Patents by Inventor Dengwei Fu
Dengwei Fu has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 10367671Abstract: High peak-to-average ratio of OFDM signals requires large back-off from an RF power amplifier's saturation power. A spectral shaper device therefore increases the output power and efficiency of the power amplifier. The shaper device performs linearization through digital predistortion, based on an out-of-band regrowth limit, as well as the EVM requirement for a particular data rate. The shaper can distribute the error energy, precisely, over frequencies such that each of the inband and out-of-band requirements is independently and individually met. The shaper distributes error energy to frequency regions in the spectrum to the maximally allowed by the standards and regulations, while not increasing the total error. The error energy is kept to the minimum where it is crucial in meeting EVM requirements. In this way, the shaper maximizes the allowable output power of the nonlinear power amplifier.Type: GrantFiled: November 28, 2017Date of Patent: July 30, 2019Assignee: AVAGO TECHNOLOGIES INTERNATIONALInventors: Dengwei Fu, Colin Fraser, Amir Eliaz, Daniel Stopler, Sandeep Shenoy
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Publication number: 20190165981Abstract: High peak-to-average ratio of OFDM signals requires large back-off from an RF power amplifier's saturation power. A spectral shaper device therefore increases the output power and efficiency of the power amplifier. The shaper device performs linearization through digital predistortion, based on an out-of-band regrowth limit, as well as the EVM requirement for a particular data rate. The shaper can distribute the error energy, precisely, over frequencies such that each of the inband and out-of-band requirements is independently and individually met. The shaper distributes error energy to frequency regions in the spectrum to the maximally allowed by the standards and regulations, while not increasing the total error. The error energy is kept to the minimum where it is crucial in meeting EVM requirements. In this way, the shaper maximizes the allowable output power of the nonlinear power amplifier.Type: ApplicationFiled: November 28, 2017Publication date: May 30, 2019Applicant: AVAGO TECHNOLOGIES INTERNATIONAL SALES PTE. LIMITEDInventors: Dengwei FU, Colin Fraser, Amir Eliaz, Daniel Stopler, Sandeep Shenoy
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Patent number: 8665931Abstract: Communication processing paths include distortions, such as DC offset in the baseband analog path, local oscillator feed-through distortion, and nonlinearity of gm's and power amplifiers which are calibrated for, separately or in combination. The cascaded DC offset and nonlinear distortions are modeled separately or in combination using even-and-odd order polynomials. A loopback path from the output of one or more distortion causing devices passes through a measurement and calculation module. The calculation module calculates predistortion polynomial's coefficients which will be stored in a look-up table to be used by a baseband predistorter to calibrate the path. The look-up table is stored locally or remotely.Type: GrantFiled: June 29, 2012Date of Patent: March 4, 2014Assignee: Broadcom CorporationInventors: Ali Afsahi, Utku Seckin, Colin Fraser, Navid Lashkarian, Konrad Kratochwil, Arya Reza Behzad, Dengwei Fu
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Publication number: 20130287076Abstract: Communication processing paths include distortions, such as DC offset in the baseband analog path, local oscillator feed-through distortion, and nonlinearity of gm's and power amplifiers which are calibrated for, separately or in combination. The cascaded DC offset and nonlinear distortions are modeled separately or in combination using even-and-odd order polynomials. A loopback path from the output of one or more distortion causing devices passes through a measurement and calculation module. The calculation module calculates predistortion polynomial's coefficients which will be stored in a look-up table to be used by a baseband predistorter to calibrate the path. The look-up table is stored locally or remotely.Type: ApplicationFiled: June 29, 2012Publication date: October 31, 2013Applicant: BROADCOM CORPORATIONInventors: Ali Afsahi, Utku Seckin, Colin Fraser, Navid Lashkarian, Konrad Kratochwil, Arya Reza Behzad, Dengwei Fu
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Patent number: 8014416Abstract: A radio frequency (RF) transmitter is coupled to and controlled by a processor to transmit data. A physical layer circuit is coupled to the RF transmitter to encode and decode between a digital signal and a modulated analog signal. The physical layer circuit comprises a high rate physical layer circuit (HRP) and a low rate physical layer circuit (LRP). The low rate channels generated by the low rate physical layer circuit (LRP) share a same frequency band as a corresponding high rate channel generated by the high rate physical layer circuit (HRP).Type: GrantFiled: February 13, 2007Date of Patent: September 6, 2011Assignee: Sibeam, Inc.Inventors: Keangpo Ricky Ho, Karim Nassiri-Toussi, Dengwei Fu, Stephen P. Pope, Jeffrey M. Gilbert, Chuen-Shen Shung, Jianhan Liu
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Patent number: 7719999Abstract: A method and apparatus of predicting link quality of a link are disclosed. One exemplary method includes a receiver receiving multi-carrier modulated signals over a period of time. A signal to noise ratio (SNR) for each received sub-carrier is estimated. An ordered sequence of the signal to noise ratios (SNR)s are constructed based on interleaving of the multi-carrier modulated signals, wherein an order of the interleaving is used to set the ordered sequence of the signal to noise ratios (SNR)s. The receiver estimates link packet error rate (PER) based upon knowledge of encoding of the multi-carrier modulated signals used during transmission and the ordered sequence.Type: GrantFiled: September 4, 2008Date of Patent: May 18, 2010Assignee: NDSSI Holdings, LLCInventors: Dengwei Fu, Sujai Chari, Mohan Ramasudha Karnam
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Publication number: 20090323563Abstract: A radio frequency (RF) transmitter is coupled to and controlled by a processor to transmit data. A physical layer circuit is coupled to the RF transmitter to encode and decode between a digital signal and a modulated analog signal. The physical layer circuit comprises a high rate physical layer circuit (HRP) and a low rate physical layer circuit (LRP). The low rate channels generated by the low rate physical layer circuit (LRP) share a same frequency band as a corresponding high rate channel generated by the high rate physical layer circuit (HRP).Type: ApplicationFiled: February 13, 2007Publication date: December 31, 2009Inventors: Keangpo Ricky Ho, Karim Nassiri-Toussi, Dengwei Fu, Stephen P. Pope, Jeffrey M. Gilbert, Chuen-Shen Shung, Jianhan Liu
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Publication number: 20090003234Abstract: A method and apparatus of predicting link quality of a link is disclosed. The method includes receiving multi-carrier modulated signals over a period of time, estimating an SNR for each received sub-carrier, constructing a sequence of the SNRs, and estimating link PER based upon knowledge of encoding and/or interleaving used during transmission, and the sequence of SNRs.Type: ApplicationFiled: September 4, 2008Publication date: January 1, 2009Inventors: Dengwei Fu, Sujai Chari, Mohan Ramasudha Karnam
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Patent number: 7440412Abstract: A method and apparatus of predicting link quality of a link is disclosed. The method includes receiving multi-carrier modulated signals over a period of time, estimating an SNR for each received sub-carrier, constructing a sequence of the SNRs, and estimating link PER based upon knowledge of encoding and/or interleaving used during transmission, and the sequence of SNRs.Type: GrantFiled: March 13, 2006Date of Patent: October 21, 2008Assignee: Tzero Technologies, Inc.Inventors: Dengwei Fu, Sujai Chari, Mohan Ramasudha Karnam
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Publication number: 20070211641Abstract: A method and apparatus of predicting link quality of a link is disclosed. The method includes receiving multi-carrier modulated signals over a period of time, estimating an SNR for each received sub-carrier, constructing a sequence of the SNRs, and estimating link PER based upon knowledge of encoding and/or interleaving used during transmission, and the sequence of SNRs.Type: ApplicationFiled: March 13, 2006Publication date: September 13, 2007Inventors: Dengwei Fu, Sujai Chari, Mohan Karnam
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Patent number: 7203718Abstract: An angle rotator uses a coarse stage rotation and a fine stage rotation to rotate an input complex signal in the complex plane according to an angle ?. The coarse stage rotation includes a memory device storing pre-computed cosine ?M and sine ?M values for fast retrieval, where ?M is a radian angle that corresponds to a most significant word (MSW) of the input angle ?. The fine stage rotation uses one or more error values that compensate for approximations and quantization errors associated with the coarse stage rotation. The rotator consolidates operations into a small number of reduced-size multipliers, enabling efficient multiplier implementations such as Booth encoding, yielding a smaller and faster overall circuit.Type: GrantFiled: October 30, 2000Date of Patent: April 10, 2007Assignee: Pentomics, Inc.Inventors: Dengwei Fu, Arthur Torosyan, Alan N. Willson, Jr.
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Publication number: 20050193047Abstract: A method of synchronizing symbol timing in a digital device includes the steps of receiving complex data samples of one or more symbols, correlating the data samples with a complex conjugate of a preamble data set, selecting between real and imaginary samples and generating a complex number based on the result. The method then determines an angle in a complex plane that represents symbol synchronization for the digital device. Disclosed embodiments include applications to communications devices, and to carrier recovery in such devices. In such embodiments the resultant angle may represent a carrier phase offset for the device.Type: ApplicationFiled: March 28, 2005Publication date: September 1, 2005Applicant: Pentomics, Inc.Inventors: Dengwei Fu, Alan Willson
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Patent number: 6874006Abstract: A rectangular-to-polar-converter receives a complex input signal (having X0 and Y0 components) and determines an angle ? that represents the position of the complex signal in the complex plane. The rectangular-to polar-converter determines a coarse angle ?1 and a fine angle ?2, where ?=?1+?2. The coarse angle ?1 is obtained using a small arctangent table and a reciprocal table. These tables provide just enough precision such that the remaining fine angle ?2 is small enough to approximately equal its tangent value. Therefore the fine angle ?2 can be obtained without a look-up table, and the fine angle computations are consolidated into a few small multipliers, given a precision requirement. Applications of the rectangular-to-polar converter include symbol and carrier synchronization, including symbol synchronization for bursty transmissions of packet data systems. Other applications include any application requiring the rectangular-to-polar conversion of a complex input signal.Type: GrantFiled: October 30, 2000Date of Patent: March 29, 2005Assignee: Pentomics, Inc.Inventors: Dengwei Fu, Alan N. Willson, Jr.
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Patent number: 6772181Abstract: A trigonometric interpolator interpolates between two data samples at an offset &mgr;, where the two data samples are part of a set of N data samples. The trigonometric interpolator fits a trigonometric polynomial to the N data samples and evaluates the trigonometric polynomial at the offset &mgr;. The trigonometric inteprolator can be utilized for data rate changing and to correct mismatches between received samples and transmitted symbols. Simulations demonstrate that the trigonometric interpolater attains better performance than “conventional” interpolators, while simultaneously reducing the required hardware. In embodiments, the filter response of the trigonometric interpolator can be modified to achieve an arbitrary frequency response in order to enhance the interpolator performance. More specifically, the frequency response of the interpolator can be shaped to effectively correspond with the frequency response of the input data samples and the offset &mgr;.Type: GrantFiled: October 30, 2000Date of Patent: August 3, 2004Assignee: Pentomics, Inc.Inventors: Dengwei Fu, Alan N. Willson, Jr.
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Patent number: 6628707Abstract: A method for an adaptive equalization apparatus in a multiple-link hopping radio system includes hopping among a plurality of radio links to receive variable-length bursts of radio signals on the plurality of radio links and equalizing amplitude and phase variations of a slow channel for each radio link from a received burst on the radio link. Further, the method includes storing the estimated tap coefficients pertinent to each radio link and using the tap weights of the current burst of the radio link to reliably pre-compensate the channel amplitude and phase distortion of a next received burst on the radio link.Type: GrantFiled: May 4, 2001Date of Patent: September 30, 2003Assignee: Radiant Networks PLCInventors: Manouchehr S. Rafie, Jun Lu, Dengwei Fu, Tushar Shah
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Publication number: 20020196844Abstract: A method for an adaptive equalization apparatus in a multiple-link hopping radio system includes hopping among a plurality of radio links to receive variable-length bursts of radio signals on the plurality of radio links and equalizing amplitude and phase variations of a slow channel for each radio link from a received burst on the radio link. Further, the method includes storing the estimated tap coefficients pertinent to each radio link and using the tap weights of the current burst of the radio link to reliably pre-compensate the channel amplitude and phase distortion of a next received burst on the radio link.Type: ApplicationFiled: May 4, 2001Publication date: December 26, 2002Applicant: Caly NetworksInventors: Manouchehr S. Rafie, Jun Lu, Dengwei Fu, Tushar Shah