535 results about "Rate adaptation" patented technology

Techniques are provided for use in controlling rate-adaptive pacing within implantable medical devices such as pacemakers or implantable cardioverter-defibrillators (ICDs). In one example, a force-frequency relationship is determined for the heart of the patient, which is representative of the relationship between cardiac stimulation frequency and myocardial contractile force. To this end, various parameters are detected for use as surrogates for contractile force, including selected systolic pressure parameters and cardiogenic impedance parameters. Rate-adaptive pacing is then controlled based on the detected force-frequency relationship to, for example, deactivate rate-adaptive pacing if the slope and/or abscissa of the force-frequency relationship indicates significant contractility dysfunction within the patient. In other examples, rather than deactivating rate-adaptive pacing, control parameters are adjusted to render the rate-adaptive pacing less aggressive. In still other examples, trends in the slope and/or abscissa of the force-frequency relationship are monitored to detect contractility dysfunction and/or heart failure and titrate medications accordingly.

A rate-adaptive method of communicating over a multipath wireless communication system uses multiple links such that each end of a link uses multiple transmit and receive antennas. A number of independent streams that are to be transmitted for each link is determined based on an overall system performance measure. In addition, the system may also jointly determine the best modulation, coding, power control, and frequency assignment for each link, based on an overall system performance measure. In OFDM systems, the number of independent streams, as well as the modulation, coding, and power control, may be determined on a tone-by-tone basis based on an overall system performance measure.

A method for improving a cooperation between a packetized data bit-rate adaptation and a data packet re-transmission transmits data packets from a server to a client with a first bit-rate; stores transmitted data packets in a server buffer; stores transmitted data packets in a client buffer; signals impairment information related to an impairment of transmitted data packets during transmitting to the server, wherein the signaled impairment information is analyzed by the server to decide if a re-transmission of data packets stored in the server buffer is required; and signals client buffer information related to a state of the client buffer to the server, wherein the client buffer information is analyzed by the server to decide if a re-transmission of data packets is required.

Embodiments of the present invention provide a method for transmitting low rate signals over an optical transport network, including: adapting the low rate signals into low rate optical channel data units of the same rate level with the low rate signals; asynchronously mapping each of the low rate optical channel data units into a low rate optical channel data tributary unit respectively, and generating justification overhead used for rate adaptation for each of the low rate optical channel data units; and forming a higher order optical channel data unit with at least one low rate optical channel data tributary unit and justification overhead corresponding to the low rate optical channel data tributary unit. The present invention enables the optical transport network to support mapping, multiplexing and highly efficient transmission of low rate signals.

An adaptive quality control loop for link rate adaptation based on modulation and/or coding schemes (also referred to as "MCS levels") and one or more spreading codes that adaptively selects channel condition thresholds in real-time without measuring all the factors that affect selecting optimal channel condition thresholds. The adaptive quality control loop involves adjusting the channel condition thresholds with variable up and down steps based on target quality metrics along with measurements such as error detection results, relative frequencies of visiting each MCS level, and transmitted data rates, wherein the target quality metrics can be a block error rate or bit error rate target criterion. If the target quality metric is a block error rate target criterion, the variable step is determined using a desired MCS error rate based on MCS probabilities, MCS error rates and the block error rate target criterion. If the target quality metric is a bit error rate target criterion, the variable step is determined using a desired MCS error rate based on MCS probabilities, MCS error rates, average rate of bit errors, data rate, and the bit error rate target criterion.

An adaptive quality control loop for link rate adaptation that selectively adjusts channel condition thresholds based on delay sensitivity of data packets being transmitted. For wireless communication systems incorporating an error correction scheme using retransmissions, the quality control loop adaptively adjusts channel condition thresholds more frequently for delay sensitive data packets, such as video, and less frequently for delay insensitive data packets, such as text messaging. Channel condition thresholds may be adjusted using fixed or variable steps based on error detection results.

A method and system for automatically adjusting the operating parameters of a rate-adaptive cardiac pacemaker in which maximum exertion levels attained by the patient are measured at periodic intervals and stored in order to compute or update a maximum exercise capacity. The slope of the rate-response curve is then adjusted to map an exertion level corresponding to the updated maximum exercise capacity to a maximum allowable pacing rate. In accordance with the invention, a maximum exercise capacity is determined by cross-checking periodic maximum exertion level sensor values with a motion-level sensor value.

A method for rate adaptation with extended MCS set for wideband eigen-beamforming transmission. A signaling method over multiple channels in a wireless telecommunication system including a transmitter and a receiver, performs the steps of obtaining an information bit stream, selecting the number of transmission streams, selecting different transmission rates for each MIMO OFDM transmission, and transmitting the information bit stream from the transmitter via said multiple channels over a plurality of transmitter antennas to the receiver according to the selected transmission rate per channel. Selecting transmission rates further includes the steps of selecting the transmission rates based on the diversity order of each stream. The method selects different transmission modes for each MIMO OFDM transmission and provides a simple, fast and efficient scheme to select the transmission rate for each eigen-mode transmission.

A method and apparatus for adaptively obtaining bandwidth requests in a broadband wireless communication system. The method and apparatus includes dynamically varying technique combinations enabling a plurality of users to efficiently request bandwidth from a shared base station. A user may “piggyback” a new bandwidth request upon, or set a “poll-me bit” within, presently allocated bandwidth. A base station may poll users, individually or in groups, by allocating unrequested bandwidth for new requests. Polling may respond to a “poll-me bit,” and/or it may be adaptively periodic at a rate based on communication status parameters, such as recent communication activity and connection QoS levels. Group polling permits a possibility of collisions. Polling policies may be established for dynamically varying user groups, or may be determined for each user. Dynamic selection of appropriate polling techniques makes use of efficiency benefits associated with each technique.

The invention provides a mobile phone near field communication system and method based on visible light. The mobile phone near field communication system and method based on the visible light are used for short distance wireless communication. According to the mobile phone near field communication system, a transmitting terminal is arranged on a mobile device provided with a light-emitting screen and a light sensor, and comprises an encoding module and a rate adaptive mechanism module; a receiving terminal is provided with an LED and comprises a light sensor array, a signal conditioning module, a decoding module and a feedback module. The encoding module encodes data into a brightness level sequence and sends the brightness level sequence out through light signals; the receiving terminal collects the light signals to conduct signal conditioning and decoding so as to obtain decoded data; the feedback module is used for feeding back a signal of data blocks which need retransmission and a signal of adjustment of brightness level numbers to the transmitting terminal; the transmitting terminal controls the retransmission of the data blocks and the adjustment of the brightness level numbers through the rate adaptive mechanism module. The mobile phone near field communication system and method based on the visible light are low in cost, easy to use, safer, free of addition of extra hardware, and capable of achieving the near field communication functions such as mobile payment, equipment matching and data exchange between mobile phones.

A streaming media system employs dynamic rate adaptation. The method includes a file format compatible with legacy HTTP infrastructure to deliver media over a persistent connection. The method further includes the ability for legacy client media players to dynamically change the encoded delivery rate of the media over a persistent connection. The method provided works transparently with standard HTTP servers, requiring no modification and leverages standard media players embedded in mobile devices for seamless media delivery over wireless networks with high bandwidth fluctuations. A system is also specified for implementing a client and server in accordance with the method.

The invention relates to cardiac rhythm management systems, and more particularly, to rate adaptive cardiac pacing systems and methods. In an embodiment, the invention includes a method for providing rate-adaptive cardiac pacing therapy from an implantable medical device, the method including sensing a pulmonary function of a patient; determining a rate of change in the pulmonary function; sensing a cardiac function of the patient; determining a rate of change in the cardiac function; and calculating a target pacing rate based on an existing pacing rate, the rate of change in the pulmonary function, and the rate of change in the cardiac function. In an embodiment, the invention includes a method of controlling a cardiac rhythm management device in response to exertion of a patient, the method including sensing the patient's pulmonary function at a first time t₁ and at a second time t₂; calculating a rate of change of the pulmonary function between time t₁ and time t₂; sensing the patient's cardiac function at time t₃ and t₄; calculating a rate of change of the cardiac function between time t₃ and time t₄; and setting a desired pacing rate. Embodiments of the invention also include cardiac rhythm management devices.

The invention discloses a file transferring method with self-adaptive control of transmission speed and a system thereof; UDP protocol is adopted to transfer file data, other commands are carried outby TCP protocol; the file data takes 'block' as a basic unit for each transferring and verifying the completeness, and transmission speed is adjusted by adopting a way of dynamically adjusting the size fine grit of a transmission 'block'; the file is divided into 1-N file fragments by a server, and each file fragment is transmitted by a UDP send data; the server transmits according to the size ofthe presetting block, a client side verifies the result weather to be retransmitted by requesting the server according to the completeness of the received block, if the sever receives the retransmitting request from the client side, the size of the block can be dynamically adjusted. In addition, the transmission speed is adjusted by dynamically adjusting the number of transmission threads. In theinvention, less network expense is increased, and network resource accessed by the client side can be effectively utilized, and the transferring time of the whole file is reduced.

A method for enhancing the bit rate and/or margin at which quadrature amplitude modulation (QAM) communication is performed over multiple bands of a communication link includes the steps of varying a spectral allocation and constellation size with which communication is performed, so as to define a combination of spectral allocation and constellation size at which the bit rate and/or margin are enhanced. The rate adaptation method identifies the spectral allocation and constellation size to use on each of the multiple bands that results in a total bit rate greater than or equal to the target bit rate, subject to specified constraints on SNR margin and/or BER limits. If more than one parameter set has this property, the rate adaptation method may for example select the spectral allocation and constellation size combination that maximizes the minimum SNR margin across the multiple bands.

The invention discloses a communication baud rate self-adaptive method, a device and a host computer thereof. The method comprises the following steps: after a slave computer receives a baud rate calibration code sent by the host computer, a built-in timer of the slave computer starts counting from a level falling edge caused by the baud rate calibration code at a preset frequency and stops counting at a level rising edge, and obtains a count value; and the slave computer obtains a baud rate generation register constant according to the count value, and the slave computer sets the baud rate generation register according to the baud rate generation register constant. By adopting the technical proposal, the self-adaptive adjustment of the communication baud rate is realized without adding any hardware, the hardware manufacturing cost is reduced, the method can be applicable to application occasions of any communication baud rates, and is especially applicable to the application occasion that a slave computer crystal oscillator is unstable.

A wireless communication network manages variable data rate communication channels using both short-term data rate adaptation and longer-term resource allocation adjustment. For example, an exemplary base station system may track the actual transmit power being used to transmit a given communication channel on a per frame basis, or faster, and use that tracked value to infer changing channel conditions, e.g., for a given current data rate, higher power indicates poorer channel conditions and lower power indicates better channel conditions. Additionally, or alternatively, channel quality information reported by a receiving mobile station can be used. Regardless, relatively fast data rate changes can be made responsive to monitoring the channel conditions, while retaining the communication resource allocation for the channel. Over the longer term, however, the allocation itself can be changed, e.g., increased or decreased, depending on whether the channel is being efficiently utilized.

In a multimedia streaming network where a client has a receiver buffer to store a plurality of packets received from a server so as to compensate for the difference between data transmission amount by the server and data usage amount by the client, the server should be able to adapt the data transmission rate based on the status of the receiver buffer. For rate adaptation purposes, server reconstructs a list of packets in the receiver buffer based on information provided by the client. The information signaled to the server is indicative of the next packet to be decoded in the client. The information can be the sequence number of the next packet to be decoded, the DON number of the next NAL unit to be decoded, or the sequence number of the packet carrying the next NAL unit to be decoded and the DON indicative of the decoding order of that next NAL unit.

A system and method for automatically adjusting the operating parameters of a rate-adaptive cardiac pacemaker in which maximum exertion levels attained by the patient are measured at periodic intervals and stored. The stored maximum exertion levels may then be used to update a long-term maximal exertion level, and the slope of the rate-response curve is adjusted to map the updated long-term maximal exertion level to a maximum allowable pacing rate. In accordance with the invention, the rate response curve is defined such that an exertion level corresponding to the patient's maximum exercise capacity would be mapped to a physiologically favorable maximum rate that is independent from a specified maximum sensor indicated rate.