Having Specific Code Synchronization Patents (Class 375/149)
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Patent number: 8238411Abstract: The invention relates to the acquisition of a code modulated signal, wherein a first set of correlation results for correlations between the code modulated signal and a first replica code with different code phases and a second set of correlation results for correlations between the code modulated signal and a second replica code with different code phases are available. In order to achieve a high sensitivity, results from both sets of correlation results are combined, wherein correlation results used in the combination are selected based on information on a relative difference between a correct code phase for both replica codes. Then, it is determined based on the combination whether at least one of the sets of correlation results comprises a correlation result representing the correct code phase for the first replica code or the second replica code, respectively.Type: GrantFiled: December 21, 2004Date of Patent: August 7, 2012Assignee: Nokia CorporationInventors: Harri Valio, Samuli Pietilä
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Patent number: 8238489Abstract: An apparatus and method for processing a signal using a single correlator are provided. The apparatus may include a first storage unit storing satellite signal samples, a correlator receiving the satellite signal samples stored in the first storage unit in units of at least two satellite signal samples and performing correlation, and a controller storing the satellite signal samples received from an RF terminal in the first storage unit and controlling the correlator based on a predetermined control value. Accordingly, it is possible to ensure speed and performance even when tracking a plurality of satellite signals using a single correlator.Type: GrantFiled: February 18, 2009Date of Patent: August 7, 2012Assignee: Core Logic, Inc.Inventors: Hwi Kim, Sung Hyuck Im, Gyu In Jee
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Patent number: 8233572Abstract: In a pulse-based communication system a transmitting device may generate a series of pulses to convey information via a communication medium to a receiving device. In some situations, interference from one or more interfering devices may alter the pulse energy as it is transmitted through the communication medium. To mitigate the effect of such interference, a receiving device may mark certain received pulses as erasures. In this way, such pulses may be ignored during the decoding operation of the receiver.Type: GrantFiled: September 25, 2007Date of Patent: July 31, 2012Assignee: QUALCOMM IncorporatedInventors: David Jonathan Julian, Amal Ekbal
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Patent number: 8228971Abstract: In one embodiment, a method for demodulating and searching for a preamble signal containing a complex phasor signal is disclosed. The complex phasor is demodulated using a phasor-rotated fast transformer. A received signal is correlated with a spreading code to produce a correlated signal. The correlated signal is coherently accumulated to produce a coherently accumulated signal. A first phasor-rotated signal transformation is performed on a real component of the coherently accumulated signal, and a second phasor-rotated signal transformation is performed on an imaginary component of the coherently accumulated signal. Finally, the signal power of the transformed real and imaginary components of the coherently accumulated signal is determined.Type: GrantFiled: July 29, 2008Date of Patent: July 24, 2012Assignee: Agere Systems Inc.Inventors: Eliahou Arviv, Daniel Briker, Gennady Zilberman
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Patent number: 8223789Abstract: To prevent a collision from occurring at the time of random access in cases such as handover, response to paging and the like where a mobile station apparatus performs random access in response to directions from a base station apparatus. In a mobile communication system in which a mobile station apparatus 200 uses a signature of a beforehand determined signature group at the time of random access with a base station apparatus 100, the signature group is comprised of a signature group managed by the base station apparatus 100 and another signature group managed by the mobile station apparatus 200. The signature group managed by the base station apparatus 100 includes signatures associated with particular random access reasons to be selected by the base station apparatus 100.Type: GrantFiled: August 31, 2009Date of Patent: July 17, 2012Assignee: Sharp Kabushiki KaishaInventors: Yasuyuki Kato, Shohei Yamada, Wahoh Oh
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Patent number: 8223894Abstract: A wireless transmission device enabled to improve an error rate performance at a receiver, by acquiring at least one of frequency diversity effect and a time diversity effect while keeping the interference resistance which is acquired by diffusion. In this transmission device, a modulation unit (101) modulates data to create a modulation symbol having in-phase components and quadrature components. An IQ individual spreading unit (102) arranges the diffusion chips, which are obtained by spreading the modulation symbol, of the in-phase components and the quadrature components, in areas extending in diffusion domains set individually for the in-phase components and the quadrature components. An IQ combining unit (103) combines the arranged spreading chips of the in-phase components and the quadrature components.Type: GrantFiled: November 8, 2010Date of Patent: July 17, 2012Assignee: Panasonic CorporationInventors: Masaru Fukuoka, Isamu Yoshii, Kenichi Miyoshi
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Patent number: 8218603Abstract: A simple and robust CTL is used for time tracking of multipath components of a spread spectrum signal transmitted over a wireless multipath fading channel. A digital code-tracking loop includes the implementations of despreading early and late data samples by use of a pseudonoise sequence, an error signal output generated by the despreading, and adjustment for a plurality of on-time, early and late samples, a data rate of a control signal provided as a fractional proportion of a data rate of error signals.Type: GrantFiled: May 7, 2010Date of Patent: July 10, 2012Assignee: InterDigital Technology CorporationInventor: Bin Li
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Patent number: 8218605Abstract: A method for generating a preamble signal for a wireless communication system including the step of combining a plurality of different short PN sequences into a long PN sequence, wherein one of the plurality of short PN sequences includes information that is configured for coarse timing synchronization, and the long PN sequence includes information that is configured for fine timing synchronization.Type: GrantFiled: November 29, 2006Date of Patent: July 10, 2012Assignee: Sony Deutschland GmbHInventors: Zhaocheng Wang, Masahiro Uno
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Patent number: 8218599Abstract: A communication technique based on direct sequence spread spectrum signaling employs, for all users sharing an access channel, a single spreading code that has a duration sufficiently longer than the symbol length that the likelihood of confusion between users is minimized if not eliminated. The length of the spreading code is sufficiently long that contention events can occur only when two bursts occur at the receiver within one chip time of one another.Type: GrantFiled: January 21, 2009Date of Patent: July 10, 2012Assignee: ViaSat, Inc.Inventors: Mark J. Miller, Mark D. Dankberg, Charles N. Pateros
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Publication number: 20120163421Abstract: A receiver for receiving a signal, the signal conforming to a protocol such that the signal comprises a synchronising portion and a data portion, each portion comprising pulses located in respective time slots, the time offsets between successive time slots being defined by the protocol, the receiver comprising: a detector configured to detect a first pulse and a second pulse of the synchronising portion; a comparison module configured to compare the time offset between the first and second pulses to a corresponding time offset defined by the protocol so as to determine the relationship between the detected time offset and the corresponding time offset; a determination module configured to determine expected times of arrival of the time slots of the data portion using the determined relationship and the time offsets defined by the protocol; and a data reader configured to read data conveyed in the data portion at the expected times of arrival.Type: ApplicationFiled: July 2, 2010Publication date: June 28, 2012Applicant: UBISENSE LIMITEDInventor: Andrew Martin Robert Ward
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Patent number: 8204024Abstract: A method is proposed for supporting downlink JD (joint detection) in a TDD CDMA communication network system, comprising steps of: judging whether the CAI (code allocation information) in a downlink timeslot will change in the next TTI (transmission time interval); if the CAI will change, inserting the changed CAI as a specific control information into a specified field in the traffic burst in the downlink timeslot corresponding to current TTI; sending the traffic burst containing the specific control information to each UE (user equipment) in the downlink timeslot via a downlink channel.Type: GrantFiled: November 4, 2004Date of Patent: June 19, 2012Assignee: ST-Ericsson SAInventors: Yueheng Li, Li Sun, Gang Wu
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Patent number: 8189541Abstract: A mobile device coupled to a common system clock receives a signal comprising a primary synchronization sequence (PSS) and a secondary synchronization sequence (SSS) in a radio frame. Sample counts are generated for timed events based on corresponding operating bandwidths. The timed events are detected at modulo sample counts of the generated sample counts according to corresponding operating bandwidths. PSS symbol timing determined via the PSS synchronization is aligned to the generated sample counts based on corresponding operating bandwidth. The generated sample counts are bit-shifted relative to the aligned PSS symbol timing for other timed events based on corresponding operating bandwidths. The one or more timed events are determined via performing modulo counting after the bit-shifting. Timing operations are performed at the determined timed events and the determined one or more timed events are refined, accordingly.Type: GrantFiled: July 13, 2009Date of Patent: May 29, 2012Assignee: Broadcom CorporationInventors: Francis Swarts, Mark Kent
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Patent number: 8189646Abstract: A spread-spectrum signal comprises a spreading waveform modulating a carrier wave and containing a real linear combination of a first waveform at a first waveform rate and a second waveform at a second waveform rate, the first waveform rate being distinct from the second waveform rate and both waveform rates being distinct and non-zero. The linear combination of the first and the second waveform is modulated with at least one binary sequence comprising a signal identification code.Type: GrantFiled: January 12, 2006Date of Patent: May 29, 2012Assignee: Centre National d'Etudes SpatialesInventors: Lionel Ries, Jean-Luc Issler, Laurent Lestarquit, Jose-Angel Avila-Rodriguez, Guenter W. Hein
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Patent number: 8189716Abstract: A method for obtaining a precise sampling frequency of a global positioning system (GPS) is applied in a GPS receiver. First, a radio frequency (RF) module of the GPS receiver is used to receive a satellite signal from at least one satellite. Then, a plurality of code delays of the satellite signal is calculated at a fixed time interval, and time differences between all adjacent two code delays among all the obtained code delays are calculated to obtain a plurality of time differences. Next, a mean value of all the obtained time differences is calculated. At last, a ratio between 1000 times of the mean value and the fixed time interval is calculated to obtain an error value, and the error is added to a standard sampling frequency of the RF module to obtain a new sampling frequency.Type: GrantFiled: March 17, 2009Date of Patent: May 29, 2012Assignee: Altek CorporationInventor: Hung-Sheng Chen
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Patent number: 8184756Abstract: Symbol timing acquisition is described for a wireless broadband signal received at a user terminal from a gateway via a satellite. In-phase and quadrature channels of the wireless signal may each be sampled at a rate of one sample per symbol. The samples may be interpolated to generate an early interpolation and a late interpolation for each of the samples. A difference measurement is obtained between the early interpolation and the late interpolation for a set of the samples. A number of the difference measurements may be averaged, and symbol timing may be modified based on the average. This process may be continued on an iterative basis to acquire symbol timing.Type: GrantFiled: December 18, 2009Date of Patent: May 22, 2012Assignee: ViaSat, Inc.Inventors: Donald W. Becker, Matthew D. Nimon, William H. Thesling
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Patent number: 8184741Abstract: A receiving device includes: a first signal processor, for receiving a radio frequency signal, and converting the radio frequency signal to generate a first signal, where the radio frequency signal includes a plurality of frames; a second signal processor, coupled to the first signal processor, for performing a Fourier transform operation on the first signal according to a synchronization signal to generate an output signal; a first filter, coupled to the first signal processor, for filtering the first signal to generate a second signal; and a synchronization detection circuit, coupled to the first filter, for detecting the second signal to generate the synchronization signal. The first signal includes a channel signal and at least a portion of neighboring channel signals from neighboring channels, and the output signal corresponds to the channel signal.Type: GrantFiled: April 9, 2008Date of Patent: May 22, 2012Assignee: Realtek Semiconductor Corp.Inventors: Wei-Hung He, Chin-Tai Chen
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Patent number: 8179949Abstract: A correlation method of a code division multiple access receiver using mapping. Digital data with each signal composed of two bits are packed by a predetermined packing unit; blocking the packed data into data blocks according to a size corresponding to the repetition period of a C/A code. The packed data are recognized as an index in a correlation value mapping table having ICV and QCV mapped with each of different indexes and the ICV and the QCV are called from the correlation value mapping table. The called ICV and QCV are integrated according to the data blocks; and calculating a phase error of a carrier wave and a phase error of the C/A code using the ICV and the QCV according to the data blocks. A signal processing method is performed using the correlation method to correct phase errors.Type: GrantFiled: April 26, 2007Date of Patent: May 15, 2012Assignee: Samsung Electro-Mechanics Co., Ltd.Inventors: Sun Jun Ko, Sung Hyuck Im, Gyu In Jee, Hak Sun Kim, Sang Do Cho
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Patent number: 8180000Abstract: A GNSS receiver including a processing unit adapted to process radio signals transmitted from an active set of signal sources and based thereon produce position/time related data. The signals of the active set are processed in parallel with respect to a real-time signal data rate of the signals by a respective tracking channel resource allocated for each signal source. The processing unit also has a monitoring channel resource adapted to process radio signals transmitted from each of at least two signal sources in an additional set of signal sources different from the signal sources in the active set. The processing unit is adapted to process the radio signals of the additional set according to a cyclic processing sequence such that the signals from any of the signal sources in the additional set can be included into a navigation solution without delay.Type: GrantFiled: June 12, 2007Date of Patent: May 15, 2012Assignee: NordNav Technologies ABInventors: Per-Ludvig Normark, Alexander Mitelman
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Patent number: 8175195Abstract: The invention relates to method and device for detecting propagation paths in pulse transmission, wherein a received signal comprises pulses on each time symbol. After synchronizing a pulse-based reception, the inventive method consists (A) in determining the arrival times of pulses of the same current time symbol, (B) in generating a path hypotheses by assigning an initial score to each dated pulse, (C) in determining the arrival times of pulses of the time symbol following the current symbol, (D) in relatively comparing the arrival times of pulses of the following time symbol with the arrival times of the path hypotheses and (E) in updating scores according to the relative comparison results. Said path detecting method is suitable for pulse information transmission, in particular in UWB.Type: GrantFiled: November 7, 2006Date of Patent: May 8, 2012Assignee: France TelecomInventors: Jean Schwoerer, Benoît Miscopein
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Patent number: 8170087Abstract: Apparatus and method for providing correlation in a CDMA receiver. A Generic Correlation Coprocessor comprises one or more correlation blocks. Each correlation block comprises a correlation input buffer coupled to one or more correlators. The correlators are coupled to an interpolator input buffer and to a correlator output buffer. One or more interpolators are coupled to the interpolation input buffer and to the correlation output buffer. The correlators correlate the received signal with PN codes to produce a correlated signal. The correlated signal is stored in the correlator output buffer and/or the interpolation input buffer, and provided from the interpolation input buffer to the one or more interpolators. The one or more interpolators interpolate the correlated signal to produce an interpolated signal. The interpolated signal is stored in the correlator output buffer. Signals are provided from the correlator output buffer to other receiver processing systems.Type: GrantFiled: September 28, 2007Date of Patent: May 1, 2012Assignee: Texas Instruments IncorporatedInventors: Filip Jozef Moerman, Raphael Defosseux
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Patent number: 8170082Abstract: Embodiments related to cross-talk mitigation are described and depicted.Type: GrantFiled: December 5, 2008Date of Patent: May 1, 2012Assignee: Infineon Technologies AGInventor: Andreas Schmid
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Patent number: 8170084Abstract: Quick frequency tracking (QFT), quick time tracking (QTT), and non-causal pilot filtering (NCP) are used to detect sporadically transmitted signaling, e.g., paging indicators. For QFT, multiple hypothesized frequency errors are applied to an input signal to obtain multiple rotated signals. The energies of the rotated signals are computed. The hypothesized frequency error with the largest energy is provided as a frequency error estimate. For QTT, coherent accumulation is performed on the input signal for a first set of time offsets, e.g., early, on-time, and late. Interpolation, energy computation, and non-coherent accumulation are then performed to obtain a timing error estimate with higher time resolution. For NCP, pilot symbols are filtered with a non-causal filter to obtain pilot estimates for one antenna for non-STTD and for two antennas for STTD. The frequency and timing error estimates and the pilot estimates are used to detect the signaling.Type: GrantFiled: August 24, 2011Date of Patent: May 1, 2012Assignee: QUALCOMM IncorporatedInventors: Parvathanathan Subrahmanya, Thejaswi Bharadwaj Madapushi Sheshadri, Vivek Chawla
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Patent number: 8160123Abstract: Described is a device for receiving radio-navigation signals by satellite, said received signals being transmitted at a carrier frequency. The device includes at least means for generating a local signal at a local frequency and a tracking device including a feedback loop called carrier loop for phase-locking the local frequency on the carrier frequency. The loop includes a hardware portion and a software portion. The software portion performs the functions of discrimination of the phase of the correlated signal and filtering of said phase. The software portion also includes correlation functions mainly dependent on the linear variation coefficients between the local phases ?local delivered after each basic computation cycle. The device makes it possible to increase the loop band and the dynamic stability without changing the pre-detection band and the workload of the software.Type: GrantFiled: March 10, 2008Date of Patent: April 17, 2012Assignee: ThalesInventors: Nicolas Martin, David Depraz, Patrice Guillard
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Patent number: 8160124Abstract: A discriminator for a code tracking block of a navigation satellite system (NSS) receiver is provided. This discriminator can advantageously use only four complex correlators, i.e. early (E), prompt (P), late (L), and one of very early (VE) and very late (VL), while providing optimized multipath mitigation. This NSS discriminator can be derived from the first-order derivative of a Teager-Kaiser (TK) operator. This differential TK (DiffTK) discriminator is more sensitive to multipath dispersions than other discriminators or correlators, thereby providing enhanced performance in the presence of multipath.Type: GrantFiled: October 22, 2009Date of Patent: April 17, 2012Assignee: Qualcomm Atheros, Inc.Inventor: Elena Simona Lohan
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Patent number: 8149686Abstract: A base station apparatus is disclosed for use in a mobile communication system including multiple cells having multiple sectors. The base station apparatus includes a synchronization channel generation unit configured to generate a synchronization channel for use in cell search by a user apparatus and a transmitting unit configured to wirelessly transmit a signal including the synchronization channel. The synchronization channel includes a primary synchronization channel and a secondary synchronization channel. The primary synchronization channel includes multiple types of sequences, and the secondary synchronization channel transmitted in a sector of a cell includes a code derived from a predefined generation polynomial equation corresponding to the primary synchronization channel.Type: GrantFiled: August 12, 2008Date of Patent: April 3, 2012Assignee: NTT DoCoMoInventors: Yoshihisa Kishiyama, Satoshi Nagata, Motohiro Tanno, Kenichi Higuchi, Mamoru Sawahashi
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Patent number: 8149963Abstract: A method and apparatus for use in connection with wireless communication to adjust the frequency of an oscillator to synchronize with a received signal by correlating a synchronization code channel with training sequences to estimate relative offsets which are employed to estimate an error, which is then filtered. The filtered output preferably provides a voltage controlling a voltage controlled oscillator (VCO). The same technique may be employed to control a numeric controlled oscillator (NCO).Type: GrantFiled: August 4, 2008Date of Patent: April 3, 2012Assignee: InterDigital Technology CorporationInventor: Alpaslan Demir
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Patent number: 8144750Abstract: A receiver includes an equalizer and a decoder which decodes data from a signal. The signal is based upon an output of the equalizer. The receiver also includes an encoder, which re-encodes the decoded data, and an error generator, which generates an error vector based upon the signal and the encoded data and which weights the error vector according to a reliability that the decoder accurately decoded the data from the signal. A controller controls the equalizer in response to the weighted error vector.Type: GrantFiled: April 1, 2004Date of Patent: March 27, 2012Assignee: Zenith Electronics LLCInventors: Richard W. Citta, Peter Ho
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Patent number: 8144824Abstract: A method for determining a communication channel location is disclosed. A first subset of a plurality of channel impulse responses is averaged over a first time period to produce a first filtered channel impulse response, and a second subset of the plurality of channel impulse responses is averaged over a second time period to produce a second filtered channel impulse response. The second time period is different from the first time period, and the second subset is different from the first subset. The communication channel location is determined using the first filtered channel impulse response and the second filtered channel impulse response.Type: GrantFiled: March 8, 2006Date of Patent: March 27, 2012Assignee: QUALCOMM IncorporatedInventors: Bojan Vrcelj, Ashok Mantravadi, Fuyun Ling, Rajiv Vijayan, Michael Mao Wang
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CDMA frequency acquisition using a simplified crystal oscillator that is not temperature compensated
Patent number: 8144821Abstract: CDMA code channels are acquired using a crystal oscillator that is not temperature compensated and that generates a tuning signal with relatively large frequency error (e.g., +/?5 ppm). Channel acquisition is first attempted at no offset from a start frequency that is obtained by fitting an ideal temperature/frequency error curve to available actual data points. Following unsuccessful pilot acquisition, the offset frequency is stepped in a “spiral” manner, and pilot acquisition is retried. When the pilot and synchronization channels are successfully acquired, but the system identification is unexpected, an adjacent channel image has been acquired, and the offset frequency is bumped by a large step (e.g., 15 kHz). Pilot acquisition is retried using spiral stepping. The crystal oscillator is calibrated after each successful acquisition of the pilot, synchronization and paging channels by retaining a data point in a frequency adjustment table for the temperature at which frequency acquisition was successful.Type: GrantFiled: January 5, 2006Date of Patent: March 27, 2012Assignee: QUALCOMM IncorporatedInventors: James A. Hutchison, IV, Ling Hang, Robbin D. Hughes -
Patent number: 8139663Abstract: The present invention relates to a method for improving synchronization and information transmission in a communication system, including: generating a signal with a time symmetric property based on a uniquely identifiable sequence c(l) from a set of sequences, sending the signal over a communication channel, receiving the signal, calculating and storing a correlation, finding the delay that result in a maximum correlation magnitude, detecting the unique sequence c(l) from the set of sequences. The method is distinguished by: generating the signal with a centrally symmetric part, s(k), the centrally symmetric part s(k) being symmetric in the shape of the absolute value thereof, storing the reverse differential correlation D(p) from a block of N received signal samples r(k), k=0, 1, . . . , N?1. The present invention also relates to a transmitter unit and a receiver unit of a communication system, and a radio communication system.Type: GrantFiled: July 18, 2008Date of Patent: March 20, 2012Assignee: Huawei Technologies Co., Ltd.Inventor: Branislav Popovic
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Patent number: 8135080Abstract: A receiver circuit in each branch has an FFT unit that performs Fourier transform on OFDM signals. A slave branch FFT window control unit determines whether an undesired wave is a preceding wave or a delay wave, and notifies a master branch of the result. In response to the notification from the slave branch, a master branch FFT window control unit controls a position of an FFT window that indicates a time range in which Fourier transform is performed on OFDM signals.Type: GrantFiled: July 29, 2008Date of Patent: March 13, 2012Assignee: Fujitsu Semiconductor LimitedInventors: Naoto Adachi, Makoto Hamaminato
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Patent number: 8121175Abstract: Provided is a radio communication device which can suppress inter-code interference between an ACK/NACK signal and a CQI signal which are code-multiplexed. In this device, a diffusion unit (214) diffuses the ACK/NACK signal inputted from a judgment unit (208) by using a ZC sequence. A diffusion unit (219) diffuses the CQI signal by using a cyclic shift ZC sequence. By using a Walsh sequence, a diffusion unit (216) further diffuses the ACK/NACK signal which has been diffused by using the ZC sequence. A control unit (209) controls the diffusion unit (214), the diffusion unit (216), and the diffusion unit (219) so that the minimum value of the difference between the CQI signals from a plurality of mobile stations and a cyclic shift amount of the ACK/NACK signal is not smaller than the minimum value of the difference between the cyclic shift amounts of the ACK/NACK signals from the plurality of mobile stations.Type: GrantFiled: August 5, 2010Date of Patent: February 21, 2012Assignee: Panasonic CorporationInventors: Sadaki Futagi, Seigo Nakao, Daichi Imamura
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Patent number: 8121228Abstract: A detector (109) and corresponding method is configured for detecting presence of a data frame. The detector includes a first correlator (123) that is configured to provide a first plurality of correlations corresponding to similarity between data as received and first information, e.g., an ordered set of coefficients, that denotes the data frame and a second correlator (125) that is configured to provide a second plurality of correlations corresponding to similarity between the data as received and second information, e.g., another ordered set of coefficients, that denotes the data frame, where the second information includes a portion of the first information. Further included is decision logic (129) coupled to the first correlator and the second correlator, where the decision logic is configured to provide an indication (111) that the data frame is present based on the first plurality of correlations and the second plurality of correlations.Type: GrantFiled: November 4, 2005Date of Patent: February 21, 2012Assignee: Freescale Semiconductor, Inc.Inventor: Robert M. Gorday
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Patent number: 8116354Abstract: A sync detection device and method for a GNSS receiver. In modernized GNSS, each satellite transmits a data signal and a pilot signal. Correlations are performed between a data symbol stream converted from the data signal with possible hypotheses to find a leading edge of a frame of the data signal (i.e. frame sync detection) and between a pilot symbol stream converted from the pilot signal with possible hypotheses to find a leading edge of a code sequence of the pilot signal (i.e. pilot sync detection). The possible hypotheses for the frame sync detection are selected according to a result of pilot sync detection when pilot sync is done. Frame sync can be efficiently achieved since a range of the selected possible hypotheses is quite limited.Type: GrantFiled: June 13, 2008Date of Patent: February 14, 2012Assignee: Mediatek Inc.Inventor: Kun-tso Chen
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Publication number: 20120027053Abstract: A method and apparatus is disclosed for reducing multi-user processing at the receiver in wireless communication systems. Detected codes are grouped according to channel impulse response and a parent code is identified for each group of detected codes. A matrix A is constructed and joint detection is performed using the identified parent codes. Data symbols of the detected codes are obtained from the data symbols of the identified parent codes.Type: ApplicationFiled: October 10, 2011Publication date: February 2, 2012Applicant: INTERDIGITAL TECHNOLOGY CORPORATIONInventors: Jung-Lin Pan, Jaeyoung Kwak, Donald M. Grieco
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Patent number: 8102897Abstract: Direct sequence spread spectrum communications can use composite codes and can operate at a plurality of different chipping rates. The composite codes can be formed using a plurality of component codes, wherein the component codes can be relatively prime and at least one of the nominal lengths of the component codes can include a plurality of prime number multiplicands. The chipping rate and code length can be reduced by dividing a master rate by one or more of the prime number multiplicands. Symbol timing and time division multiple access timing can be tied to epochs of the component codes.Type: GrantFiled: January 28, 2009Date of Patent: January 24, 2012Assignee: L-3 Communications, Corp.Inventors: Vaughn L. Mower, Merle L. Keller, Kent R. Bruening
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Patent number: 8102899Abstract: A receiver arranged to receive a plurality of spread spectrum signals including a first spread spectrum signal from which interference caused by one or more others of said plurality of signals is to be removed, wherein at least one of said other spread spectrum signals has a spreading factor which is unknown to said receiver. The receiver comprises means for estimating a spreading factor of said at least one other spread spectrum signal having an unknown spreading factor, said estimating means selecting the spreading factor to be smallest possible spreading factor, means for despreading said at least one other spread spectrum signal using said estimated spreading factor, and means for estimating interference in the first spread spectrum signal caused by said at least one other spread spectrum signal.Type: GrantFiled: May 28, 2001Date of Patent: January 24, 2012Assignee: Intellectual Ventures I LLCInventors: Markku Juntti, Kari Horneman
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Patent number: 8098715Abstract: In one of its aspects, the technology concerns a method of processing a signal which includes physical data channels which have been channelized using spreading codes. The method comprises (1) despreading unoccupied spreading codes (e.g., codes which are essentially unobscured by traffic data) included in the signal to obtain unoccupied code despread values, (2) using the unoccupied code despread values to form an impairment covariance matrix; and (3) using the impairment covariance matrix along with a channel estimate to form a processing parameter. The processing parameter can be one of combining sets and a signal quality estimate. In another of its aspects, the technology concerns a coherent, linear equalizer apparatus configured to process a signal which includes physical data channels which have been channelized using spreading codes.Type: GrantFiled: June 9, 2008Date of Patent: January 17, 2012Assignee: Telefonaktiebolaget LM Ericsson (Publ)Inventors: Tracy Fulghum, Gregory E. Bottomley, Yi-Pin Eric Wang
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Patent number: 8098754Abstract: Allocation of multiple training sequences transmitted in a MIMO timeslot from multiple transmit antenna elements is provided. For example, a method of generating signals in a MIMO timeslot, the method comprising: selecting a first training sequence; preparing a first data payload; generating a first signal including the prepared first data payload and the first training sequence; transmitting the first signal in a MIMO timeslot from a first antenna of a network element; selecting a second training sequence, wherein the second training sequence is different from first training sequence; preparing a second data payload; generating a second signal including the prepared second data payload and the second training sequence; and transmitting the second signal in the MIMO timeslot from a second antenna of the network element.Type: GrantFiled: May 4, 2005Date of Patent: January 17, 2012Assignee: Sony CorporationInventors: Vishakan Ponnampalam, Martin W. Beale
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Patent number: 8098713Abstract: An embodiment for wirelessly communicating a signal includes a transmitter generating and transmitting a wireless signal over a wireless communication channel. The wireless signal includes a guard band, data represented within a plurality of data-bearing subcarriers, and a plurality of pilot signals represented within a plurality of pilot subcarriers. In an embodiment, the plurality of pilot signals have variable pilot signal parameters selected from a group of parameters that includes pilot power and pilot spacing with respect to adjacent pilots. An embodiment further includes a receiver receiving a channel-affected version of the wireless signal, and producing a corrected signal by applying corrections to the received signal based on estimated channel perturbations within the received signal, where the estimated channel perturbations are determined based on the plurality of pilot signals. The receiver also produces an output data symbol from the corrected signal.Type: GrantFiled: April 14, 2008Date of Patent: January 17, 2012Assignee: General Dynamics C4 SystemsInventors: Robert John Baxley, John Eric Kleider, Kelly Anderson
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Patent number: 8090007Abstract: The present invention is a position-based modulation system for communications devices. The device may comprise one or more of the following features: (a) a global positioning system (GPS) receiver capable of receiving positioning data from GPS satellites; (b) a radio frequency (RF) transceiver having at least a first channel and a second channel; (c) a geographical information system (GIS) database of topographical data; (d) a processor capable of optimizing transceiving parameters of the RF transceiver based on the positioning data and topographical data; and (e) a bus linking the GPS receiver, RF transceiver, GIS database, and processor.Type: GrantFiled: September 26, 2006Date of Patent: January 3, 2012Assignee: Rockwell Collins, Inc.Inventor: James P. Mitchell
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Patent number: 8090005Abstract: One embodiment of the invention provides a method of creating a set of secondary spreading codes for use in a satellite navigation system comprising a constellation of satellites. Each satellite in the constellation employs a tiered spreading code comprising at least a primary code and a secondary code. Each satellite in the constellation is allocated a different secondary spreading code from the set of secondary spreading codes. The method involves generating an initial set of bit patterns, where each bit pattern represents a potential secondary spreading code. The method further involves performing an optimization process on bit patterns within the initial set of bit patterns. As a result of the optimization, at least some of the bit patterns in the initial set are modified or replaced, to create a final set of bit patterns for use as the set of secondary spreading codes.Type: GrantFiled: July 1, 2005Date of Patent: January 3, 2012Assignee: European Space AgencyInventors: Brian Barnes, Steve Legate
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Patent number: 8090004Abstract: Provided is a high frequency radio apparatus for correcting a frequency of a carrier of the own apparatus in accordance with a frequency of a reception carrier when performing spread spectrum communication using very weak power. A carrier demodulating part demodulates a spread code received from a communication counterpart radio apparatus by using default carrier data, and sends the demodulated spread code to a synchronization timing detecting part. When the synchronization timing detecting part detects the spread code from the carrier demodulated data, a carrier frequency deviation detecting part performs a frequency analysis of the spread code to detect a deviation amount of the carrier frequency. A carrier data generating part generates corrected carrier data based on the detected deviation amount. A DBPSK modulating part uses the corrected carrier data to perform data transmission to the communication counterpart radio apparatus.Type: GrantFiled: March 2, 2006Date of Patent: January 3, 2012Assignee: Nihon Dempa Kogyo Co., Ltd.Inventors: Kaoru Kobayashi, Nobuo Tsukamoto
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Patent number: 8086228Abstract: A method and apparatus for identifying a code group representative of a predetermined number of base stations is disclosed. A chip offset within a frame is input into a first correlator. A plurality of samples of chips at which a primary synchronization code (PSC) has been detected are input into the first correlator. Output of the first correlator is multiplied by the complex conjugate of the PSC to obtain a magnitude for the signals being transmitted at the chips inputted into the first correlator. The magnitude is summed over four frames. The summed signals view of a predetermined set of decision variables is evaluated. A case number, a code group, a timeslot location, and a system frame number are determined based on the evaluation and noise estimation.Type: GrantFiled: October 27, 2008Date of Patent: December 27, 2011Assignee: InterDigital Technology CorporationInventors: Alpaslan Demir, Donald M. Grieco, John W. Haim, Andrew F. Bednarz, Phillip J. Pietraski, Louis J. Guccione, Prabhakar R. Chitrapu
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Patent number: 8081724Abstract: A wireless network comprising a plurality of base station capable of communicating with a plurality of mobile station in a coverage area of the wireless network. A first base station transmits an enhanced synchronization identifier parameter to a mobile station. The enhanced synchronization identifier parameter may apply to less than all of the plurality of base stations defined by the System Identifier/Network Identifier (SID/NIC) value associated with the wireless network.Type: GrantFiled: October 15, 2004Date of Patent: December 20, 2011Assignee: Samsung Electronics Co., Ltd.Inventor: Purva R. Rajkotia
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Patent number: 8077759Abstract: A method and an apparatus for new cell identification in a WCDMA network with a given neighbor set are described. Aspects of a system for new cell identification in a WCDMA network with a given neighbor set may include a baseband processor that enables determination of a primary synchronization position and at least one scrambling code based on received configuration information from one or more base stations. The baseband processor may also enable determination of a slot boundary in at least one signal received from the one or more base stations based on the determined primary synchronization position. The system may also include a multipath detector that enables unscrambling of the received at least one signal based on the determined slot boundary and at least a portion of the one or more scrambling codes.Type: GrantFiled: April 7, 2006Date of Patent: December 13, 2011Assignee: Broadcom CorporationInventors: Mark Kent, Francis Swarts, Uri Landau
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Patent number: 8077756Abstract: A disclosed signal transmitting method includes the steps of a) categorizing plural digital signals, obtained by performing A/D conversion on plural analog signals consecutively arranged in a time direction, into plural signal groups in an order starting from lower bits of the plural digital signals, b) performing code spreading on the plural digital signals by using a different spread frequency for each signal group and using different spread codes for each bit, c) multiplexing the spread digital signals, and d) transmitting the multiplexed plural digital signals.Type: GrantFiled: December 5, 2008Date of Patent: December 13, 2011Assignee: Fujitsu LimitedInventor: Hideki Yoshizawa
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Patent number: 8064557Abstract: A programmable synchronizing unit for a signal receiver has a received data memory for buffering received data, a correlation value data memory for storing correlation values, a data path for correlating the received data with the correlation values, a result data memory for buffering the received data correlated with the correlation values by means of the data path, and a control unit for addressing the received data memory, the result data memory and the correlation value data memory (26) and for controlling the data path as a function of a synchronization program which is stored in a program memory.Type: GrantFiled: November 17, 2000Date of Patent: November 22, 2011Assignee: Infineon Technologies AGInventors: Burkhard Becker, Markus Doetsch, Peter Jung, Tideya Kella, Joerg Plechinger, Peter Schmidt, Sven Simon, Michael Schneider
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Patent number: 8064499Abstract: Common components are used to detect messages from a variety of transmitters, and the characteristics of each detected message are used to dynamically configure the demodulation process for each message. Channelization is selectively performed before, after, or before-and-after de-spreading, depending upon the particular environment and/or the particular characteristics of the received messages. Frequency synchronization to each transmitter is achieved by initializing a tracking loop within the demodulator associated with the transmitter, and code-phase synchronization to each transmitter is achieved by selectively inserting or deleting bits, based on the frequency and code-phase characteristics of the detected message.Type: GrantFiled: November 9, 2007Date of Patent: November 22, 2011Assignee: Comtech Mobile Datacom CorporationInventor: James F. Stafford
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Patent number: 8059630Abstract: The present invention provides a unique manner of identifying the Frame boundaries in multiple identical/non-identical Synchronization Channels (SCHs) in different sub-frames via a new sub frame position difference method. The method implements the differences between the different sub-frames carried by the SCH. The sub frame identity, and hence the frame boundary, can be identified by calculating the difference between the positions, based on time or number of slots/sub-frames or any data packets, of the two subsequent slots/sub-frames or any identical data packets.Type: GrantFiled: August 23, 2007Date of Patent: November 15, 2011Assignee: Samsung Electronics Co., LtdInventor: Basu Mallick Prateek