Abstract: A portable terminal having a wireless charger coil and an antenna element on the same plane is provided, in which a shielding member is attached to an inner surface of an external part, a first coil is attached to one surface of the shielding member, facing the inner surface of the external part, and a second coil is attached to the one surface of the shielding member, surrounding the first coil on the same plane.

Abstract: A method and apparatus for measuring a distance in a wireless environment are provided, in which a first device transmits a distance measurement signal to a second device and receives at least one response signal for the distance measurement signal from the second device, matches the received response signal with a reference signal to detect an earliest response signal, and calculates a time taken from the transmission of the distance measurement signal to the second device and the reception of the response signal from the second device using a peak value of the matched reference signal.

Abstract: A wireless power receiver that receives wireless power from a wireless power transmitter and a control method thereof are provided, wherein the wireless power receiver receives the wireless power from the wireless power transmitter; rectifies the wireless power; monitoring a voltage value of the rectified wireless power; determines whether a ripple of the voltage value of the wireless power is greater than or equal to a preset threshold; and if the ripple of the voltage value of the wireless power is greater than or equal to the preset threshold, changes at least one element value of the wireless power receiver to suppress the ripple below the preset threshold.

Abstract: A method and system for sensorless tracking of an indoor target using a wireless distance measuring technology. A location tracking apparatus is initially moved, and then it is determined whether or not an initial traveling direction of the location tracking apparatus is forward or backward with respect to the target. A minimum distance between the location tracking apparatus and the target during the movement is determined, the minimum distance is stored, and the location tracking apparatus is moved to a location corresponding to the minimum distance, where it is determined whether the location tracking apparatus is directed forward or backward with respect to the target at the location corresponding to the minimum distance. The location tracking apparatus is then moved to the target.

Abstract: An indoor location system having a sensor and a method for checking an indoor location using the indoor location system are disclosed. The method includes: calculating a current location coordinate by using nodes; calculating a first movement distance by comparing the current location coordinate and a stored previous location coordinate; calculating a second movement distance through a sensor; and storing the current location coordinate instead of the previous location coordinate when the distance between the first movement distance and the second movement distance is smaller than a predetermined threshold value. Accordingly, an accurate location of an object can be recognized indoors and an error can be prevented from being caused when the location of the object is recognized.

Abstract: A wireless power transmission apparatus and method for wirelessly transmitting power to a wireless power reception apparatus electromagnetically coupled to the wireless power reception apparatus and supplying power for loads of the wireless power reception apparatus is provided. The apparatus includes a power generator for generating power having a fixed oscillation frequency; a power transmission resonator, which has a resonance frequency identical to the oscillation frequency, for wirelessly transmitting the power generated by the power generator to the wireless power reception apparatus; and a power transmission resonance frequency controller for controlling the resonance frequency of the power transmission resonator in response to a change of the resonance frequency of the power transmission resonator.

Abstract: A coil structure and a charging control method in a wireless charger having a primary coil are provided to supply an induced electromotive force suitable for a charging target having a secondary coil. Concentric coils having different radii are arranged in a wireless charger, and a coil suitable for the location of a charging target placed on the wireless charger is selected. An input power corresponding to the selected coil is determined, and the determined power is applied to the selected coil. Then the same charging efficiency can be provided irrespective of a location of a charging target placed on the wireless charger.

Abstract: A wireless charger of an inductive coupling type for charging a portable device provided with a rechargeable built-in battery having a second coil, includes a housing provided with a touch pad on one surface; a first coil retained within the housing; and a driving means for horizontally moving the first coil in a plane parallel to the one surface on which the touch pad is installed, wherein when the portable device is placed on the touch pad, the touch pad senses the position of the portable device to activate the driving means and displaces the first coil to a position facing the second coil.

Abstract: Disclosed is a method and apparatus for efficient wireless charging of a mobile terminal. The method includes detecting the mobile terminal by a charging apparatus, receiving a unique identifier of the mobile terminal from the mobile terminal and determining if the mobile terminal is a rechargeable device, when the mobile terminal is a rechargeable device, applying a direct voltage to a first coil of the charging apparatus and arranging the charging apparatus and the mobile terminal, and terminating an application of the direct voltage and then applying an alternating voltage, to supply charging power required for the mobile terminal.

Abstract: Disclosed is a frequency hopping modulation method in a communication system. The method includes: generating a frequency hopping pattern according to a hopping frequency's level; generating a hopping frequency through use of the frequency hopping pattern; modulating an original signal to a frequency hopping spread signal by multiplying the original signal by the hopping frequency; generating a chirp pulse code for diversifying the frequency hopping spread signal; and modulating the frequency hopping spread signal to a chirp pulse signal by multiplying the frequency hopping spread signal by the chirp pulse code.

Abstract: A method and apparatus for measuring a distance in a wireless environment are provided, in which a first device transmits a distance measurement signal to a second device and receives at least one response signal for the distance measurement signal from the second device, matches the received response signal with a reference signal to detect an earliest response signal, and calculates a time taken from the transmission of the distance measurement signal to the second device and the reception of the response signal from the second device using a peak value of the matched reference signal.

Abstract: Disclosed are a system and a method for an indoor location determination using a matrix pencil. The system comprises a transmitter node that creates and transmits a transmission packet having a plurality of same symbols. A receiver node receives the transmission packet, calculates a delay time by using the symbols in the transmission packet and a matrix pencil algorithm, and calculates a distance between the transmitter node and the receiver node by using the delay time. The delay time estimation using the matrix pencil can reduce an error ratio and therefore can estimate more exactly the distance between the nodes.

Abstract: A method and system for sensorless tracking of an indoor target using a wireless distance measuring technology. A location tracking apparatus is initially moved, and then it is determined whether or not an initial traveling direction of the location tracking apparatus is forward or backward with respect to the target. A minimum distance between the location tracking apparatus and the target during the movement is determined, the minimum distance is stored, and the location tracking apparatus is moved to a location corresponding to the minimum distance, where it is determined whether the location tracking apparatus is directed forward or backward with respect to the target at the location corresponding to the minimum distance. The location tracking apparatus is then moved to the target.

Abstract: An indoor location system having a sensor and a method for checking an indoor location using the indoor location system are disclosed. The method includes: calculating a current location coordinate by using nodes; calculating a first movement distance by comparing the current location coordinate and a stored previous location coordinate; calculating a second movement distance through a sensor; and storing the current location coordinate instead of the previous location coordinate when the distance between the first movement distance and the second movement distance is smaller than a predetermined threshold value. Accordingly, an accurate location of an object can be recognized indoors and an error can be prevented from being caused when the location of the object is recognized.