Abstract: Provided is a link synchronization method for a radio frequency repeater that can perform link route switching at an accurate time point by measuring reception signal power at a predetermined period for a predetermined time duration, accumulating and comparing them with a reference level, and detecting a link termination time point. The method includes: a) setting up an initial link route; b) measuring received signal power in the initial link route; c) accumulating the reception signal power received for a predetermined time at a predetermined period, when the reception signal power is detected; d) setting up a reference level for link switching based on the accumulated reception signal power; e) detecting a link termination time point by finding an edge in a waveform of the accumulated reception signal power based on the reference level; and f) switching the current link route based on the detected link termination time point.

Abstract: An adaptive feedback estimation and cancellation (AFEC) apparatus includes: a controller for generating and outputting control information by using a synchronization signal from an external synchronization acquisition unit and base station information, in order to remove a feedback signal that exists in a forward/reverse repeater signal to be repeated and then send the forward/reverse repeater signal; a first feedback prediction canceller for adaptively removing a feedback signal that exists in the forward repeater signal based on the control information from the controller and automatically adjusting the gain of the forward repeater signal; and a second feedback prediction canceller for adaptively removing a feedback signal that exists in the reverse repeater signal based on the control information from the controller and automatically controlling the gain of the reverse repeater signal.

Abstract: An adaptive feedback estimation and cancellation (AFEC) apparatus includes: a controller for generating and outputting control information by using a synchronization signal from an external synchronization acquisition unit and base station information, in order to remove a feedback signal that exists in a forward/reverse repeater signal to be repeated and then send the forward/reverse repeater signal; a first feedback prediction canceller for adaptively removing a feedback signal that exists in the forward repeater signal based on the control information from the controller and automatically adjusting the gain of the forward repeater signal; and a second feedback prediction canceller for adaptively removing a feedback signal that exists in the reverse repeater signal based on the control information from the controller and automatically controlling the gain of the reverse repeater signal.

Abstract: Provided is a link synchronization method for a radio frequency repeater that can perform link route switching at an accurate time point by measuring reception signal power at a predetermined period for a predetermined time duration, accumulating and comparing them with a reference level, and detecting a link termination time point. The method includes: a) setting up an initial link route; b) measuring received signal power in the initial link route; c) accumulating the reception signal power received for a predetermined time at a predetermined period, when the reception signal power is detected; d) setting up a reference level for link switching based on the accumulated reception signal power; e) detecting a link termination time point by finding an edge in a waveform of the accumulated reception signal power based on the reference level; and f) switching the current link route based on the detected link termination time point.

Abstract: The present invention relates to a satellite IP multicasting system and method for constructing an IP multicast network by a unit of internet node having a router for subscriber connection or a switch, and for transmitting a multicasting packet transmitted from a content provider into a local IP multicast network via a satellite. The satellite IP multicasting system features a backbone network, a content provider, a satellite network and a local network.

Abstract: Provided is a digital audio amplifier capable of increasing self-oscillation frequency by using a phase lead-lag compensator. The digital audio amplifier includes the phase lead-lag compensator which increases the self-oscillation frequency by lead-lag-compensating for the phase of an output signal and making a feedback of the compensated output signal. In addition, the digital audio amplifier further includes a bandwidth control means which controls the bandwidth of an error amplifier. Accordingly, the digital audio amplifier can adjust the self-oscillation frequency and reduce the extent to which the self-oscillation frequency varies in accordance with the variation of the output signal by using the bandwidth control means that inserts a pole into the error amplifier.

Abstract: A circuit for driving a gate of a power metal-oxide semiconductor field effect transistor (MOSFET), which uses a higher voltage than a gate controller is provided. The circuit is able to safely and effectively transmits an output signal of a gate controller irrespective of a frequency and a duty-cycle of the output signal when transmitting the output signal of the gate controller to the power MOSFET using a higher voltage than the gate controller. Accordingly, the circuit is suitable for a case where the duty-cycle of the output signal of the gate controller dramatically changes and the frequency is irregular.

Abstract: The present invention relates to a satellite IP multicasting system and method for constructing an IP multicast network by a unit of internet node having a router for subscriber connection or a switch, and for transmitting a multicasting packet transmitted from a content provider into a local IP multicast network via a satellite. The satellite IP multicasting system features a backbone network, a content provider, a satellite network and a local network.

Abstract: A method for monitoring and controlling traffic in real time at an asynchronous transfer mode (ATM) switching node, comprising the steps of retrieving the virtual path identifier (VPI)/virtual channel identifier (VCI) field and cell loss priority (CLP) field from the header of a received ATM cell to determine the validity of the cell by checking the effective value of the header for VPI/VCI field, comparing cell monitoring counter value (Cm) with cell control counter value (Cc) to detect violation of traffic parameter when the cell is determined to be valid, determining whether the present user's connection violates the negotiated parameter by means of traffic control data (Active_Idle) and CLP when the cell violates the traffic parameter, holding, tagging and discarding the cell according as the cell violates the negotiated parameter, transferring the result of controlling the valid cell to the physical layer to process the cell, and reporting the cell monitoring counter value to a control panel of uppe