Abstract: The present invention relates to an apparatus capable of flexibly regulating coverage of a repeater in a long term evolution system (hereinafter referred to as an LTE system). The present invention provides an apparatus for regulating transmission power of a repeater in an LTE (LONG TERM EVOLUTION) system, the apparatus including a sink signal detector that detects a sink signal of a reception signal received through an IF/RF receiver of the repeater, a sink signal power measurer that measures a size of power of the sink signal detected through the sink signal detector, and an amplification controller that calculates a gain of an amplifier of the repeater for maintaining coverage of the repeater based on the size of the power of the sink signal measured through the sink signal power measurer, and controls the amplifier of the repeater according to the calculated gain.

Abstract: The present invention relates to an apparatus capable of flexibly regulating coverage of a repeater in a long term evolution system (hereinafter referred to as an LTE system). The present invention provides an apparatus for regulating transmission power of a repeater in an LTE (LONG TERM EVOLUTION) system, the apparatus including a sink signal detector that detects a sink signal of a reception signal received through an IF/RF receiver of the repeater, a sink signal power measurer that measures a size of power of the sink signal detected through the sink signal detector, and an amplification controller that calculates a gain of an amplifier of the repeater for maintaining coverage of the repeater based on the size of the power of the sink signal measured through the sink signal power measurer, and controls the amplifier of the repeater according to the calculated gain.

Abstract: The present invention relates to an optical relay system for transmitting multi-band frequency signals with limited bands by using optical lines. According to the present invention, a plurality of band-limited signals are band-combined into one signal by using a combiner, and the signals are transmitted through multiple outputs by using a distributor, and thus a multi-stage filter is not necessary. In addition, the present invention is capable of effectively solving various problems such as damage to the original signals caused by the band combination of the multi-stage filter, and there is no need to precisely connect each of the band-limited signals to the determined ports of the combiner and the signals can be connected to random ports, thereby improving convenience of use.

Abstract: The present invention relates to an optical relay system for transmitting multi-band frequency signals with limited bands by using optical lines. According to the present invention, a plurality of band-limited signals are band-combined into one signal by using a combiner, and the signals are transmitted through multiple outputs by using a distributor, and thus a multi-stage filter is not necessary. In addition, the present invention is capable of effectively solving various problems such as damage to the original signals caused by the band combination of the multi-stage filter, and there is no need to precisely connect each of the band-limited signals to the determined ports of the combiner and the signals can be connected to random ports, thereby improving convenience of use.

Abstract: The present invention relates to an optical relay system that transmits a band-limited multi-band frequency signal via an optical line. According to an embodiment of the present invention, since a remote unit includes a multiplexer that fixes a power flow direction to combine wireless signals of various bands and outputs the combined signals to a mobile terminal, or distributes wireless signals wireless signals received from the mobile terminal and fixes a power flow direction to output the distributed wireless signals, even if frequency bands of signals combined by the multiplexer overlap or are adjacent, power delivery in a direction opposite to the power delivery direction of a signal during a signal combining process can be prevented, reducing signal distortion, and thus improving efficiency in combining a number of signals.

Abstract: A system and a method for canceling an echo is disclosed. In accordance with the system and the method, a plurality of independently and variably delayed adaptive algorithm blocks are selectively applied to a delayed feedback signal to generate a plurality of echo components in parallel, thereby canceling the echo component from an input 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: 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: A system and a method for canceling an echo is disclosed. In accordance with the system and the method, a plurality of independently and variably delayed adaptive algorithm blocks are selectively applied to a delayed feedback signal to generate a plurality of echo components in parallel, thereby canceling the echo component from an input signal.

Abstract: Capacity enhancement schemes are described for forward and reverse links of distributed cellular base stations consisting of a central unit and one or more remote units. In general, in one aspect, reverse link capacity is shared among remote units. The capacity sharing can be determined dynamically. The forward link capacity can also be enhanced by estimating the location of the mobile stations.

Abstract: A device for compensating for the nonlinearity of a power amplifier which has a simple configuration and can precisely linearize the transfer characteristics of the power amplifier by predistorting an input signal of the power amplifier. The nonlinearity compensation device of the present invention converts an RF input signal into an IF band rather than a baseband and predistorts the RF input signal in digital domain, and thus any modulation or demodulation process is obviated and the simultaneous processing of signals in multiple channels is facilitated. A first downconverter receives the RF input signal and converts the frequency band of the signal into the IF band to output an IF input signal. A predistortion unit receives and predistorts the IF input signal to compensate for the nonlinearity, and outputs an IF predistorted signal. An upconverter converts the frequency band of the IF predistorted signal into the RF band to provide such a signal to the amplifier.

Abstract: A die casting system includes a vessel defining a reservoir with a controlled heater and an agitator for maintaining the bath of semi-solid metal in a homogeneous isothermal state, a transfer system capable of transferring a known quantity of metal in its semi-solid state to a mold cavity in a die casting machine, the transfer system including a heated suction tube, a vacuum source for vacuum ladling semi-solid metal from the bath to a die, and a plunger tip providing a path for free air flow to allow evacuation of the suction tube during casting and a metal replacement system for replacing the known quantity of transferred metal with a similar amount of liquid metal so that a stable homogeneous isothermal bath of semi-solid metal is controllably maintained to be available for die casting operations.

Abstract: A device for compensating for the nonlinearity of a power amplifier which has a simple configuration and can precisely linearize the transfer characteristics of the power amplifier by predistorting an input signal of the power amplifier. The nonlinearity compensation device of the present invention converts an RF input signal into an IF band rather than a baseband and predistorts the RF input signal in digital domain, and thus any modulation or demodulation process is obviated and the simultaneous processing of signals in multiple channels is facilitated. A first downconverter receives the RF input signal and converts the frequency band of the signal into the IF band to output an IF input signal. A predistortion unit receives and predistorts the IF input signal to compensate for the nonlinearity, and outputs an IF predistorted signal. An upconverter converts the frequency band of the IF predistorted signal into the RF band to provide such a signal to the amplifier.

Abstract: An apparatus and process is provided for producing a semi-solid material suitable for directly casting into a component wherein the semi-solid material is formed from a molten material and the molten material is introduced into a container. Semi-solid is produced therefrom by agitating, shearing, and thermally controlling the molten material. The semi-solid material is maintained in a substantially isothermal state within the container by appropriate thermal control and thorough three dimensional mixing. Extending from the container is a means for removing the semi-solid material from the container, including a temperature control mechanism to control the temperature of the semi-solid material within the removing means.

Abstract: Disclosed is a method and apparatus for rapidly producing a metal component from partially solidified metal slurry. A source of metal alloy slurry is provided and maintained under conditions to maintain the slurry state, for example by shearing at a temperature between a liquidus and solidus thereof. The slurry is dispensed through a source nozzle and deposited upon a substrate or upon previously dispensed slurry in a predetermined, controlled manner to produce a component of desired geometry. The substrate may be planar or contoured and may comprise an element of the component being produced. A temperature, pressure or chemical composition controlled deposition environment may be provided to facilitate producing a component having desired characteristics.

Abstract: An apparatus and process is provided for producing semi-solid material suitable for directly casting into a component wherein the semi-solid material is formed from a molten material and the molten material is introduced into a container. Semi-solid is produced therefrom by agitating, shearing, and thermally controlling the molten material. The semi-solid material is maintained in a substantially isothermal state within the container by appropriate thermal control and thorough three dimensional mixing. Extending from the container is a means for removing the semi-solid material from the container, including a temperature control mechanism to control the temperature of the semi-solid material within the removing means.

Abstract: An apparatus and process is provided for producing semi-solid material and directly casting the semi-solid material into a component wherein the semi-solid material is formed from a molten material and the molten material is introduced into a container. Semi-solid is produced therefrom by agitating, shearing, and thermally controlling the molten material. The semi-solid material is maintained in a substantially isothermal state within the container by appropriate thermal control and thorough three-dimensional mixing. Extending from the container is a means for removing the semi-solid material from the container, including a temperature control mechanism to control the temperature of the semi-solid material within the removing means.