With Particular Output Combining Patents (Class 455/273)
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Patent number: 6947716Abstract: An antenna switching apparatus which detects an antenna of good reception with high precision and suppresses control errors in antenna switching. A comparator compares a noise component obtained from a selected antenna with a threshold for noise detection. When noise detection occurs a predetermined number of times within a predetermined time, an antenna switching control unit outputs an antenna switching control signal to switch to another antenna. If all antennas are switched within a predetermined time, a noise switching count analyzing unit outputs a sensitivity control signal, deciding that the threshold should be changed. A noise detection sensitivity setting unit, when supplied with the sensitivity control signal within a predetermined time, increases the threshold to lower the noise detection sensitivity of the comparator.Type: GrantFiled: July 19, 2002Date of Patent: September 20, 2005Assignee: Pioneer CorporationInventor: Yasushi Ono
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Patent number: 6941123Abstract: A signal processing method and apparatus for obtaining a diversity gain in the communication system equipping the antenna array when a background noise is a space white noise or a non white noise is disclosed. The signal processing method and apparatus includes steps and functions of calculating a covariance matrix, estimating at least two time invariance vectors by performing an eigen-disintegration operation, estimating a channel vector and outputting a beam-forming vector. The present invention can improve the performance of the antenna array by using at least two time invariance vectors and it also increase a communication quality and quantity of the communication system, if the present invention is implemented to the wireless communication system.Type: GrantFiled: December 6, 2002Date of Patent: September 6, 2005Assignees: SAS Technologies Co., Ltd.Inventors: Jin-Ho Choi, Sung-Soo Ahn
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Patent number: 6940932Abstract: The present invention relates to receivers, and, more particularly, to improved diversity receivers. In some environments, such as those subject to multipath reflection or shadowing, some carriers may be received with low power. In these cases, diversity receivers may provide an improvement of around 3 dB to 6 dB, the latter figure referring to cases where the communication channel is under severe multipath fading and in mobile reception. A diversity receiver effectively comprises two or more separate receivers, or diversity branches, each with its own antenna. Each set of received carriers from each diversity branch is then combined. The present invention provides an improved method and apparatus for receiving multi-carrier signals.Type: GrantFiled: June 29, 2001Date of Patent: September 6, 2005Assignee: Nokia OyInventor: Jukka Henriksson
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Patent number: 6928276Abstract: A signal reception circuit includes a main antenna which receives signals in at least two predetermined reception frequency bands. A sub-antenna receives a signal in one of the reception frequency bands of the main antenna. A filter for interrupting a signal in the same frequency band as the reception frequency band of the sub-antenna is provided on a transmission line of a reception signal of the main antenna. A filter reflection signal in the same frequency band as the reception frequency band of the sub-antenna is induced in the sub-antenna, due to the antenna coupling thereof. The phase of the filter reflection signal is adjusted by a phase shifter between the main antenna and the filter, so that the induced signal of the sub-antenna is in phase with the reception signal of the sub-antenna. As a result, the level of the composed signal of the induced signal and the reception signal and is to be transmitted from the sub-antenna to a signal processing unit is greatly improved.Type: GrantFiled: December 3, 2002Date of Patent: August 9, 2005Assignee: Murata Manufacturing Co., Ltd.Inventor: Yuichi Kushihi
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Patent number: 6925312Abstract: A first radio base station (281) and a second radio base station (282) are co-located at a base station site (20) and share the base station site's common antenna (22). The common (shared) antenna is connected through an amplifier (321) of the first radio base station (which serves as a master amplifier) and an antenna sharing unit 50 to remaining components (341) of the first radio base station, and also through the master amplifier and the antenna sharing unit to an amplifier (322) and remaining components (342) of the second radio base station. The antenna sharing unit (50), also known as the “coupler”, includes a tower mounted amplifier simulator (64).Type: GrantFiled: September 17, 2001Date of Patent: August 2, 2005Assignee: Telefonaktiebolaget LM Ericsson (publ)Inventor: Ulf Skarby
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Patent number: 6925293Abstract: An antenna diversity system for receiving frequency-modulated (FM) radio signals with the phase-controlled summation of antenna signals for motor vehicles equipped with a multi-antenna system having at least two antenna output signals, and a receiver with an input for each of a first and a second received signal path, wherein the second of the two received signal paths contains a phase-shifter controlled by a phase-controller. The received signal has the same phase on the output of the phase-shifter as in the first signal path. The two received signals are added up in a phase-coincident manner in a summation circuit, and the added-up signal is supplied to the FM frequency modulator.Type: GrantFiled: February 14, 2001Date of Patent: August 2, 2005Assignee: FUBA Automotive GmbH & Co. KGInventors: Heinz Lindenmeier, Jochen Hopf, Leopold Reiter
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Patent number: 6862316Abstract: Outputs from respective elements of an array antenna 21 are demodulated, and the demodulated outputs are stored in storage means 29. The demodulated outputs are multiplied by tap coefficients of adaptive array antenna, then the multiplied outputs are combined by combining means 28, and the combined output is provided via a feed forward filter 22 to an adaptive equalizer 23, wherein it is equalized to obtain a decision symbol. During reception of a training signal the tap coefficients of adaptive array antenna and tap coefficients of the adaptive equalizer 23 are subjected to convergence processing by tap coefficient calculating means 24 so that an error signal becomes small, and then tap coefficients of the feed forward filter 22 and the adaptive equalizer 23 are subjected to convergence processing by tap coefficient calculating means 25 so that an error signal becomes small.Type: GrantFiled: March 27, 2001Date of Patent: March 1, 2005Assignee: NTT DoCoMo, Inc.Inventors: Shigeru Tomisato, Tadashi Matsumoto
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Patent number: 6853694Abstract: 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: GrantFiled: July 27, 2000Date of Patent: February 8, 2005Assignee: Dataradio Inc.Inventors: André Beaudin, Richard Vallée, Michel D. Martin
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Patent number: 6842421Abstract: A novel antenna diversity technique for OFDM receivers is disclosed. A method and apparatus are disclosed for combining in the frequency domain the various signals received on each of the multiple antennas in an OFDM communication system. At the OFDM transmitter, the transmitted signal is differentially encoded over frequency, as opposed to time, to differentially encode the transmitted signal in the frequency domain with respect to consecutive bins (OFDM sub-carriers). The OFDM receiver processes a signal received on a number of diversity branches and combines the received signals using a post-detection combining technique after differential decoding. Each frame is independently processed by a differential decoder and then delayed to align each symbol in a given frame. The post-detection combining of the frame data inherently scales the received samples and thereby implements an optimal maximum ratio combining mechanism.Type: GrantFiled: September 17, 1999Date of Patent: January 11, 2005Assignee: Lucent Technologies Inc.Inventors: Mohsen Sarraf, Mohammad Hossein Zarrabizadeh
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Patent number: 6836672Abstract: A base station in a communication network which has a number of receiver or transmitter circuits (TRX) and a number of splitters (SP1, . . . SP6) is provided with switchable divider circuitry, if the number of receiver or transmitter circuits (TRX) is other than 2n(n=2, 3, 4, . . . ). The divider circuit has at least an input, preferably two inputs (IN-A, IN-B), an attenuation member, preferably two members (AT1, AT2) and a divider element (DE), preferable three elements (DE1, DE2, DE3) and is connected parallel to a respective splitter (SP) so as to offer further splitter outputs for being connected to the inputs of remaining receivers or transmitter circuits (TRX) other than 2n.Type: GrantFiled: March 28, 2002Date of Patent: December 28, 2004Assignee: Lucent Technologies Inc.Inventors: Norbert Bogner, Albrecht Schuh
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Patent number: 6834179Abstract: In the access control system, a code transmitter-end transceiver unit and a vehicle-end transceiver unit emit signals approximately synchronously on approximately the same carrier frequency. As a result of superimposition, a new code signal arises and its code information item is compared with an expected set point code information item. When there is correspondence, an enable signal for locking or unlocking or releasing the immobilizer is generated. The synchronous transmission/reception makes illegitimate monitoring more difficult.Type: GrantFiled: January 30, 2002Date of Patent: December 21, 2004Assignee: Siemens AktiengesellschaftInventor: Nikolas Bergerhoff
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Patent number: 6823021Abstract: Methods and systems consistent with this invention receive a plurality of transmitted signals in a receiver having a plurality of receive elements, wherein each transmitted signal has a different spatial location. Such methods and systems receive the plurality of transmitted signals at the plurality of receive elements to form a plurality of receive element signals, form a combined signal derived from the plurality of receive element signals, and detect each of the plurality of transmitted signals from the combined signal by its different spatial location. To achieve this, methods and systems consistent with this invention generate a plurality of arbitrary phase modulation signals, and phase modulate each of the plurality of receive element signals with a different one of the phase modulation signals to form a plurality of phase modulated signals.Type: GrantFiled: October 27, 2000Date of Patent: November 23, 2004Assignee: Greenwich Technologies AssociatesInventor: Carl M. Elam
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Patent number: 6823174Abstract: An adaptive antenna is implemented using a plurality of modular array element modules. Each array element module comprises an antenna element of the adaptive antenna. Each antenna element is coupled to a weighting circuit is also coupled to a previous weighting circuit within a previous array element module in a concatenated manner. Each weighting circuit is configured to apply a complex weight to the antenna samples and add the result to the output of the previous weighting circuit. Each antenna element is also coupled to a cross-correlation measurement circuit configured to cross-correlate antenna samples with adaptation error samples to provide cross-correlation measurement samples to a controller which determines a weight applied by the weighting circuit.Type: GrantFiled: October 11, 1999Date of Patent: November 23, 2004Assignee: Ditrans IP, Inc.Inventors: Wesley K. Masenten, Robert A. Dell-Imagine
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Publication number: 20040219899Abstract: A compensating correction value for adjusting analog signals received from multiple antenna elements takes into account the effects of colored noise, co-channel interference, and inter-sample interference. The method of generating the compensating correction value for analog combining architectures considers the total channel impulse response over a block of time.Type: ApplicationFiled: April 30, 2003Publication date: November 4, 2004Inventors: Minnie Ho, Sumeet Sandhu
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Publication number: 20040198452Abstract: An array antenna system comprising an array of antenna elements and a receiver which uses a subset of the signals from the antenna elements, the selection of the subset of signals which should be used for a particular user is made on the basis of measurements of potential performance of the receiver with each subset of signals, combined, rather than of each individual signal.Type: ApplicationFiled: July 30, 2002Publication date: October 7, 2004Inventor: Sebastien Joseph Armand Roy
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Patent number: 6792258Abstract: A diversity receiver for receiving digital signals has a soft-decision decoder in each of its receiving sections, to provide confidence values for the received decoded digital values, and combines the values from the receiving sections in dependence upon the confidence values. The receiver is especially suitable for use with COFDM, and has two sections, the outputs of which are applied to a soft-decision combiner which combines the signals in dependence upon confidence values received from the demodulators. The output is then applied to a Viterbi decoder. The combining can simply involve switching but preferably involves averaging. Synchronisation and squelching can be provided. The system can be used with frequency diversity, spatial or polarisation diversity, or with antenna pattern diversity, in which case it can constitute an automatic rotator. The system automatically switches between different types of diversity reception, e.g.Type: GrantFiled: April 17, 2000Date of Patent: September 14, 2004Assignee: British Broadcasting CorporationInventors: Christopher Ryan Nokes, Oliver Paul Haffenden, Jonathan Highton Stott, Peter Neil Moss
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Patent number: 6792290Abstract: An antenna apparatus that can increase capacity in a cellular communication system. The antenna operates in conjunction with a mobile subscriber unit and provides a plurality of antenna elements, each coupled to a respective signal control component such as a phase shifter. The phase shift for each antenna element is programmed for optimum reception during, for example, an idle mode when a pilot signal is received. The antenna array creates a beam former for signals to be transmitted from the mobile subscriber unit, and a directional receiving array to more optimally detect and receive signals transmitted from the base station. By directionally receiving and transmitting signals, multipath fading is greatly reduced as well as intercell interference. The phase shifters are adjusted in a coarse and a fine mode. In the coarse mode all phase shifters are jointly incremented through several phase shift values until a signal quality metric is optimized.Type: GrantFiled: February 2, 2001Date of Patent: September 14, 2004Assignee: IPR Licensing, Inc.Inventors: James Arthur Proctor, Jr., Lawrence Wayne La Mont, Jr., George Rodney Nelson, Jr., Kenneth Marvin Gainey
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Patent number: 6768913Abstract: A radio communication system includes a base station having a directional antenna for generating a plurality of beams. A first set of the beams is used to receive signals which are decoded at the base station. A second set of the beams is used for interrogating a cell to identify beams which should be added to the first set of beams (for example, in response to mobile terminals entering the cell). In one embodiment, the second set of beams comprises a plurality of searcher beams produced by a fixed-beam phased array antenna. In a second embodiment, the second set of beams comprises a single searcher beam which is scanned through the cell by an adaptive phased array antenna. The radio communication system can be used to communicate with indoor mobile terminals through a plurality of radio heads, and also can be used to communicate with orbiting satellites.Type: GrantFiled: June 1, 2000Date of Patent: July 27, 2004Assignee: Ericsson Inc.Inventors: Karl J. Molnar, Gregory E. Bottomley, Sandeep Chennakeshu
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Patent number: 6760603Abstract: A wireless communication system base station uses a dual-polarized antenna array to receive two signal groups having orthogonal polarizations. In a preferred embodiment a first signal group is received using a first sub-array of odd-numbered antenna elements, while a second signal group is received using a second sub-array of even-numbered antenna elements. Dipoles within the odd-numbered elements are selected so that they have a common polarization orthogonal to the dipoles selected in the even-numbered elements. The two signal groups thus have orthogonal polarizations. Base station signal processing hardware performs separate spatial channel estimation for these two groups, and uses the polarization diversity to improve performance in both the uplink and downlink. The use of polarization diversity allows the physical dimensions of the antenna array to be kept to a minimum.Type: GrantFiled: February 10, 2003Date of Patent: July 6, 2004Assignee: Kathrein-Werke KGInventors: Shimon B. Scherzer, Piu Bill Wong
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Patent number: 6751264Abstract: Embodiments of the present invention relate generally to receivers. One embodiment relates to a digital FM receiver having multiple sensors (e.g. antennas). In one embodiment, the digital receiver includes a baseband unit having a channel processing unit. In one embodiment, the channel processing unit is capable of calculating or estimating a phase difference between the incoming signals prior to combining them. One embodiment uses phase estimation method for diversity combining the signals while another embodiment utlizes a hybrid phase lock loop method. Also, some embodiments of the present invention provide for echo-cancelling after diversity combining. An alternate embodiment of the channel processing unit utilizes a space-time unit to diversity combine and provide echo cancelling for the incoming signals.Type: GrantFiled: July 27, 2001Date of Patent: June 15, 2004Assignee: Motorola, Inc.Inventors: Yui-Luen Ho, Junsong Li, Azfar Inayatullah
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Patent number: 6741838Abstract: A transmission side device combines two independent transmission signals (S1, S2) together to produce two combined signals, i.e., a sum signal (S1+S2) and a difference signal (S1−S2), and transmits the produced signals over two radio wave propagation paths, respectively. After the sum signal and the difference signal are received by the reception side device, the sum signal and the difference signal, as received, are subjected to an AGC control operation and a complex-level multiplication operation with a weighting coefficient based on correlation control, and then separated into two, restored, independent signals.Type: GrantFiled: December 15, 2000Date of Patent: May 25, 2004Assignee: NEC CorporationInventor: Ichiro Tsujimoto
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Patent number: 6735427Abstract: A system is provided which combines the advantages of Adaptive Antenna Arraying and Adaptive Locally-Optimum Detection, as well as Adaptive Filtering, signal processing techniques and achieves the capabilities of all these techniques. The present invention represents the first successful integrated system for performing signal processing techniques associated with an Adaptive Antenna Array (AAA) system and an Adaptive Locally-Optimum Detection (ALOD) system. The system automatically distributes interference signals among Adaptive Antenna Arraying and Adaptive Locally-Optimum Detection sub-systems according to which sub-system's algorithms can provide a more optimum suppression of the interference signals. The system permits an adaptive antenna array with a given number of antenna elements to effectively suppress a larger number of interferers than it otherwise could, and to adapt more quickly to a rapidly changing interference scenario.Type: GrantFiled: March 27, 2003Date of Patent: May 11, 2004Assignee: The Johns Hopkins UniversityInventor: James H. Higbie
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Publication number: 20040087294Abstract: An improved receiving phased array communication system supplies oscillating waveform signals with different phase delays to downconverting mixers in the processing channels of the receiving phased array communication system to compensate for phase difference in the received signal over the antenna elements therein. Similarly, an improved transmitting phased array communication system supplies oscillating waveform signals with different phase delays to the upconverting mixers in the processing channels of the transmitting phased array communication system to introduce phase difference in the transmit signal for transmission over the antenna elements therein. The oscillating waveform signals with different phase delays are preferably derived from a local oscillator that generates a local oscillating signal, and a delay line network having a plurality of fixed delay lines arranged in a serial manner to introduce increasing fixed phase delays in the local oscillating signal.Type: ApplicationFiled: November 4, 2002Publication date: May 6, 2004Applicant: TIA Mobile, Inc.Inventor: James June-Ming Wang
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Publication number: 20040087275Abstract: A composite beamforming technique is provided wherein a first communication device has a plurality of antennas and the second communication has a plurality of antennas. When the first communication device transmits to the second communication device, the transmit signal is multiplied by a transmit weight vector for transmission by each the plurality of antennas and the transmit signals are received by the plurality of antennas at the second communication device. The second communication device determines the best receive weight vector for the its antennas, and from that vector, derives a suitable transmit weight vector for transmission on the plurality of antennas back to the first communication device. Several techniques are provided to determine the optimum transmit weight vector and receive weight vector for communication between the first and second communication devices so that there is effectively joint or composite beamforming between the communication devices.Type: ApplicationFiled: October 28, 2003Publication date: May 6, 2004Inventors: Gary L. Sugar, Chandra Vaidyanathan, Yohannes Tesfai
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Patent number: 6725028Abstract: An optimum combiner that reduces the amount of interference imposed upon a first base station by transmissions of other base stations within the same communication system. Two antennas are used to receive transmissions within a receiving station. A rake receiver is coupled to each antenna. By optimally combining the signals that are received by each independent finger of the rake receiver, interference that is correlated between a finger associated with the first antenna and a finger associated with the second antenna can be minimized with respect to the desired signal. Optimum combining requires determination of optimum combining coefficients.Type: GrantFiled: May 30, 2001Date of Patent: April 20, 2004Assignee: Qualcomm IncorporatedInventors: Mario Bonaccorso, Fuyun Ling, Nagabhushana Sindhushayana, Peter Black
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Patent number: 6714584Abstract: A CDMA adaptive antenna receiving apparatus is provided with plural receivers of which each is for receiving one or more of desired signal components incoming at the same time. Each of the plural receivers includes plural adaptive receiving units for updating sequentially a directivity in accordance with one desired signal component. The plural adaptive receiving units which are included in the same receiver employ a symbol decision error of the same receiver in common. Each receiver further includes a means for detecting the incoming directions of the plural desired signal components and a means for controlling directivities of the plural adaptive receiving units in accordance with the incoming directions of the plural desired signal components and directivities of the plural adaptive receiving units.Type: GrantFiled: April 6, 1999Date of Patent: March 30, 2004Assignee: NEC CorporationInventors: Naoto Ishii, Shousei Yoshida, Akihisa Ushirokawa
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Patent number: 6714774Abstract: Antenna reception diversity is provided for wireless communications such that a received signal (r) can be produced by combining antenna signals (vi) with their associated fading amplitudes (&agr;i) as estimated by a linear receiver (32). Also, antenna signals (v1i) can be combined with their associated correlation values (&agr;1i) in place of estimated fading amplitudes. Further, inherent characteristics of a non-linear wireless communication receiver can be exploited such that a received signal (r2, r3) can be produced without any additional overhead that would otherwise be needed to provide estimated fading amplitudes.Type: GrantFiled: August 8, 2000Date of Patent: March 30, 2004Assignee: Texas Instruments IncorporatedInventors: Mohammed H. Nafie, Anand G. Dabak, Timothy M. Schmidl
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Patent number: 6701141Abstract: An apparatus for implementing true time delay digital beamformers for forming transmit and/or receive beams in array antennas. The apparatus includes a mixed signal application-specific integrated circuit (ASIC), which is comprised of an analog-to-digital converter (A/D) as an input circuit, an internal digital delay circuit, and a digital-to-analog converter (D/A) as an output circuit. The internal digital delay circuit provides true time delays that are selectable based on digital control, whereas the A/D and D/A circuits provide the interface circuits for the analog input and output signals. Formation of receive beams are accomplished by a plurality of mixed signal ASICs, low pass filters and analog combiners, where these components are connected in a configuration to combine a plurality of low pass filtered and time delayed analog signals located at the outputs of a plurality of mixed signal ASICs.Type: GrantFiled: May 18, 1999Date of Patent: March 2, 2004Assignee: Lockheed Martin CorporationInventor: Larry K. Lam
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Patent number: 6701165Abstract: A method and apparatus are disclosed for beam selection in a non-stationary subscriber radio unit having a multi-beam antenna array. The disclosed multi-beam antenna array acts in an omni-directional manner whenever signal-to-noise ratio (SNR) performance is sufficient, and excludes individual branches, as necessary, on the basis of SNR performance. A multi-mode approach is used to select appropriate antennas in the multi-beam antenna array. A given mode is established on the basis of the SNR of the received signal. Generally, if the SNR of the received signal satisfies predefined criteria, the non-stationary subscriber radio unit will operate the multi-beam antenna array in an omni-directional-like manner, by equally combining the received signal from each individual narrow-beam antenna branch.Type: GrantFiled: June 21, 2000Date of Patent: March 2, 2004Assignee: Agere Systems Inc.Inventors: Ming-Ju Ho, Michael Scott Rawles, Raymond R. Thomas, Wen-Kai Yen
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Publication number: 20040038714Abstract: An antenna for communicating with mobile devices in a land-based cellular communication system via an antenna beam having a width, azimuth angle and downtilt angle. The antenna includes: a two dimensional array of radiating elements (31-34); and a feed network (35-39) from a feed line to the radiating elements. The feed network includes: downtilt phase shifting means (35,36) for varying the phase of signals supplied to or received from the radiating elements so as to vary the downtilt angle of the antenna beam; azimuth phase shifting (38,39) means for varying the phase of signals supplied to or received from the radiating elements so as to vary the azimuth angle of the antenna beam; and beam width adjustment means (37) for varying the power or phase of signals supplied to or received from the radiating elements so as to vary the width of the antenna beam.Type: ApplicationFiled: June 16, 2003Publication date: February 26, 2004Inventors: Daniel Rhodes, Andrew Thomas Gray, Arthur George Roberts, Peter Bruce Graham
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Patent number: 6696923Abstract: In a transponder application, at least one transponder and at least one interrogating reader, the reader has at least two receiving units so disposed, for instance at different distances, relatively to the transponder, that signals from the same are received at different levels by the receiving units. By combination, e.g. by subtraction, of the received signals, disturbing signals received at practically the same level are eliminated while the difference of useful transponder signals is available. This substantially improves system performance in transponder applications and allows to increase the operating distance between reader and transponder.Type: GrantFiled: March 7, 2001Date of Patent: February 24, 2004Assignee: Datamars SAInventors: Takamasa Ishii, Peter Stegmaier, Jean-Marc Jobin
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Patent number: 6678508Abstract: A mobile communications device includes at least two receivers and a memory module. The power consumption of the mobile communications device is controlled by selectively awakening and sleeping the receivers as needed to ensure that the desired quality of reception to check the control channel for messages from an associated base station and to handle incoming communications is maintained. The mobile communications device may operate in single receiver mode or dual receiver diversity mode. In the dual receiver diversity mode, the mobile communications device may switch between one of a number of diversity combining techniques based on the quality of reception.Type: GrantFiled: February 7, 2000Date of Patent: January 13, 2004Assignee: Ericsson Inc.Inventors: Ravinder David Koilpillai, David R. Irvin
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Publication number: 20030236081Abstract: A method of processing radio signals received via multiple antennas in a radio receiver having at least one of the following: at least two antennas, each antenna delivering in use an antenna signal; at least two elements of an antenna array, each antenna element delivering an antenna signal; at least two antenna arrays each having a plurality of antenna elements, each antenna array delivering an antenna signal; the antenna signals being combined to deliver a combined signal, wherein for each antenna signal an iterative channel estimation is performed to control the combining process of the antenna signals. Advantages of the invention are improvement of error rate performance of multiple antenna radio receivers, because the antenna gain can be enhanced due to reducing the combining losses.Type: ApplicationFiled: May 15, 2003Publication date: December 25, 2003Applicant: ALCATELInventor: Volker Braun
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Patent number: 6665545Abstract: A method for forming an adaptive phased array transmission beam pattern at a base station without any knowledge of array geometry or mobile feedback is described. The approach is immune to the problems which plague methods which attempt to identify received angles of arrival from the mobile and map this information to an optimum transmit beam pattern. In addition, this approach does not suffer the capacity penalty and mobile handset complexity increase associated with mobile feedback. Estimates of the receive vector propagation channels are used to estimate transmit vector channel covariance matrices which form objectives and constraints in quadratic optimization problems leading to optimum beam former solutions for the single user case, and multiple user case. The new invention in capable of substantial frequency re-use capacity improvement in a multiple user cellular network.Type: GrantFiled: May 2, 2000Date of Patent: December 16, 2003Assignees: The Board of Trustees of the Leland Stanford Jr. University, Cisco Technology Inc.Inventors: Gregory Gene Raleigh, Suhas Nagraj Diggavi, Vincent Knowles Jones, IV, Arogyaswami Joseph Paulraj
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Publication number: 20030203743Abstract: A MIMO radio transceiver to support processing of multiple signals for simultaneous transmission via corresponding ones of a plurality of antennas and to support receive processing of multiple signals detected by corresponding ones of the plurality of antennas. The radio transceiver provides, on a single semiconductor integrated circuit, a receiver circuit or path for each of a plurality of antennas and a transmit circuit or path for each of the plurality of antennas. Each receiver circuit downconverts the RF signal detected by its associated antenna to a baseband signal. Similarly, each transmit path upconverts a baseband signal to be transmitted by an assigned antenna.Type: ApplicationFiled: October 11, 2002Publication date: October 30, 2003Applicant: Cognio, Inc.Inventors: Gary L. Sugar , Robert M. Masucci , David G. Rahn
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Patent number: 6636729Abstract: Signals received from antennas are input to weighting factor calculation sections 105 and 106. Weighting factor calculation section 105 calculates weighting factors so as to eliminate an interference signal using the antenna reception signals and known signals of a desired signal. Weighting factor calculation section 106 sequentially updates weighting factors so as to minimize the difference between a combined signal and its reference signal using the weighting factors calculated by weighting factor calculation section 105 as the initial values. On the other hand, reception quality measurement section 108 measures the reception quality of the combined signal and outputs the measurement result to weighting factor switching section 107. After receiving the measurement result, weighting factor switching section 107 switches weighting factors to be used for combination at the time the reception quality changes.Type: GrantFiled: November 22, 1999Date of Patent: October 21, 2003Assignee: Matsushita Electric Industrial Co., Ltd.Inventors: Katsuhiko Hiramatsu, Atsushi Matsumoto
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Patent number: 6622013Abstract: Desired signal power detection sections 109 to 116 measure a signal power level from a communication partner received at respective antennas 101 to 108. Antenna set selection section 117 obtains a sum of signal power levels from the communication partner received at four antennas belonging to each of antenna sets A to D each composed of combined antennas selected in advance to form a predetermined radiation pattern, for each antenna set, and selects an antenna set with the sum being the highest. Switch 120 connects received signals only from antennas belonging to the selected antenna set to reception RF sections 121 to 124. Received signal inputted to respective reception RF sections 121 to 124 are converted into respective intermediate-frequency signals, combined in signal combining section 125, and demodulated in demodulation section 126 to be a desired signal.Type: GrantFiled: December 7, 1999Date of Patent: September 16, 2003Assignee: Matsushita Electric Industrial Co., Ltd.Inventors: Kenichi Miyoshi, Katsuhiko Hiramatsu
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Publication number: 20030125001Abstract: A signal reception circuit includes a main antenna which receives signals in at least two predetermined reception frequency bands. A sub-antenna receives a signal in one of the reception frequency bands of the main antenna. A filter for interrupting a signal in the same frequency band as the reception frequency band of the sub-antenna is provided on a transmission line of a reception signal of the main antenna. A filter reflection signal in the same frequency band as the reception frequency band of the sub-antenna is induced in the sub-antenna, due to the antenna coupling thereof. The phase of the filter reflection signal is adjusted by a phase shifter between the main antenna and the filter, so that the induced signal of the sub-antenna is in phase with the reception signal of the sub-antenna. As a result, the level of the composed signal of the induced signal and the reception signal and is to be transmitted from the sub-antenna to a signal processing unit is greatly improved.Type: ApplicationFiled: December 3, 2002Publication date: July 3, 2003Applicant: Murata Manufacturing Co., Ltd.Inventor: Yuichi Kushihi
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Patent number: 6535721Abstract: A base station and receiver system for use in a base station which achieves enhanced dependability by logically separating the diversity reception paths into different failure paths. In one embodiment, the receiver system includes a first diversity reception path for receiving a first radio signal and a second diversity reception path for receiving a second radio signal. The first and second radio signals may be amplitude and phase shifted versions of the same information signal according to well known principles of diversity reception. At least one demodulator diversity combines the first and second radio signals and demodulates the diversity combined first and second radio signals. Additionally, the first and second diversity paths are logically separated into different failure paths.Type: GrantFiled: September 30, 1998Date of Patent: March 18, 2003Assignee: Qualcomm IncorporatedInventors: Joseph P. Burke, Peter D. Heidmann
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Publication number: 20030032403Abstract: An antenna switching apparatus which detects an antenna of good reception with high precision and suppresses control errors in antenna switching. A comparator compares a noise component obtained from a selected antenna with a threshold for noise detection. When noise detection occurs a predetermined number of times within a predetermined time, an antenna switching control unit outputs an antenna switching control signal to switch to another antenna. If all antennas are switched within a predetermined time, a noise switching count analyzing unit outputs a sensitivity control signal, deciding that the threshold should be changed. A noise detection sensitivity setting unit, when supplied with the sensitivity control signal within a predetermined time, increases the threshold to lower the noise detection sensitivity of the comparator.Type: ApplicationFiled: July 19, 2002Publication date: February 13, 2003Applicant: Pioneer CorporationInventor: Yasushi Ono
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Patent number: 6519478Abstract: A wireless communication system base station uses a dual-polarized antenna array to receive two signal groups having orthogonal polarizations. In a preferred embodiment, a first signal group is received using a first sub-array of odd-numbered antenna elements, while a second signal group is received using a second sub-array of even-numbered antenna elements. Dipoles within the odd-numbered elements are selected so that they have a common polarization orthogonal to the dipoles selected in the even-numbered elements. The two signal groups thus have orthogonal polarizations. Base station signal processing hardware performs separate spatial channel estimation for these two groups, and uses the polarization diversity to improve performance in both the uplink and downlink. The use of polarization diversity allows the physical dimensions of the antenna array to be kept to a minimum.Type: GrantFiled: February 11, 2000Date of Patent: February 11, 2003Assignee: Metawave Communications CorporationInventors: Shimon B. Scherzer, Piu Bill Wong
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Publication number: 20030003890Abstract: A method and apparatus is provided for calculating possible values of a combination ratio for signals received via a plurality of antennas (A1 to An) according to different algorithms by means of a plurality of algorithm units (31 to 33), calculating an SIR value for each of a plurality of composite signals which are generated using the possible values, respectively (SIR calculation units (41 to 43)), determining which composite signal has the highest quality (determining unit (44)), and selecting the composite signal having the highest quality as a received signal (selecting unit (45)).Type: ApplicationFiled: July 12, 2002Publication date: January 2, 2003Inventor: Toyohisa Tanaka
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Publication number: 20020183096Abstract: Delay profiles of respective branch received signals received through a plurality of antennas are formed; peaks on each of formed delay profile signals are detected; the maximum peaks are obtained among detected peaks on the respective delay profile signals; and average delay differentials between the delay profiles are obtained by averaging a desired number of delay differentials among the maximum peaks.Type: ApplicationFiled: May 29, 2002Publication date: December 5, 2002Inventors: Takenobu Arima, Kazuyuki Miya
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Publication number: 20020132581Abstract: The information terminal unit (3) comprises a transceiver (231) and a processor (232), while the variable directional antenna (1) comprises a main antenna element (201) to which the transceiver directly supplies a radio frequency signal, and a plurality of sub antenna elements (202 to 207). The sub antenna elements are connected with variable phase shifter circuits (212 to 217) for determining a phase shift amount of a reflecting wave, respectively. The control circuit (220) receives the directivity data from the CPU (232) of the information terminal unit (3) and analyzes the received data to control the phase shift amount of each variable phase shifter circuit (212 to 217) .Type: ApplicationFiled: March 12, 2002Publication date: September 19, 2002Applicant: NEC CORPORATIONInventor: Masaki Ichihara
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Patent number: 6449469Abstract: A directional antenna system includes several antenna elements, a phase shift/attenuation circuit, and a switching system. The circuit synthesizes four antenna patterns which are oriented toward the front, back, left, and right sides of a vehicle. The system switches between antenna patterns depending upon received signal strength at any particular moment.Type: GrantFiled: March 1, 1999Date of Patent: September 10, 2002Assignee: Visteon Global Technologies, Inc.Inventor: Shunji Miyahara
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Patent number: 6445904Abstract: A repeater diversity system includes a null antenna having a given phase center and polarization for receiving a communications signal from a remote signal source, a donor antenna for transmitting a signal to a base station, and a diversity null antenna having the same phase center as the receive null antenna and a polarization orthogonal to the polarization of the main null antenna. A combining network is coupled to the main null antenna and the diversity null antenna for combining the signals therefrom and an uplink channel module is coupled with the combining network for delivering diversity combined receive signals to the donor antenna.Type: GrantFiled: February 17, 2000Date of Patent: September 3, 2002Assignee: Andrew CorporationInventors: Breck W. Lovinggood, William P. Kuiper
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Patent number: 6434375Abstract: The present invention describes an inexpensive as well as efficient smart antenna processor for a code division multiple access (CDMA) wireless communications system, such as a 3rd generation (3G) CDMA2000 or W-CDMA system. Separate channel estimation is not required in the present invention, in contrast to a CDMA system with a conventional smart antenna. In addition, the phase distortions due to the different radio frequency (RF) mixers can be automatically compensated in the present invention. Thus, separate phase calibration is not necessary for a smart antenna processor according to the present invention, if the reverse link demodulation is concerned. Furthermore, bit error rate (BER) performance of a CDMA system with the adaptive algorithm in the present invention can be smaller than that of a conventional algorithm, for fading and additive white Gaussian noise (AWGN) environments.Type: GrantFiled: September 13, 2000Date of Patent: August 13, 2002Assignee: NeoReach, Inc.Inventors: Tatcha Chulajata, Hyuck M. Kwon, Kyung Y. Min
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Patent number: 6430215Abstract: A spread spectrum radio transmission digital mobile communication device having RAKE receiving functions. By adding an arrangement of an adaptive antenna to control directivity of a receiving antenna to the spread spectrum radio transmission digital mobile communication device, it is possible to decrease influence of a co-channel interference wave and influence of a delay wave having a delay time smaller than chip time width in a diffusion signal, as not achievable by RAKE receiving functions.Type: GrantFiled: May 23, 2000Date of Patent: August 6, 2002Assignee: Matsushita Electric Industrial Co., Ltd.Inventors: Norihito Kinoshita, Kazuyuki Miya
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Publication number: 20020102950Abstract: A method and apparatus for selecting an optimal set of antennas from a plurality of antennas for use by a transmitter and/or receiver having a plurality of RF chains to transmit and/or receive a wireless signal on a wireless link. According to the invention information concerning transmission of wireless signals on the wireless link is determined and an optimal set of antennas from the plurality of antennas is selected based on the information. Thereafter, the RF chains are connected to the optimal set of antennas to permit transmission and/or reception of the wireless signal from the RF chains on the wireless link via the optimal set of antennas. The RF chains correspond in number to the number of antennas in the optimal set of antennas, and the number of antennas included in the plurality of antennas is greater than the number of RF chains.Type: ApplicationFiled: January 26, 2001Publication date: August 1, 2002Inventors: Dhananjay A. Gore, Rohit U. Nabar, Arogyaswami Paulraj, Sumeet Sandhu
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Patent number: 6415140Abstract: A space diversity antenna system provided with dither circuitry in the signal path to one of the antennas to switch a circuit element in and out of the signal path at a high rate. The circuit element can be an amplitude attenuator or a phase changer. This switching results in the substantial elimination of nulling between the two antennas.Type: GrantFiled: April 28, 2000Date of Patent: July 2, 2002Assignee: BAE Systems Aerospace Inc.Inventors: James A. Benjamin, Joseph F. Camerlin, David M. Cooper