Abstract: An automatic gain control (AGC) circuit and method for performing AGC for an orthogonal frequency-division multiplexing (OFDM) receiver measures signal power of input digital signals that are derived from incoming data frames with preambles to produce gain change signals when the signal power differs from a reference target power level. The gain of an amplifier of the OFDM receiver is changed in response to the gain change signals until a preamble of the data frames is detected for the first time. The gain of the amplifier of the OFDM receiver is further changed in response to the gain change signals, after the preamble is detected, only during periods when the preambles of the data frames are being processed by the OFDM receiver such that the gain of the amplifier is not changed during periods when other portions of the data frames are being processed by the OFDM receiver.
Abstract: A digraphic keypad includes a configuration of specific keys. These specific keys include an “S” key, an “O” key, a “U” key, an “A” key, an “N” key, an “I” key, a “T” key, an “E” key, an “R” key, an “H” key, a “D” key and an “L” key.
Abstract: A resonance scanning system and method for testing equipment for electromagnetic resonances uses a resonance detection subsystem with at least one probe to identify at least one of a resonating location, a resonating frequency and a quality factor of a resonance of the equipment and an automatic scanning subsystem to displace the probe to different testing locations of the equipment so that the resonance detection subsystem can determine if any of the different testing locations of the equipment exhibits electromagnetic resonances.
Type:
Grant
Filed:
June 1, 2009
Date of Patent:
March 27, 2012
Assignee:
The Curators of the University of Missouri
Inventors:
David J. Pommerenke, Wei Huang, Peng Shao, Jiang Xiao
Abstract: An OFDM-based device and method for performing synchronization utilizes a time-domain preamble of an incoming OFDM-based signal to compute an estimated fine frequency offset. The computation of the estimated fine frequency offset involves multiplying values of the time-domain preamble with conjugates of corresponding values of a selected base station time-domain preamble, averaging the resulting multiplied values in predefined segments and self-correlating the resulting averaged values to derive a self-correlation value, which is used to compute the estimated fine frequency offset.
Abstract: A device and method for performing a channel profile estimation for an OFDM-based wireless communication system uses an averaged frequency coherence metric to select a particular channel profile, which is a current channel profile estimate. The averaged frequency coherence metric is derived using correlations between pilot subcarriers of an OFDM-based signal at predefined subcarrier locations for multiple frames of the OFDM-based signal. The selected channel profile may be used for channel estimation, as well as for link adaptation, to improve the performance of these processes.
Abstract: A device and method for performing a channel estimation for an OFDM-based wireless communication system using sparsely spaced pilot subcarriers estimates missing pilot subcarriers in an interpolation window using pilot subcarriers that are outside of the interpolation window to produce estimated pilot subcarriers for the interpolation window. The pilot subcarriers in the interpolation window and the estimated pilot subcarrier are used to compute pilot channel estimates for the interpolation window, which are then used to derive data channel estimates for the interpolation window.
Abstract: Priority-biased compound arbitration at a switching fabric ingress. The ingress includes a plurality of ingress queues and a priority-biased arbitration engine configured to arbitrate between the ingress queues. The ingress further includes exit first-in-first-out queues (FIFOs) configured to forward cells from the ingress queues to a switching fabric and a throughput-biased arbitration engine configured to arbitrate between the exit FIFOs.
Abstract: A Turbo decoder and method for decoding a double-binary circular recursive systematic convolutional (DBCRSC) encoded signal with unknown initial and final states executes iterations of forward and backward recursion on a payload block of the DBCRSC encoded signal and a padded block using an estimated forward state metric (FSM) and an estimated backward state metric (BSM), which are updated at one or more iterations.
Abstract: A soft-bit de-mapping device and method of generating soft bits for decoding quantizes a log-likelihood ratio (LLR) value for a received value using functions bits and channel parameter bits to generate the soft bits. The function bits are generated by quantizing an LLR function for the received value, which includes modifying an original curve of the LLR function to a modified curve such that a segment of the original curve with the lowest slope is protected in the modified curve for a fixed equal quantization step-size. The channel parameter bits are generated by quantizing a channel parameter for the received value to generate channel.
Abstract: An optical encoder and method for measuring displacement information using an optical encoder uses an encoder member with multiple digital diffractive optic regions to optically diffract an incident beam of light to produce output beams of light having intensity distribution patterns, which are used to generate electrical signals that provide relative displacement information of the encoder member.
Abstract: A stepper motor device uses compensating non-sinusoidal driving values to compensate for operational non-sinusoidal drive characteristics of a motor of the device due to at least design and manufacturing imperfections in the motor. The compensating non-sinusoidal driving values may be derived using back electromagnetic force produced from the motor or using measured rotational positions of the motor when the motor is driven using known driving values.
Type:
Grant
Filed:
September 29, 2008
Date of Patent:
October 4, 2011
Assignee:
Arcus Technology, Inc.
Inventors:
Christopher C. Chang, Edward Li, Thomas Judge
Abstract: A method for reducing power consumption in a multi-user digital communication system and mobile station employing the method adjusts receive and transmit mode durations of the mobile device using downlink and uplink allocations from a base station of the system, as well as other factors.
Abstract: A system and method for motivating users to improve their wellness utilizes complex event processing on sensor and user-interaction data of the users collected over time using inference and predictive models in order to deliver personalized interactions to motive the users toward their wellness goals.
Abstract: Loop-elimination in a network is provided by establishing a physical topology based domain within the network and restricting protocol data units that are received within the physical topology based domain from being consumed at a network node outside of the physical topology based domain, wherein the protocol data units include loop-elimination information. The loop-elimination technique may also include identifying a logical based domain that exists within the network and then restricting protocol data units that are received within the physical topology based domain and the logical based domain from being consumed outside of the physical topology based domain and the logical based domain.
Type:
Grant
Filed:
December 9, 2002
Date of Patent:
May 10, 2011
Assignee:
Alcatel-Lucent USA Inc.
Inventors:
Shriram Srinivasan, Shantanu R. Kothavale
Abstract: A method and system for distributing data packets within a network node is disclosed. The method and system for distributing data packets within a network node involves the utilization of a moving weighted average function to dynamically distribute the data packets in a balanced fashion. By utilizing a moving weighted average function to dynamically distribute the data packets in a balanced fashion, data packets are distributed more efficiently thereby increasing the overall efficiency of network operations. The method and system include computing a ratio matrix based on a moving weight average function of a load over a plurality of data ports and distributing data packets to the plurality of data ports based on the ratio matrix.
Abstract: An Orthogonal Frequency Division Multiple Access (OFDMA) device and method of correcting frequency offset in OFDMA signals computes an estimated frequency offset, which is used for producing a frequency offset-compensated mixer signal using a reference clock signal. The frequency offset-compensated mixer signal is used to produce a digital down-converted signal from an incoming OFDMA signal. The digital down-converted signal is digitally corrected for sampling errors using the estimated frequency offset.
Type:
Grant
Filed:
January 10, 2007
Date of Patent:
March 22, 2011
Assignee:
Amicus Wireless Technology Ltd.
Inventors:
Chaohuang Zeng, Won-Joon Choi, Jingnong Yang
Abstract: An apparatus and method for transmitting outgoing data uses data descriptors for multiple sets of contiguous data blocks stored in buffers. When new sets of contiguous data blocks are created due to acknowledgement signals for particular data blocks of the multiple sets of contiguous data blocks, new data descriptors are generated for some of the new sets of contiguous data blocks. These new data descriptors are placed in spaces in the buffers where the particular data blocks were originally stored.
Abstract: A packet-based traffic switching system with error detection and correction without taking the system offline. The system tests offline paths without interfering with other online paths. Also, the system tests online paths even while no data cell traffic is sent over the paths. The system responds to the addition or removal of paths or path components without interrupting cell traffic. The system detects and selectively flushes defective paths without impacting paths that are working properly. The system initializes new switching fabrics automatically without using software to set values. Thus, the system tests online paths and corrects errors without going offline.
Type:
Grant
Filed:
June 4, 2003
Date of Patent:
January 25, 2011
Assignee:
Alcatel-Lucent USA Inc.
Inventors:
Gregory S. Mathews, Eric Anderson, Philip Ferolito, Mike Morrison
Abstract: A decoder and method for decoding a tail-biting convolutional encoded signal using Viterbi decoding scheme performs a traceback operation for a first portion of a total code block, which includes a code block of the tail-biting convolutional encoded signal and a padded block. During the traceback operation for the first portion, a particular state at a predefined position within the first portion is stored as a circular state. The circular state is used as a traceback starting state for at least one subsequent portion of the total code block to produce a decoded signal of the code block.
Abstract: A device and method of performing channel estimation for an OFDM-based wireless communication system performs a Least Square interpolation with a statistical channel profile consideration on pilot channel estimates to derive data channel estimates at data subcarrier locations.