Having Saw Or Charge-transfer Device Patents (Class 375/151)
  • Patent number: 11165555
    Abstract: A technique of separating a sequence of modulation shift keying (MSK) symbols into a first portion and a second portion and separately comparing the first portion of the sequence of MSK symbols and the second portion of the sequence of MSK symbols against a first portion of a reference sequence of MSK symbols and a second portion of the reference sequence of MSK symbols allows a low complexity detection of a start field delimiter in a wireless communication packet.
    Type: Grant
    Filed: September 22, 2020
    Date of Patent: November 2, 2021
    Assignee: TEXAS INSTRUMENTS INCORPORATED
    Inventors: Wenxun Qiu, Tomas Motos, Marius Moe
  • Patent number: 9977644
    Abstract: Methods, systems, and computer readable media for conducting interactive sound propagation and rending for a plurality of sound sources in a virtual environment scene are disclosed. According to one method, the method includes decomposing a virtual environment scene containing a plurality of sound sources into a plurality of partitions and forming a plurality of source group clusters, wherein each of the source group clusters includes two or more of the sound sources located within a common partition. The method further includes determining, for each of the source group clusters, a single set of sound propagation paths relative to a listener position and generating a simulated output sound at a listener position using sound intensities associated with the determined sets of sound propagation paths.
    Type: Grant
    Filed: July 29, 2015
    Date of Patent: May 22, 2018
    Assignee: The University of North Carolina at Chapel Hill
    Inventors: Carl Henry Schissler, Dinesh Manocha
  • Patent number: 9869770
    Abstract: Control and feature systems for processing signals from a satellite positioning system include an expert system receiver manager; a joint detection, carrier centring and bit sync acquisition subsystem; peak detection; a multi-dimensional measurement interpolation subsystem; a system for mode switching between a navigational signal; and power control module for receiver.
    Type: Grant
    Filed: December 12, 2014
    Date of Patent: January 16, 2018
    Assignee: QUALCOMM Incorporated
    Inventors: Mangesh Chansarkar, Sundar Raman, Charles P. Norman, Paul A. Underbrink, Henry D. Falk, James Brown, Robert Harvey, Peter Michali, William Higgins, Gensheng Zhang, Qingwen Zhang
  • Patent number: 8687674
    Abstract: A surface acoustic wave (SAW) correlator spread-spectrum (SS) receiver is disclosed which utilizes a first demodulation stage with a chip length n and a second demodulation stage with a chip length m to decode a transmitted SS signal having a code length l=n×m which can be very long (e.g. up to 2000 chips or more). The first demodulation stage utilizes a pair of SAW correlators which demodulate the SS signal to generate an appropriate code sequence at an intermediate frequency which can then be fed into the second demodulation stage which can be formed from another SAW correlator, or by a digital correlator. A compound SAW correlator comprising two input transducers and a single output transducer is also disclosed which can be used to form the SAW correlator SS receiver, or for use in processing long code length signals.
    Type: Grant
    Filed: October 6, 2005
    Date of Patent: April 1, 2014
    Assignee: Sandia Corporation
    Inventor: Robert W. Brocato
  • Patent number: 8472410
    Abstract: A baseband processing module includes an RX interface, a rake receiver combiner module, and may include additional components. The RX interface receives the baseband signals from an RF front end and creates baseband RX signal samples there from. The rake receiver combiner module includes control logic, an input buffer, a rake despreader module, and an output buffer. The rake despreader module is operable to despread the baseband RX signal samples in a time divided fashion to produce channel symbols including pilot channel symbols and physical channel symbols.
    Type: Grant
    Filed: March 5, 2010
    Date of Patent: June 25, 2013
    Assignee: Broadcom Corporation
    Inventors: Mark David Hahm, Huaiyu (Hanks) Zeng, Joseph Boccuzzi, Nelson R. Sollenberger
  • Patent number: 8463185
    Abstract: A system is for encoding information on a passive surface acoustic wave (SAW) device. The system includes a requesting unit configured to wirelessly transmit an impulse signal. The impulse signal is a signal that includes only a single pulse. A SAW device has an interdigital transducer (IDT) configured to physically store coded data. The SAW device is configured to receive the impulse signal. In response to receiving the impulse signal, the SAW device excites the IDT to generate a coded signal that includes the stored coded data and frequency components at a fundamental frequency.
    Type: Grant
    Filed: August 1, 2012
    Date of Patent: June 11, 2013
    Assignee: Research In Motion Limited
    Inventors: Peter J. Edmonson, Colin K. Campbell
  • Patent number: 8442164
    Abstract: Apparatus for determining a location of a peak in correlation output samples, the apparatus being arranged to receive samples from at least one correlator over a plurality of symbol time periods; combine samples from a period that is longer than the symbol time period into combined samples; and determine the position of a peak in the combined samples.
    Type: Grant
    Filed: August 14, 2008
    Date of Patent: May 14, 2013
    Assignee: NXP B.V.
    Inventor: Ivan Lawrow
  • Patent number: 8355425
    Abstract: The present invention relates to an ultra-wideband signal receiver comprising: at least a first set of sampling cells for sampling the waveform of a received signal; at least a second set of sampling cells for sampling the waveform of the received signal, with a predefined delay ?; and at least one correlator for delivering information depending on the correlation between the waveforms thus sampled.
    Type: Grant
    Filed: January 23, 2006
    Date of Patent: January 15, 2013
    Assignee: Groupe des Ecoles des Telecommunications (GET) Institut National des Telecommunications (INT)
    Inventor: Yang Ni
  • Patent number: 8260204
    Abstract: A system is for encoding information on a passive surface acoustic wave (SAW) device. The system includes a requesting unit configured to wirelessly transmit an impulse signal. The impulse signal is a signal that includes only a single pulse. A SAW device has an interdigital transducer (IDT) configured to physically store coded data. The SAW device is configured to receive the impulse signal. In response to receiving the impulse signal, the SAW device excites the IDT to generate a coded signal that includes the stored coded data and frequency components at a fundamental frequency.
    Type: Grant
    Filed: December 14, 2011
    Date of Patent: September 4, 2012
    Assignee: Research In Motion Limited
    Inventors: Peter J. Edmonson, Colin K. Campbell
  • Patent number: 8099048
    Abstract: A system is for encoding information on a passive surface acoustic wave (SAW) device. The system includes a requesting unit configured to wirelessly transmit an impulse signal. The impulse signal is a signal that includes only a single pulse. A SAW device has an interdigital transducer (IDT) configured to physically store coded data. The SAW device is configured to receive the impulse signal. In response to receiving the impulse signal, the SAW device excites the IDT to generate a coded signal that includes the stored coded data and frequency components at a fundamental frequency.
    Type: Grant
    Filed: May 12, 2010
    Date of Patent: January 17, 2012
    Assignee: Research In Motion Limited
    Inventors: Peter J. Edmonson, Colin K. Campbell
  • Patent number: 8032107
    Abstract: Disclosed is a circuit for improved power management of a wireless device, comprising an input signal from an antenna, an oscillator, a mixer and a circuit for correlating. In a first analog embodiment of the circuit, the circuit for correlating comprises a surface acoustic wave (SAW) and the circuit further comprises an operational amplifier and a reference voltage. In a second digital embodiment of the circuit, the circuit for correlating comprises a digital correlator and the circuit further comprises a digital comparator.
    Type: Grant
    Filed: June 24, 2004
    Date of Patent: October 4, 2011
    Assignee: Cypress Semiconductor Corporation
    Inventor: Paul Beard
  • Patent number: 7899109
    Abstract: An m-code GPS receiver receives m-code GPS communication signals having a multimodal autocorrelation, using an m-code mode identifier unambiguously determining a mode value of one of the m-code modal peaks coherently aligned to a coherent unimodal detected envelope, based on sequential probability estimation in an m-code envelope tracking filter using filter residual estimation or with a coherent m-code and c/a-code tracking filter also based on filter residual estimation, for generating m-code phase errors, for unambiguous and precise m-code code phase tracking in closed feedback loops, for preferred use in navigation systems.
    Type: Grant
    Filed: August 8, 2006
    Date of Patent: March 1, 2011
    Assignee: The Aerospace Corporation
    Inventor: Randal K. Douglas
  • Patent number: 7825805
    Abstract: Apparatus, systems, devices and methods for providing an orthogonal frequency coding technique for surface acoustic wave sensors incorporating the use of multiple parallel acoustic tracks to provide increased coding by phase shifting and delaying a code sequence. The surface acoustic wave sensor includes parallel tracks with multiple reflectors with differing delay offsets to form a complex code sequence. The reflectors may be uniform, but alternatively could include fingers withdrawn, have reflector position modulation, differing frequencies or be spatially weighted.
    Type: Grant
    Filed: February 7, 2007
    Date of Patent: November 2, 2010
    Assignee: University of Central Florida Research Foundation, Inc.
    Inventors: Donald Malocha, Derek Puccio
  • Patent number: 7804887
    Abstract: The present invention is a dramatically enhanced RF link for low-data-rate applications (1-100 bps), using one or more transmitters to communicate with one or more receivers, at dramatically enhanced ranges. The receiver of the present invention can rapidly search, detect, and lock in on narrow band signal transmissions, that may be present in a much larger frequency band and which may be changing frequency during the duration of the message. These receivers enable ultra-low noise floor detection of longer range, more highly attenuated, signal transmissions, by decreasing the receiver bandwidth.
    Type: Grant
    Filed: November 10, 2009
    Date of Patent: September 28, 2010
    Assignee: Applied Research Associates, Inc.
    Inventor: Edward A. Page
  • Patent number: 7756194
    Abstract: Disclosed is a circuit for decoding code phase modulated (CPM) signals, including a pseudo-noise (PN) code storage device, storing one or more reference PN codes, a peak detector having an output with decoded CPM data, and a correlation block, including a correlation multiplexer, a plurality of shift registers coupled to the correlation multiplexer, a selection circuit coupled to the plurality of shift registers, and a correlator coupled to the code storage device and correlation multiplexer. Also disclosed is a method for operating the circuit in two operating modes for decoding CPM signals.
    Type: Grant
    Filed: December 30, 2005
    Date of Patent: July 13, 2010
    Assignee: Cypress Semiconductor Corporation
    Inventors: Stephen O'Connor, Robert Mack, David Wright, Ham Prince
  • Patent number: 7747220
    Abstract: An IDT produces a SAW when excited by a single electrical pulse and can be fabricated to embody a code, which code provides for a passive autocorrelation of a SAW input to the IDT and thereby lends itself to further application as a signal generator in a communication device. However, internal dimensions of IDTs are inversely proportional to operating frequency, such that high frequency IDTs present significant manufacturing difficulties. Fabrication of IDTs for high frequency applications is simplified by exploiting a harmonic frequency SAW generated by IDTs. An IDT may therefore be designed according to fundamental frequency internal dimension criteria but can operate at a multiple of the fundamental frequency, thereby providing much higher frequency operation than conventional SAW systems. Operation of a second harmonic SAW system at 2.4 GHz based on a fundamental frequency of 1.2 GHz is contemplated.
    Type: Grant
    Filed: September 28, 2007
    Date of Patent: June 29, 2010
    Assignee: Research In Motion Limited
    Inventors: Peter J. Edmonson, Colin K. Campbell
  • Patent number: 7711038
    Abstract: Implementation of an improved matched filter system for despreading a PN code from a spread spectrum signal utilizes a matched filter system that may be broadly conceptualized as a system that optimizes the number of multipliers and adders utilized by the system in despreading a PN code from a spread spectrum signal. This lowers the power consumption of the improved matched filter system and increases the speed at which the system despreads the PN code from the spread spectrum signal.
    Type: Grant
    Filed: June 27, 2000
    Date of Patent: May 4, 2010
    Assignee: SiRF Technology, Inc.
    Inventors: Paul A. Underbrink, Steven A. Gronemyer
  • Patent number: 7639734
    Abstract: The present invention is a dramatically enhanced RF link for low-data-rate applications (1-100 bps), using one or more transmitters to communicate with one or more receivers, at dramatically enhanced ranges. The receiver of the present invention can rapidly search, detect, and lock in on narrow band signal transmissions, that may be present in a much larger frequency band and which may be changing frequency during the duration of the message. These receivers enable ultra-low noise floor detection of longer range, more highly attenuated, signal transmissions, by decreasing the receiver bandwidth.
    Type: Grant
    Filed: March 8, 2006
    Date of Patent: December 29, 2009
    Assignee: Applied Research Associates, Inc.
    Inventor: Edward A. Page
  • Patent number: 7623037
    Abstract: A surface acoustic wave sensor or tag having multiple transducer/antenna pairs each having a different center frequency. The bandwidth of each transducer/antenna pair is inversely proportional to the number of transducer/antennas pairs used and the bandwidth is the sum of the bandwidth of the transducer/antenna pairs. Implementing a SAW sensor or tag with multiple transducer/antenna pairs significantly reduces device losses and improves the performance of the device since the individual transducer/antenna pair's fractional bandwidth is reduced by the ratio of the system bandwidth to the number of transducer antenna pairs used in the sensor.
    Type: Grant
    Filed: September 15, 2006
    Date of Patent: November 24, 2009
    Assignee: University of Central Florida Research Foundation, Inc.
    Inventor: Donald C. Malocha
  • Patent number: 7508860
    Abstract: Provided are a pulse signal generator for UWB radio transception and a radio transceiver having the same. The pulse signal generator includes: an envelope generator generating a plurality of envelope signals; a local oscillator array composed of a plurality of high frequency oscillators, each outputting two oscillation signals having a phase difference from each other; a multiplier array receiving the envelope signals and the oscillation signals and outputting signals obtained by respectively multiplying the envelope signals by the oscillation signals; and an I channel adder and a Q channel adder outputting an I channel pulse signal and a Q channel pulse signal by adding output signals having the same phase components among the signals output from the multiplier array, respectively.
    Type: Grant
    Filed: December 3, 2004
    Date of Patent: March 24, 2009
    Assignee: Electronics and Telecommunications Research Institute
    Inventors: Seok-Bong Hyun, Geum-Young Tak, Byung Jo Kim, Kyung Hwan Park, Jeen Hur, Seong-Su Park
  • Patent number: 7388899
    Abstract: The ultra wide band communication system of the present invention includes a transmitter (station) and a receiver (station). The transmitter and the receiver employ spreading code comprised of code groups, which respectively comprise varied, auto-correlated codes. Consecutive information bits are spread and de-spread with differing code and the code groups are correlated with each other (e.g., orthogonal) so as to reduce channel impulse response estimation noise. At the receiver, subsequent channel estimates can be added or averaged with an initial channel estimate so as to reduce the channel impulse response estimation noise and thereby provide a relatively more accurate channel response.
    Type: Grant
    Filed: March 24, 2003
    Date of Patent: June 17, 2008
    Assignee: Texas Instruments Incorporated
    Inventor: Hirohisa Yamaguchi
  • Patent number: 7386035
    Abstract: Provided is a method of compensating for energy loss and eliminating inter-symbol interference (ISI) and inter-chip interference (ISI) in wireless signals, and a rake receiver for wireless LANs adopting the same. The rake receiver compensates for energy loss of a CCK signal transmitted in a multi-path wireless channel environment and eliminates ISI and ICI from the received CCK signal because a DFE structure per chip used for calculating ICI components, is connected in parallel with a DFE structure per symbol, thus eliminating ISI and ICI components.
    Type: Grant
    Filed: November 4, 2004
    Date of Patent: June 10, 2008
    Assignees: Samsung Electronics Co. Ltd., Research and Industrial Cooperation Group
    Inventors: Sung-hyun Hwang, Hyun-cheol Park, Yu-sung Lee
  • Patent number: 7356094
    Abstract: A digital broadcast receiving apparatus for receiving a broadcast signal generated by combining sub signals modulated using a random sequence generated based on an initial value set in accordance with a frequency of a broadcast channel by a signal transmission control use signal and a main signal generated based on information source data and reproducing the information source data contained in the received broadcast signal.
    Type: Grant
    Filed: March 10, 2000
    Date of Patent: April 8, 2008
    Assignee: Sony Corporation
    Inventors: Yasunari Ikeda, Toshihisa Hyakudai, Takahiro Okada, Tamotsu Ikeda
  • Patent number: 7349498
    Abstract: A system and method is disclosed for evaluating a data group of oversampled bits to detect edge transitions and for improving use of information available from a sampled data while maintaining acceptable noise rejection. An edge detection system for receiving a serial data stream includes a sampler for collecting a sample pattern from the serial data stream, the sample pattern including a succession of a plurality of data samples from the data stream with the plurality of data samples including multiple samples during a bit time associated with the data stream; a memory, coupled to the sampler, for storing one or more successive sample patterns; and a correlator, coupled to the memory, for producing a sample condition signal using a set of predefined patterns by comparing the stored sampled patterns to the predefined patterns.
    Type: Grant
    Filed: October 7, 2002
    Date of Patent: March 25, 2008
    Assignee: International Business Machines Corporation
    Inventors: Hayden C Cranford, Jr., Vernon R. Norman, Martin L. Schmatz
  • Patent number: 7327780
    Abstract: The invention provides methods and apparatus for multiple user detection (MUD) processing that have application, for example, in improving the capacity CDMA and other wireless base stations. One aspect of the invention provides a multiprocessor, multiuser detection system for detecting user transmitted symbols in CDMA short-code spectrum waveforms. A first processing element generates a matrix (hereinafter, “gamma matrix”) that represents a correlation between a short-code associated with one user and those associated with one or more other users. A set of second processing elements generates, e.g., from the gamma matrix, a matrix (hereinafter, “R-matrix”) that represents cross-correlations among user waveforms based on their amplitudes and time lags. A third processing element produces estimates of the user transmitted symbols as a function of the R-matrix.
    Type: Grant
    Filed: March 14, 2002
    Date of Patent: February 5, 2008
    Assignee: Mercury Computer Systems, Inc.
    Inventors: John H. Oates, Steven R. Imperiali, Alden J. Fuchs, Kathleen J. Jacques, Jonathan E. Greene, William J. Jenkins, Frank P. Lauginiger, David E. Majchrzak, Paul E. Cantrell, Mirza Cifric, Ian N. Dunn, Michael J. Vinskus
  • Patent number: 7274729
    Abstract: A structure of a spectrum spreading communication device which solves the problem with the conventional spectrum spreading communication using Barker codes, etc., and limits the rise of the side-lobe of a correctional signal independently of the order of information codes by use of a code sequence having a code length of at least 14. The spectrum spreading communication device uses a pseudo-noise code having code length of at least 14 and a self-correlation side-lobe of not greater than 3 as a pseudo-noise code of a direct spreading communication device which uses the pseudo-noise codes whose polarities are inverted so as to deal with also digital information. Thus, even when the pseudo-noise code length is 14 or more, the side-lobe of the correction coefficient can be restricted. Accordingly, the error rate of the spectrum spreading communication device is reduced and the processing gain is improved.
    Type: Grant
    Filed: December 9, 2003
    Date of Patent: September 25, 2007
    Assignee: Hitachi, Ltd.
    Inventors: Takashi Shiba, Akitsuna Yuhara, Yoshihiro Yamada, Yasuhiro Ohta
  • Patent number: 7269207
    Abstract: A method and device for estimating a target chip index value in a code-division multiple access receiver. The receiver receives signals from a transmitter that uses a plurality of transmitted chips for data transmission through a plurality of multipath channels. As each channel is expressible as a channel impulse response at a given instant in time, the impulse response can be sampled and the samples indexed by a plurality of delay sample indices. The target chip index value can be determined based on the first moment of the delay sample indices over an impulse response.
    Type: Grant
    Filed: February 5, 2003
    Date of Patent: September 11, 2007
    Assignee: Nokia Corporation
    Inventors: Jorma Lilleberg, Kim Rounioja, Thomas A. Sexton
  • Patent number: 7158763
    Abstract: A SAW communication device has a main IDT mounted on an SAW substrate to receive an RF signal received by an antenna and convert the RF signal to an acoustic wave which travels along the SAW substrate in opposite directions from the main IDT. At least two secondary IDTs are mounted on the SAW substrate on opposite sides of and spaced from the main IDT to receive and reflect the acoustic wave in a modulated form such that the modulated acoustic wave from one secondary IDT is delayed relatively to the modulated acoustic wave from a secondary IDT on the opposite side of the main IDT to the one secondary IDT. The main IDT is also operable to receive and convert the reflected modulated acoustic waves to a further RF signal with a concatenated waveform corresponding to the two modulated acoustic waves and transmit the further RF signal from the antenna.
    Type: Grant
    Filed: May 2, 2003
    Date of Patent: January 2, 2007
    Assignee: P. J. Edmonson Ltd.
    Inventors: Peter J. Edmonson, Colin K. Campbell
  • Patent number: 7090724
    Abstract: The contents by weight ratio of lanthanum oxide, gallium oxide, and silicon oxide, which are components, in the longitudinal cross-section and transverse cross-section of the straight part, excluding the shoulder part, of a Langasite single crystal ingot grown by pulling-up Langasite is within a range of ±0.05% with respect to the target amounts at all measured locations, and because of having a superior homogeneity in the content of components over the entire ingot, when used, for example, in a piezoelectric device such as an surface acoustic wave filter, has properties for industrial application that contribute to the stabilization of characteristics as well as reducing the costs.
    Type: Grant
    Filed: December 21, 2000
    Date of Patent: August 15, 2006
    Assignee: Mitsubishi Materials Corporation
    Inventors: Shouqi Wang, Satoshi Uda
  • Patent number: 6990138
    Abstract: The invention relates notably to a method for modulating information symbols to be transmitted in a CDMA communication network by using a non-orthogonal modulation code comprising M spreading sequences (sm 1?m?M), each comprising in N chips (sm,n 1?n?N), the M spreading sequences having the same energy. According to the invention, the amplitude of the chips take a plurality of values the number M of spreading sequences is higher than the number of chips N per spreading sequence.
    Type: Grant
    Filed: October 26, 2001
    Date of Patent: January 24, 2006
    Assignee: Alcatel
    Inventors: Elie Bejjani, Celine Durand
  • Patent number: 6904107
    Abstract: A method of estimating a communication path formed of a plurality of channels, the method necessitating an estimate of the impulse response C1, C2, . . . , Cn of the channels, including the following steps of (1) acquiring a space statistic of the transmission path, and (2) establishing a corrected impulse response (C1, C2, . . . , Cn) at least by weighting the impulse responce estimates (C1, C2, . . . , Cn) by the space statistic and an estimate of the additive noise (N01, N02, . . . , N0n) of the channels.
    Type: Grant
    Filed: April 10, 1998
    Date of Patent: June 7, 2005
    Assignee: Nortel Matra Cellular
    Inventors: Nidham Ben Rached, Jean-Louis Dornstetter
  • Patent number: 6847676
    Abstract: An all-lag rotating-reference correlator correlates a received spread-spectrum signal with a rotating reference code, and produces in each sampling instance N correlation lags corresponding to the correlation of the received signal with 0, 1, . . . , N?1 lags (or delays) of the rotating reference code, wherein N is the length of the rotating reference code. The rotating reference code is time-variant and is generated by a rotation of a basic reference code. The received signal, possibly embedded in noise and interference, consists of periodic replicas of the basic reference code with or without data modulation. The first embodiment of the present invention describes a method and apparatus of an all-lag rotating-reference correlator which is applicable to situations where data modulation is not present in the received signal.
    Type: Grant
    Filed: June 30, 2000
    Date of Patent: January 25, 2005
    Assignee: University of Hong Kong
    Inventors: Tung Sang Ng, Chin Long Cheng, Kun Wah Yip
  • Patent number: 6825794
    Abstract: SAW devices such as interdigital transducers (IDTs) have been widely used in RADAR applications and as filters. An IDT produces a SAW when excited by a single electrical pulse and can be fabricated to embody a code, which code provides for a passive autocorrelation of a SAW input to the IDT and thereby lends itself to further application as a signal generator in a communication device. However, internal dimensions of IDTs are inversely proportional to operating frequency, such that high frequency IDTs present significant manufacturing difficulties. Fabrication of IDTs for high frequency applications is simplified by exploiting a harmonic frequency SAW generated by IDTs. An IDT may therefore be designed according to fundamental frequency internal dimension criteria but can operate at a multiple of the fundamental frequency, thereby providing much higher frequency operation than conventional SAW systems.
    Type: Grant
    Filed: May 23, 2001
    Date of Patent: November 30, 2004
    Assignee: Research In Motion Limited
    Inventors: Peter J. Edmonson, Colin K. Campbell
  • Patent number: 6775318
    Abstract: The present invention provides an apparatus and method for code group identification and frame synchronization for cell searching used in wide-band DS-CDMA cellular systems. This method characterizes each secondary synchronization code sequence (SSCS) with a corresponding theoretical frequency sequence, which represents the occurrence times of CS1 to CS16 in a corresponding SSCS. Thus, 64 secondary synchronization code sequences corresponding to 64 code groups defined in DS-CDMA systems also corresponds to 64 theoretical frequency sequences. By characterizing the SSCS transmitted by a base station, a real frequency sequence can be generated. Comparing the real frequency sequence with the 64 theoretical frequency sequences, one can determine one or two candidate code groups, which may be employed by the base station.
    Type: Grant
    Filed: December 14, 2000
    Date of Patent: August 10, 2004
    Assignee: Industrial Technology Research Institute
    Inventors: Po-Tsun Chen, Ho-Chi Hwang, Yun-Yen Chen, Muh-Rong Yang
  • Publication number: 20040120388
    Abstract: A structure of a spectrum spreading communication device which solves the problem with the conventional spectrum spreading communication using Barker codes, etc., and limits the rise of the side-lobe of a correctional signal independently of the order of information codes by use of a code sequence having a code length of at least 14. The spectrum spreading communication device uses a pseudo-noise code having code length of at least 14 and a self-correlation side-lobe of not greater than 3 as a pseudo-noise code of a direct spreading communication device which uses the pseudo-noise codes whose polarities are inverted so as to deal with also digital information. Thus, even when the pseudo-noise code length is 14 or more, the side-lobe of the correction coefficient can be restricted. Accordingly, the error rate of the spectrum spreading communication device is reduced and the processing gain is improved.
    Type: Application
    Filed: December 9, 2003
    Publication date: June 24, 2004
    Inventors: Takashi Shiba, Akitsuna Yuhara, Yoshihiro Yamada, Yasuhiro Ohta
  • Patent number: 6697418
    Abstract: It is the object of the invention to provide a structure of a novel spectrum spreading communication device which solves the problem with the conventional spectrum spreading communication using Barker codes, etc. and limits the rise of the side-lobe of a correctional signal independently of the order of information codes by use of a code sequence having a code length of at least 14. The spectrum spreading communication device uses a pseudo-noise code having a code length of at least 14 and a self-correlation side-lobe of not greater than 3 as a pseudo-noise code of a direct spreading communication device which uses the pseudo-noise codes whose polarities are inverted so as to deal with also digital information. Thus, even when the pseudo-noise code length is 14 or more, the side-lobe of the correction coefficient can be restricted. Accordingly, the error rate of the spectrum spreading communication device is reduced and the processing gain is improved.
    Type: Grant
    Filed: April 26, 2000
    Date of Patent: February 24, 2004
    Assignee: Hitachi, Ltd.
    Inventors: Takashi Shiba, Akitsuna Yuhara, Yoshihiro Yamada, Yasuhiro Ohta
  • Patent number: 6462698
    Abstract: SAW devices such as interdigital transducers (IDTs) have been widely used in RADAR applications and as filters. An IDT produces a SAW when excited by a single electrical pulse and can be fabricated to embody a code, which code provides for a passive autocorrelation of a SAW input to the IDT and thereby lends itself to further application as a signal generator in a communication device. However, conventional SAW expanders and compressors typically have insertion losses greater than 20 dB, which can have a profound effect on an RF link budget in a communication system. Insertion losses are drastically reduced by using a single phase unidirectional transducer (SPUDT-type) instead of a conventional IDT as a SAW expander/compressor. A SPUDT-type reflects SAW components which are lost in conventional IDT designs so that a stronger SAW is directed toward a transmission element. In a receiver, a SPUDT-type directs a stronger SAW toward a compressor IDT.
    Type: Grant
    Filed: May 24, 2001
    Date of Patent: October 8, 2002
    Assignee: Research in Motion Limited
    Inventors: Colin K. Campbell, Peter J. Edmonson
  • Publication number: 20010053179
    Abstract: SAW devices such as interdigital transducers (IDTs) have been widely used in RADAR applications and as filters. An IDT produces a SAW when excited by a single electrical pulse and can be fabricated to embody a code, which code provides for a passive autocorrelation of a SAW input to the IDT and thereby lends itself to further application as a signal generator in a communication device. However, conventional SAW expanders and compressors typically have insertion losses greater than 20 dB, which can have a profound effect on an RF link budget in a communication system. Insertion losses are drastically reduced by using a single phase unidirectional transducer (SPUDT-type) instead of a conventional IDT as a SAW expander/compressor. A SPUDT-type reflects SAW components which are lost in conventional IDT designs so that a stronger SAW is directed toward a transmission element. In a receiver, a SPUDT-type directs a stronger SAW toward a compressor IDT.
    Type: Application
    Filed: May 24, 2001
    Publication date: December 20, 2001
    Inventors: Colin K. Campbell, Peter J. Edmonson
  • Patent number: 6226319
    Abstract: A spread spectrum demodulation circuit includes a correlation signal generator which generates a correlation signal from a reception signal to which a quadrature phase shift keying and a spread spectrum modulation are performed. First and second delay elements have different delay times, and delay the correlation signal to obtain first and second delay signals, respectively. First and second adders add the correlation signal and the first and second delay signals to obtain first and second addition signals, respectively. First and second distributors distribute the first and second addition signals, respectively. First and second multiplication circuits obtain first and second multiplication signals from distributed signals inputted from the first and second distributors, respectively. A data demodulation circuit demodulates the first and second multiplication signals to recover a transmission information signal.
    Type: Grant
    Filed: September 14, 1998
    Date of Patent: May 1, 2001
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Masatoshi Ohtsuka, Naoki Koga
  • Patent number: 6134264
    Abstract: It is the object of the invention to provide a structure of a novel spectrum spreading communication device which solves the problem with the conventional spectrum spreading communication using Barker codes, etc. and limits the rise of the side-lobe of a correctional signal independently of the order of information codes by use of a code sequence having a code length of at least 14. The spectrum spreading communication device uses a pseudo-noise code having a code length of at least 14 and a self-correlation side-lobe of not greater than 3 as a pseudo-noise code of a direct spreading communication device which uses the pseudo-noise codes whose polarities are inverted so as to deal with also digital information. Thus, even when the pseudo-noise code length is 14 or more, the side-lobe of the correction coefficient can be restricted. Accordingly, the error rate of the spectrum spreading communication device is reduced and the processing gain is improved.
    Type: Grant
    Filed: July 21, 1997
    Date of Patent: October 17, 2000
    Assignee: Hitachi, Ltd.
    Inventors: Takashi Shiba, Akitsuna Yuhara, Yoshihiro Yamada, Yasuhiro Ohta