1296 results about "Fading" patented technology

An antenna apparatus which can increase capacity in a cellular communication system. The antenna operates in conjunction with a mobile subscriber unit and provides a plurality of antenna elements, each coupled to a respective signal control component such as a switch. The switch position of each antenna element is programmed for optimum reception during, for example, an idle mode which receives a pilot signal. The antenna array creates a beamformer for signals to be transmitted from the mobile subscriber unit, and a directional receiving array to more optimally detect and receive signals transmitted from the base station. By directionally receiving and transmitting signals, multipath fading is greatly reduced as well as intercell interference. Various techniques for determining the proper arrangement of signal control components for each antenna element are accommodated.

User-selected application icons can be added into a control center interface. The corresponding applications may be accessed either from the springboard or from the control center interface. Operation of slider controls in the control center interface can temporarily fade out all aspects of the control center interface except for the slider control being operated during that control's operation. The temporary fading out of most of the other aspect of the control center interface causes the content that had been at least partially obscured and overlaid by the previously opaque control center interface to become visible during the slider control's operation. While the slider control is being actively operated, the control center interface becomes transparent except for the control itself. Consequently, the effects of the slider control's operation relative to the value of the parameter to which it pertains are immediately apparent during that operation.

The present invention relates to a system that facilitates multi-tasking in a computing environment. A focus area component defines a focus area within a display space—the focus area occupying a subset area of the display space area. A scaling component scales display objects as a function of proximity to the focus area, and a behavior modification component modifies respective behavior of the display objects as a function their location of the display space. Thus, and more particularly the subject invention provides for interaction technique(s) and user interface(s) in connection with managing display objects on a display surface. One aspect of the invention defines a central focus area where the display objects are displayed and behave as usual, and a periphery outside the focus area where the display objects are reduced in size based on their location, getting smaller as they near an edge of the display surface so that many more objects can remain visible. In addition or alternatively, the objects can fade as they move toward an edge, fading increasing as a function of distance from the focus area and / or use of the object and / or priority of the object. Objects in the periphery can also be modified to have different interaction behavior (e.g., lower refresh rate, fading, reconfigured to display sub-objects based on relevance and / or visibility, static, etc.) as they may be too small for standard rendering. The methods can provide a flexible, scalable surface when coupled with automated policies for moving objects into the periphery, in response to the introduction of new objects or the resizing of pre-existing objects by a user or autonomous process.

An OFDM subcarrier method and apparatus effectively reassigns subcarriers with respect to a data stream from a plurality of Digital Audio Broadcast (DAB) services or programs to reduce selective effects (e.g., selective channel fading) of the transmission channel (e.g., an FM station) on some of the DAB services or programs but not on others. In one embodiment, a symbol reassignment encoder at the transmitter shuffles the data or symbols in the data stream from the DAB services to effectively reassign the subcarriers used by each of the DAB services. The reassignment spreads the selective effects of the transmission channel, e.g., channel fading, over a larger group of DAB services, to improve the robustness and quality of the overall transmission channel.

An apparatus for adjusting the transmission bit rate and fragmentation threshold of a wireless station in response to transmission errors is disclosed. In particular, the illustrative embodiment of the present invention is based on a wireless station that employs both an IEEE 802.11 radio and a Bluetooth radio, and determines whether transmission errors of the IEEE 802.11 radio are due to fading, or interference from the Bluetooth radio. It will be clear to those skilled in the art how to make and use alternative embodiments of the present invention for protocols other than IEEE 802.11 and Bluetooth, as well as stations that employ wireline or non-RF-wireless transceivers.

An OFDM demodulation (1) is provided which includes a guard correlation / peak time detection circuit (12) to generate a peak timing Np of a guard interval correlation value, and a timing synchronization circuit (13) to estimate a symbol-boundary time Nx from the peak timing Np. The timing synchronization circuit (13) calculates the symbol-boundary time Nx by filtering the peak time Np by a DLL (delay locked loop) filter (43). Further, the DLL filter (43) includes a limiter (52) to limit the range of phase-error component and an asymmetric gain circuit (53) to change the magnitude of the gain correspondingly to the polarity of the phase error to prevent the timing from being pulled out due to a fading or multipath.

One or more median filter circuits are used to filter radio link control measurements corresponding to one or more radio link parameters of interest, such as received signal quality or round trip delay measurements, such as might be used by a base station to trigger mobile station handoff. As such measurements are particularly susceptible to measurement outliers arising from rapid but short-lived changes in radio link propagation paths, for example, the application of median filtering to such measurements is particularly advantageous. That is, by operation of median filtering, which is a non-linear filtering process, outliers in a stream of control measurements, such as are caused by instantaneous changes in channel fading or other propagation phenomena, are discarded rather than averaged in with the other measurements. Non-linear filtering as implemented by exemplary median filtering does not impair or otherwise limit the bandwidth of the underlying control measurements.

The method is for estimating the fading coefficients of a plurality of transmission channels on which signals to be sent, generated as a function of a sequence of symbols, are transmitted according to a particular modulation, e.g. AM-PSK modulation. The fading coefficients are estimated by using estimations of the transmitted symbols obtained in advance, thus obtaining DC components of the received signal by coherent demodulation locked to the phases of the transmitted AM-PSK signals, and processing these DC components. The method may not require the choice of a stochastic distribution model of the channel fading, thus it remains efficient even when the channel characteristics vary significantly. Moreover, the method works correctly even if the received stream is disturbed by inter-symbolic interference (ISI) and / or by multi-path fading.

An apparatus that adaptively allocates transmission power for beam-forming combined with orthogonal space time block codes in a distributed wireless communication system, the apparatus including: sub-arrays for beam-forming, which are geographically distributed and each of which includes a plurality of distributed antennas placed in random groups. A central processing unit provides predetermined combinable power allocation schemes according to subsets in a plurality of the sub-arrays, identifying performances of the schemes by using information on large-scale fading of each of the sub-arrays fed back from a receiving party, setting a subset having best performance as an optimal subset according to the identified performances, and performing power allocation according thereto.

A system and method for selecting an appropriate transmit power and data rate at which a communication signal is transmitted over a link between nodes in a wireless ad-hoc communication network based on factors such as variations in path loss in the link, fading conditions, noise level estimation and overall link quality. The system and method perform the operations of computing path loss in the link based on information provided to the source node from the destination node pertaining to characteristics of a message that was transmitted by the source node and received by the destination node, determining a noise factor at the destination node, and calculating the power level and rate at which the data is transmitted over the link from the source node to the destination node based on the path loss and the noise factor. More specifically, the method calculates the power level based on the path loss, the noise factor and signal fading, and determines the rate based on the calculated power level. Furthermore, the path loss is computed dynamically as conditions of said link change over time. Accordingly, the system and method are capable of determining the proper level of transmit power and data rate for assuring that the destination node will receive the data transmitted by the source node at a reliability of at least 90%.

Frame configuration determination section 101 judges a communication situation based on the transmission path information indicating the level of fluctuations of the transmission path due to fading and data transmission speed information indicating the transmission speed of the transmission data based on the level of the reception signal and determines the interval of inserting a known pilot symbol and the modulation system of a transmission digital signal. Quadrature baseband modulation section 102 modulates the transmission digital signal to a quadrature baseband signal according to the modulation system indicated from frame configuration determination section 101. Pilot symbol generation section 103 generates a pilot symbol known between the transmitting and receiving sides. Frame configuration section 104 inserts the known pilot symbol output from pilot symbol generation section 103 at the insertion interval instructed from frame configuration determination section 101 to configure a frame. This makes it possible to flexibly improve the data transmission efficiency and the quality of data at the same time.

The present invention relates to a system that facilitates multi-tasking in a computing environment. A focus area component defines a focus area within a display space—the focus area occupying a subset area of the display space area. A scaling component scales display objects as a function of proximity to the focus area, and a behavior modification component modifies respective behavior of the display objects as a function their location of the display space. Thus, and more particularly the subject invention provides for interaction technique(s) and user interface(s) in connection with managing display objects on a display surface. One aspect of the invention defines a central focus area where the display objects are displayed and behave as usual, and a periphery outside the focus area where the display objects are reduced in size based on their location, getting smaller as they near an edge of the display surface so that many more objects can remain visible. In addition or alternatively, the objects can fade as they move toward an edge, fading increasing as a function of distance from the focus area and / or use of the object and / or priority of the object. Objects in the periphery can also be modified to have different interaction behavior (e.g., lower refresh rate, fading, reconfigured to display sub-objects based on relevance and / or visibility, static, etc.) as they may be too small for standard rendering. The methods can provide a flexible, scalable surface when coupled with automated policies for moving objects into the periphery, in response to the introduction of new objects or the resizing of pre-existing objects by a user or autonomous process.

A system abstracts channel information from field data gathered in actual wireless communication system environments. The abstracted data is then transformed into control signals or programming codes that can be used to control channel simulators so as to recreate the field conditions, including path loss, slow fading, fast fading, path delay, fading power spectral density with and without line-of-sight (LOS), and different kind of handoff scenarios, such as soft, softer, intra-band hard, inter-band hard handoffs. The system thus can accurately simulate a realistic wireless communication link originated from multiple signal sources in different band channels and formed by multipath signal propagation. The simulated realistic wireless communication link can be condensed by selecting the most useful scenarios from its original field data files or modified by tuning its parameters as desired.

An orthogonal frequency division multiplexing (OFDM) technique which is time division multiplexed to reduce the overall effect on individual services from conditions such as selective fading. In accordance with the principles of the present invention, all available subcarriers in a channel are assigned to fewer than all of the requesting services, e.g., to just one particular service for a period of time. The period of time is preferably independent of the length of a conventional data frame. Thereafter, a second service is assigned access to the use of all available subcarriers for a period of time corresponding to its required bandwidth, and so on until all requesting services are allotted a portion of time for access to all available subcarriers. Any one service may utilize any number of the available subcarriers in a particular superframe containing one cycle of transmissions for all services.

The invention provides an identifying method for a battery capacity fading mechanism. The method comprises the steps of sampling and recording the charging capacity C and voltage V of a battery in the constant current charging process with a preset frequency to obtain a C-V curve; counting to obtain a V-dQ / dV curve by using a point counting method according to the C-V curve; comparing the V-dQ / dV curves corresponding to different circular charging and discharging times of the battery and analyzing the battery capacity fading mechanism. By using the constant current charging voltage curve, the capacity increment curve of the battery is obtained by fast calculating through a counting method, the internal condition of the battery is obtained in a non-damage mode, the capacity fading condition of the battery is more comprehensively learned, and the internal mechanism of the battery capacity fading is identified. The invention also provides an identifying system for the battery capacity fading mechanism.

The specification and drawings present a new method, system, apparatus and software product for defining an adaptive preamble length of a preamble for a continuous connectivity transmission using a control channel, e.g., a UL (uplink) dedicated physical control channel (DPCCH), for transmitting the preamble. Such a preamble would reduce the accuracy requirement for the initial power setting after a transmission gap and also help the channel estimation and the synchronization of a data channel, e.g., an enhanced dedicated channel (E-DCH). The preamble length can be optimized and defined using a predetermined criterion depending on: a) a degree of fading of a multipath channel which is used for transmitting data on the data channel and / or b) a throughput relative to a nominal throughput in the data channel.

In one aspect, an image of an event is obtained from a camera, and an object is detected in the image. Data of a textured 3d model of the event and data from the object are combined to depict virtual viewpoints of the event which differ from a real viewpoint of the camera. The object is at least partially faded out at a virtual viewpoint which meets a specified criterion, such as a specified angular offset, or exceeding a specified difference from the viewpoint of the camera. The fading can occur over multiple virtual viewpoints, or over a time period in which the fading is otherwise apparent to a human viewer. In another aspect, an animation is provided in which one object is faded out at a specified virtual viewpoint so that it does not fully occlude another object. For instance, the objects can be participants in a sports event.

In a transmission power control apparatus for measuring SIR, which is a ratio of a receive signal to an interference signal, and controlling transmission power of a mobile station in such a manner that the measured SIR will agree with a target SIR, a fading detector detects the rate of change in fading, a correction unit corrects the target SIR based upon the rate of change in fading, and a transmission power control command creation unit creates a command for controlling transmission power of the mobile station in such a manner that the measured SIR will agree with the corrected target SIR, and transmits this command. Further, a searcher detects multipath and the levels of signals that arrive via respective ones of the paths, a level-difference calculation unit calculates level differences between the paths, a correction unit corrects the target SIR based upon the level differences between the paths, and a transmission power control command creation unit creates a command for controlling transmission power of the mobile station in such a manner that the measured SIR will agree with the corrected target SIR, and transmits this command.

The “repeating object extractor” described herein automatically segments and identifies audio objects such as songs, station identifiers, jingles, advertisements, emergency broadcast signals, etc., in an audio stream. The repeating object extractor performs a computationally efficient joint segmentation and identification of the stream even in an environment where endpoints of audio objects are unknown or corrupted by voiceovers, cross-fading, or other noise. Parametric information is computed for a portion of the audio stream, followed by an initial comparison pass against a database of known audio objects to identify known audio objects which represent potential matches to the portion of the audio stream. A detailed comparison between the potential matches and the portion of the audio stream is then performed to confirm actual matches for segmenting and identifying the audio objects within the stream, an alignment between matches is then used to determine extents of audio objects in the audio stream.

Beat matching for two audio streams extracts beats from each, computes a conversion ratio from one stream to the other stream by an initial beat alignment plus a stability-maintaining beat alignment. A variable resampling converter or time scale modifier adjusts one stream to align beats with those of the other (reference) stream. Thus for cross-fading two music streams the beats of the fading-in stream can be matched to those of the fading-out stream for a seamless transition.

A system abstracts channel information from field data gathered in actual wireless communication system environments. The abstracted data is then transformed into control signals or programming codes that can be used to control channel simulators so as to recreate the field conditions, including path loss, slow fading, fast fading, path delay, fading power spectral density with and without line-of-sight (LOS), and different kind of handoff scenarios, such as soft, softer, intra-band hard, inter-band hard handoffs. The system thus can accurately simulate a realistic wireless communication link originated from multiple signal sources in different band channels and formed by multipath signal propagation. The simulated realistic wireless communication link can be condensed by selecting the most useful scenarios from its original field data files or modified by tuning its parameters as desired.

Most modern integrated circuit transceivers, especially wireless LAN, utilize a direct conversion radio architecture, which is highly advantageous from the perspectives of cost and flexibility, there exist several performance impairments, including gain and phase imbalances between the in-phase (I) and quadrature (Q) of a transmitter or receiver. Disclosed herein is a signal processing methodology and system for compensation of I / Q imbalance for a direct conversion packet-switched OFDM communications system. The imbalance, which accounts for transmitter I / Q imbalance, RX I / Q imbalance, phase / frequency error, and dispersive multipath fading. Both frequency dependent I / Q imbalance and frequency independent cases are considered, covering both wideband and narrowband modulation. The proposed estimation algorithms operate within the fully compliant framework of existing multi-user OFDM radio standards (WLAN, LTE, WimAX). These algorithms accurately estimate and correct transceiver I / Q imbalance on a packet-by-packet basis, all within the receiver's digital baseband.

An OFDM transceiver has a transmitter, a receiver, and a loopback switch. The loopback switch configured is for selectively establishing a physical connection between an output terminal of the transmitter and an input terminal of the receiver. The transmitter is configured for outputting to the output terminal an OFDM signal generated based on a local oscillator signal. The receiver is configured for demodulating the OFDM signal, received via the physical connection, using the local oscillator signal and determining amplitude and phase imbalance parameters based on performing frequency-domain estimation of amplitude and phase imbalances. Hence, the receiver is configured for performing imbalance compensation on a received wireless OFDM signal based on the determined amplitude and phase imbalance parameters. Hence, amplitude and phase imbalances can be estimated accurately despite channel fading and frequency variations encountered between the transmitter of the wireless OFDM signal and the receiver.

The present invention provides methods, apparatus and systems for delivery of digital data to stationary receivers over a terrestrial wireless link at a low data rate using a new coded orthogonal frequency division multiplexing (COFDM) scheme. Digital data is encoded and modulated using coded orthogonal frequency division multiplexing (COFDM) to produce a data stream. The data stream is communicated to a stationary receiver via a terrestrial wireless link having a ratio of (i) 50% coherence bandwidth to (ii) allocated channel bandwidth of not greater than 50%. The COFDM scheme employed by the present invention overcomes the degradation of multipath fading induced by terrestrial channels, such as the Ultra High Frequency (UHF) broadcast channel.

The method is for estimating the fading coefficients of a plurality of transmission channels on which signals to be sent, generated as a function of a sequence of symbols, are transmitted according to a particular modulation, e.g. AM-PSK modulation. The fading coefficients are estimated by using estimations of the transmitted symbols obtained in advance, thus obtaining DC components of the received signal by coherent demodulation locked to the phases of the transmitted AM-PSK signals, and processing these DC components. The method may not require the choice of a stochastic distribution model of the channel fading, thus it remains efficient even when the channel characteristics vary significantly. Moreover, the method works correctly even if the received stream is disturbed by inter-symbolic interference (ISI) and / or by multi-path fading.

The invention discloses a detecting method and system for the health state of an extended-range electric vehicle power battery. The detecting method includes the steps that the environment temperature and environment humidity of the environment where an extended-range electric vehicle is located are obtained; the temperature of the power battery is obtained; traveling environment information of the extended-range electric vehicle is obtained; a first accumulative charging capacity sequence corresponding to the environment temperature, the environment humidity, the temperature of the power battery and the traveling environment information is obtained from a first battery capacity fading table; the first health state of the power battery is calculated according to the first accumulative charging capacity sequence. According to the detecting method and system for the health state of the extended-range electric vehicle power battery, factors affecting performance states and cycling life of the power battery are considered, so that the obtained health state value is more accurate, and stable and reliable work of a battery pack can be ensured.

A cordless modem comprises a radio pair interfaced to a standard data / fax modem which allows a user of a personal computer to wirelessly connect to a telephone line. One end of the radio pair is a remote unit interfaced to the modem contained within the PC while the other end is a base unit connected to a standard telephone wall jack. The base unit can selectively discriminate and adjust for signals received from a telephone voice handset or data signals received from the cordless modem remote unit. Upon receiving an off-hook signal or an incoming call signal, the base unit identifies the type of data (i.e., voice or computer modem data) and adapts accordingly by placing an FM modulator in either of a narrow band deviation or a wide band deviation covering the required range of the particular signal combined with local echo. That is, when voice data is present, a low deviation, narrow filter combination is selected. If, on the other hand, the computer data from the cordless modem is detected, a higher deviation, wider bandwidth filter is selected. In addition, the remote unit switches a pre-detection filter from one mode to another depending on whether it is connected to a computer modem or to a voice handset. Security from eavesdroppers as well as the mitigation of signal fading is provided by overlaying a pseudo-random number (PN) code on the FM modulated signal.

The robot in this invention can detect the fading or loss of wireless network signal as an indication of being removed from its working area and enter into alert mode. The purpose of robot entering into alert mode is to deter physical theft, e.g., by sounding an alarm, to protect confidential data loss, and to render the robot useless to an unauthorized person, reducing the incentives for theft. A number of techniques are employed in this invention: confidential data stored on the robot is encrypted; administrator is required to log in the robot to enable robot operations; robot is to detect abnormal conditions such as fading of wireless network signal, sudden loss of wireless network signal, loss of connectivity to management server, and physical disconnection of any computing part from itself; robot is to resume normal operations without administrator intervention when abnormal condition is rectified; an Internet management server instructs the robot to delete stored data when the robot fails to authenticate itself; and place the reset button of a computing part of the robot such that the reset button is only accessible when the computing part is physically disconnected from the robot.

Apparatus, and an associated method, for space-time encoding data to be communicated upon a communication channel susceptible to fading. Multi-rate data services can be effectuated through appropriate selection of the code rate by which data is encoded. And, the coding of space-time encoded data is facilitated as different permutations of coded data symbols are separate transmitted upon separate communication paths.

Satellite communication methods and systems are disclosed. Various embodiments employ dummy bursts to monitor the communication channel between a user terminal and a hub. In some embodiments, dynamic link adaptation can also be employed to optimize channel performance. In some embodiments, the link margin can be estimated based on the signal quality of a traffic or dummy burst that is received at the hub and compared with a threshold value. If the link margin is less than a first / low threshold then the hub can instruct the terminal to change any of various communication parameters according to a predetermined algorithm to mitigate channel fading. If the link margin is greater than a second / high threshold then the hub can instruct the terminal to change any of various communication parameters according to a predetermined algorithm to reduce overcompensation for channel fading.