Patents by Inventor Ray Liu

Ray Liu 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: 20140185596
    Abstract: There is provided a communication system including a transmitting section and a receiving section which includes a plurality of receivers. The transmitting section includes a communication unit which receives a plurality of signals respectively from the plurality of receivers, and stores a plurality of time-reversed signals corresponding to the received plurality of signals with respect to the plurality of receivers, and a first conversion unit which converts, by a first factor, a plurality of information sequences to be respectively transmitted to the plurality of receivers and forward the plurality of converted information sequences to the communication unit. The communication unit generates, based on the plurality of converted information sequences, a plurality of output signals to be respectively transmitted to the plurality of receivers, each of the plurality of the output signals including a location-specific signature unique to the corresponding receiver.
    Type: Application
    Filed: December 3, 2013
    Publication date: July 3, 2014
    Applicant: University Of Maryland At College Park
    Inventors: Feng HAN, Yu-Han YANG, Beibei WANG, Yongle WU, K.J. Ray LIU
  • Patent number: 7848443
    Abstract: Pilot data and data-bearer data are formed to be mutually orthogonal and in each other's null-space. Data to be transmitted is first modulated with the data-bearer matrix and then pilot data is added thereto. The pilot data may be added to each modulated symbol, thereby increasing significantly the density of pilot information available at the receiver for channel state estimation. When pilot data is added across an entire transmitted block of data, data detection performance is improved for even fast fading Rayleigh fading channels.
    Type: Grant
    Filed: June 21, 2006
    Date of Patent: December 7, 2010
    Assignee: University of Maryland
    Inventors: Chaiyod Pirak, Z. Jane Wang, K. J. Ray Liu
  • Patent number: 7720168
    Abstract: Maximum diversity in multiple antenna distributed frequency broadband systems such as MIMO-OFDM is achievable through space-frequency (SF) and space-time-frequency (STF) coding. Full-rate full-diversity coding is achieved through a combination of maximal minimum product distance symbol set design and formation of codeword blocks. Full-diversity codes are also achieved which have reduced symbol transmission rates, such as through mapping of space-time (ST) codes to SF codes. The reduction in symbol rate may be offset by the fact that any ST code may be mapped to a full-diversity SF code.
    Type: Grant
    Filed: May 26, 2005
    Date of Patent: May 18, 2010
    Assignee: University of Maryland
    Inventors: Weifeng Su, K. J. Ray Liu, Zoltan Safar
  • Patent number: 7653122
    Abstract: A power controlled sub-band assignment and power allocation among users in a multiband UWB system aims to reduce power consumption without compromising performance. The overall transmit power is minimized under the practical constraints, including packet error rate, transmission rate, and FCC regulations. To insure the system feasibility in variable channel conditions, an optimization scheme manages the assignment of UWB devices to respective channels subject to their suitability to the requested users' transmission rates. An inexpensive suboptimal approach reduces the complexity of the optimization procedure and achieves a comparable performance to those of the complex full search optimization routine. The suboptimal scheme obtains the feasible solutions adaptively when the channels assignment, initially calculated under the optimization criteria, is not feasible for the user's rate requirement.
    Type: Grant
    Filed: May 31, 2006
    Date of Patent: January 26, 2010
    Assignee: University of Maryland
    Inventors: Wipawee Siriwongpairat, Zhu Han, K. J. Ray Liu
  • Publication number: 20080178207
    Abstract: The invention discloses an optical disc comprising a substrate, a multi-layer structure, and a plurality of ribs. The substrate has a first surface and a second surface set opposite to the first surface. The multi-layer structure is formed on the first surface of the substrate and comprises at least one recording layer. The ribs are formed on the second surface of the substrate. The ribs are used for increasing the rigidity of the optical disc, such that a runout of the optical disc can be suppressed while the optical disc is rotated.
    Type: Application
    Filed: September 4, 2007
    Publication date: July 24, 2008
    Inventors: JIA-RAY LIU, Fung-Hsu Wu
  • Publication number: 20080063828
    Abstract: The invention provides an optical disc with its substrate formed of a biodegradable material mixed with a plurality of microcapsules encapsulating an additive and/or mixed with the additive. Therefore, the substrate of the optical disc, according to the invention, is biodegradable, with a long life expectancy as desired.
    Type: Application
    Filed: June 4, 2007
    Publication date: March 13, 2008
    Inventors: Chen Peng, Fung-Hsu Wu, Jia-Ray Liu
  • Publication number: 20070156450
    Abstract: The present invention is a system and method of remotely monitoring patient health care characteristics. The system utilizes at least two micro-scale to millimeter-scale sensors, a wireless network, a central hub and pre-processing center and a means for notifying a clinician of the remote patient's condition. The system and method includes sensor to sensor coordination, modular-based sensors and processing, and allows a clinician to remotely configure the system.
    Type: Application
    Filed: January 4, 2006
    Publication date: July 5, 2007
    Inventors: Steven Roehm, Ray Liu, Gopal Avinash, Bruce Friedman
  • Publication number: 20070156626
    Abstract: The present invention is a system and method of remote patient monitoring to allow a patient to initiate and activate sensing systems. In the system and method, standard parameters can be sensed, and the information can then be processed and sent to the physician or clinician. The clinician then has the ability to remotely configure or reconfigure the parameters of the sensing system so as to probe for more targeted information based on the initial sensed data.
    Type: Application
    Filed: January 4, 2006
    Publication date: July 5, 2007
    Inventors: Steven Roehm, Ray Liu, Gopal Avinash
  • Publication number: 20070118399
    Abstract: An informatics system permits data entities from a wide range of data sources to be accessed and evaluated. The sources of the data entities may be simply data sources, such as for articles and other non-patient or population specific information, as well as controllable and prescribable sources, such diagnostic imaging, clinical and other sources forming part of the patient care path. The entities are organized, analyzed in accordance with a domain framework, which may be altered by a user to focus on factors and informational components of interest. Holistic and integrated understanding of such factors are there fore available, and refinement of healthcare processes can be made to provide improved care in a more time and cost effective manner.
    Type: Application
    Filed: November 22, 2005
    Publication date: May 24, 2007
    Inventors: Gopal Avinash, Ray Liu, Steven Roehm
  • Patent number: 6377812
    Abstract: In a mobile cellular communications system power control and space-time diversity are applied in combination to the uplink and downlink. In the uplink, mobile powers and equalization/diversity combining vectors at base stations are, calculated jointly, with the result that the mobile transmitted power is minimized, while the Signal to Noise Ratio (SNR) at each link is maintained above a threshold. In the downlink, a multitap transmit diversity strategy adjusts the transmit weight vectors with the result that the SNR at each mobile is set to a specified value. The combination of power control and space-time diversity apply to networks with fading channels, including networks in which the number of cochannels and multipaths are larger than the number of antenna elements. The invention achieves the optimal solution for the uplink that minimizes the mobile power, and achieves a feasible solution for the downlink if there exists any.
    Type: Grant
    Filed: November 20, 1998
    Date of Patent: April 23, 2002
    Assignee: University of Maryland
    Inventors: Farrokh Rashid-Farrokhi, K. J. Ray Liu, Leandros Tassiulas
  • Patent number: 5991464
    Abstract: A system (1) for enhancing the resolution of a video image by a predetermined enhancement factor is provided. System (1) generally includes an interpolation subsystem (10), a data storage module (20), and a pixel insert positioning module (30). Included within interpolation subsystem (10) are a classification module (100), a bilinear interpolation module (200), and an adaptive interpolation module (300). Classification module (100) receives the original image pixels in a specified field of the given video image and designates for each original image pixels it receives one of a plurality of predefined classifications. Based upon this classification, one of the bilinear interpolation (200) and adaptive interpolation (300) modules is selected for actuation in generating the supplementary image pixels necessary to support resolution enhancement.
    Type: Grant
    Filed: April 3, 1998
    Date of Patent: November 23, 1999
    Assignee: Odyssey Technologies
    Inventors: Pohsiang Hsu, Kuo Juey Ray Liu
  • Patent number: 5953388
    Abstract: An algorithm is created and applied to reconstruct the wavelet coefficients of an image from the Radon transform data for use in computed tomography, with a disclosed method that uses the properties of wavelets to localize the Radon transform such that a local region of the cross section of a body can be reconstructed using almost completely local data to significantly reduce the amount of exposure and computations in X-ray tomography. The described algorithm is based on the observation that for some wavelet bases with sufficiently many vanishing moments, the ramp-filtered version of the scaling function as well as the wavelet function has extremely rapid decay, with the variance of the elements of the nullspace is being negligible in the locally reconstructed image.
    Type: Grant
    Filed: August 18, 1997
    Date of Patent: September 14, 1999
    Assignee: George Mason University
    Inventors: David Francis Walnut, Carlos Alberto Berenstein, K. J. Ray Liu, Farrokh Rashid-Farrokhi
  • Patent number: 5790686
    Abstract: A method for estimating the translational motion of an object is provided that first computes a plurality of DCT/DST coefficients for two sequential frames. These transform coefficients are then used to compute a pseudo phase function which is then fed into an inverse transform decoder. The output of the decoder is searched for peak values which are then used to determine the displacement of the object.
    Type: Grant
    Filed: September 19, 1995
    Date of Patent: August 4, 1998
    Assignee: University of Maryland at College Park
    Inventors: Ut-Va Koc, K. J. Ray Liu
  • Patent number: 5339265
    Abstract: A universal transform processor using at least a one dimensional (1-D) transform processor to produce N dimensional transforms without transposition and providing a fully pipelined structure with a through put rate of N clock cycles for an N.times.N successive serial input with parallel output data. The universal transform processor can efficiently compute Discrete Cosine, Sine, Hartley, Fourier, Lapped Orthogonal, and Complex Lapped transforms for continuous input data stream. The architecture is regular, modular, and has only local interconnections in both data and control paths. The universal transform processor is practical for very large scale integrated (VLSI) implementation.
    Type: Grant
    Filed: August 31, 1992
    Date of Patent: August 16, 1994
    Assignee: University of Maryland at College Park
    Inventors: K. J. Ray Liu, Chin-Te Chiu