Abstract: Embodiments may relate to a method and system for performing a handover from a serving base station to a target base station. A signal for detecting a base station searching signal (BS-SS) may be transmitted from the base station to a user equipment. The target base station may receive a request for the signal for detecting the BS-SS and the signal for detecting the BS-SS may be transmitted from the serving base station to the target base station. The user equipment that had broadcasted the BS-SS to the plurality of base stations is identified, based on the receipt signal of the BS-SS. A handover may be performed from the serving base station to the target base station based on confirmation of the serving base station.

Abstract: Provided are a Neighbor Cell List (NCL) automatic configuration apparatus and method for implementing Self-organizing Network (SON) and a mobile communication system for the same. The NCL automatic configuration apparatus and method collect at least one of neighbor cell information including cell searching information necessary for a handover of a user equipment to a neighbor cell and distance information between a corresponding base station and a neighbor cell. An NCL generator calculates weightings of neighbor base stations, calculates sum of the weightings and configures an NCL with base stations having higher weightings, on the basis of the at least one neighbor cell information.

Abstract: Embodiments for providing a method of controlling timing of a downlink backhaul sub-frame and a relay system for the same are disclosed. According to the present invention, a control signal is transmitted to user equipment during a control symbol period of a sub-frame and a data starting point of the sub-frame is set after a time (SG1) for switching from a transmission mode to a reception mode to receive backhaul data of a base station during a backhaul symbol period. Timing of a transmission sub-frame and a reception sub-frame is delayed by the SG1. A sum of a length of the SG1 and a time (SG2) for switching from the reception mode to the transmission mode is shorter than a length of a symbol having a normal CP. At this time, the lengths of the SG1 and the SG2 are identical to each other or the length of the SG2 is shorter than the length of the SG1. In such a case, the backhaul data are received up to a last symbol period of backhaul symbols of the reception sub-frame.

Abstract: A method for setting transmit power of a small base station by using a signal to interference and noise ratio (SINR) received by the small base station while the small base station is providing service and a mobile telecommunication system using the same. In one embodiment, a mobile telecommunication system includes a network base station configured to variably set a transmit power so that a signal to interference and noise ratio received from a user equipment may fall between an upper limit and a lower limit of a predetermined target signal to interference and noise ratio.

Abstract: A method of recognizing states and locations of user equipment in a network by using a random access (RA) channel at a base station without alteration of the conventional network environment or configurations of user equipment. A mobile communication system of an embodiment includes a first base station; and one or more second base stations having service regions smaller than a service region of the first base station. The first base station is operable to broadcast configuration information to the user equipment for connecting to at least one of the one or more second base stations. The user equipment is operable to transmit an uplink signal to at least one of the one or more second base stations in accordance with the configuration information received from the first base station, and at least one of the one or more second base stations is operable to transmit information on the user equipment that transmitted the uplink signal to the first base station after receiving the uplink signal.

Abstract: The present invention relates to a method for reducing a resource element group (REG) size, which is used at a control channel element (CCE) for a relay physical downlink control channel (R-PDCCH), for the purpose of easy interleaving by a physical resource block (PRB) unit for the R-PDCCH, and a mobile telecommunication system for the same. The mobile telecommunication system of the present invention includes reducing the CCE size to 8 REGs or less of the R-PDCCH to be included in a single PRB.

Abstract: A Wavelength Division Multiplexed Passive Optical Network (WDM-PON) includes a plurality of broadband light sources, each broadband light source being connected to receive a respective data signal and generating a corresponding modulated broadband optical signal. An Array Waveguide Grating (AWG) is connected for receiving each modulated broadband optical signal through a respective branch port and for generating a filtered broadband signal. The AWG implements a filter function comprising a respective pass-band associated with each branch port such that the filtered broadband signal exhibits a respective intensity peak associated with each pass-band. Each intensity peak is modulated with data from a respective one of the broadband light sources. A bandwidth of the respective modulated broadband optical signal generated by each broadband light source is at least equal to the width of a channel-band of the AWG.

Abstract: Embodiments of the present invention may provide an apparatus and a method for transmitting and receiving a random access channel (RACH) in a single carrier-frequency division multiple access (SC-FDMA) system. A frequency domain RACH signal may be mapped to a localized sub-frequency band of an entire frequency band available to the SC-FDMA system. A guard band including at least one sub carrier may be allocated between the RACH signal band and other channel signal bands. A guard time may be allocated between the RACH signal and other channel signals in the time domain. The RACH signal may include a short message including information related to a mobile station. The RACH signal may be detected in a frequency based method, a time based method or a sliding matched filter based method. Receiver complexity can be decreased if the RACH signal includes a CAZAC code sequence for a preamble. In such a case, a receive delay may be simply calculated and then adjusted more accurately.

Abstract: An apparatus and a method for interference cancellation using a multi-user multiple input multiple output (MU-MIMO) scheme in a single carrier frequency division multiple access (SC-FDMA) system are disclosed. Received data of every terminal are classified into first received data and second received data. The first received data has lower reliability and the second received data has higher reliability than the first received data. The second received data is transmitted to an upper layer. Interference signals are formed with the second received data based on a channel estimation value. The interference signals are removed from the first received data, and the interference signal free first received data is transmitted to the upper layer.

Abstract: A method for measuring a self-interference (SI) which occurs in a relay and controlling radio resources of a base station based on the measured SI, and a mobile telecommunication system using the same. The mobile telecommunication system includes a relay which calculates intensity of SI; and a base station which performs radio resource management based on the calculated SI intensity. The method for measuring SI includes calculating intensity of SI using a relay; and performing radio resource management at a base station based on the calculated SI intensity.

Abstract: A colorless optical transceiver and an optical communication system including the same are disclosed herein. A controlling unit of the colorless optical transceiver forms a control current based on intensity of an external-injection light provided from an external light source. A light source driving unit coupled to the controlling unit forms a driving current based on the control current. An internal light source is coupled to the light source driving unit, the internal light source being configured to receive the external-injection light and the driving current and to convert the driving current into a colorless sending light, wherein a wavelength of the colorless sending light is locked by that of the external-injection light. The light output from the internal light source is controlled based on intensity of external-injection light calculated by using optical loss, which varies according to the distances between optical devices and connection state.

Abstract: Techniques for controlling a light source in a wavelength division multiplexed passive optical network (WDM-PON) are disclosed. In one particular exemplary embodiment, the techniques may be realized as an apparatus for controlling a light source in a wavelength division multiplexed passive optical network (WDM-PON). The apparatus may include a digital signal processing device configured to output a pilot tone signal. The apparatus may also include an amplifier configured to modulate a modulation current and the pilot tone signal, and output an amplitude modulated signal. The apparatus may further include a capacitor configured to AC couple the amplitude modulated signal to a bias current applied to a light source; and a monitoring photodiode configured to detect an output optical signal of the light source and transmit the detected output optical signal to the digital signal processing device to control the output optical signal of the light source.

Abstract: A system for generating an optical CATV comb comprising a plurality of wavelength division multiplexed (WDM) optical CATV signals. A set of one or more lasers generate a plurality of narrow-band continuous wave (CW) lights, each CW light having a respective predetermined wavelength and optical power level. An optical MUX couples the plurality of CW lights into a WDM continuous wave light. A broadband optical modulator responsive to a CATV signal modulates the WDM continuous wave light to generate the optical CATV comb.

Abstract: A method of providing locations services of a mobile station in a worldwide interoperability for microwave access (WiMAX) network including an access service network (ASN) is provided. For executing a paging and location update (PLU), a serving base station transmits a scanning interval allocation response message (MOB-SCN-RSP) defined in the WiMAX wireless standard to a target mobile station, which transmits a scanning result report message (MOB-SCN-REP) defined in the standard to the serving base station in response to the MOB-SCN-RSP. The serving base station generates a location measurement result based on the MOB-SCN-REP and transmits to the ASN gateway. The ASN gateway forms a location response based on the location measurement result and transmits the location response to an LCS server. The LCS server creates a location service response of the target mobile station based on the location response and transmits the location service response to the LCS client.

Abstract: An apparatus, a method and a relay system for removing self-interference (SI). If a relay transmitting end transmits relay-reference signals (R-RS) through a region where a base station does not transmit signals, based on a protocol predetermined with the base station, a relay receiving end obtains SI channel values from signals transmitted by the relay transmitting end and received through a self-interference channel with use of the R-RS, removes the SI from transmitting signals of an uplink or an downlink based on the SI channel values, and relays the SI removed transmitting signals.

Abstract: A method of managing cells of base stations (BSs) and a mobile telecommunication system for the same, capable of allowing a user equipment (UE), which had not been permitted, to access the CSG BS if the UE meets an access condition, are disclosed. In accordance with the method and the system, an outdoor BS, manages a list of indoor BSs of a CCSG selected among indoor BSs of the CSG. The indoor BSs of the CCSG allow the UE to access the indoor BSs of the CCSG when the UE meets an access condition. The outdoor BS broadcasts a reporting criteria and reporting information, receives measurement values that meet the reporting criteria and an identity of the indoor BS as the reporting information from the UE, recognizes the environment of the UE based on the measurement value, checks the identity of the indoor base station in the list of the CCSG and allows the UE to access the indoor base station based on a check result.

Abstract: In a Wavelength Division Multiplexed Passive Optical Network (WDM-PON) including, a system for overlaying an analog broadcast signal. An Optical Line Terminal of the WDM-PON includes a broadband light source for generating uplink seed light for each uplink channel of the WDM-PON, and a modulator for modulating the analog broadcast signal onto the uplink seed light. An Optical Network Terminal of the WDM-PON receives the uplink seed light from the Optical Line Terminal, and includes an optical divider for dividing the received seed light into a first signal and a second signal; a light source for generating an uplink data signals using the first signal as seed light; and an RF receiver for detecting the analog broadcast signal modulated on the second signal.

Abstract: Described is a method for controlling the wavelength of a laser in a wavelength division multiplexed (WDM) system. The method includes generating broadband light having a dithered optical power and a wavelength spectrum that includes a plurality of WDM wavelengths. The broadband light is spectrally filtered to generate a spectrally-sliced optical signal having a wavelength spectrum that includes one of the WDM wavelengths. The spectrally-sliced optical signal is injected into a laser and a dithered optical power of the laser is determined. A parameter of the laser is controlled in response to the determination of the dithered optical power to thereby align a wavelength of the laser to the wavelength spectrum of the spectrally-sliced optical signal.

Abstract: A communication terminal including a housing having elastic key buttons integrally coupled thereto is provided. The housing is configured to define an external appearance of the communication terminal. Each of the key buttons may have one end thereof integrally coupled to the housing and a free end at an opposite end thereof. A plurality of key-input switches may be respectively positioned beneath each key button. Each of the key-input switches may detect a corresponding key-input when the free end of the key button is brought into contact with the key-input switch.

Abstract: Embodiments of the present invention may provide an apparatus and a method for transmitting an orthogonal frequency division multiplexing access (OFDMA) symbol in an OFDMA system. A bandwidth limit parameter for generating an OFDMA symbol may be adaptively determined based on the received signal quality of a receiver. An OFDMA symbol may be generated based on the bandwidth limit parameter and transmitted to the receiver. According to embodiments, when the received signal quality of the receiver is bad, the bandwidth limit parameter may be first adjusted before the modulation scheme is changed to have a lower data rate. In such a case, the downlink date rate may be maintained with enhancing the received signal quality of the receiver.