By Signal Quality (e.g., Signal To Noise Ratio) Patents (Class 455/135)
  • Patent number: 7269396
    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: Grant
    Filed: March 23, 2002
    Date of Patent: September 11, 2007
    Assignee: Robert Bosch GmbH
    Inventors: Lothar Vogt, Detlev Nyenhuis
  • Patent number: 7269397
    Abstract: A method and apparatus for measuring communications link quality provides accurate on-chip estimation of the difficulty of achieving a particular bit error rate (BER) for a communications link. A low cost/complexity accumulator circuit connected to internal signals from a clock/data recovery (CDR) circuit provides a measure of high frequency and low frequency jitter in a received signal. The low frequency jitter measurement is used to correct the high frequency jitter measurement which may otherwise contain error. The corrected output may be used to adjust operational characteristics of the link or otherwise evaluate the link for operating margin. The correction may be performed by subtracting a portion of the low frequency jitter measurement from the measured high frequency jitter, or the value of the low frequency jitter measurement may be used to select between two or more correction factors that are then applied to the high frequency jitter measurement.
    Type: Grant
    Filed: June 14, 2006
    Date of Patent: September 11, 2007
    Assignee: International Business Machines Corporation
    Inventors: Juan-Antonio Carballo, Jeffrey L. Burns, Ivan Vo
  • Patent number: 7260370
    Abstract: The present invention provides a method and system for operating a wireless communication system in which received signals from a plurality of antennas are weighted and combined with a beam forming operation to form an output signal. The beam forming operation determines weights adjusted to increase a desired signal power in the output signal while reducing the power in the output signal of out-of-band components. In an embodiment of the present invention, beam forming operations are performed with maximal ratio combining (MRC). Alternatively, a constant modulus algorithm (CMA) can be used for beam forming operations. In an alternate embodiment, improved interference suppression is performed with a novel algorithm referred to as an interference nulling algorithm (INA). The INA receives an error signal which is 180° out of phase with a combination of the channels for individual antennas, referred to as the SUM channel.
    Type: Grant
    Filed: December 10, 2003
    Date of Patent: August 21, 2007
    Inventors: James June-Ming Wang, Jack Winters, Meng Chang Doong, Chau Chin Yang
  • Patent number: 7254129
    Abstract: Disclosed are a wireless phone and a wireless communication method wherein communication quality estimation is made for both circuit switching and packet communication modes and sound of both the modes is interpolated mutually so as to improve the sound quality. The switching between first and second sound signals is performed at intervals of a speech pitch period based on quality information of first and second sound signals, where the first and second signals are received and decoded, respectively, through a first wireless communication in circuit switching mode and a second wireless communication in packet communication mode. A delay control signal is outputted to compensate for the time difference between the first and second sound signals, based on the quality information of the two sound signals, and the time difference is compensated for based on the delay control signal.
    Type: Grant
    Filed: September 10, 2003
    Date of Patent: August 7, 2007
    Assignee: Samsung Electronics Co., Ltd.
    Inventor: Takahiko Kishi
  • Publication number: 20070178862
    Abstract: A method for weight training for beamforming in handset terminals deployed in a system employing Frequency Division Duplexing and Time-Division Multiple Access (FDD/TDMA). Generally there is signal in time slots that are not destined for a certain terminal. During this time the receiver scans a beam around the terminal and measures received signal strength, determining the best beam angle and storing corresponding weights for transmission.
    Type: Application
    Filed: January 25, 2007
    Publication date: August 2, 2007
    Applicant: MOTIA, INC.
    Inventors: Jack Winters, James June-Ming Wang
  • Patent number: 7239885
    Abstract: A method for initial downlink transmit power adjustment for non-real time services in a wireless communications network begins by estimating an initial downlink transmit power level for non-real-time services. The estimated power level is then compared with a threshold. A determination is made whether an increase in the estimated power level would affect neighboring cells. If an increase would not affect neighboring cells, then the initial downlink transmit power level is adjusted by a predetermined amount.
    Type: Grant
    Filed: December 2, 2003
    Date of Patent: July 3, 2007
    Assignee: InterDigital Technology Corporation
    Inventor: Guodong Zhang
  • Patent number: 7236740
    Abstract: A method and apparatus for retransmitting data in a mobile communication system wherein a receiver determines whether an initial data block received from a transmitter has an error. Upon detecting an error from the initial data block, the receiver estimates a current channel state and determines a retransmission frequency and a power level of the initial data block according to the estimated current channel state. Thereafter, the receiver transmits a retransmission request message of the initial data block together with the determined retransmission frequency and the determined power level to the transmitter. The transmitter retransmits the initial data block as many times as the retransmission frequency at the requested power level. The receiver then determines whether the retransmitted data blocks have errors, and provides the retransmitted data blocks to an upper layer upon failure to detect errors from the retransmitted data blocks.
    Type: Grant
    Filed: July 5, 2001
    Date of Patent: June 26, 2007
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Chang-Hoi Koo, Kyou-Woong Kim, Hwan-Joon Kwon
  • Patent number: 7224726
    Abstract: An adaptive receiver is disclosed for optimally receiving and processing signals. The receiver utilizes one or more memory blocks to store groups of incoming symbols. The groups of symbols are processed by a channel estimation subsystem to determine channel characteristics. The receiver determines the appropriate demodulation and decoding strategy to implement based on the determined channel characteristics. The receiver includes a plurality of demodulation and decoding schemes, one of which is selected based on the results of a channel estimation analysis.
    Type: Grant
    Filed: March 28, 2002
    Date of Patent: May 29, 2007
    Assignee: Broadcom Corporation
    Inventors: Randall Perlow, Charles Brooks, Steven Jaffe, Tianmin Liu
  • Patent number: 7221412
    Abstract: Disclosed in a digital broadcasting receiver comprising first means for performing pre-scan processing for successively tuning in on channels previously set, to examine whether or not a received signal on each of the channels is of a predetermined quality or more, and temporarily registering the channel numbers of the channels on which the received signals are of the predetermined quality or more in a storage device as receivable channel candidates, and second means for performing normal scan processing for successively tuning in on the receivable channel candidates temporarily registered in the storage device by the first means, to acquire and register necessary channel information.
    Type: Grant
    Filed: January 14, 2002
    Date of Patent: May 22, 2007
    Assignee: Sanyo Electric Co., Ltd.
    Inventor: Toru Shibusawa
  • Patent number: 7212793
    Abstract: A radio reception apparatus is a radio reception apparatus for demodulating a multicarrier signal modulated according to multicarrier modulation. It includes a plurality of antenna sections, each for receiving a multicarrier signal, a plurality of carrier selection sections, each of the carrier selection sections selecting at least one subcarrier signal for each of the antenna sections out of the multicarrier signal received by each of the antenna sections, an antenna selection section for selecting a reception antenna section from among the antenna sections based on the signal strengths of the subcarrier signals selected by the carrier selection sections, and a demodulation section for demodulating the multicarrier signal received by the antenna section selected by the antenna selection section.
    Type: Grant
    Filed: July 29, 2004
    Date of Patent: May 1, 2007
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Tsuyoshi Kogawa, Hideo Kasami
  • Patent number: 7212749
    Abstract: An Improved Signal Receiver Having Wide Band Amplification Capability is disclosed. Also disclosed is a receiver that is able to receive and reliably amplify infrared and/or other wireless signals having frequency bandwidths in excess of 40 MHz. The receiver of the present invention reduces the signal-to-noise ratio of the received signal to ?th of the prior systems. The preferred receiver eliminates both the shunting resistor and the feedback resistor on the input end by amplifing the signal in current form. Furthermore, the receiver includes transconductance amplification means for amplifying the current signal without the need for Cascode stages. Finally, the receiver includes staged amplification to amplify the current signal in stages prior to converting the signal into a voltage output.
    Type: Grant
    Filed: March 15, 2005
    Date of Patent: May 1, 2007
    Assignee: ZiLOG, Inc.
    Inventors: T. Allan Hamilton, Alan Grace
  • Patent number: 7187912
    Abstract: A radio frequency transceiver for a wireless local area network (LAN) may have two or more antennae. An active antenna that delivers a data-bearing signal having a signal quality at least as good as any of the antennae may be selected based upon measurements of the signal quality during a preamble field of data frames having a substantially longer preamble field than other data frames.
    Type: Grant
    Filed: March 30, 2004
    Date of Patent: March 6, 2007
    Assignee: Intel Corporation
    Inventor: Boris Ginzburg
  • Patent number: 7171175
    Abstract: In a method (300) for receiving a radio signal, there are steps of: receiving (301, 303) first and second received signal components by use of first and second antennas having different properties; processing (305) a received signal component to produce a sampled signal component; producing (307) at least one combined signal, which is a linear combination of at least two sampled signal components; and selecting (306) at least one set of complex values for coefficients of the linear combination so that a quality of a combined signal is at least equal to the quality of that sampled signal component having the best quality. Furthermore, the antennas are alternately connected (302, 304) via a switching element to radio frequency means so that received signal components are interleaving and so that first and second parts of a certain piece of transmitted information are received with the first and second antennas, respectively. A corresponding receiver device is also presented.
    Type: Grant
    Filed: October 16, 2001
    Date of Patent: January 30, 2007
    Assignee: Nokia Corporation
    Inventors: Saku Lahti, Ilkka Kontola
  • Patent number: 7171235
    Abstract: The invention relates to an arrangement and method for reducing losses at the transmitting end of a radio apparatus, especially one that operates in more than one system. An interfering transmitter is provided with two antenna filters one of which is a low-pass-type filter and the other a band-pass filter. The filter (BPF) with a higher stop-band attenuation is used only when the receiver (330, LNA) susceptible to interference is in receive state. At other times, the filter (LPF) with a lower stop-band attenuation and, hence, a lower pass-band attenuation, is used as the transmitting-end filter. Advantageously the selection between the different filters is realized using MEMS-type switches (SW31 to SW34). The invention minimizes the mean current consumption of the radio-frequency power amplifier (PA) of the said radio apparatus. The space required by and the production costs of the arrangement according to the invention are relatively small.
    Type: Grant
    Filed: December 20, 2001
    Date of Patent: January 30, 2007
    Assignee: Nokia Corporation
    Inventor: Sami Haapoja
  • Patent number: 7162211
    Abstract: Methods and apparatus for scheduling mobile stations (MSs) to download data and/or to control the rate of downloading to an MS from a base station (BS) as a function of downlink channel condition information are described. Artificial channel variations, which can be measured at the MS, and feedback to a BS for scheduling purposes, are introduced through the use of two or more transmitter antennas at a BS. Each of the antennas transmits a signal at the same frequency having the same information content, e.g., modulated data. However the signals are made to differ with time in their phase and/or amplitude to introduce what appear to be channel variations to the MSs.
    Type: Grant
    Filed: December 29, 2003
    Date of Patent: January 9, 2007
    Assignee: QUALCOMM Incorporated
    Inventors: Pramod Viswanath, Rajiv Laroia, David N. C. Tse
  • Patent number: 7149486
    Abstract: Each mobile communication terminal receives an evaluation function threshold value of each base station transmitted from the base station, and calculates the evaluation function value of each base station on the basis of communication quality between the mobile communication terminal and base station. The mobile communication terminal compares the calculated evaluation function value of each base station with the received evaluation function threshold value, selects a base station which is highly likely to select the mobile communication terminal on the basis of the comparison result, and transmits a communication request to the selected base station.
    Type: Grant
    Filed: March 24, 2005
    Date of Patent: December 12, 2006
    Assignee: Kabushiki Kaisha Toshiba
    Inventor: Kengo Kurose
  • Patent number: 7133698
    Abstract: The fading correlation monitor 103 detects an angle spread of the communication terminal apparatus 200-1 and decides whether the angle spread has a larger or smaller relationship with a preset threshold value. When the estimated angle spread is smaller than the threshold value, the interference wave is suppressed by carrying out directive reception which is carried out by an AAA receiver 106 as well as performing directive transmission which is carried out in a transmitting circuit 122.While, when the estimated angle spread is larger than the predetermined value, the distortion of the signals due to the fading is compensated by carrying out diversity receiving which is carried out in a diversity receiver 107 as well as performing diversity transmission which is carried out in a diversity transmitter 123.On account of this, even when the fading correlation is small, it is possible to carry out a radio communication with a satisfactory communication quality.
    Type: Grant
    Filed: June 26, 2001
    Date of Patent: November 7, 2006
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Kenichi Miyoshi, Mitsuru Uesugi
  • Patent number: 7133654
    Abstract: A method and apparatus for measuring communications link quality provides accurate on-chip estimation of the difficulty of achieving a particular bit error rate (BER) for a communications link. A low cost/complexity accumulator circuit connected to internal signals from a clock/data recovery (CDR) circuit provides a measure of high frequency and low frequency jitter in a received signal. The low frequency jitter measurement is used to correct the high frequency jitter measurement which may otherwise contain error. The corrected output may be used to adjust operational characteristics of the link or otherwise evaluate the link for operating margin. The correction may be performed by subtracting a portion of the low frequency jitter measurement from the measured high frequency jitter, or the value of the low frequency jitter measurement may be used to select between two or more correction factors that are then applied to the high frequency jitter measurement.
    Type: Grant
    Filed: August 7, 2003
    Date of Patent: November 7, 2006
    Assignee: International Business Machines Corporation
    Inventors: Juan-Antonio Carballo, Jeffrey L. Burns, Ivan Vo
  • Patent number: 7127221
    Abstract: In a receiver circuit for demodulating a high-frequency signal, a limiting amplifier stage with a downstream sigma-delta converter is connected in series with a mixer stage that transforms a high-frequency signal that is supplied at its input into an intermediate-frequency signal. The intermediate-frequency signal at the output of the limiting amplifier stage is value-discrete and time-continuous. The described receiver architecture has a high sensitivity, is substantially independent of production tolerances, and occupies a small area; therefore, it is particularly suitable for mobile radio applications.
    Type: Grant
    Filed: March 10, 2003
    Date of Patent: October 24, 2006
    Assignee: Infineon Technologies AG
    Inventors: Markus Hammes, Stefan Heinen, Stefan Van Waasen, Andre Hanke, Elmar Wagner
  • Patent number: 7120404
    Abstract: A method and apparatus for operating a radio reception system, which comprises a plurality of receivers assigned to a common output device, in which one of the receivers is designated as audio receiver and is tuned to a frequency of a radio transmitter, and outputs a signal received from the transmitter to the output device. At least one second receiver is designated as search receiver, and continuously searches its own reception frequency band for a frequency of the same transmitter. The system changes to a frequency of this transmitter, which was found by the search receiver, if the quality of the signal received by the audio receiver falls below a certain limit.
    Type: Grant
    Filed: July 13, 2001
    Date of Patent: October 10, 2006
    Assignee: Harman Becker Automotive Systems GmbH
    Inventor: Stefan Gierl
  • Patent number: 7116942
    Abstract: A radio communication apparatus includes a radio signal processing section which produces a first signal. A power calculation section produces a power value signal of the first signal. A correlation detection section produces correlative value signals corresponding to a correlation between the first signal and a known signal. A first and a second detection section detect a beginning of the reception signal, using the power value signal and the correlative value signal respectively. The first and the second detection section respectively produce a first detection and a second detection signal, each of which include information of a beginning timing of the reception signal. A select control section is supplied with the first and the second detection signals and selectively outputs one of them. A demodulation section demodulates a data signal from the first signal using an output signal from the select control section.
    Type: Grant
    Filed: November 8, 2002
    Date of Patent: October 3, 2006
    Assignee: Kabushiki Kaisha Toshiba
    Inventor: Jun Hasegawa
  • 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: 7099415
    Abstract: A receiver which receives broadcast waves from a plurality of broadcasting systems is provided with signal amplifiers that amplify signals received from each of the broadcasting systems. The outputs of the signal amplifiers are superposed to produce a superposed signal. The superposed signal is then demodulated and reception information is reproduced. When the condition of the reception information has deteriorated, at least one of the signals from the signal amplifiers whose signal quality has deteriorated and the signals from the signal amplifiers whose noise level is high are excluded from the superposed signal.
    Type: Grant
    Filed: February 8, 2002
    Date of Patent: August 29, 2006
    Assignee: Pioneer Corporation
    Inventor: Susumu Ohsawa
  • Patent number: 7099637
    Abstract: A method of evaluating the quality of a radio link in a mobile radiocommunication system from the net bit rate transmitted on the link.
    Type: Grant
    Filed: August 2, 2001
    Date of Patent: August 29, 2006
    Assignee: Alcatel
    Inventor: Pascal Agin
  • Patent number: 7079859
    Abstract: A best-cell amendment method is disclosed for amending hysteresis margins according to the degree of congestion. A radio network controller (RNC) compares the average value P(k) of transmission power of a downlink shared channel PDSCH of cell k and a first threshold value P_threshold1 to measure the degree of congestion. If the RNC determines that the degree of congestion in cell k is high, it sets a small hysteresis margin hm_a, and if RNC determines that the degree of congestion in cell k is low, it sets a large hysteresis margin hm_b.
    Type: Grant
    Filed: July 29, 2003
    Date of Patent: July 18, 2006
    Assignee: NEC Corporation
    Inventors: Takahiro Nobukiyo, Kojiro Hamabe
  • Patent number: 7076212
    Abstract: A weight vector of a precedent frame calculated by a weight vector calculator (4) and stored in a memory (3) is applied to a signal received through a plurality of antennas (ANT1, . . . ANTn) for removing an interference wave component. A synchronous position is detected from the signal subjected to removal of the interference wave component by a method of correlation synchronization, and supplied to the weight vector calculator (4). The weight vector calculator (4) executes calculation of a weight vector with the detected synchronous position as a start position. Thus, when signals of the same frequency are received in a CS in an overlapping manner, the synchronous position of a signal received from a desired PS can be correctly specified.
    Type: Grant
    Filed: October 25, 2000
    Date of Patent: July 11, 2006
    Assignee: Sanyo Electric Co., Ltd.
    Inventors: Yoshiharu Doi, Takeo Miyata
  • Patent number: 7076203
    Abstract: A transmit wave receiving apparatus comprises a wave receiving device, a signal monitoring device and a wave receiving control device. The wave receiving device receives transmit waves, which are transmitted from wave transmitting systems. The signal monitoring device monitors signal levels and signal qualities of the transmit waves, which are received by the wave receiving device. The wave receiving control device controls the wave receiving device so as to halt a wave receiving operation for the transmit wave having a large signal level, when it is judged from monitoring results by the signal monitoring device that the signal qualities of the transmit waves in all of the wave receiving systems are unfavorable.
    Type: Grant
    Filed: September 18, 2002
    Date of Patent: July 11, 2006
    Assignee: Pioneer Corporation
    Inventor: Susumu Ohsawa
  • 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: 7072662
    Abstract: To insure the communication quality best suited to the type of data between the transmission system and the receiver. In a wireless communication system for controlling the data communication quality between the transmission system and a mobile wireless terminal via a predetermined communication path. The transmission system changes the modulation system in the data output unit corresponding to the type of contents to be transmitted to the mobile wireless terminal to control the data communication quality.
    Type: Grant
    Filed: October 12, 2001
    Date of Patent: July 4, 2006
    Assignee: Sony Corporation
    Inventor: Tetsuya Naruse
  • Patent number: 7061881
    Abstract: A method of determining transmission power of transmitted pilot symbols used for estimating channel coefficients in a transmission frame of a multicarrier transmission system having OFDM-CDMA, MC-CDMA, MC-CDM or MC-SS-MA frequency domain spreading sequences. The method includes determining a performance level to be achieved by the transmission, deducing the signal to noise ratio level introduced by the channel from the performance level to be achieved, deducing a single code transmission power Q0 of the pilot symbols for a single spreading code from the signal to noise ratio level, deducing an increase in power ? for transmitting the pilot symbols using a number of spreading codes K, and determining the transmission power Q of the pilot symbols at predetermined times, based on the following equations: Q=?(K?1)+Q0; K>1; ?>0; and Q0>?.
    Type: Grant
    Filed: September 4, 2001
    Date of Patent: June 13, 2006
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: David Mottier, Thomas Saelzer
  • Patent number: 7054600
    Abstract: The application relates to transmission power control in transmission systems, in particular mobile radio systems. One object of the invention is to indicate a way of guaranteeing, compared with the state of the art, improved, in particular dynamic, control of transmission powers within predefinable emitted interference requirements with, in particular, increased efficiency and reduced power consumption. For this purpose, the invention provides for the filtering of an amplified transmission signal to be divided up between a narrower-band tunable pre-filter (4) and a broadband post-filter (10). To perform this operation, a signal-amplification circuit is proposed which comprises a tunable filter (4) which is connected downstream of a power amplifier (2).
    Type: Grant
    Filed: April 10, 2002
    Date of Patent: May 30, 2006
    Assignee: Lucent Technologies Inc.
    Inventors: Norbert Bogner, Kai-Uwe Ritter, Horst Schenkel
  • Patent number: 7050405
    Abstract: Novel data transmission method and apparatus in a communication system require novel method and apparatus for power control and rate of data determination, which are disclosed.
    Type: Grant
    Filed: December 6, 2002
    Date of Patent: May 23, 2006
    Assignee: Qualcomm Incorporated
    Inventors: Rashid Ahmed Attar, Naga Bhushan
  • Patent number: 7024168
    Abstract: A mobile station with a receiver having antenna diversity where the diversity processing is controlled from the base band processing circuit and only turned on when the performance gain justifies extra power consumption. The base band processing circuit may be instructed by the network that it can cease diversity reception after evaluating cell leads within a system.
    Type: Grant
    Filed: July 7, 1999
    Date of Patent: April 4, 2006
    Assignee: Telefonaktiebolaget L M Ericsson (publ)
    Inventors: Kjell Gustafsson, Torsten Carlsson, Torgny Palenius
  • 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: 7016660
    Abstract: An antenna diversity receiving system is disclosed which includes an antenna device with a plurality of FM antennas and a controllable switching circuit for sequentially switching through one of the plurality of FM antennas via an antenna cable to a receiver upon reception of a switching control signal. The receiver has a multipath detector coupled to a pulse generator for generating a pulse signal to be used as such switching control signal. To secure accurate detection of the switching control signal, the pulse generator is coupled to a pulse shaper to convert the pulse signal of the pulse generator into a pulse signal pair. The pulse signal pair has a first signal pulse followed by a second signal pulse having a signal polarity opposite to the signal polarity of the first signal pulse. The pulse signal pair has a waveform varying symmetrically around a reference level and is supplied through the antenna cable to the antenna device.
    Type: Grant
    Filed: August 24, 2001
    Date of Patent: March 21, 2006
    Assignee: Mannesman VDO AG
    Inventors: Pieter Meijer, Peter Wegner
  • Patent number: 7016653
    Abstract: A radio terminal that receives signals from a plurality of radio stations to calculate its current position has: interference canceling means for canceling each interference signal from the plurality of received signals; a plurality of delay profile generating means for generating delay profiles of the plurality of interference-canceled received signals with use of respective corresponding codes; and position calculating means for calculating its current position, which is a signal receiving point, with use of the plurality of delay profiles, whereby advantageously reducing the capacity of a memory mounted in the mobile terminal while the position calculation is speeded up
    Type: Grant
    Filed: June 27, 2002
    Date of Patent: March 21, 2006
    Assignee: Hitachi, Ltd.
    Inventors: Katsuhiko Tsunehara, Mikio Kuwahara
  • 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: 6992730
    Abstract: Process for mobile reception of television signals in which an output signal (SA) is derived from n different (S1 . . . S5) and is supplied to the reproduction part of the receiver, the n input signals (S1 . . . S5) being weighted, the output signal (SA) being formed by summing of the weighted input signals, and the quality of each of the n input signals (S1 . . . S5) being evaluated using at least one given criterion for determining the adaptively determined weighting factors, characterized in that the n input signals (S1 . . . S5) are time-synchronized before their evaluation, summing and weighting, and the horizontal and/or vertical video synchronization pulses contained in the input signals (S1 . . . S5) are used for control of time synchronization.
    Type: Grant
    Filed: May 20, 2000
    Date of Patent: January 31, 2006
    Assignee: Hirschmann Electronics GmbH & Co. KG
    Inventors: Wolfgang Sautter, Achim Ratzel, Dieter Schenkyr
  • 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: 6985544
    Abstract: It is an object of the present invention to improve the diversity gain by conducting linear prediction of fading fluctuations and switching antennas.
    Type: Grant
    Filed: December 8, 2003
    Date of Patent: January 10, 2006
    Assignee: Uniden Corporation
    Inventors: Masaki Matsui, Muneki Ito, Akio Horibe, Shigeo Sato
  • Patent number: 6980781
    Abstract: A wireless communication system exposes first stage filtered energy estimates to a second stage filter whose length dynamically varies with time. With the second stage filter, it is possible to further suppress noise in low SNR conditions without affecting the overall filtering response time.
    Type: Grant
    Filed: February 11, 2002
    Date of Patent: December 27, 2005
    Assignee: DENSO Corporation
    Inventor: Marcus Dibuduo
  • Patent number: 6968197
    Abstract: In mobile communication systems employing the CDMA method, the communication quality is acquired from the CDMA pilot channel. A communication quality acquisition apparatus comprises a delay profile acquisition unit comprising a control unit, synchronization unit and measurement unit, in addition to a data storage unit. The communication quality is measured by the synchronization unit and the measurement unit which are alternatively controlled by the control unit. When the communication quality is acquired through the CDMA pilot channel, the data acquisition efficiency can be significantly raised.
    Type: Grant
    Filed: April 4, 2001
    Date of Patent: November 22, 2005
    Assignee: NTT DoCoMo, Inc.
    Inventors: Shinichi Mori, Tetsuro Imai, Yoshihiro Ishikawa, Mikio Iwamura
  • Patent number: 6959171
    Abstract: A method includes monitoring a variable-rate data communication channel to determine its signal-to-noise ratio, and adjusting the data transmission rate of the variable rate data communication channel based on its signal-to-noise ratio.
    Type: Grant
    Filed: February 28, 2002
    Date of Patent: October 25, 2005
    Assignee: Intel Corporation
    Inventors: Chih C. Tsien, Jiewen Liu
  • Patent number: 6907094
    Abstract: The present invention provides a diversity receiving device with superior interference resistance in a simple construction, comprising a plurality of antennas (11, 12); an antenna switching device (13) that selects any one of a plurality of antennas (11, 12) and carries out connection switching thereof; a demodulator (14) that demodulates a wireless signal and obtains a baseband spread spectrum signal; an A/D converter (15) that A/D converts the baseband spread spectrum signal and generates chip data; a digital matched filter (16) that finds the correlation value of the chip data and the spreading code; a maximum correlation value detection portion (18) that detects the maximum correlation value; an average value calculation portion (21) that finds the average value per frame of the maximum correlation value; and a level comparison device (22) that compares the above-mentioned average value and a predetermined threshold value, and outputs a control signal to the antenna switching device (13) to control antenn
    Type: Grant
    Filed: March 12, 2002
    Date of Patent: June 14, 2005
    Assignee: Uniden Corporation
    Inventors: Masaki Matsui, Shigeo Sato, Toshiaki Fujikura, Akio Horibe, Muneki Ito
  • Patent number: 6907261
    Abstract: Apparatus, and an associated method, for a CDMA communication system. Both closed-loop, power-controlled communication services and best-effort communication services, upon shared channels, are provided in the communication system. A predictor predicts subsequent power level requirements in the system and an allocator allocates power levels at which to communicate best-effort communication signals to effectuate the best-effort communication services.
    Type: Grant
    Filed: September 28, 2001
    Date of Patent: June 14, 2005
    Assignee: Nokia Corporation
    Inventors: Giridhar D. Mandyam, Zhigang Rong, Lin Ma
  • Patent number: 6907260
    Abstract: The present invention provides a transmit power controlling method for reducing an influence of incorrect control in a mobile communication system in the CDMA mode. A likelihood of transmit power controlling signal is generated on the basis of the transmit power controlling signal transmitted by a radio base station and the receiving quality, a variation amount of the transmit power is generated on the basis of the likelihood, and the transmit power of a mobile station is controlled on the basis of the variation amount.
    Type: Grant
    Filed: December 21, 1999
    Date of Patent: June 14, 2005
    Assignees: KDDI Corporation, Hitachi, Ltd.
    Inventors: Katsuhiko Tsunehara, Takashi Yano, Takaki Uta, Toshiro Suzuki, Toshinori Suzuki
  • Patent number: 6847810
    Abstract: A system for selecting an antenna from a diversity of antennas in a DECT, PWT, or TDMA-based telecommunication system. The system combines multiple criteria to improve antenna diversity selections. The principal selection process is based on preamble diversity comparisons that operate in real-time. A preamble diversity switching circuit measures receive signal strength indicators (RSSI) from a plurality of antennas and selects the antenna that provides the highest RSSI value when the difference between the RSSI values exceeds a threshold. When the value of the RSSI difference falls below the threshold, the next selection process, a cyclical redundancy check (CRC) process is employed. The CRC process decodes a CRC value from a signal's content and compares it to a second threshold. If a CRC error is detected and the CRC value exceeds the second threshold, another antenna is selected.
    Type: Grant
    Filed: February 27, 2001
    Date of Patent: January 25, 2005
    Assignee: Ericsson Inc.
    Inventors: Qun Shen, Michael Lenzo
  • 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: 20040266473
    Abstract: The present invention provides a transmit power controlling method for reducing an influence of incorrect control in a mobile communication system in the CDMA mode. A likelihood of transmit power controlling signal is generated on the basis of the transmit power controlling signal transmitted by a radio base station and the receiving quality, a variation amount of the transmit power is generated on the basis of the likelihood, and the transmit power of a mobile station is controlled on the basis of the variation amount.
    Type: Application
    Filed: July 27, 2004
    Publication date: December 30, 2004
    Inventors: Katsuhiko Tsunehara, Takashi Yano, Takaki Uta, Toshiro Suzuki, Toshinori Suzuki
  • Publication number: 20040253955
    Abstract: A wireless communications device (100) includes a primary radio frequency branch (134) and a diversity branch (136), which is enabled and disabled to balance performance and power consumption. Diversity mode operation of the device is controlled, for example, based on one or more of an estimated channel quality indicator, data reception, data rate, state or mode of the station, estimated signal to noise ratio of a pilot signal, battery power level, distance from a serving cell, among other factors.
    Type: Application
    Filed: June 10, 2003
    Publication date: December 16, 2004
    Inventors: Robert T. Love, Kenneth A. Stewart