By Signal Strength Patents (Class 455/134)
  • Patent number: 7113746
    Abstract: A method, an apparatus, and a computer program product for facilitating local signaling among a plurality of agents are presented. An agent 100 including a digital processor 102 a transmitter 104, and a directional receiver 106 comprising a plurality of angular regions 108 is configured to enable the selection of a signal from a plurality of signals received on the basis of local data such as the strength of the received signal. The local data may be incorporated into a cumulative data portion of a signal that is passed from local agent 100 to local agent 100 across a plurality of agents 100 in order to provide a gradient across the plurality of agents 100. The gradient could be used, for example, to determine a shortest path across the agents. The signaling techniques described can also be used to determine the distance and direction to objects in the signaling path.
    Type: Grant
    Filed: August 2, 2001
    Date of Patent: September 26, 2006
    Assignee: HRL Laboratories, LLC
    Inventors: David W. Payton, Bruce Hoff, Mike Howard, Craig Lee
  • Patent number: 7107085
    Abstract: A mobile communication terminal having adaptive array antennas is provided that is capable of transmitting signals to an intended base station without interfering other devices, even when a reception error occurs. The mobile communication terminal basically performs array transmission/reception using weight vectors produced in reception to weight and combine signals received via antennas, and thereby receives a desired signal. In transmission, the mobile communication terminal uses the weight vectors used in reception to weight and combine transmission signals and transmits them. However, when an error detection circuit detects a reception error in the desired signal, a transmission control unit turns off a switch for the antenna and transmits the transmission signals in a non-directional pattern via the antenna, so that the transmission signal reaches the intended base station.
    Type: Grant
    Filed: July 13, 2001
    Date of Patent: September 12, 2006
    Assignee: Sanyo Electric Co., Ltd
    Inventor: Yoshiharu Doi
  • Patent number: 7092706
    Abstract: A signal strength compensation unit for mobile radio receivers is connected upstream of the channel estimator and the channel equalizer and compensates for, in particular, the great, brief signal strength fluctuations within a data burst. Likewise, a method for signal strength compensation compensates for brief signal strength fluctuations within the data burst. To these ends, a signal strength average is determined from the signal strengths for the previously received data symbols. The current signal is then aligned with this signal strength average. The inventive signal strength compensation allows the bit error rate during data equalization to be significantly reduced.
    Type: Grant
    Filed: April 11, 2003
    Date of Patent: August 15, 2006
    Assignee: Infineon Technologies AG
    Inventor: Bin Yang
  • Patent number: 7079820
    Abstract: Combining signals includes receiving first signals having a first frequency and second signals having a second frequency. A first weight reflecting a signal-to-noise ratio associated with a first signal is determined for each first signal, and a first signal output is generate from the first signals in accordance with the first weights. A second weight reflecting a signal-to-noise ratio associated with a second signal is determined for each second signal, and a second signal output is generate from the second signals in accordance with the second weights. The first signal output and the second signal output are combined to yield a combined signal output.
    Type: Grant
    Filed: December 7, 2004
    Date of Patent: July 18, 2006
    Assignee: Raytheon Company
    Inventors: George P. Bortnyk, David J. Lupia
  • Patent number: 7072627
    Abstract: A first signal component is received having a first signal strength and a second signal component is received having a second signal strength. A difference is identified between the first signal strength and the second signal strength. A determination is made as to whether the difference between the first signal strength and the second signal strength exceeds a threshold. If the difference between the first signal strength and the second signal strength exceeds a threshold, the first signal strength is adjusted to reduce the difference between the first signal strength and the second signal strength.
    Type: Grant
    Filed: June 27, 2002
    Date of Patent: July 4, 2006
    Assignee: Microsoft Corporation
    Inventor: Louis F. Coffin, III
  • Patent number: 7062287
    Abstract: 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.
    Type: Grant
    Filed: February 8, 2002
    Date of Patent: June 13, 2006
    Assignee: Fujitsu Limited
    Inventors: Satoshi Nakamura, Morihiko Minowa, Noriyuki Kawaguchi, Kensuke Sawada, Tokuro Kubo, Dai Kimura
  • Patent number: 7043199
    Abstract: An uplink power control system for terminals in a satellite communication system provides closed loop power control using feedback signals generated at a satellite. The satellite performs inter-beam routing of uplink signals from satellite terminals, and processing of uplink signals to generate terminal transmission-specific feedback information that is transmitted in downlink signals to the terminals. The satellite also generates a beacon signal. An uplink power control algorithm at each terminal uses the beacon signal and feedback data to adjust transmit power.
    Type: Grant
    Filed: June 6, 2001
    Date of Patent: May 9, 2006
    Assignee: Hughes Network Systems LLC
    Inventors: Jerry Dai, Stan Kay, Yezdi Antia, Zhenliang Shi, Anwer Khan, Gaguk Zakaria
  • Patent number: 7035362
    Abstract: Described is a method for the clock-pulse selection in a baseband combiner of a space-diversity receiver. The method provides for driving the clock recovery circuit by means of the main signal, filtered and sampled, or by the diversity signal, filtered and sampled as well, and it is characterized by calculating the average power of the equalized main signal and the average power of the equalized diversity signal; and by driving the clock recovery circuit by means of the signal chosen according to a comparison between the average powers of the signals at the output of the equalizers. Advantageously, the invention provides for a hysteresis on the power comparison and guarantees a soft change with respect to the selection performed at the preceding time of processing.
    Type: Grant
    Filed: March 6, 2002
    Date of Patent: April 25, 2006
    Assignee: Alcatel
    Inventors: Morena Ferrario, Roberto Pellizzoni, Roberto Valtolina, Arnaldo Spalvieri
  • Patent number: 7023901
    Abstract: Spreading factor (SF) estimation in a code division multiple access (CDMA) spread spectrum system where the SF of the data channel may change on a frame-by-frame basis to reflect a change in the data rate for each corresponding frame. The SF estimation methods despread the data channel for all possible SF values, perform maximal ratio combining (MRC) when resolved multipaths occur, take the absolute value of the MRC results, and average these absolute values over many symbol periods to obtain decision statistics for the various SF's. The SF estimation methods then post-process these decision statistics and make a SF decision.
    Type: Grant
    Filed: December 4, 2001
    Date of Patent: April 4, 2006
    Assignee: Texas Instruments Incorporated
    Inventor: Aris Papasakellariou
  • Patent number: 6996127
    Abstract: A method, and corresponding apparatus, applies to individual base stations in a wireless communications systems, where each base station performs rate assignment to mobile stations optimally, but independently of the other base stations. Different base stations affect each other through other cell interference, and continuously modify their reversed link rate assignment based on the other-cell interference received and the requested rates from the mobile stations. The base stations converge to a stable condition with uncoordinated optimizations. The optimizing technique maximizes total through put in each cell (maximizing rates) while maintaining interference to other cells at a minimum level, and being subject to at least some of the following constraints: mobile station's maximum transmit power, mobile station's requested rate, discrete set of possible rates, maximum rise-over-thermal interference at the base station, and minimum required received error per bit normalized for noise.
    Type: Grant
    Filed: May 28, 2003
    Date of Patent: February 7, 2006
    Assignee: Qualcomm Incorporated
    Inventors: Ramin Rezaiifar, Jack Holtzman
  • Patent number: 6996078
    Abstract: A particular cell of a hybrid time division multiple access/code division multiple access communication system has a base station and a plurality of user requirements. Timeslots having unacceptable interference for the uplink are estimated. Timeslots having unacceptable interference for the downlink are estimated. An availability list is produced. The availability list indicates available uplink and downlink timeslots having acceptable interference levels. Uplink and downlink timeslots are assigned using the availability list.
    Type: Grant
    Filed: July 20, 2001
    Date of Patent: February 7, 2006
    Assignee: InterDigital Technology Corporation
    Inventors: Jung-Lin Pan, Ariela Zeira
  • Patent number: 6992584
    Abstract: A mobile device (MS) is disclosed comprising a GPS receiver (14) and an audible alarm (13, 15) configured to sound, during operation of the GPS receiver, in response to either adverse performance of the GPS receiver or to an event which is adverse or likely to be adverse to the performance of the GPS receiver. The alarm may sound in response to the inability of the GPS receiver to either acquire or track a GPS signal, or obtain or maintain a position fix. Also, the alarm may sound in response to movement of the GPS receiver, including acceleration and higher order movement of the GPS receiver, in so far as that movement is adverse to the performance of the GPS receiver.
    Type: Grant
    Filed: January 22, 2002
    Date of Patent: January 31, 2006
    Assignee: Koninklijke Philips Electronics N.V.
    Inventors: Saul R. Dooley, Andrew T. Yule
  • Patent number: 6987750
    Abstract: A method and apparatus for evaluating interference within a timeslot of a received TDMA signal is described. An average received signal strength is calculated for a plurality of repeating segments within a TDMA timeslot. The segment sizes are dependent upon the efficiency of the error correction coding scheme utilized by a selected channel type. The calculated received signal strengths for the plurality of the segments are applied to a lowpass filter. The output of the lowpass filter is processed to determine the level of interference within the timeslot.
    Type: Grant
    Filed: April 23, 2004
    Date of Patent: January 17, 2006
    Assignee: Telefonaktiebolaget LM Ericsson (publ)
    Inventors: Jan Söderkvist, Peter Wahlström
  • Patent number: 6987973
    Abstract: The method consists in the use of the average network traffic data and a series of measurements taken within a part of a network, along with the recording of the signals, received from all base stations within reach of a given point. The measurement area is divided into polygonal sections, relating to specific P measurements and the total area of such section represents the weight of a given measurement. Subsequently, based on the most powerful signal criterion, individual P measurements are assigned to specific network cells. Further on, the based on the differences between signal power value calculated, measurement weights and the assumed distances between channels, values of certain formulae are calculated, which then provide the basis for determination of the minimum distances between channels.
    Type: Grant
    Filed: December 4, 2001
    Date of Patent: January 17, 2006
    Assignee: Polska Telefonia Cyfrowa Sp. Zoo.
    Inventors: Pawel Wawrzynski, Grzegorz Lehmann
  • Patent number: 6987958
    Abstract: A method provides a technique for optimally combining communication beams. The method forms a plurality of beams from captured signals. One beam is selected as the primary beam while a subset of the others are applied to auxiliary receivers. A digital signal processor weights and combines these primary and secondary beams.
    Type: Grant
    Filed: January 16, 2002
    Date of Patent: January 17, 2006
    Assignee: Cingular Wirless II, Inc.
    Inventors: Titus Lo, Dennis Rosenauer, Douglas Frank Stolarz
  • Patent number: 6968169
    Abstract: A receiver that uses multiple antennas to receive signals arriving over multiple paths and is configured for enhanced received signal path detection accuracy and improved reception quality includes a receive weight generating circuit that generates receive weights for every antenna based on signals received from the antennas, a summing circuit that calculates sums of results obtained by multiplying the signals from the antennas and the receive weights of the individual antennas generated by the receive weight generating circuit and path detection circuit that detects the paths of the received signals based on the sums calculated by the summing circuit.
    Type: Grant
    Filed: September 20, 2001
    Date of Patent: November 22, 2005
    Assignee: Hitachi Kokusai Electric Inc.
    Inventor: Tetsuhiko Miyatani
  • Patent number: 6946958
    Abstract: A contactless data storage medium has at least two antennas, in each case for different transmission bands. This makes it possible to configure a data storage medium such that it can be operated with read/write units that operate in accordance with different standards. At least two of the antennas form a unit, so that a configuration such as this can be produced at very low cost.
    Type: Grant
    Filed: May 13, 2003
    Date of Patent: September 20, 2005
    Assignee: Infineon Technologies AG
    Inventors: Harald Gundlach, Michael Hochholzer, Gerald Holweg, Andreas Müller-Hipper, Jens Riedel, Walter Kargl
  • Patent number: 6947473
    Abstract: A receiver recovers data for at least one of a plurality of users from radio signals generated by the plurality of users. The receiver includes data detectors, each of which is associated with one of a plurality of temporal displacements in communications paths through which the radio signals pass. Each of the data detectors estimates a user data symbol for one of the plurality of users from at least one of the radio signals. The receiver also includes a signal strength estimator to estimate signal strengths of the radio signals, and a receiver controller to assign user codes and the temporal displacements to each the plurality of data detectors according to the signal strengths of the radio signals. The receiver controller assigns a first user code for a first user to a first number of data detectors and a second user code for a second user to a second number of data detectors. The first number of data detectors has different temporal displacements than the second number of data detectors.
    Type: Grant
    Filed: August 3, 1999
    Date of Patent: September 20, 2005
    Assignee: Siemens AG
    Inventor: Leo Rademacher
  • Patent number: 6940914
    Abstract: A system and method for estimating a channel in a wireless receiver is disclosed. The method preferably applies to a communication system using the OFDM standard. The method comprises receiving a block of “n” transmitted symbols, the symbols including pilot symbols and “d” data symbols, estimating a channel using the pilot symbols to create a channel estimate, choosing a group of “m” strongest symbols from the “d” received symbols, compensating the “m” strongest symbols using the channel estimate to create a group of “m” compensated symbols, re-estimating the channel using the group of “m” compensated symbols and pilot symbols; and either (1) repeating the steps of choosing a group of “m” strongest symbols, compensating the group of “m” strongest symbols and re-estimating the channel, or (2) using a latest channel estimate to compensate all symbols within the block.
    Type: Grant
    Filed: June 11, 2001
    Date of Patent: September 6, 2005
    Assignee: Cingular Wireless II, LLC
    Inventors: Titus Lo, Ruifeng Wang
  • Patent number: 6922453
    Abstract: A diversity receiver carries out error detection, error correction, and data detection on each detected data string 21. An output switching unit 17 outputs a decoded data string 24 of a branch selected by a branch selector 16. The branch selector 16 selects a branch of highest priority in priority information 29 from branches of which a data detection signal 25 indicates that the data is valid and of which the number of error symbols 22 coincides with a minimum value. In the priority information 29, higher priority is assigned to a branch that includes an antenna of which the coverage is closer to that of an antenna included in a branch selected at the immediately-previous time. Thus, selected from the plurality of branches having the minimum number of error symbols 22 is the one that includes the antenna of which the coverage is closest to the coverage of the antenna included in the branch selected at the immediately-previous time.
    Type: Grant
    Filed: May 9, 2002
    Date of Patent: July 26, 2005
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Kenji Miyanaga, Hidetoshi Yamasaki, Yoshio Urabe, Hitoshi Takai, Kenichi Mori
  • Patent number: 6888456
    Abstract: A method and an apparatus for determining whether an object is moved are provided. The object is disposed in a communication system having many base stations. The apparatus includes a receiver, a controller, and a warning device. During a predetermined period, the apparatus respectively receives and measures signals from each of the base stations to derive a first average value. Meanwhile, a tolerable probability value is inputted. According to the tolerable probability value and the first average value, the apparatus gets a tolerable range. Next, the apparatus continues to receive and measure signals to derive a second average value. Finally, the apparatus determines whether the object is moved in accordance with the second average value and the tolerable range. If moved, the apparatus sends out a warning signal.
    Type: Grant
    Filed: May 8, 2003
    Date of Patent: May 3, 2005
    Assignee: Benq Corporation
    Inventors: Steven D. Cheng, Chunming Chen
  • Patent number: 6873835
    Abstract: A method of selecting between first and second antennas in a quadrature amplitude modulation receiver having in-phase (I) and quadrature (Q) signal channels for demodulating signals received by the antennas, comprising the steps of imultaneously connecting the first antenna to the I channel to obtain a first output signal having a first amplitude, and the second antenna to the Q channel to obtain a second output signal having a second amplitude; measuring the first and second amplitude to obtain a greater amplitude for one on the antennas; and switching to said of the antennas having the greater amplitude for demodulating the received signals.
    Type: Grant
    Filed: January 3, 2002
    Date of Patent: March 29, 2005
    Assignee: Symbol Technologies, Inc.
    Inventor: Dean Kawaguchi
  • Patent number: 6865378
    Abstract: The invention provides a radio reception apparatus by which a delay by initialization of an equalizer is minimized and an equalization process with a minimum preamble signal can be performed normally to assure a high transmission efficiency and suppress an increase of the power consumption. First and second RF sections convert the frequencies of reception data from first and second antennae. A comparison section compares reception sensitivities of outputs of the first and second RF sections to select the output having a higher reception sensitivity.
    Type: Grant
    Filed: October 31, 2001
    Date of Patent: March 8, 2005
    Assignee: NEC Corporation
    Inventor: Yasuhiko Wakabayashi
  • Patent number: 6853694
    Abstract: A combiner for use in a spatial diversity radio receiver which receives multiple data signals through spaced apart antennae. The combiner includes a receiving component configured for receiving strength-indicative signals, each strength-indicative signal being indicative of the strength of one of the received data signals, and demodulated data signals. A control signal generating component configured for generating control signals generates control signals responsive to the strength-indicative signals. A combining component configured for combining signals combines, in linear proportions determined by the control signals, those of the demodulated data signals which are both above a predetermined strength threshold level (“combiner threshold”) and differ in strength by less than a predetermined margin of preferably between 3 dB and 12 dB (e.g. 6 dB) to provide a combined output data signal. When more than the margin separates the signal strengths, only the strongest signal is used.
    Type: Grant
    Filed: July 27, 2000
    Date of Patent: February 8, 2005
    Assignee: Dataradio Inc.
    Inventors: André Beaudin, Richard Vallée, Michel D. Martin
  • Patent number: 6839563
    Abstract: An optical pulse signal from a machine tool measuring probe is received by a photodiode (28). To reduce interference from xenon strobe beacons, fluorescent lights etc., the pulse signal is processed by an AGC amplifier (30) with low frequency signal cancellation, and the pulses are then detected by a threshold detector (32). The threshold of this detector (32) is variable by a circuit (50), in accordance with the overall amplitude of the signal pulses, in order to provide the best rejection of interference pulses.
    Type: Grant
    Filed: February 11, 1999
    Date of Patent: January 4, 2005
    Assignee: Renishaw, PLC
    Inventors: Steve Kirby, Jonathan P Fuge
  • Publication number: 20040266374
    Abstract: The invention relates to the field of wireless communications, more particularly to a method of and device for switching between antennae in communication with a diversity receiver, each of the antennae receiving signals transmitted from a single source. A packet from a transmitter is received by respective antenna communicating with a diversity receiver. The signal strength of the preamble of the packet received in a first antenna is sampled. If the signal strength is of sufficient magnitude to affect reliable reception, the associated antenna is selected for the duration of the packet transmission. If the signal strength is below a predetermined threshold the signal strength of the preamble of the packet received in a second antenna is sampled and compared to the sample associated with the first antenna. If the magnitude of the second sample is greater, the signal associated with the second antenna is selected.
    Type: Application
    Filed: June 30, 2003
    Publication date: December 30, 2004
    Applicant: IceFyre Semiconductor Corporation
    Inventors: Aryan Saed, Phil Guillemette
  • Patent number: 6836660
    Abstract: A microcellular communications network includes a plurality of base station units and corresponding antenna units. The microcells connected to their respective base station units over a telephone system. The microcells providing received signal strength indication (RSSI) level signals and Supervisory, Audio Tone (SAT) frequencies to the base station for hand-in evaluation. The base stations having a scanning receiver for processing the RSSI level signals and SAT frequencies and for performing hand-in for neighboring cells.
    Type: Grant
    Filed: August 28, 2000
    Date of Patent: December 28, 2004
    Assignee: ADC Tolocommunications, Inc. and ADC Mobile Systems, Inc.
    Inventor: Philip M. Wala
  • Publication number: 20040258024
    Abstract: A forward link power control mechanism measures the reverse link power control bits which are transmitted on the forward traffic channel. At the remote station, the reverse link power control bits from multiples base stations or multiple signal paths are measured, combined, and filtered to yield an improved measurement of the forward link signal quality. The reverse link power control bits which are deemed unreliable are omitted from use in the power control loop. The remote station generates a set of forward link power control bit in accordance with the measurements and transmits these bits to all base stations in communication with the remote station. Each base station adjusts its gain of the forward traffic channel in accordance to its measurement of the forward link power control bit.
    Type: Application
    Filed: June 25, 2004
    Publication date: December 23, 2004
    Inventors: Edward G. Tiedemann, Keith W. Saints
  • Publication number: 20040253968
    Abstract: RF communications received by a wireless terminal from a servicing base station are used to determine the channel quality such as reported bit error probability (BEP). The RF communications may be in the form of RF bursts that are part of a data frame. An estimated BEP may be determined from the signal to noise ratio (SNR) of the RF bursts and or a sequence of soft decisions extracted from the RF bursts, and their historical performance. The SNR maps to an estimated BEP based upon the modulation format of the RF bursts. The soft decisions decode to produce a data block. When the soft decisions decoded favorably, the re-encoded data block produces a sequence of re-encoded decisions. Comparing the re-encoded decisions to the soft decisions yields a re-encoded bit error (RBER). The reported BEP may be based upon the estimated BEP, RBER, and/or RBER threshold. The RBER threshold may be adaptively incremented or decremented depending upon whether or not the RF communications were properly decoded.
    Type: Application
    Filed: May 14, 2004
    Publication date: December 16, 2004
    Inventors: Li Fung Chang, Yongqian Wang, Xiaoxin Qiu, Nelson R. Sollenberger
  • Patent number: 6816070
    Abstract: A method of generating a warning signal for a walkie-talkie includes: providing a detector and a timer; using the timer to count time; using the detector to determine whether the strength of a radio frequency (RF) signal which includes a standard CTCSS tone received by the walkie-talkie is larger than a predetermined value; using the detector to determine whether the strength of a RF signal which includes a non-standard CTCSS tone received by the walkie-talkie is larger than the predetermined value; if so, resetting the timer; and issuing a warning signal when the time counted by timer reaches a predetermined time.
    Type: Grant
    Filed: April 22, 2003
    Date of Patent: November 9, 2004
    Assignee: Conwise Technology Corporation Ltd.
    Inventors: Jany-Yee Hsu, Ming-Hui Chen
  • Publication number: 20040198276
    Abstract: The present invention provides a method and system for receiving a plurality of information signals at a receiver. The information signals each traveling through a corresponding transmission channel. The receiver includes a plurality of receiver channels, wherein each receiver channel receives a corresponding information signal. An amplitude of each received information signal associated with each receiver channel is adjusted so the amplitudes of all the received information signals are as great as possible, while still maintaining a target level of signal error of each of the received information signals. The amplitudes of the received information signals can be additionally adjusted so that the signal errors of each of the received information signals are approximately equal. Each receiver channel can be calibrated by measuring a noise reference and a distortion reference for aiding in the estimation of the received information bit stream.
    Type: Application
    Filed: March 26, 2002
    Publication date: October 7, 2004
    Inventors: Jose Tellado, John Dring
  • Publication number: 20040142669
    Abstract: A method and a device for a receiver for electromagnetic waves having at least two antennas are described; using this method and this device it is possible to effectively suppress multipath interference, while a portion of the antenna signals may also be utilized for other purposes at least temporarily, e.g., to allow better utilization of the possibilities of RDS activities. To do so, a first antenna signal (1) is used as the basis for generating a playback signal (23) when the signal quality of the first antenna signal (1) is above a defined threshold for undisturbed reception—case 1. In this case 1, the signal quality of the first antenna signal (1) is determined. If the signal quality of the first antenna signal (1) falls below this threshold—case 2—then a new signal y generated from at least two antenna signals (1, 2) is used as the basis for generating the playback signal (23).
    Type: Application
    Filed: March 22, 2004
    Publication date: July 22, 2004
    Inventors: Lothar Vogt, Detlev Nyenhuis
  • Patent number: 6760551
    Abstract: The present invention is a decoder for decoding a signal. The decoder includes a discriminator and a threshold generator. The discriminator receives the signal and generates an output voltage equal to a first voltage if the signal is less than a threshold level that is input to the discriminator and equal to a second voltage if the signal is greater than the threshold level. The threshold level depends on the output from the discriminator in a preceding time interval that depends on the impulse response of a transmission link through which the input signal has passed. The threshold generator implements a low-pass analog filter that receives the output voltage during each of the clock periods and generates therefrom a filtered output signal.
    Type: Grant
    Filed: October 29, 2002
    Date of Patent: July 6, 2004
    Assignee: Agilent Technologies, Inc.
    Inventors: Adrian Wan-Chew Seet, Ken Nishimura, Richard C. Walker
  • Patent number: 6745052
    Abstract: A communication receiver (400) minimizes a combined local and global mean square error for signal equalization. A base station (101) or a mobile station (102-104) may include a plurality of antennas (292) for receiving a plurality of signals transmitted from a common source. The plurality of signals carry a common stream of data symbols. A pre-processing block (299) processes the received signals to produce a plurality of processed received signals (298). A signal equalizer (401) minimizes a combined local and global MSE over the processed received signals (298) to produce a combined signal (499). A decoder decodes the combined signal (499) to retrieve the stream of data symbols. A processor is configured for combining a local MSE and a global MSE in accordance with an adjustable weighting factor &agr; to produce the combined local and global MSE.
    Type: Grant
    Filed: July 27, 2001
    Date of Patent: June 1, 2004
    Assignee: Qualcomm, Incorporated
    Inventors: Ivan Jesus Fernandez Corbaton, John E. Smee, Srikant Jayaraman
  • Patent number: 6731921
    Abstract: A circuit for changing over between the frequency-modulated HF signals of at least two receiving antennas is described, having a control unit that changes over between the individual antennas as a function of the quality of the antenna output signal. A detector is provided which, when a signal that exceeds the defined reception level is no longer being furnished by any of the antennas, applies to the control unit a signal that effects the changeover to a specific antenna.
    Type: Grant
    Filed: June 14, 2002
    Date of Patent: May 4, 2004
    Assignee: Robert Bosch GmbH
    Inventors: Uwe Militz, Carsten Zeitz
  • Publication number: 20040048588
    Abstract: A receiver is operable at microwave frequencies and includes a substrate and waveguide-to-microstrip transition formed on the substrate for receiving microwave radio frequency (RF) signals. Surface mounted receiver components are interconnected with microstrip formed on the substrate and receive the RF signals from the waveguide-to-microstrip transition and convert the signal to an intermediate frequency (IF) for further processing. The surface mounted receiver components include a mixer circuit that receives a local oscillator (LO) signal and RF signal to produce the IF signal. A diplexer circuit and a temperature compensated attenuator circuit received the IF signal from the mixer and attenuates the IF signal to provide high signal linearity and high order modulation.
    Type: Application
    Filed: January 7, 2003
    Publication date: March 11, 2004
    Applicant: Xytrans, Inc.
    Inventors: Danny F. Ammar, Stephen A. Stahly
  • Publication number: 20040023629
    Abstract: The invention relates to a receiving unit for searching for at least one unused transmission channel in a communications device in a network of distributed stations and/or for monitoring transmission channels such that specific messages can be determined for that communications device, and to a method for its use, in particular in a local broadband network or a digital broadband home network.
    Type: Application
    Filed: June 19, 2003
    Publication date: February 5, 2004
    Inventor: Otto Klank
  • Patent number: 6683906
    Abstract: A radio communication apparatus subjects each signal which is received via a multi-path and demodulated, to a Hadamard transform at each of fingers, by use of an M-ary quadrature coding scheme, obtains correlation values of codes, combines correlation values output from fingers which obtain valid correlation values, and demodulates a received signal based on a maximum correlation value of combined correlation values. The radio communication apparatus includes an operation unit which obtains a difference between a maximum value and a second largest value of the correlation values of a corresponding one of the fingers, and a lock controller which enables and locks the correlation values output from the corresponding one of the fingers when the difference obtained by the operation unit is greater than or equal to a predetermined value.
    Type: Grant
    Filed: March 1, 2000
    Date of Patent: January 27, 2004
    Assignee: Fujitsu Limited
    Inventor: Takanori Iwamatsu
  • Publication number: 20040009757
    Abstract: Techniques for inner/outer loop tracking that is stable and provides desirable loop convergence characteristics are disclosed. In one aspect, the contribution from any one inner loop to the tracking function of the outer loop is limited, to prohibit any one received signal component from dominating the outer loop. In another aspect, the rate of outer loop tracking variation is controlled to provide inner and outer loop stability. Various other aspects are also presented. These aspects have the benefit of providing stable inner and outer loop control, as well as efficient convergence and tracking by the various loops, resulting in reduced frequency error and improved communication performance.
    Type: Application
    Filed: October 1, 2002
    Publication date: January 15, 2004
    Inventors: Parvathanathan Subrahmanya, Jeremy H. Lin
  • Publication number: 20030211836
    Abstract: A method and apparatus for direct tuning of a component embedded within an integrated circuit includes processing that begins by providing a plurality of frequency dependent control input signals to an input of the integrated circuit. The processing continues for each of the plurality of frequency dependent control input signals by incrementally adjusting the power level of each frequency dependent controlled input signal until the signal strength of an output of the integrated circuit is at a desired signal strength level. The corresponding power level is recorded to produce an adjusted power level for the frequency dependent control input signal. The adjusted power level of each of the plurality of frequency dependent control input signals is plotted to produce a signal strength to frequency relationship. The processing continues by comparing the signal strength to frequency relationship with a desired signal strength to frequency relationship.
    Type: Application
    Filed: May 7, 2002
    Publication date: November 13, 2003
    Inventor: Shahla Khorram
  • Publication number: 20030203723
    Abstract: The power of a signal received on a spatial channel in a wireless radio communications system can be estimated. One embodiment of the invention includes receiving a signal at a plurality of antenna elements, the received signal including a first component from a first radio and a second component from a second radio. Then the contribution of the first component to the received signal may be estimated by calculating a first power estimate for the first radio using the received signal, calculating a second power estimate for the second radio using the received signal, and estimating the contribution of the first component to the received signal, the estimation using the first power estimate and the second power estimate. In one embodiment the first power estimate is an SINR of the first component.
    Type: Application
    Filed: March 27, 2002
    Publication date: October 30, 2003
    Inventors: Johan L. Persson, Mitchell D. Trott
  • Publication number: 20030186657
    Abstract: The invention relates to a method for estimating a channel of a mobile radiotelephone channel during a multipath reception. According to said method, an interpolation of the channel coefficients which are determined on the basis of the respective impulse response, in two adjacent time intervals (slot 1 and slot 2), is carried out. Before said interpolation, the individual components of the impulse response are examined to determine whether they belong to one and the same transmission path, and an interpolation is only carried out for the components to which this applies. (1′ and 1″ resp.
    Type: Application
    Filed: January 10, 2003
    Publication date: October 2, 2003
    Inventors: Yingjie Gao, Benjamin Schwarze
  • Patent number: 6628698
    Abstract: A CDMA reception apparatus has a plurality of fingers and performs RAKE reception by RAKE-combining outputs from the plurality of fingers. The apparatus includes a multi-path detecting section and delay profile generating section. The multi-path detecting section detects a multi-path consisting of a plurality of radio waves arriving with some delay times by despreading a reception signal. The delay profile generating section generates a delay profile by obtaining the reception power levels of all reception signals in the multi-path detected by the multi-path detecting section. A difference di in level between the signal having the ith highest level and the signal having the (i+1)th highest level of the data of the delay profile is obtained. The operation of a finger corresponding to a signal having a low level is stopped on the basis of the difference di and a predetermined threshold dTH.
    Type: Grant
    Filed: December 6, 1999
    Date of Patent: September 30, 2003
    Assignee: NEC Corporation
    Inventor: Toshiyuki Oda
  • Patent number: 6628930
    Abstract: A radio receiver having a circuit arrangement for checking the quality of reception at an alternative frequency to a received transmit frequency. The radio receiver has two tuners for converting the received signals to two different intermediate frequencies and a switch, which is preferably switched by a microprocessor, for optionally forwarding signals from signal processing branches that are each connected to one of the tuners. This reduces the cost of implementing the second receiver, at the same time reducing the barely noticeable impairment of the set program when checking the quality of reception at the alternate frequency. The latter is achieved by positioning the switch upstream from an analog-digital converter, operating at a sampling frequency, of an intermediate frequency stage. The different intermediate frequencies are selected so that they both meet the following condition: f0=(n+R)fa where n is a natural number, and 0≦R≦1 applies.
    Type: Grant
    Filed: July 13, 2000
    Date of Patent: September 30, 2003
    Assignee: Robert Bosch GmbH
    Inventors: Lothar Vogt, Karl-Heinz Black
  • Publication number: 20030157910
    Abstract: A receiver circuit for a mobile radio receiver has a controllable amplifier with a variable gain level, an analog-digital converter stage, a digital filter configuration for the purpose of channel selection and a signal strength estimator. The signal strength estimator is connected downstream of the filter configuration in the signal path and has the purpose of determining the signal strength in the selected user signal. The amplifier is controlled in dependence on the user-channel signal strength determined by the signal strength estimator.
    Type: Application
    Filed: March 5, 2003
    Publication date: August 21, 2003
    Inventors: Dieter Bruckmann, Andre Neubauer
  • Patent number: 6603961
    Abstract: A diversity receiving apparatus for receiving data that has been primarily modulated and then secondarily modulated includes a plurality of uni-directivity antennas arranged so that they orient in different directions, a signal information detector for detecting signal information of all frequency bands of received signals of each of the uni-directivity antennas, a branch selector for selecting one of received signals of the individual branches received by the uni-directivity antennas, a secondarily modulated data demodulator for demodulating data that has been secondarily modulated as the received signal selected by the branch selector, and a primarily modulated data demodulator for primarily demodulating data that has been primarily modulated as an output signal of the secondarily modulated data demodulator, wherein the branch selector is controlled corresponding to an output signal of the signal information detector.
    Type: Grant
    Filed: February 1, 2000
    Date of Patent: August 5, 2003
    Assignee: Sony Corporation
    Inventor: Shinichi Kuroda
  • Patent number: 6597238
    Abstract: A demodulating circuit 1 contains an electric field level detector 2 for detecting an electric field strength from a received modulation signal, comparators 3a to 3n for outputting electric field strength information PS, a detector 5 for outputting a detection signal corresponding to a modulation signal, both a low-pass filter 6 and a digital filter 12 for removing a noise component from the detection signal, and a data comparator 7 for comparing the detection signal with a reference voltage to output a digital signal. This demodulating circuit 1 further includes a control circuit 4 for controlling a cutoff frequency used in a digital filter 12, an output voltage amplitude of the detector 5, and the reference voltage of the data comparator 7 in accordance with both the electric field strength information PS and control condition information PC saved in an EEPROM 11 and supplied from a CPU 10, and also a judging circuit 9 for judging the digital signal at preselected timing to produce a demodulation signal.
    Type: Grant
    Filed: April 21, 2000
    Date of Patent: July 22, 2003
    Assignee: Matsushita Electric Industrial Co., Ltd
    Inventors: Hidenori Matsumoto, Atsuhiko Hashigaya
  • Publication number: 20030109235
    Abstract: In accordance with the present invention, a receiver circuit and a method of controlling voltage pulses, thereby improving the performance of the receiver are provided. The receiver circuit includes a switch for blocking high voltages and for converting voltage signals to current signals. The switch includes first and second signal terminals and a control terminal. The switch exhibits an ON resistance when closed, wherein the ON resistance is controlled by an electric value at the control terminal. The receiver circuit also includes a control circuit coupled to the switch for controlling the ON resistance of the switch in closed mode. The first switch signal terminal is coupled to an output of a transducer and the second switch signal terminal is coupled to an input of a low-noise amplifier circuit. The switch is a transmit/receive switch which is open during a transmission time interval and closed during a reception time interval.
    Type: Application
    Filed: December 11, 2001
    Publication date: June 12, 2003
    Applicant: Koninklijke Philips Electronics N.V.
    Inventor: Benoit R. Veillette
  • Patent number: 6577353
    Abstract: In a system for optimizing television reception by a television receiver receiving a diversity of input signals from a plurality of antennas, one of a plurality of combiners and television tuners selects the strongest combination of input signals for viewing and another scans the various combinations of input signals searching for a combination significantly stronger than the combination being viewed. A plurality of multiplexers selects the output signal of one combiner and transmits the selected signal to one of the tuners. A signal evaluation module evaluates the strength of the combinations of input signals and compares the strength of each combination of input signals to the strength of the viewing signal, looking for a superior signal. A control processor controls the combination of input signals selected by the combiners and the combiner output signal selected by the multiplexers.
    Type: Grant
    Filed: October 21, 1999
    Date of Patent: June 10, 2003
    Assignee: General Electric Company
    Inventors: Kenneth Brakeley Welles, II, Mark Lewis Grabb, John Erik Hershey
  • Patent number: 6574461
    Abstract: The present invention relates to a method for diversity selection for antenna paths in a radio receiver (R2; R3) comprising a plurality of antennas (A, B; N) and a selection switch (SW; SWI) for selecting one of said antennas, which method comprises the following steps: generation of average interference powers (AIA, AIB; AIN) of antenna signals received over a period of time to each of the antenna's (A, B; N); generation of carrier signal strength (CSA, CSB; CSN) of radio signals (RSA, RSB) received to each of the antenna's (A, B; N); selecting one of the antennas (A, B; N) in dependence of the best carrier signal strength (CSA, CSB; CSN) in relation to average interference signal strength (AIA, AIB, AIN).
    Type: Grant
    Filed: June 18, 1998
    Date of Patent: June 3, 2003
    Assignee: Telefonaktiebolaget LM Ericsson (publ)
    Inventor: Johan Sköld