Single Bit (delta) Patents (Class 375/247)
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Patent number: 8571151Abstract: Certain aspects of the present disclosure relate to a method for emulating N-bits uniform quantization of a received pulse signal by using one-bit signal measurements. One method for wireless communications includes receiving a signal transmitted over a wireless channel, wherein the signal comprises a sequence of pulses, applying gain values to the pulses to obtain a binary matrix for each gain value, generating a probability vector for each gain value using the binary matrix obtained for that gain value, and generating an output signal by linearly combining the probability vectors.Type: GrantFiled: October 13, 2009Date of Patent: October 29, 2013Assignee: QUALCOMM IncorporatedInventors: Yann Barbotin, Petru Cristian Budianu
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Patent number: 8547135Abstract: A self-modulated voltage reference circuit may generate a reference voltage by receiving an internal reference voltage of a programmable device at a first input of a comparator block of the programmable device, receiving a feedback voltage at a second input of the comparator block, generating a pulse density modulated (PDM) signal based on a difference between the reference voltage and the feedback voltage, outputting the PDM signal at a digital output pin of the programmable device, and filtering the PDM signal to generate the output reference voltage.Type: GrantFiled: August 27, 2010Date of Patent: October 1, 2013Assignee: Cypress Semiconductor CorporationInventors: Archana Yarlagadda, Dave Van Ess, Jeffrey Dahlin
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Patent number: 8467485Abstract: A mobile terminal with smart antennas, comprises a plurality of groups of radio frequency signal processing modules (300), for transforming received multi-channel radio frequency signals to multi-channel baseband signals; a smart antenna processing module (306), for smart antenna baseband processing said multi-channel baseband signals output from said plurality of groups of radio frequency signal processing module so as to combine said multi-channel baseband signals into single-channel baseband signals, according to control information received one-off as said smart antenna processing module is enabled; and a baseband processing module (303-305), for providing said control information to said smart antenna processing module according to data from said smart antenna processing module, and baseband processing said single-channel baseband signals outputted from said smart antenna processing module.Type: GrantFiled: April 25, 2011Date of Patent: June 18, 2013Assignee: ST-Ericsson SAInventors: Yanzhong Dai, Luzhou Xu
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Patent number: 8451916Abstract: A relay-based communication system and method processing a signal without a cyclic prefix is provided. An apparatus for generating a relay signal includes a signal receiving unit which receives a source signal transmitted from a source node to a relay node and detects a received signal, a signal conversion unit which extracts samples corresponding to a first time duration from the received signal, sums the received signal and the extracted samples in a second time duration, and generates a converted received signal, a relay signal generation unit which generates a relay signal cooperating with the source signal based on the converted received signal according to a space frequency block code (SFBC) scheme, and a signal transmission unit which transmits the generated relay signal to a destination node.Type: GrantFiled: April 7, 2008Date of Patent: May 28, 2013Assignees: Samsung Electronics Co., Ltd., Postech Academy-Industry FoundationInventors: Ui Kun Kwon, Young-Doo Kim, Gi Hong Im, Dae-Young Seol, Won-Jae Shin
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Patent number: 8369551Abstract: A hearing aid with wireless signal transmission is provided which includes a radio reception unit for wireless reception of modulated and/or coded audio signals, a device to estimate the reception quality of the received audio signal, a device to generate an acoustic limit signal whose level increases when the estimated reception quality of the received audio signal decreases, a device to heterodyne a demodulated and/or decoded audio signal with the limit signal, and a device to output the audio signal heterodyned with the limit signal to a hearing aid wearer. To generate a limit signal, the hearing aid includes a device to generate an impulse response and a device to perform the operation of convolving the demodulated and/or decoded audio signal with the impulse response. This convolution produces a desired signal which appears closer to the hearing aid wearer when the estimated reception quality is better.Type: GrantFiled: March 5, 2009Date of Patent: February 5, 2013Assignee: Siemens Medical Instruments Pte. Ltd.Inventor: Ulrich Kornagel
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Patent number: 8358509Abstract: An information handling system device includes a plurality of electronic components; an electric circuit including at least one trace for connecting two or more of the plurality of electronic components and transmitting data between the plurality of electronic components via at least one electric signal; and a substrate including an insulating material for serving as a base for the electric circuit and the plurality of electronic components, wherein the at least one electric signal transmitted between the plurality of electronic components is transmitted utilizing slope manipulation to provide a slope directly proportional to a data value.Type: GrantFiled: January 30, 2009Date of Patent: January 22, 2013Assignee: International Business Machines CorporationInventors: Kevin J. Bills, Mahesh Bohra, Jinwoo Choi, Lloyd A. Walls
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Patent number: 8350497Abstract: An controlled LED lighting system that operates using a single conductor to power and control LED nodes is disclosed. The controlled LED lighting system modulates control data onto a nominally constant DC signal transmitted down a single conductor serial line. Nodes coupled the serial line draw power into a local capacitor and demodulate the data signal. Each node shunts the serial line when additional power is not required such that the data signal is received by every node on the serial line.Type: GrantFiled: December 7, 2011Date of Patent: January 8, 2013Assignee: Neofocal Systems, Inc.Inventors: Mark Peting, Dale Beyer, Tsutomu Shimomura
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Patent number: 8311131Abstract: The present invention relates to a method for interpolating, for the purpose of measurement of lengths and/or angles, at least two position-dependent, periodic analog signals that are phase-shifted with respect to each other and that are generated by scanning a measuring scale. According to the inventive method, the analog signals are converted to a digital data stream using a sigma-delta modulator, the data streams are combined with correctional factors and then with each other to generate a string of results, and said string of results is used to generate new correctional values by the use of a quality criterion to be satisfied for interpolation and also to generate the output signals of interpolation. The values (d) of the string of results are accumulated over a specified time interval in order to generate the correctional values (k1, k2) and the output signals (w).Type: GrantFiled: December 4, 2002Date of Patent: November 13, 2012Assignee: Dr. Johannes Heidenhain GmbHInventor: Roman Woyzichovski
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Patent number: 8145181Abstract: An electric power transmission system for communications includes on/off switches; high-voltage power assemblies; groups of high-voltage devices each being powered by the high-voltage power assembly; a carrier waves communications network comprising a transformer and filter, a filter, and a carrier waves coupling device interconnecting the transformer and filter and the filter, wherein the transformer and filter includes a low-voltage power assembly for communications and the filter includes a high-voltage power assembly for communications; and low and high-voltage devices. Data can be communicated between the low-voltage devices, between the high-voltage devices, or between the low-voltage device and the high-voltage device by transmitting carrier waves over the AC power.Type: GrantFiled: October 21, 2008Date of Patent: March 27, 2012Inventor: Ming-Wei Lu
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Patent number: 8144799Abstract: Soft decision sections (503, 506) provisionally decide each modulated signal (502, 505) separated using an inverse matrix calculation of a channel fluctuation matrix at separation section (501). Signal point reduction sections (508, 510, 514, 516) reduce candidate signal points of a multiplexed modulated signal using the provisional decision results (504, 507). Soft decision sections (512, 518) make a correct decision using the reduced candidate signal points and obtain received data (RA, RB) of each modulated signal. This allows received data RA, RB with a good error rate characteristic to be obtained with a relatively small number of calculations without reducing data transmission efficiency.Type: GrantFiled: November 1, 2010Date of Patent: March 27, 2012Assignee: Panasonic CorporationInventors: Yutaka Murakami, Kiyotaka Kobayashi, Masayuki Orihashi, Akihiko Matsuoka, Daichi Imamura, Rahul Malik
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Patent number: 8098718Abstract: A digital-to-analog converter (DAC) includes a mismatch shaping feedback vector quantizer configured to store state information in expanded format using One-Hot Encoding of a matrix. The expanded state format storage enables implementation of a simplified state sorter for the vector feedback mechanism of the vector quantizer. The simplified state sorter may minimize the variance of ones (or other symbols representing state values) in the matrix, and allow performing sorting in a reduced number of clock cycles. For example, sorting may be performed on a predetermined edge of single clock cycle, or on two edges of the same clock cycle. The matrix may be normalized periodically or as needed, to avoid overflow and underflow. The DAC may be used as a quantizer of a modulator of an access terminal in a cellular communication system.Type: GrantFiled: December 17, 2009Date of Patent: January 17, 2012Assignee: Qualcomm IncorporatedInventors: Matthew D. Sienko, Joseph G. Hamilton, Iain W. Finlay
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Patent number: 8059724Abstract: A data transmission system and method includes providing a current to a first conductor by a current source to transmit a first binary digit while isolating a second conductor from the current source. In response to a command to transmit a second binary digit, amount of current provided by the current source to the first conductor is decreased from a maximum value to zero while simultaneously increasing the amount of current provided to the second conductor from zero to a maximum value. The increase and the decrease in the amount of current are done the same rate. A first and a second signal corresponding to the current provided to the first and the second conductors each have a transition edge with a leading section, a midsection and trailing section such that an average slope of the midsection is greater than average slope of the leading section and the average slope of the trailing section.Type: GrantFiled: March 11, 2008Date of Patent: November 15, 2011Assignee: SanDisk IL LtdInventor: Tavi Salomon
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Patent number: 8031783Abstract: A method and apparatus for converting a high precision digital word into a high precision analog value is disclosed. A sigma delta modulator applies a digital input signal to a dither signal to generate a combined signal for sampling. A digital-to-analog converter quantizes the combined signal. An analog filter provides a cutoff at a bandwidth of interest to remove out of band quantization noise and signals. An I transfer function and a Q transfer function can be coupled between the sigma delta modulator and the digital-to-analog converter for mapping of the combined signal. The apparatus can also include a phase interpolator for receiving the output signal and outputting a clock recovery phase.Type: GrantFiled: April 5, 2010Date of Patent: October 4, 2011Assignee: Maxim Integrated Products, Inc.Inventors: James L. Gorecki, Tong Liu
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Patent number: 7965157Abstract: Briefly, in accordance with one embodiment of the invention, a resonator such as an electromechanical resonator may be coupled with a cancellation network to reduce and/or cancel an anti-resonance effect in the resonator, which may be due to, for example, a static capacitance inherent in the resonator. Cancellation of an anti resonance effect from the resonator response may allow a resonance effect of the resonator to be a predominant effect to allow the resonator to be utilized as a bandpass filter having a relatively higher Q, for example in a bandpass sigma-delta modulator that may be utilized in a digital RF receiver.Type: GrantFiled: July 20, 2005Date of Patent: June 21, 2011Assignee: National University of SingaporeInventors: Yong Ping Xu, Rui Yu
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Patent number: 7956783Abstract: An analog-to-digital converter includes a delta circuit, a sigma circuit, and a quantizer circuit and further includes a feedback circuit that modulates a reference voltage provided to the quantizer circuit based on the quantizer circuit output. Modulation of the quantizer reference voltage dithers the quantizer circuit to effectively reduce or avoid lock bands. The analog-to-digital converter may be used in combination with a microelectromechanical (MEMS) device such as a gyroscope, an accelerometer, or a pressure sensor.Type: GrantFiled: June 5, 2009Date of Patent: June 7, 2011Assignee: Analog Devices, Inc.Inventor: John A. Geen
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Method and arrangement for reducing the mutual interference of network subscribers in radio networks
Patent number: 7945210Abstract: The object of the invention, which relates to a method and an arrangement for reducing the mutual interference of network subscribers in radio networks, is to provide a solution by means of which data collisions are reduced and thus the data throughput rate of a radio cell is increased. According to the invention, this object is achieved in terms of the method in that the cell size of a radio cell is adjusted by reducing the receiver sensitivity of one or more devices belonging to the radio cell if the device receives interference which disrupts its communication from another device belonging to a different radio cell.Type: GrantFiled: December 13, 2005Date of Patent: May 17, 2011Assignee: NXP B.V.Inventor: Volker Aue -
Patent number: 7928876Abstract: A method of controlling a sigma delta modulator with a loop which establishes a signal transfer function, STF, and a quantization noise transfer function, NTF, of the sigma delta modulator, wherein the sigma delta modulator receives an input signal, x(n), and provides a modulated output signal, y(n) in response to the input signal. The method is characterized in comprising the step of controlling the sigma delta modulator to change the quantization noise transfer function, NTF, in response to a signal feature, A(n), which is correlated with the input signal.Type: GrantFiled: April 11, 2005Date of Patent: April 19, 2011Assignee: Audioasics A/SInventors: Henrik Thomsen, Claus Erdmann Fuerst
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Patent number: 7817725Abstract: The present invention aims to provide a transmitter circuit that is capable of suppressing quantization noise and operating with a high efficiency, a data converter section 13 and a data conversion method for use therein, and a communications device using the same. The data converter section 13 of the present invention performs a predetermined data conversion operation on an input signal. The data converter section 13 includes: a signal processing section 133 for discretizing the input signal to produce a signal having a lower resolution magnitude-wise than that of the input signal; a subtractor section 134 for subtracting the input signal from the signal having a lower resolution to extract quantization noise; a filter 135 for extracting quantization noise near an intended wave frequency; and a subtractor section 136 for removing the quantization noise near the intended wave frequency from the signal having a lower resolution.Type: GrantFiled: March 9, 2005Date of Patent: October 19, 2010Assignee: Panasonic CorporationInventors: Toru Matsuura, Hisashi Adachi
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Patent number: 7791518Abstract: Embodiments of a system for processing a signal may include a receiver configured to receive an input analog signal and an up converter coupled with the receiver and configured to up convert the analog signal to an up converted analog signal. Embodiments may further include an amplifier coupled with the up converter and configured to amplify the up converted analog signal to generate an amplified signal and also a bandpass filter coupled with the amplifier and configured to filter the amplified signal to generate a filtered analog signal. According to embodiments, the filtered analog signal may be fed to a quanitizer of the ADC. Intermediate signals made thus avoid the flicker noise region typically associated with an integrator of the ADC and may minimize the quantization noise associated with converting higher frequency analog signals.Type: GrantFiled: July 11, 2008Date of Patent: September 7, 2010Assignee: Texas Instruments IncorporatedInventor: Ganesh Balachandran
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Patent number: 7738613Abstract: Systems and methods for converting a data stream from a first sample rate to a second sample rate, where the data is received in bursts. In one embodiment, a method includes receiving bursty audio data on a first input line and receiving synchronization data on a second input line that is separate from the first input line. An input sample rate is then estimated for the received audio data based on the received synchronization data and the audio data is converted to an output sample rate. The input sample rate is determined by counting samples received in a time interval and potentially low-pass filtering the result. The audio data may be in packetized, parallel, or other forms, and the synchronization data may include individual signals, such as pulses or bits received at regular or irregular intervals.Type: GrantFiled: March 20, 2004Date of Patent: June 15, 2010Assignee: D2Audio CorporationInventors: Jack B. Andersen, Joel W. Page, Daniel L. W. Chieng, Douglas D. Gephardt
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Patent number: 7720160Abstract: A method and apparatus for converting a high precision digital word into a high precision analog signal is disclosed. A sigma delta modulator applies a digital input signal to a dither signal to generate a combined signal for sampling. A digital-to-analog converter quantizes the combined signal. An analog filter provides a cutoff at a bandwidth of interest to remove out of band quantization noise and signals. An I transfer function and a Q transfer function can be coupled between the sigma delta modulator and the digital-to-analog converter for mapping of the combined signal. The apparatus can also include a phase interpolator for receiving the output signal and outputting a clock recovery phase.Type: GrantFiled: December 14, 2006Date of Patent: May 18, 2010Assignee: Maxim Integrated Products, Inc.Inventors: James L. Gorecki, Tong Liu
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Patent number: 7697466Abstract: At a base station apparatus, known pilot signals for use in channel estimation are transmitted, and in addition thereto MCS pilot signals that are used to perform adaptive modulations respectively corresponding to a plurality of modulation schemes are multiplexed and output. A mobile station apparatus dispreads the respective MCS signals out of the multiplex signal, compares these to known symbols patterns, and sends the MCS pilot signals that show a matching relationship to the base station apparatus as a mobile station reception result. Upon receiving the mobile station reception result from the mobile station apparatus, the base station apparatus selects the modulation scheme of the optimum modulation level for the downlink signals. This configuration makes it possible to switch the modulation schemes in an accurate and simple way.Type: GrantFiled: July 15, 2002Date of Patent: April 13, 2010Assignee: Panasonic CorporationInventors: Kazunari Hashimoto, Sadaki Futagi, Kenichi Miyoshi
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Patent number: 7653141Abstract: Methods and apparatus for transmitting and receiving symbols in a communication system having a plurality of frequency bands are provided. A first symbol is transmitted on a first tone using a first constellation mapping and a second symbol is transmitted on a second tone using a second constellation mapping different from the first constellation mapping. The first symbol is retransmitted on the second tone using the second constellation mapping and the second symbol is retransmitted on the first tone using the first constellation mapping. The first and second symbols are detected from a combination of the received transmitted and retransmitted first and second signals.Type: GrantFiled: March 31, 2006Date of Patent: January 26, 2010Assignee: Panasonic CorporationInventors: Shaomin Samuel Mo, Alexander D. Gelman
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Patent number: 7639757Abstract: A pulse modulator has a subtraction stage that produces a control error signal from the difference between a complex input signal and a feedback signal. A signal conversion stage converts the control error signal to a control signal. The control signal is multiplied by a complex mixing signal at the frequency ?0 in a first multiplication stage. At least one of the real and imaginary parts of the up-mixed control signal is then quantized by a quantization stage to produce a real pulsed signal. The pulsed signal is then employed to produce the feedback signal for the subtraction stage in a feedback unit. The pulse modulator according to the invention allows the range of reduced quantization noise to be shifted toward a desired operating frequency ?0.Type: GrantFiled: May 6, 2004Date of Patent: December 29, 2009Assignee: LITEF GmbHInventor: Guenter Spahlinger
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Patent number: 7630445Abstract: Establishing slot boundaries includes receiving a feedback signal reflecting feedback information describing a signal modified according to a diversity parameter adjustment. The feedback signal includes slots and bits. A slot boundary is established for each of the slots by: partitioning the bits into periods; comparing the bits of each period; and establishing the slot boundaries in accordance with the comparison.Type: GrantFiled: October 25, 2005Date of Patent: December 8, 2009Assignee: Magnolia Broadband Inc.Inventors: Yair Karmi, Phil Fu-Wei Chen
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Patent number: 7605737Abstract: One embodiment of the present invention includes a data transmission system. The system comprises a data transmitter that provides a plurality of data bits over at least one data line. The data transmitter comprises a clock that provides a clock signal associated with timing for latching the plurality of data bits and a data encoder configured to encode error data associated with the data transmission system in the clock signal.Type: GrantFiled: April 4, 2007Date of Patent: October 20, 2009Assignee: Texas Instruments IncorporatedInventors: Robert F. Payne, Richard M. Prentice
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Patent number: 7561635Abstract: A noise-shaping coder with variable or reconfigurable characteristics is disclosed. In one exemplary embodiment, an improved apparatus for signal modulation is disclosed. The apparatus generally comprises a noise-shaping coder having programmable coefficients, programmable coder order, programmable oversampling frequency, and/or programmable dither. In a second exemplary embodiment, an improved method for implementing noise shaping coding is disclosed. The apparatus generally comprises a means for switching from one order coder to another order coder, as well as switching oversampling frequency.Type: GrantFiled: August 3, 2004Date of Patent: July 14, 2009Assignee: STMicroelectronics NVInventors: Steven R. Norsworthy, Jason Rupert Redgrave
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Publication number: 20090046784Abstract: A differential signal output device is disclosed that outputs transmission data as a differential signal. The device includes a first differential signal generation circuit that amplifies a signal representing the transmission data and generates the differential signal from the amplified signal; a dummy data generation circuit that is synchronized with a reference clock of the transmission data and generates dummy data that change only in a bit where the transmission data do not change; and a second differential signal generation circuit that amplifies a signal representing the dummy data and generates another differential signal from the amplified signal.Type: ApplicationFiled: August 11, 2008Publication date: February 19, 2009Inventors: Nobunari Tsukamoto, Hidetoshi Ema
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Patent number: 7450648Abstract: A signal processing device uses a ?? modulator having varying effective orders to ensure an S/N ratio by selecting a high order when a 1-bit music signal is output via the ?? modulator. The signal processing device prevents noise during switchover by shifting to a low order just before the ?? modulator is bypassed if this occurs. The present invention provides a digital signal processing device which can switch between an original sound signal and a ?? modulation signal and yield a sufficient S/N ratio for a reprocessed ?? modulation signal. If any 1-bit original sound signal is input, little switching noise is generated.Type: GrantFiled: March 21, 2005Date of Patent: November 11, 2008Assignee: Sony CorporationInventor: Shigeo Tagami
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Patent number: 7430239Abstract: A preprocessing unit converts an analog signal to a processed signal at a sample rate controlled by a first clock signal. A digital phase locked loop locks on the processed signal and outputs a phase signal using the first clock signal. A bit decision unit outputs a digital signal and a third clock signal using the phase signal, the first clock signal and an output signal from the preprocessing unit. A clock divider produces the first clock signal from the second clock signal. A quantizer produces the output signal by quantizing the analog signal amplitude. A phase detector determines a phase difference between the output signal and the second clock signal to feed an amplitude that indicates a phase difference. A sample and hold unit samples the output signal using the second clock signal and holds samples of the output signal for a clock period of first clock signal.Type: GrantFiled: October 24, 2002Date of Patent: September 30, 2008Assignee: Koninklijke Philips Electronics N.V.Inventor: Josephus Arnoldus Henricus Maria Kahlman
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Patent number: 7385538Abstract: Methods and devices for an improved delta sigma modulator. The delta sigma modulator has multiple filters with at least one high order filter processing the MSBs of the quantizer fractional output and at least one lower order filter processing the LSBs of the quantizer fractional output. The outputs of these filters are then combined with the input through a combiner with the result being received by the quantizer. The quantizer then produces the output integer bitstream along with the fractional bitstream.Type: GrantFiled: September 29, 2006Date of Patent: June 10, 2008Assignee: Kaben Wireless Silicon Inc.Inventor: Tom Riley
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Patent number: 7310382Abstract: A power amplifier comprises a level-discretization modulator (210) and a mixing and amplifying stage (225), in combination with a properly designed negative feedback path. The feedback path forms an error compensation loop together with a properly selected forward path. The forward path includes at least the mixing and amplifying stage (225), which provides frequency up-conversion to the radio frequency band and switch-based amplification. The negative feedback path includes a down-conversion mixer (280) for down-conversion to the initial frequency band, and compensates for distortion caused by components of the forward path.Type: GrantFiled: April 25, 2002Date of Patent: December 18, 2007Assignee: Telefonaktiebolaget LM Ericsson (publ)Inventors: Tony Fondén, Richard Hellberg
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Patent number: 7308032Abstract: A method and a device for spectrally shaping nonlinear intersymbol interference (NLISI) in an oversampling digital-to-analog converter are disclosed. At least one higher-order shaper circuit is provided, so as to shape NLISI, causing energy associated with NLISI to fall outside a signal band. The signal-to-noise ratio achieved is better than signal-to-noise rations obtained in prior art NLISI reducing methods and devices.Type: GrantFiled: December 31, 2003Date of Patent: December 11, 2007Assignee: HRL Laboratories, LLCInventor: Peter Capofreddi
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Patent number: 7292171Abstract: The invention relates to a method and device for the conversion of digital signals comprising a phase involving modulation with the aid of a vector lattice encoder. The inventive method comprises iterative steps which are performed on N output candidates, consisting in filtering (Hx, Hq), determining the difference between the filtered signals calculating two possible evolutions for said options, pre-selecting the candidates that minimise the difference, weighting the difference with a cost function (W), marking the candidates eliminated for a subsequent iteration, and selecting the best candidate over a period determined by a historical decision dimension. The invention also relates to the use thereof in relation to a digital audio signal amplifier.Type: GrantFiled: February 2, 2005Date of Patent: November 6, 2007Assignee: Anagram Technologies SAInventor: Thierry Heeb
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Patent number: 7289565Abstract: A method and apparatus reliably encode and decode information over a communication system. The method includes transforming two coefficients into two pairs of random variables, one random variable in each pair having substantially equal energy as one random variable in the other pair. The method further includes quantizing each of the pairs of random variables and entropy coding each quantized random variable separately creating an encoded bitstreams. The encoded bitstreams are received by a decoder which first determines which channels of the communication system are working. The encoded bitstream is entropy decoded, inversed quantized and inversed transformed. An inverse transform performs three different transformations depending upon which channels are working, i.e., whether the first, second or both channels are working.Type: GrantFiled: November 22, 2004Date of Patent: October 30, 2007Assignee: AT&T Corp.Inventors: Hamid Jafarkhani, Michael T. Orchard, Amy R. Reibman, Yao Wang
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Patent number: 7266152Abstract: A device for performing predetermined processing on an input signal that may have a signal amplitude of more than one bit. The input signal is obtained by subjecting one-bit serial signals to predetermined signal processing, wherein the signal amplitude of more than one bit is converted to a one-bit serial signal by accumulating the signal amplitudes that exceed one bit, delaying the accumulated signal on the basis of the input signal, and outputting the accumulated signal.Type: GrantFiled: July 29, 2003Date of Patent: September 4, 2007Assignee: Sony CorporationInventors: Masayoshi Noguchi, Gen Ichimura, Nobukazu Suzuki
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Patent number: 7257164Abstract: The present invention relates to Class-D amplifiers, and in particular to bit-flipping sigma-delta modulator (SDM) implementations of such amplifiers. Such amplifiers are particularly although not exclusively suitable for audio equipment such as hi-fi and personal music amplifiers. The present invention provides a bit flipping sigma delta modulator (BF SDM) having a multiple feedback loop filter structure. The modulator comprises a quantiser coupled to a bit flipping means, a look ahead quantiser to determine the next quantiser output, and a controller which determines whether to change the output of the bit flipping circuit. The modulator comprises a feedback loop arranged to add feedback from the output of the modulator to its input. The modulator comprises compensation circuit to adjust the states of the modulator in order to correct for bit flipping of the output of the quantiser. This adjusts the input to the quantiser to correspond to an input having feedback from a non bit flipped quantiser output.Type: GrantFiled: February 4, 2004Date of Patent: August 14, 2007Assignee: Wolfson Microelectronics plcInventor: Anthony J. Magrath
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Publication number: 20070183513Abstract: A signal processing system for changing a level of an input signal to generate an output signal is disclosed. The signal processing system includes a shifter, a sigma-delta modulator, and a level adjuster. The shifter is utilized for receiving the input signal and for bit-shifting the input signal according to a first predetermined gain to generate a first adjustment signal. The sigma-delta modulator is utilized for generating the output signal according a second adjustment signal and the first adjustment. The level adjuster is utilized for adjusting a level of the output signal according to a second predetermined gain to generate the second adjustment signal.Type: ApplicationFiled: February 2, 2007Publication date: August 9, 2007Inventors: Wen-Chi Wang, Bing-I Chang
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Patent number: 7236112Abstract: A self-tuning filter that is well suited for use as a output digital filter in a direct conversion delta-sigma transmitter is constructed as a high pass finite impulse response filter having a cutoff frequency of twice the desired carrier frequency. The filter is clocked using the same clock as used for the commutatation within the transmitter. The aliasing effect of the digital filter produces a passband centered around the carrier frequency which allows the information contained in the spectrum around the passband to be transmitted, while effectively filtering out the quantization noise produced by the commutation. When the commutator clock frequency is changed in order to change the carrier frequency, the passband automatically moves to track the new carrier frequency. The output filter may be constructed using series connected flip-flops with analog taps and an analog summer connected to respective Q and Q outputs, thereby producing an analog output.Type: GrantFiled: January 20, 2006Date of Patent: June 26, 2007Assignee: TechnoConcepts, Inc.Inventor: Ronald M. Hickling
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Patent number: 7227482Abstract: In a first-order complex band-pass filter, multiplexers are alternately switched over between time intervals of phases A and B, where the multiplexers includes two multiplexers provided at input and output stages, and a multiplexer provided in a feedback circuit of each of first-order filters and being switching over whether to invert a sign of a feedback signal. Then in a circuit part sandwiched between the multiplexers, a processing performed by an I circuit part and a processing performed by a Q circuit part are alternately switched over so that a sign of a signal inputted to an adder is inverted.Type: GrantFiled: April 24, 2006Date of Patent: June 5, 2007Assignee: Semiconductor Technology Academic Research CenterInventors: Hao San, Haruo Kobayashi, Hiroki Wada, Akira Hayakawa, Hiroyuki Hagiwara, Yoshitaka Jingu, Kazuyuki Kobayashi, Toshiro Tsukada
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Patent number: 7224757Abstract: A delta-sigma modulator that provides improved SNR performance in applications such as low-power mobile wireless communications and high frequency radar applications is disclosed. Multiple comparators 10, each comprising a sequence of three latches 20, 22, 24, connect the modulator's input filter circuit 12 to the modulator's output interfaces 14, providing quantization of the integrated, filtered signal provided by the filter circuit 12. A clock signal having a cycle period Tc enables a first latch 20 connected to the signal input of each comparator 10 to provide a digital signal to the signal input of a second latch 22. The second latch 22 supplies a digital signal to a third latch 24 in the sequence, in response to the signal received from the first latch 20, by a lagged clock signal derived from the given clock signal Tc by providing a first lag time TL where Tc/2?TL>0. A third latch in the sequence is enabled by a clock signal having a second lag time TS=Tc/2+TE, and the delay TE<<Tc/2.Type: GrantFiled: March 12, 2003Date of Patent: May 29, 2007Assignee: HRL Laboratories, LLCInventor: Peter D. Capofreddi
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Patent number: 7194036Abstract: A method of processing a digital data stream in a digital processing system includes filtering the digital data stream being processed through a delta-sigma modulator having a selected signal transfer function passing a frequency band of interest.Type: GrantFiled: March 26, 2003Date of Patent: March 20, 2007Assignee: Cirrus Logic, Inc.Inventor: John Laurence Melanson
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Patent number: 7145954Abstract: A coding method, specifies temporal and/or non-temporal pulse characteristics, where pulse characteristic values are relative to one or more non-fixed reference characteristic values within at least one delta value range or discrete delta value layout. The method allocates allowable and non-allowable regions relative to the one ore more non-fixed references. The method applies a delta code relative to the allowable and non-allowable regions. The allowable and non-allowable regions are relative to one or more definable characteristic values within a characteristic value layout. The one or more definable characteristic values are relative to one or more characteristic value references. In addition, the one or more characteristic value references can be a characteristic value of a given pulse such as a preceding pulse or a succeeding pulse.Type: GrantFiled: August 15, 2000Date of Patent: December 5, 2006Assignee: Time Domain CorporationInventors: Marcus H. Pendergrass, Mark D. Roberts, James L. Richards
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Patent number: 7136420Abstract: An eight-channel PCM recorder is utilized for recording two channels of delta-sigma modulated audio signals. Employed to this end is a PCM adapter comprising a bit stream divider for dividing the bit streams of the delta-sigma modulated signals into series of sixteen-bit segments, and a reformatter for rearranging the bit segments into eight signals having a format in agreement with the format of the PCM signals normally handled by the PCM recorder. The eight reformatted delta-sigma signals are introduced into the PCM recorder thereby to be recorded in place of the eight channels of PCM signals.Type: GrantFiled: August 6, 2002Date of Patent: November 14, 2006Assignee: TEAC CorporationInventor: Kazuo Watanabe
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Patent number: 7116721Abstract: A feedback noise-shaper of an order of at least three implements a first pole set defining a signal transfer function of a selected corner frequency and a second pole set having at least one pole at a frequency at least twice the selected corner frequency defining a noise transfer function.Type: GrantFiled: May 20, 2002Date of Patent: October 3, 2006Assignee: Cirrus Logic, Inc.Inventors: John Laurence Melanson, Heling Yi
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Patent number: 7113118Abstract: A signal encoding apparatus encodes one-bit signals of a plurality of n channels in a delta-sigma manner. The apparatus includes a phase modulator for phase-modulating the one-bit signals as original signals to add data of inverted phases to the one-bit signals. Information data related to the one-bit signals are added to the phase-modulated one-bit signal by rearranging the data of inverted phases based on a plurality of m channel units of the n channels, where n?m?2 and by exclusive ORing the information data and the phase-modulated one-bit signal data.Type: GrantFiled: July 19, 2001Date of Patent: September 26, 2006Assignee: Sony CorporationInventors: Masayoshi Noguchi, Gen Ichimura
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Patent number: 7110460Abstract: A delta-sigma modulator of an order of at least three having a signal transfer function defining a signal low-pass response, the signal transfer function has a numerator and a denominator, the denominator defined by a product of first and second functions defining respective first and second pole sets such that a roll-off frequency of a low-pass response defined by the first pole set is at least twice a roll-off frequency of a low-pass response defined by the second pole set. The delta-sigma modulator also has a noise transfer function defining a noise high-pass response, the noise transfer function having a numerator and a denominator, the denominator defined by the product of the first and second functions. The numerator of the noise transfer function differs from the numerator of the signal transfer function and characterizes the noise high-pass response.Type: GrantFiled: August 10, 2004Date of Patent: September 19, 2006Assignee: Cirrus Logic, Inc.Inventors: John Laurence Melanson, Heling Yi
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Patent number: 7098828Abstract: A complex band-pass ?? AD modulator is provided with a subtracter device, a complex band-pass filter, first and second AD converters, and first and second DA converters. The first and second DA converters and first and second logic circuits are sandwiched by first and second multiplexers. At a first timing of a clock signal, the first multiplexer inputs and outputs the first and second digital signals as they are, and at a second timing thereof, the first multiplexer inputs the first and second digital signals, and outputs the first digital signal as a second digital signal and outputs the second digital signal as a first digital signal. The second multiplexer inputs and outputs first and second analog signals similarly. The first and second logic circuits substantially noise-shapes non-linearities of the first and second DA converters by realizing complex digital and analog filters, using high-pass and low-pass element rotation methods.Type: GrantFiled: June 22, 2005Date of Patent: August 29, 2006Assignee: Semiconductor Technology Academic Research CenterInventors: Hao San, Haruo Kobayashi, Hiroki Wada, Atsushi Wada
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Patent number: RE41518Abstract: A bandpass sigma-delta modulator using acoustic resonators or micro-mechanical resonators. In order to improve resolution at high frequencies, acoustic resonators or micro-mechanical resonators are utilized in a sigma-delta modulator instead of electronic resonators. The quantized output is fed back using a pair of D/A converters to an input summation device. In fourth order devices, the feed back is to two summation devices in series. Such a sigma-delta modulator is usable in a software defined radio cellular telephone system and in other applications where high-frequency and high-resolution A/D conversion is required.Type: GrantFiled: July 27, 2006Date of Patent: August 17, 2010Inventor: Yong-Ping Xu
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Patent number: RE43489Abstract: Systems and methods for converting a digital input data stream from a first sample rate to a second, fixed sample rate using a combination of hardware and software components. In one embodiment, a system includes a rate estimator configured to estimate the sample rate of an input data stream, a phase selection unit configured to select a phase for interpolation of a set of polyphase filter coefficients based on the estimated sample rate, a coefficient interpolator configured to interpolate the filter coefficients based on the selected phase, and a convolution unit configured to convolve the interpolated filter coefficients with samples of the input data stream to produce samples of a re-sampled output data stream. One or more hardware or software components are shared between multiple channels that can process data streams having independently variable sample rates.Type: GrantFiled: January 23, 2009Date of Patent: June 26, 2012Assignee: D2Audio CorporationInventors: Jack B. Andersen, Larry E. Hand, Daniel L. W. Chieng, Joel W. Page, Wilson E. Taylor, Tonya Andersen