Patents by Inventor Cheng-Hsuan Wu

Cheng-Hsuan Wu 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).

  • Publication number: 20100295734
    Abstract: A method of enhancing accuracy of position estimation for a wireless communication system includes receiving a plurality of input measurements required for estimating a position of a target, and generating a plurality of Gaussian probability density functions corresponding to the plurality of input measurements, the plurality of Gaussian probability density functions being used for estimating the position of the target.
    Type: Application
    Filed: November 8, 2009
    Publication date: November 25, 2010
    Inventors: Cheng-Hsuan Wu, Chin-Tseng Huang, Yung-Szu Tu, Jiunn-Tsair Chen
  • Publication number: 20100289699
    Abstract: A method for determining a position of a mobile station in a wireless communication system includes generating a state equation set according to a current state of the mobile station, for predicting a position and a velocity of the mobile station after a predetermined period, and corresponding the state equation set to a graphic interface for calculating the position and the velocity after the predetermined period.
    Type: Application
    Filed: November 9, 2009
    Publication date: November 18, 2010
    Inventors: Cheng-Hsuan Wu, Chin-Tseng Huang, Yung-Szu Tu, Jiunn-Tsair Chen
  • Publication number: 20100272198
    Abstract: A method and related system of transmission channel detection condition in a wireless communication system are disclosed. The method includes receiving a symbol, performing a channel estimation operation to generate a channel estimation result according to the symbol, performing a cross correlation operation on the channel estimation result and an initial channel estimation result to generate an operation result, and determining whether the condition of the transmission channel have changed or not.
    Type: Application
    Filed: July 12, 2009
    Publication date: October 28, 2010
    Inventors: Yung-Szu Tu, Jiunn-Tsair Chen, Yen-Chin Liao, Cheng-Hsuan Wu
  • Publication number: 20100272167
    Abstract: The present invention provides a method for simplifying a probabilistic rate adaptation procedure in a wireless communication system, which comprises calculating a conditional probability density function of SNR of a transmitted signal by the probabilistic rate adaptation procedure, to generate an SNR estimation result, taking logarithm on the SNR estimation result to generate a logarithm result, and partitioning SNR values into a plurality of regions according to the logarithm result, to generate a discrete function from the SNR estimation result.
    Type: Application
    Filed: April 28, 2009
    Publication date: October 28, 2010
    Inventors: Yen-Chin Liao, Yung-Szu Tu, Cheng-Hsuan Wu, Jiunn-Tsair Chen
  • Publication number: 20100265929
    Abstract: A method for determining a modulation and coding scheme for signals with packets of different lengths comprises the steps of: grouping signals according to their packet lengths, wherein each group has a weighting for each modulation and coding scheme; transmitting signals with different modulation and coding schemes; adjusting weights of each modulation and coding scheme of each group according to the quality of receiving the transmitted signals; determining a modulation and coding scheme according to the weightings of each modulation and coding scheme in the group corresponding to the packet length of the signal to be transmitted.
    Type: Application
    Filed: September 30, 2009
    Publication date: October 21, 2010
    Applicant: RALINK TECHNOLOGY CORPORATION
    Inventors: YEN CHIN LIAO, YUNG SZU TU, CHENG HSUAN WU, JIUNN TSAIR CHEN
  • Publication number: 20100260249
    Abstract: A method of examining the eligibility of a modulation and coding scheme includes determining a range of pseudo signal-to-noise ratio (pseudo-SNR) corresponding to a range of packet correct rate (PCR) acceptable for a transmitter, obtaining a first score of a positive acknowledgement (ACK) and a second score of a negative acknowledgement (NACK) according to the range of pseudo-SNR and the range of PCR, applying weighting to a score of a response message, which is one of an ACK message and a NACK message, and a pseudo-SNR corresponding to an immediately preceding response message when receiving the response message, for generating a pseudo-SNR corresponding to the response message, and examining the eligibility of a modulation and coding scheme in use according to the pseudo-SNR corresponding to the response message.
    Type: Application
    Filed: September 8, 2009
    Publication date: October 14, 2010
    Inventors: Yung-Szu Tu, Jiunn-Tsair Chen, Chun-Hsien Wen, Cheng-Hsuan Wu
  • Publication number: 20100254479
    Abstract: A method for determining a modulation and coding scheme comprises the steps of: transmitting signals with different modulation and coding schemes and adjusting weighting of each modulation and coding scheme based on the quality of transmitted signals on a receiving end; adjusting the weighting of each modulation and coding scheme based on suggested modulation and coding schemes; determining a modulation and coding scheme to use according to the weighting of each modulation and coding scheme.
    Type: Application
    Filed: September 3, 2009
    Publication date: October 7, 2010
    Applicant: RALINK TECHNOLOGY CORPORATION
    Inventors: YEN CHIN LIAO, YUNG SZU TU, CHENG HSUAN WU, JIUNN TSAIR CHEN
  • Publication number: 20100254322
    Abstract: A method for adjusting a modulation and coding scheme based on signal quality comprises the steps of: determining a reference modulation and coding scheme based on signal reception qualities of transmitted signals according to a plurality of modulation and coding schemes; determining a temporary modulation and coding scheme according to a modulation and coding scheme selection method; determining a final modulation and coding scheme according to a first table and the differences between the reference modulation and coding scheme and the temporary modulation and coding scheme.
    Type: Application
    Filed: August 31, 2009
    Publication date: October 7, 2010
    Applicant: RALINK TECHNOLOGY CORPORATION
    Inventors: YEN CHIN LIAO, CHUN HSIEN WEN, CHENG HSUAN WU, JIUNN TSAIR CHEN
  • Publication number: 20100190457
    Abstract: An approximation method for SNR soft information for a transmitter of a communications system includes obtaining a conditional probability density function (PDF) corresponding to a response message of a transmitted packet, obtaining a PDF of a probability distribution model, and a mean and a variance of the PDF, by approximating the conditional PDF corresponding to the response message with the probability distribution model, and calculating a second mean and a second variance of a second PDF approximated to a conditional PDF of SNR corresponding to the transmitted packet according to the mean and the variance of the PDF, and a first mean and a first variance of a first PDF approximated to a conditional PDF of SNR corresponding to another transmitted packet immediately preceding the transmitted packet.
    Type: Application
    Filed: June 7, 2009
    Publication date: July 29, 2010
    Inventors: Yung-Szu Tu, Jiunn-Tsair Chen, Chun-Hsien Wen, Cheng-Hsuan Wu, Chien-Cheng Lin
  • Publication number: 20100182198
    Abstract: The method for beamforming in a wireless communication system comprises the steps of: receiving a sounding packet so as to estimate channel state information between a transmitter and a receiver; generating a beamforming matrix in accordance with the channel state information; generating a beamforming steering matrix by multiplying the beamforming matrix by a rotation matrix; and feeding back the beamforming steering matrix.
    Type: Application
    Filed: July 8, 2009
    Publication date: July 22, 2010
    Applicant: RALINK TECHNOLOTY CORPORATION
    Inventors: Chun Hsien Wen, Jiunn Tsair Chen, Cheng Hsuan Wu, Yen Chin Liao
  • Publication number: 20100179975
    Abstract: A method for decomposing a barrel shifter decomposes N, the number of digits of input word, into N1 to Nm, and utilizes m layers of shifter circuit layer, which are composed of a plurality of barrel shifters, such that each barrel shifter performs a shifting procedure to obtain the desired output word.
    Type: Application
    Filed: July 8, 2009
    Publication date: July 15, 2010
    Applicant: RALINK TECHNOLOGY CORPORATION
    Inventors: Yen Chin Liao, Chun Hsien Wen, Cheng Hsuan Wu, Jiunn Tsair Chen
  • Publication number: 20090254797
    Abstract: Considering both performance and cost of an iterative receiver, the present invention provides an iterative signal receiving method for a wireless communications system. The iterative signal receiving method includes utilizing a channel estimating (CE) process to perform channel estimation for a received signal according to first log-likelihood ratio (LLR) data to generate second LLR data, and then generating the first LLR data according to an error correction code (ECC) decoding process and the second LLR data. When the ECC decoding process is a convolutional decoding process, the CE process is a zero-forcing process, a minimum mean square error (MMSE) process or an interpolation-based process. When the ECC decoding process is a low density parity check code (LDPC) decoding process, the CE process is a maximum likelihood (ML) process or a maximum a posteriori (MAP) process.
    Type: Application
    Filed: February 9, 2009
    Publication date: October 8, 2009
    Inventors: Cheng-Hsuan Wu, Yao-Nan Lee, Jiunn-Tsair Chen
  • Publication number: 20090245400
    Abstract: A method that selects an error-correction code for use in a multiple-input multiple output (MIMO) wireless communication system is disclosed that optimizes the performance of the MIMO wireless communication system. The method selects the error-correction code according to at least one system parameter and at least one channel parameter of the MIMO wireless communication system, such that the selected error-correction code matches the hardware configuration and channel setting of the MIMO wireless communication system.
    Type: Application
    Filed: January 29, 2009
    Publication date: October 1, 2009
    Applicant: RALINK TECHNOLOGY CORPORATION
    Inventors: Jiunn-Tsair Chen, Cheng-Hsuan Wu, Yai-Nan Lee
  • Publication number: 20090232068
    Abstract: The present invention provides a method for dynamic channel assignment for a wireless communication system. First, a respective channel allocation probability vector at each mobile terminal is randomly generated, and is then sent to the base stations covering the mobile terminal. Subsequently, the channel allocation probability vectors are integrated into channel allocation information for the mobile terminals covered by the base station. Afterwards, based on the channel allocation information, a corresponding channel allocation notice is sent to the mobile terminals covered by the base station, respectively. Finally, according to the channel allocation notice, the channels of the base station are assigned for the mobile terminals covered by the base station.
    Type: Application
    Filed: January 22, 2009
    Publication date: September 17, 2009
    Inventors: Cheng-Hsuan WU, Jiunn-Tsair Chen
  • Publication number: 20080117050
    Abstract: A wireless radio frequency identification (RFID) system is provided. The wireless RFID system includes at least one passive RFID tag, at least one active RFID tag and at least one sink apparatus. The active RFID tag transmits a wireless query signal to detect whether the passive RFID tag and /or other active RFID tags are in its scanning range according to a transmission specification. Moreover, the active RFID tag collects the detecting result into an inventory data, converts itself to one passive RFID tag, and transmits the inventory data to other active RFID tags utilizing the same method. Then, an identification data in the passive RFID tag and /or the inventory data in the active RFID tag are read by the sink apparatus according to the above-mentioned transmission specification. Therefore, the wireless RFID only uses a signal transmission specification to route the data back to the sink apparatus.
    Type: Application
    Filed: May 25, 2007
    Publication date: May 22, 2008
    Applicant: INDUSTRIAL TECHNOLOGY RESEARCH INSTITUTE
    Inventors: Cheng-Hsuan Wu, Jiunn-Tsair Chen, Shu-Hsien Wang, Jian-Ren Chen
  • Publication number: 20080019345
    Abstract: Disclosed is a method and apparatus for dynamic channel assignment (DCA) in a wireless network, which describes the complex channel assignment problem with a decoding problem. The invention describes the decoding problem with a normal graph and specifies all the local rules enforced by all the nodes at access point sides and subscriber sides. Then, the invention carries out the sum-product algorithm to solve the DCA. It is not only a fully-distributed low-complexity DCA technology, but also significantly increases the network throughput. The invention further adopts the concept of subscriber exclusive region to guarantee the link quality between a subscriber and an access point.
    Type: Application
    Filed: August 19, 2006
    Publication date: January 24, 2008
    Inventors: Cheng-Hsuan Wu, Jiunn-Tsair Chen