reference when measuring quadratures of received data pulses.

Journal ArticleDOI
Litong Feng1, Lai-Man Po1, Xuyuan Xu1, Yuming Li1, Ruiyi Ma1 
TL;DR: Experimental results show that the proposed RIPPG can obtain greatly improved performance in accessing heart rates in moving subjects, compared with the state-of-the-art facial video-based RIPPG methods.
Abstract: Remote imaging photoplethysmography (RIPPG) can achieve contactless monitoring of human vital signs. However, the robustness to a subject’s motion is a challenging problem for RIPPG, especially in facial video-based RIPPG. The RIPPG signal originates from the radiant intensity variation of human skin with pulses of blood and motions can modulate the radiant intensity of the skin. Based on the optical properties of human skin, we build an optical RIPPG signal model in which the origins of the RIPPG signal and motion artifacts can be clearly described. The region of interest (ROI) of the skin is regarded as a Lambertian radiator and the effect of ROI tracking is analyzed from the perspective of radiometry. By considering a digital color camera as a simple spectrometer, we propose an adaptive color difference operation between the green and red channels to reduce motion artifacts. Based on the spectral characteristics of photoplethysmography signals, we propose an adaptive bandpass filter to remove residual motion artifacts of RIPPG. We also combine ROI selection on the subject’s cheeks with speeded-up robust features points tracking to improve the RIPPG signal quality. Experimental results show that the proposed RIPPG can obtain greatly improved performance in accessing heart rates in moving subjects, compared with the state-of-the-art facial video-based RIPPG methods.

Proceedings ArticleDOI
21 Feb 2015
TL;DR: The purpose of this paper is to give a brief introduction to the EEG signals and BCI system and a review on the conventional methods that are used for feature extraction of the signal.
Abstract: Brain Computer Interface (BCI) systems are the devices which are proposed to help the disabled, people who are incapable of making motor response to communicate with computer using brain signal. The aim of BCI is to interpret brain activity into digital form which acts as a command for a computer. One key challenge in current BCI research is how to extract features of random time-varying EEG signals and its classification as accurately as possible. Feature extraction techniques are used to extract the features which represent a unique property obtained from pattern of brain signal. Earlier EEG analysis was restricted to visual inspection only. The visual inspection of the signal is very subjective and hardly allows any standardization or statistical analysis. Hence, several different techniques were intended in order to quantify the information of the brain signal. Many linear and non-linear methods for feature extraction exist. The purpose of this paper is to give a brief introduction to the EEG signals and BCI system. The paper also includes a review on the conventional methods that are used for feature extraction of the signal.

Patent
22 Jan 2015
TL;DR: In this paper, a physical information acquisition method in which a corresponding wavelength region of visible light with at least one visible light detection unit coupled to an image signal processing unit is detected.
Abstract: A physical information acquisition method in which a corresponding wavelength region of visible light with at least one visible light detection unit coupled to an image signal processing unit is detected, each said visible light detection unit comprising a color filter adapted to transmit the corresponding wavelength region of visible light; a wavelength region of infrared light with at least one infrared light detection unit coupled to the image signal processing unit is detected; and, with the signal processing unit, a first signal received from the at least one visible light detection unit by subtracting a product from said first signal is corrected, said product resulting from multiplication of a second signal received from the at least one infrared light detection unit and a predetermined coefficient factor.

Journal ArticleDOI
TL;DR: GEVIs provide a powerful tool to study the dynamics of neural populations at mesoscopic spatial scales in the awake cortex by introducing a straightforward projection method to separate a signal dominated by membrane voltage from a signaldominated by hemodynamic activity.
Abstract: Genetically encoded voltage indicators (GEVIs) promise to reveal the membrane potential of genetically targeted neuronal populations through noninvasive, chronic imaging of large portions of cortical space. Here we test a promising GEVI in mouse cortex during wakefulness, a challenging condition due to large hemodynamic activity, and we introduce a straightforward projection method to separate a signal dominated by membrane voltage from a signal dominated by hemodynamic activity. We expressed VSFP-Butterfly 1.2 plasmid in layer 2/3 pyramidal cells of visual cortex through electroporation in utero. We then used wide-field imaging with two cameras to measure both fluorophores of the indicator in response to visual stimuli. By taking weighted sums and differences of the two measurements, we obtained clear separation of hemodynamic and voltage signals. The hemodynamic signal showed strong heartbeat oscillations, superimposed on slow dynamics similar to blood oxygen level-dependent (BOLD) or “intrinsic” signals. The voltage signal had fast dynamics similar to neural responses measured electrically, and showed an orderly retinotopic mapping. We compared this voltage signal with calcium signals imaged in transgenic mice that express a calcium indicator (GCaMP3) throughout cortex. The voltage signal from VSFP had similar signal-to-noise ratios as the calcium signal, it was more immune to vascular artifacts, and it integrated over larger regions of visual space, which was consistent with its reporting mostly subthreshold activity rather than the spiking activity revealed by calcium signals. These results demonstrate that GEVIs provide a powerful tool to study the dynamics of neural populations at mesoscopic spatial scales in the awake cortex.

Patent
Park Mangyu1
02 Jul 2015
TL;DR: In this paper, a display panel with data lines and gate lines, the gate lines including odd-numbered gate lines and even-number gate lines is shown, and the display device also includes a timing controller to generate a gate output enable signal.
Abstract: A disclosed display device includes a display panel with data lines and gate lines, the gate lines including odd-numbered gate lines and even-numbered gate lines The display device also includes a timing controller to generate a gate output enable signal, and a gate output enable signal division circuit to extract odd-numbered high logic periods of the gate output enable signal to output a first gate output enable signal and to extract even-numbered high logic periods of the gate output enable signal to output a second gate output enable signal The display device further includes a gate driver to supply a first gate pulse to an odd-numbered gate line in response to the first gate output enable signal and a second gate pulse to an even-numbered gate line in response to the second output enable signal

Journal ArticleDOI
TL;DR: Ioacoustics is suggested as a technique for range verification in particle therapy at locations, where the tumor can be localized by ultrasound imaging and could offer the possibility of combining anatomical ultrasound and Bragg peak imaging, but further studies are required for translation to clinical application.
Abstract: Purpose: Range verification in ion beam therapy relies to date on nuclear imaging techniques which require complex and costly detector systems. A different approach is the detection of thermoacoustic signals that are generated due to localized energy loss of ion beams in tissue (ionoacoustics). Aim of this work was to study experimentally the achievable position resolution of ionoacoustics under idealized conditions using high frequency ultrasonic transducers and a specifically selected probing beam. Methods: A water phantom was irradiated by a pulsed 20 MeV proton beam with varying pulse intensity and length. The acoustic signal of single proton pulses was measured by different PZT-based ultrasound detectors (3.5 and 10 MHz central frequencies). The proton dose distribution in water was calculated by Geant4 and used as input for simulation of the generated acoustic wave by the matlab toolbox k-WAVE. Results: In measurements from this study, a clear signal of the Bragg peak was observed for an energy deposition as low as 1012 eV. The signal amplitude showed a linear increase with particle number per pulse and thus, dose. Bragg peak position measurements were reproducible within ±30 μm and agreed with Geant4 simulations to better than 100 μm. The ionoacoustic signal pattern allowed for a detailed analysis of the Bragg peak and could be well reproduced by k-WAVE simulations. Conclusions: The authors have studied the ionoacoustic signal of the Bragg peak in experiments using a 20 MeV proton beam with its correspondingly localized energy deposition, demonstrating submillimeter position resolution and providing a deep insight in the correlation between the acoustic signal and Bragg peak shape. These results, together with earlier experiments and new simulations (including the results in this study) at higher energies, suggest ionoacoustics as a technique for range verification in particle therapy at locations, where the tumor can be localized by ultrasound imaging. This acoustic range verification approach could offer the possibility of combining anatomical ultrasound and Bragg peak imaging, but further studies are required for translation of these findings to clinical application.

Patent
09 Mar 2015
TL;DR: In this article, the authors proposed a method to detect a linear impairment in a cable under test by using a random signal transmitted down the cable, which causes a reflected signal to be combined with the random signal.
Abstract: Detecting a linear impairment in a cable under test by using a random signal transmitted down the cable. The impairment causes a reflected signal to be combined with the random signal. The combined signal extends over a plurality of sub-bands. A method and apparatus perform the steps of: (a) receiving the combined signal from a test point upstream from the impairment; (b) tuning to each sub-band and receiving a part of the combined signal within each sub-band; (c) determining an autocorrelation function of each part of the combined signal of each sub-band, to produce a plurality of autocorrelation functions; (d) combining the autocorrelation functions to form a combined function; (e) detecting the reflected signal from the combined function; and (f) determining, from the combined function, a time delay associated with the reflected signal and the distance from the test point to the impairment.

Journal ArticleDOI
TL;DR: The proposed technique is compared to conventional SM as well as to spatial multiplexing (SMX), and the results indicate that in most cases, ESM provides a substantial performance gain over conventional SM and SMX while reducing the maximum-likelihood (ML) decoder complexity.
Abstract: In this paper, we introduce a new spatial modulation (SM) technique using one or two active antennas and multiple signal constellations. The proposed technique, which we refer to as Enhanced SM or ESM, conveys information bits not only by the index(es) of the active antenna(s), but also by the constellations transmitted from each of them. The main feature of ESM is that it uses a primary signal constellation during the single active antenna periods and some other secondary constellations during the periods with two active transmit antennas. The secondary signal constellations are derived from the primary constellation by means of geometric interpolation in the signal space. We give design examples using two and four transmit antennas and QPSK, 16QAM, and 64QAM as primary modulations. The proposed technique is compared to conventional SM as well as to spatial multiplexing (SMX), and the results indicate that in most cases, ESM provides a substantial performance gain over conventional SM and SMX while reducing the maximum-likelihood (ML) decoder complexity.

Patent
04 Mar 2015
TL;DR: In this article, a control circuit may limit the electrosurgical signal to a first maximum power when the impedance between the first and second electrodes exceeds a first mode threshold, and the second maximum power may be greater than the first.
Abstract: Various embodiments are directed to electrosurgical systems for providing an electrosurgical signal to a patient. A control circuit may, for a first application period, apply the electrosurgical signal to first and second electrodes according to a first mode. In the first mode, the control circuit may limit the electrosurgical signal to a first maximum power when the impedance between the first and second electrodes exceeds a first mode threshold. The control circuit may also, for a second application period after the first application period, apply the electrosurgical signal according to a second mode. In the second mode, the control circuit may limit the electrosurgical signal to a second mode maximum power when the impedance between the first and second electrodes exceeds a second mode threshold. The second maximum power may be greater than the first maximum power.