Patents Assigned to Her Majesty the Queen in Right of Canada as represented by
the Minister of Industry through Communications Research
Centre
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Patent number: 7418144Abstract: A curved wavelet transform and a related image/video compression system are disclosed. The curved wavelet transform (CWT) is carried out by applying one-dimensional (1-D) wavelet filters along curves, rather than along only horizontal and vertical directions. The image/video compression system includes a curve determination unit, a curved wavelet transform unit, a wavelet coefficient quantization unit, a wavelet coefficient coding unit, and a curve coding unit. The quantization and coding of the wavelet coefficients are related to the curves. In one embodiment, recursive wavelet filters are used for inverse wavelet decomposition. The system provides higher compression capability than conventional wavelet-based image compression systems.Type: GrantFiled: March 1, 2005Date of Patent: August 26, 2008Assignee: Her Majesty the Queen in right of Canada, as represented by the Minister of Industry, Through the Communications Research Centre CanadaInventors: Demin Wang, Liang Zhang, Andre Vincent
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Patent number: 7382952Abstract: The invention relates to an optical fiber polarizer comprising an optical fiber with at least a core, a cladding and surrounding medium (or outer cladding) where one or more sections of the optical fiber include periodic/aperiodic (chirped, quasi-periodic) modulation of the dielectric properties of the fiber in the direction of propagation of the light (the longitudinal axis of the fiber). The modulation of the dielectric properties of the fiber is such that it introduces periodic/aperiodic birefringence along the direction of propagation of the light, such a modulation usually but not necessarily being confined to the vicinity of the core region of the fiber. Means are included to attenuate preferentially some of the modes of propagation of the fiber, specifically modes of one principal state of polarization and not the orthogonal state of polarization.Type: GrantFiled: September 26, 2005Date of Patent: June 3, 2008Assignee: Her Majesty the Queen in Right of Canada as represented by the Minister of Industry, Through the Communications Research Centre CanadaInventor: Kenneth O. Hill
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Patent number: 7379643Abstract: A retro-reflective sensor for sensing mechanical, chemical or temperature related information, is disclosed. The sensor is formed of an optical waveguide suitable for use in-situ in a high temperature environment having a Bragg grating written into a core region thereof with short-pulsed electromagnetic radiation, said optical waveguide having a glass transition temperature substantially higher than that of silica. Preferably the sensor is written into a length of sapphire fiber or within a zirconium waveguide. Preferably the pulse duration of the short pulsed electromagnetic radiation is less than 500 picoseconds.Type: GrantFiled: October 5, 2005Date of Patent: May 27, 2008Assignee: Her Majesty the Queen in Right of Canada as represented by the Minister of Industry, through the Communications Research Centre CanadaInventors: Stephen J. Mihailov, Dan Grobnic, Christopher Smelser, Robert Walker, Ping Lu, Huimin Ding, George Henderson, Xiaoli Dai
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Patent number: 7340375Abstract: A method and device are provided for an improved system and method of estimating the noise floor of a wideband signal without full knowledge of the nature of the narrowband signals contained therein, and provides digital characteristics to allow real-time signal processing with low levels of computational complexity. The method and device require very little a priori knowledge of the nature of the signals, allow both robust performance in non-ideal environments, and automated maximum sensitivity threshold setting.Type: GrantFiled: February 15, 2000Date of Patent: March 4, 2008Assignee: Her Majesty the Queen in right of Canada, as represented by the Minister of Industry Through the Communications Research CentreInventors: Francois Patenaud, Martial Dufour
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Patent number: 7307666Abstract: The invention relates to a transmitter identification system, which utilizes an identification signal embedded into a digital television signal, enabling the transmitter of origin to be identified at a receiving station. Ideally the identification signal is an orthogonal pseudo-random sequence time synchronized to the signal frame structure of the digital television signal. Particularly designed for single frequency networks, identification of the various transmitted signals enables the network to be tuned to eliminate or minimize multi-path effects at certain locations, which receive transmissions from various transmitters.Type: GrantFiled: November 12, 2004Date of Patent: December 11, 2007Assignee: Her Majesty the Queen in Right of Canada as represented by the Minister of Industry through the Communications Research Centre CanadaInventors: Yiyan Wu, Xianbin Wang, Sebastien Lafleche, Benoit Ledoux, Bernard Caron
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Patent number: 7245795Abstract: The invention relates to an optical waveguide device for monitoring a characteristics of light, e.g. a wavelength. The device incorporates a waveguide, such as an optical fiber, with an embedded tilted Bragg grating operating in a regime of wavelength detuning. The grating is designed to disperse light azimuthally in two or more different directions about the fiber axis, said directions changing with wavelength. A photodetector array is provided for detecting the azimuthal distribution of light. A processor coupled to the photodetector array determines wavelength information from the detected azimuthal distribution of the out-coupled light.Type: GrantFiled: November 15, 2005Date of Patent: July 17, 2007Assignee: Her Majesty the Queen in Right of Canada as represented by the Minister of Industry, through the Communications Research Centre CanadaInventors: Robert Walker, Stephen J. Mihailov, Ping Lu, Dan Grobnic, Xiaoli Dai, Huimin Ding, George Henderson, Christopher Smelser
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Patent number: 7190244Abstract: A capacitively loaded multilevel transmission line network for operation at a microwave frequency f is disclosed wherein microstrip conductors are disposed over or under a uniplanar transmission line (UTL), electrically connected thereto at or near opposing ends of the UTL and coupled to portions of the UTL separated therefrom by a thin dielectric film. The microstrip conductors and the portions of the UTL coupled thereto form thin-film microstrip (TFMS) shunt stubs capacitively loading the ends of the UTL for increasing its electrical length. The present invention enables considerable size reduction of microwave circuits having uniplanar transmission lines.Type: GrantFiled: November 18, 2004Date of Patent: March 13, 2007Assignee: Her Majesty the Queen in Right of Canada as represented by the Minister of Industry, through the Communications Research Centre CanadaInventor: Khelifa Hettak
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Patent number: 7187818Abstract: A planar lightwave circuit device includes one or more planar lightwave circuits (PLCs) each having an optical layer deposited on a substrate, and a package base including one or more support structures for suspending the planar lightwave circuit above a portion of the package base. Each substrate has a first coefficient of thermal expansion, whereas the package base has a second coefficient of thermal expansion. The first and second coefficients of thermal expansion differ such that a change in temperature causes the support to apply one of a compressive and a tensile force to the planar lightwave circuit in a plane within or parallel to the plane of the planar lightwave circuit. The induced stress can modify the optical performance of the PLC device, e.g. to reduce the temperature sensitivity of the device and thus maintain device performance, or for providing efficient passive or dynamic tuning of the device.Type: GrantFiled: January 14, 2005Date of Patent: March 6, 2007Assignee: Her Majesty the Queen in right of Canada, as represented by the Minister of Industry, through the Communications Research Centre CanadaInventors: Amelia Georgeta Grobnic, Robert James
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Patent number: 7031571Abstract: A novel Bragg grating filter in optical waveguiding fiber with suppressed cladding mode coupling and method of producing same is disclosed. The novel grating structure is induced in both the core and the cladding of the optical fiber irrespective of the photosensitivity of the core or cladding to actinic radiation. Such core and cladding of the optical fiber need not be chemically doped to support the grating. The method incorporates an ultra short duration pulse laser source. Electromagnetic radiation provided from the laser propagates to a diffractive element positioned a specific distance to the target material such that the diffracted electromagnetic radiation forms a 2-beam interference pattern, the peaks of which are sufficiently intense to cause a change in index of refraction.Type: GrantFiled: March 19, 2004Date of Patent: April 18, 2006Assignee: Her Majesty the Queen in right of Canada, as represented by the Minister of Industry through the Communications Research Centre CanadaInventors: Stephen J. Mihailov, Dan Grobnic, Christopher Smelser, Robert Walker, Ping Lu, Huimin Ding, George Henderson, Xiaoli Dai
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Patent number: 6987591Abstract: A volume hologram for modifying a characteristic of an input microwave beam and a method for manufacturing thereof are disclosed. The hologram is fabricated from a multi-layer artificial dielectric wherein each layer is made of a dielectric material and includes a lattice of inclusions, for example metal disks disposed on one side thereof, and wherein a pre-determined three-dimensional grating pattern of dielectric perturbations is induced by spatial modulating the lattice of the inclusions. The hologram can be designed for efficiently steering, reshaping, combining or splitting microwave beams.Type: GrantFiled: July 16, 2004Date of Patent: January 17, 2006Assignee: Her Majesty the Queen in right of Canada, as represented by the Minister of Industry through the Communications Research Centre CanadaInventors: Jafar Shaker, Michel Cuhaci, Apisak Ittipiboon
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Patent number: 6944803Abstract: A class of codes and associated methods and devices are provided. Advantageously, such codes when used as constituent codes in composite codes intended for iterative decoding, as compared to the standard practice of using convolutional codes, may allow better error-correcting performance to be achieved, especially at low error rates and high code rates, for a given decoder complexity. State sequencing in these codes is driven not by source data alone, as is the case with convolutional codes, but rather by a sequence that includes both the source data and so-called “inserted” data elements, the inserted data elements having a linear dependence on the state sequencing state. In decoding, state transition intervals involving one or more inserted data elements are handled in a special way.Type: GrantFiled: July 6, 2001Date of Patent: September 13, 2005Assignee: Her Majesty the Queen in right of Canada, as represented by the Minister of Industry through the Communications Research Centre CanadaInventor: Andrew William Hunt
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Patent number: 6940463Abstract: An ultra-wideband antenna for operating in a frequency is disclosed wherein a monopole antenna extends from a ground plane. The monopole has an effective length L of one quarter wavelength at the lowest frequency f1. A dielectric resonator antenna (DRA) surrounds the monopole antenna for resonating at substantially between or at two and three times the lowest frequency f1, the DRA is of a height of less than ¾ L and is disposed in such a manner as being above the ground plane and either contacting or spaced therefrom by a gap G, wherein 0?G?0.2 H. The ultra-wideband antenna is of a much greater bandwidth than the sum of bandwidth of the monople or the DRA alone.Type: GrantFiled: July 24, 2003Date of Patent: September 6, 2005Assignee: Her Majesty the Queen in Right of Canada, as represented by the Minister of Industry, through the Communications Research Centre CanadaInventors: Apisak Ittipiboon, Aldo Petosa, Soulideth Thirakoune, David Lee, Marc Lapierre, Yahia Autar
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Patent number: 6911950Abstract: The invention relates to a steerable antenna platform including two independently controllable motors for rotating a flat plate or a parabolic dish antenna about two perpendicular axes. The antenna platform includes a semicircular yoke rotatable about a fixed axes with bearings mounted on either end thereof for pivotally supporting the antenna. The antenna platform also includes a ball joint for supporting the center of the antenna, enabling a reduction in the requirements of the two motors.Type: GrantFiled: January 8, 2004Date of Patent: June 28, 2005Assignee: Her Majesty the Queen in right of Canada, as represented by the Minister of Industry, through the Communications of Research CentreInventor: Brian A. Harron
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Patent number: 6728927Abstract: A system and method are provided for designing high-spread, high-distance interleavers for turbo-codes. The first approach is called high-spread random interleaving, and is based on a new and more effective definition of interleaver spread. The second approach is called dithered-diagonal interleaving. Both methods can be used to design interleaves of arbitrary length. The second approach can actually achieve the theoretical maximum spread for many specific block sizes, and at the same time include significant dither for the elimination of low-weight codewords. Both design methods are easy to implement and require very little processing. Also provided is a method for modifying any interleaver to improve the distance spectrum for a specific turbo-code. It is shown that, for a block size of only 512 data bits and for a code rate of ⅓, the flares in the packet error rate (PER) and bit error rate (BER) curves can be kept below 10−8 and 10−10, respectively.Type: GrantFiled: May 25, 2001Date of Patent: April 27, 2004Assignee: Her Majesty the Queen in Right of Canada, as represented by the Minister of Industry through the Communications Research CentreInventor: Stewart N. Crozier
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Patent number: 6718508Abstract: A method for generating new forward error correction codes, called skew codes, for the reliable transmission of data in noisy channels is disclosed. The method involves adding additional sets of parity equations across the third dimension of a cubic array of bits. The parity equations are applied to the cubic array such that the rectangular patterns of one square array do not match up with a rectangular pattern in another square array. By selecting skew mapping parameters of the parity equations from a set of quadratic residues of prime numbers according to specific design rules, the resulting codes are well suited to low-complexity high-speed iterative decoding, and have error correction performance and error detection capability, particularly for applications requiring high code rates.Type: GrantFiled: May 25, 2001Date of Patent: April 6, 2004Assignee: Her Majesty the Queen in right of Canada, as represented by the Minister of Industry through the Communication Research CentreInventors: John Lodge, Andrew Hunt, Paul Guinand
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Patent number: 6693983Abstract: Digital signals transmitted on an RF carrier modulated in phase and amplitude and subject to noise constitute separate bursts each comprising information symbols of data and a pair of separated unique words. The signals are subjected to processing which involves reception of the signals and an initial conversion to approximate baseband and then analog to digital sampling. Quadrature and in phase samples are then stored in a buffer. The buffered samples are subjected to coarse timing, coarse frequency synchronization, a first phase correction, fine timing, further phase and amplitude correction and finally to fine frequency correction and subsequent reliability estimation.Type: GrantFiled: October 5, 1999Date of Patent: February 17, 2004Assignee: Her Majesty the Queen in right of Canada, as represented by the Minister of Industry through the Communication Research CentreInventors: Michael L. Moher, Stewart N. Crozier, Paul Guinand
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Patent number: 6678323Abstract: This invention relates to reducing bandwidth requirements for stereoscopic imagery and video signals. The invention comprises a method of producing two streams of images or signals for producing images, separately for the left eye and for the right eye. One image of each stereoscopic pair in the streams is of reduced quality relative to the other. On occurrence of a significant change in image content, or similar occurrence, the image quality of the two streams are switched or transposed, whereby the higher quality image is seen alternately by one eye and then the other. Intervals between switching are indeterminate, and such switching is continued for the duration of the streams of images or video signals.Type: GrantFiled: January 24, 2001Date of Patent: January 13, 2004Assignee: Her Majesty the Queen in right of Canada, as represented by the Minister of Industry through Communications Research CentreInventors: Wa James Tam, Lew Bohdan Stelmach
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Patent number: 6625333Abstract: A method for temporal interpolation of an image sequence using object-based image analysis is disclosed. The method comprises the steps of image segmentation for partitioning a known image into objects, motion estimation, object-based motion field processing, determination of object depth order, detection of covered areas and newly exposed areas, adaptive interpolation using motion projection, and graceful degradation for alleviating remaining visible artifacts. The method produces interpolated images of high quality in real time for every type of image areas including fast moving objects, covered areas, and newly exposed areas.Type: GrantFiled: August 6, 1999Date of Patent: September 23, 2003Assignee: Her Majesty the Queen in Right of Canada as represented by the Minister of Industry through Communications Research CentreInventors: Demin Wang, André Vincent
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Patent number: 6530059Abstract: A method of creating tail-biting recursive systematic convolutional and turbo codes, and the associated encoders, are described herein. According to the method, symbols from the set of data to be transmitted are used to preset the starting state of the encoder, and are replaced in a systematic set by an equivalent number of tail-biting symbols that force the ending state of the encoder to be the same as the starting state. The presetting of the starting state allows for simpler calculations in choosing the tail-biting symbols, and allows a message to be transmitted with a reduced number of symbols The reduction in the number of symbols used for overhead in this invention provides an increase in the data transmission rate.Type: GrantFiled: June 1, 1999Date of Patent: March 4, 2003Assignee: Her Majesty the Queen in right of Canada, as represented by the Minister of Industry Through the Communication Research CentreInventors: Stewart N. Crozier, Andrew Hunt, John Lodge, Paul Guinand
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Patent number: 6510536Abstract: Methods of reduced-complexity max-log-APP processing are disclosed for use with Turbo and Turbo-like decoders. The invented methods of decoding are derived from max-log-APP processing and significantly lower the processing required for decoding convolutional codes by eliminating a portion of the calculations conventionally associated with max-log-APP processing. The disclosed embodiments provide simplified methods of metric combining based on determining the bits of an MLSE sequence with different alternative approaches. Also disclosed is an early stopping method that uses the reduced-complexity max-log-APP decoder to reduce the average number of decoding operations required by an iterative Turbo decoder.Type: GrantFiled: June 1, 1999Date of Patent: January 21, 2003Assignee: Her Majesty the Queen in right of Canada, as represented by the Minister of Industry through the Communications Research CentreInventors: Stewart N. Crozier, Ken Gracie, Andrew Hunt, John Lodge, Paul Guinand