Abstract:
본 발명은 가시광 통신에서 역반사기(Retroreflector)를 이용한 통신 방향 정렬 방법에 있어서, 제1 통신 장치에서 제2 통신 장치로 통신 방향을 설정하는 과정과, 제1 통신 장치에서 제2 통신 장치로 통신 설정 신호를 출력하는 과정과, 제2 통신 장치의 역반사기에서 통신 설정 신호를 수신하여 역반사하는 과정과, 제2 통신 장치에서 역반사기가 역반사한 방향으로 통신 방향을 설정하는 과정을 포함한다. 가시광 통신, 역반사기(Retroreflector), 통신 정렬
Abstract:
In a wireless communication system according to the present invention, a transmitter determines communication states of first devices which employ a first communication method for a first time section, determines the length of a second time section which will be allocated to the first devices based on the communication states, and transmits information on the second time section having the determined length to the first devices before the second time section starts. The first time section and the second time section are included in a frame allocated for a second communication method different from the first communication method. A frequency used for the first communication method and a frequency used for the second communication method are the same. A signal transmission operation of the second devices employing the second communication method is stopped during the first time section and the second time section.
Abstract:
A method for performing sector sweeping in a wireless communication system according to present invention comprises: determining whether a station (STA) to perform communication is detected by performing, by an access point (AP), first sector sweeping; determining whether an STA location changes by performing second sector sweeping when an STA is detected; and increasing a sector sweeping cycle, and transmitting information on the increased sector sweeping cycle when the STA location does not change.
Abstract:
The present invention relates to a method for improving transmission performance by enabling a user, who is located in a femto-cell boundary in a macro-cell base station, to select a base station for receiving a service by recognizing the environment of oneself and considering the operation information of nearby base stations in a heterogeneous-cell operation environment where femto-cells are operated in the operation area of a macro-cell base station. A method for a terminal to select a serving base station according to the present invention includes the following steps: a step of receiving operation information, which contains at least one among the number of multi-antennas, used frequency bands, and load status for at least one small base station, from a macro-cell base station; and a step of transmitting a message, which requests a handover to a base station having maximum average transmission capacity by using the operation information, to the macro-cell base station. According to the present invention, a user located on a heterogeneous-cell boundary can request neighboring cell operation information, which includes the number of antennas, frequency resource utilization information, and cell loads, from a serving macro-cell base station, and the serving macro-cell base station can obtain operation information of a corresponding neighboring cell through a backhaul network and provide the operation information for the user. As a result, the user can estimate the average transmission capacity of the serving macro-cell base station and neighboring cell based on the received operation information, and select a base station capable of providing a service with highest quality, therefore, the performance of the user located on the heterogeneous-cell boundary can be improved. [Reference numerals] (410) Service;(420) Preamble signal;(425) Detect neighboring cell ID;(430) Request neighboring cell operation information;(440) Exchange information (wired backhaul network);(450) Neighboring cell information;(455) Calculate transmission capacity;(460) Select target cell;(470) Request handover;(AA) Femto-cell
Abstract:
PURPOSE: A method and a device of transmitting a signal from multiple wireless power receivers to a wireless power transmitter supply power in order of urgent needs for wireless charging by reasonably determining predetermined priority. CONSTITUTION: A wireless power transceiving system includes a wireless power transmitter (200) and a wireless power receiver (210). The wireless power transmitter includes a control unit (201), a wireless power transmission unit (202), and a communication unit (203). The communication unit receives power management information including information about the capacity of each wireless power receiver from at least one wireless power receiver. The control unit analyzes the power management information and determines whether or not the output capacity of the wireless power transmitter is greater than the total amount of the capacity of at least one wireless power receiver. The wireless power transmission unit transmits wireless power to at least one wireless power receiver. [Reference numerals] (201,212) Control unit; (202) Wireless power transmission unit; (203,213) Communication unit; (211) Wireless power reception unit
Abstract:
PURPOSE: A device and a method for measuring a position by using a global positioning system and a visible light communication are provided to measure a position in a dead zone by using a visible light communication when the position is measured by using a global positioning system signal even if mobile communications or wireless internet communications are not available. CONSTITUTION: A mobile terminal comprises a GPS receiver (102), a GPS position calculation unit (106), a visible light communication device position calculation unit (116), and a control unit. The GPS receiver receives a GPS signal. The GPS position calculation unit measures a first position by using the GPS signal. A visible light signal transceiver transmits or receives a visible light signal. The visible light communication device position calculation unit calculates a position of a visible light communication device by using visible light communication device position information through the visible light signal transceiver. The position calculation unit calculates a third position by using a position of the visible light communication device and a second position in which is the previous position of the first position when the first position exceeds a predetermined error range. The control unit calculates the third position by activating a visible light communication mode and controlling the position calculation unit as the first position exceeds the predetermined error range. [Reference numerals] (102) GPS receiver; (104) GPS signal processing unit; (106) GPS position calculation unit; (108) First storing unit; (110) Control unit; (112) Visible light transceiver; (114) Visible light signal processing unit; (116) Visible light communication device position calculation unit; (118) Second storing unit; (120) Position calculation unit; (130) Display unit
Abstract:
PURPOSE: A visible light communication method in an information display device including an LED backlight unit and the information display device therefor are provided to operate the information display device as a visible light communication device by using the LED backlight unit in the information display device. CONSTITUTION: A control unit(130) receives an additional information request for a specific object. The control unit searches for a memory for additional information corresponding to the additional information request. A display unit(100) outputs a content image. An LED backlight unit(110) includes a plurality of LEDs placed on a rear surface of the display unit. A backlight driver(120) transmits the additional information by controlling the lighting of an LED block on a position of the specific object under the control of the control unit. [Reference numerals] (100) Display unit; (110) Backlight unit; (120) Backlight driver; (130) Control unit; (140) Communication unit; (150) Visible light receiving unit; (160) Memory; (AA,BB) Additional information; (CC) Image information
Abstract:
PURPOSE: A proxy communication system and its control method in BAN(Body Area Network) environment are provided to perform data transmission between a coordinator and a sensor in BAN environment in a wireless manner. CONSTITUTION: A second control part(852) controls a second communication part(851) to request a link proxy for linking between at least one searched sensor by a coordinator(800) and the coordinator. The second communication part receives the link proxy corresponding to the request. A first control part(820) controls a first communication part to request data by linking at least one searched sensor. A third control part(862) controls a third communication part(861) to transmit the data corresponding to the data request. [Reference numerals] (810,853,863) Storage part; (820,852,862) Control part; (841) First communication module; (842) Second communication module; (843) n-th communication module; (865) Sensor part; (S30,854,864) Display part; (S40,851,861) Communication part
Abstract:
PURPOSE: An apparatus and method for improving brightness in visible light communication using an LED(Light Emitting Diode) are provided to improve a brightness function and have the performance having excellent bit error rate. CONSTITUTION: A channel coding unit(510) generates an input signal of n bits to which K bits generated from a bit adder is added into the codewords of p bits. The codewords of the p bits are generated for the same input signal received from the input unit. A bit selector selects one from the codewords of p bits generated for the same input signal through the channel coding unit. A modulating unit(520) modulates the codewords selected through the bit selector for the data transmission.