摘要:
Disclosed is an apparatus and method for cooperative reception diversity based on signal point rearrangement or superposition modulation in a relay system, the method includes receiving a superposition-modulated symbol from a transmitting unit, demodulating the received symbol and decoding the demodulated symbol, modulating the received symbol using superposition modulation different from the superposition modulation used in the transmitting unit, and then relaying the modulated symbol to a reception unit, calculating an LLR of the symbol when a certain superposition-modulated symbol is received from a transmitting unit, calculating an LLR of a symbol modulated using superposition modulation different from the superposition modulation used in the transmitting unit when the symbol modulated using the different superposition modulation is received from a relay station, and summing and combining an LLR of each symbol received through the transmitting unit and relay station.
摘要:
A method and apparatus for method for providing cooperative reception diversity based on signal point rearrangement and superposition modulation performed at a relay station is discussed. A first technique performs superposition modulation at a relay station and a second technique employs signal point rearrangement at a relay station. The superposition modulation is a different type of superposition modulation than that employed by the transmitter of the signal. Similarly, the signal point rearrangement is a different type of signal point rearrangement than that employed by the transmitter of the signal. As a result of the superposition modulation or signal point rearrangement performed by the relay station, the reliability of a signal received by a reception unit at the destination receiver is improved.
摘要:
A selective cooperative relaying method, the method including: determining, by a base station, whether a mobile station for which the base station provides a service is the mobile station necessary for direct transmission or is the mobile station necessary for cooperative relaying via a relay station; and selecting, by a base station, mobile stations using a simple relaying scheme, a cooperative transmission diversity scheme, or a cooperative receiving diversity scheme from mobile stations necessary for the cooperative relaying via the relay station.
摘要:
A selective cooperative relaying method, the method including: determining, by a base station, whether a mobile station for which the base station provides a service is the mobile station necessary for direct transmission or is the mobile station necessary for cooperative relaying via a relay station; and selecting, by a base station, mobile stations using a simple relaying scheme, a cooperative transmission diversity scheme, or a cooperative receiving diversity scheme from mobile stations necessary for the cooperative relaying via the relay station.
摘要:
Provided is a chemical vapor deposition (CVD) apparatus, including: a reaction chamber including an inner pipe having an internal space, and an external pipe configured to cover the inner pipe so as to maintain a sealing state thereof; a wafer holder disposed within the inner pipe and receiving a plurality of wafers stacked therein; and a gas supplier including at least one stem pipe disposed at the outside of the reaction chamber so as to supply a reactive gas thereto, a plurality of branch pipes connected to the stem pipe to introduce the reactive gas from the outside of the reaction chamber into the reaction chamber, and a plurality of spray nozzles provided with the branch pipes to spray the reactive gas to the plurality of respective wafers.
摘要:
Provided is a chemical vapor deposition (CVD) apparatus, including: a reaction chamber including an inner pipe having an internal space, and an external pipe configured to cover the inner pipe so as to maintain a sealing state thereof; a wafer holder disposed within the inner pipe and receiving a plurality of wafers stacked therein; and a gas supplier including at least one stem pipe disposed at the outside of the reaction chamber so as to supply a reactive gas thereto, a plurality of branch pipes connected to the stem pipe to introduce the reactive gas from the outside of the reaction chamber into the reaction chamber, and a plurality of spray nozzles provided with the branch pipes to spray the reactive gas to the plurality of respective wafers.
摘要:
There is provided a method of manufacturing a semiconductor light emitting device, the method including: sequentially growing a first conductivity type semiconductor layer, an active layer, and a second conductivity type semiconductor layer on a semiconductor growth substrate to form a light emitting part; forming a support part on the second conductivity type semiconductor layer to be coupled to the light emitting part; separating the semiconductor growth substrate from the light emitting part; and applying an etching gas to the semiconductor growth substrate to remove a residue of the first conductivity type semiconductor layer from a surface of the semiconductor growth substrate.
摘要:
A chemical vapor deposition (CVD) apparatus, including: a reaction chamber including an internal chamber having an internal space, an external chamber configured to cover the internal chamber so as to maintain a sealing state thereof; a wafer holder disposed within the internal chamber for a plurality of wafers stacked therein; a gas supplier including an inner pipe having an inner path, an external pipe having an external path, a refrigeration pipe having a cooling path. The inner path of the inner pipe supplies a first process gas into the reaction chamber. The external path of the external pipe surrounds the inner pipe to supply a second process gas therethrough. The refrigeration pipe supplies a refrigerant to prevent temperature rise in the inner pipe.
摘要:
A method for recycling a wafer is provided. The method removes residues remaining on the wafer separated from a semiconductor layer, using HCl and Cl2 gases under high temperature and low pressure conditions. According to the method, damage of a surface of the wafer is minimized. In addition, since reduction in thickness and an outer diameter of the wafer is minimized, a number of attempts at reprocessing the wafer may be increased.