摘要:
Provided are a virtual multi-antenna method for an orthogonal frequency division multiplexing (OFDM) system and an OFDM-based cellular system. The virtual multi-antenna method includes grouping sub-carriers in a frequency domain of an OFDM symbol and generating at least one group including G sub-carriers; and regarding the G sub-carriers included in the at least one group as multiple channels used in a multi-antenna technique and virtually applying the multi-antenna technique to the transmission and reception of the OFDM symbol. The virtual multi-antenna method can effectively reduce an interference signal and obtain the effects of a spatial division multiple access (SDMA) technique without physically using multiple antennas.
摘要:
Provided are a virtual multi-antenna method for an orthogonal frequency division multiplexing (OFDM) system and an OFDM-based cellular system. The virtual multi-antenna method includes grouping sub-carriers in a frequency domain of an OFDM symbol and generating at least one group including G sub-carriers; and regarding the G sub-carriers included in the at least one group as multiple channels used in a multi-antenna technique and virtually applying the multi-antenna technique to the transmission and reception of the OFDM symbol. The virtual multi-antenna method can effectively reduce an interference signal and obtain the effects of a spatial division multiple access (SDMA) technique without physically using multiple antennas.
摘要:
Disclosed is a transmitting and receiving method for reducing a time-varying channel distortion in an orthogonal frequency division multiplex (OFDM) system. In the present invention, the transmitter defines M sub-channels in one data group, mathematically analyzes a change of channel for each path causing a time-varying channel distortion in a high-speed mobile environment by approximation, calculates a weight value based on the mathematical analysis and assigns the calculated weight value to transmit data of each sub-channel. Subsequently, the receiver combines the signals of these M sub-channels and demodulates the combined signals. Accordingly, the present invention greatly reduces a distortion caused by the time-varying channel to improve a bit error rate and a channel estimation performance.
摘要:
Provided is a fuel cell including an anode electrode, a cathode electrode, and an electrolyte/ion exchange membrane between the anode electrode and the cathode electrode. The cathode electrode uses an iron redox couple as an oxidizer. The iron redox couple is regenerated by an oxidizing substance. The fuel cell does not need a noble metal catalyst, is thus economical in manufacturing costs, and has high power density, thereby improving energy conversion efficiency. Furthermore, the fuel cell is capable of decomposing an oxidizing substance, such as NOx, Cl2, Br2, or O3.
摘要:
Provided is a fuel cell including an anode electrode, a cathode electrode, and an electrolyte/ion exchange membrane between the anode electrode and the cathode electrode. The cathode electrode uses an iron redox couple as an oxidizer. The iron redox couple is regenerated by an oxidizing substance. The fuel cell does not need a noble metal catalyst, is thus economical in manufacturing costs, and has high power density, thereby improving energy conversion efficiency. Furthermore, the fuel cell is capable of decomposing an oxidizing substance, such as NOx, Cl2, Br2, or O3.
摘要:
The present invention relates to method of providing color to aid in the expression and purification of proteins of E. coli. Vector according to the present invention includes the His-tagged Vitreoscilla hemoglobin (VHb) coding gene upstream of the multiple cloning site. The vector was designed to express target proteins as VHb fusions, which can be purified in one step by affinity chromatography. Due to the color of the heme in VHb, the VHb-fused target proteins have a red color that provides a visual aid for estimating their expression level and solubility. The red color can also be used as a visual marker throughout purification, while the concentration of the fusion protein can be determined by measuring the amount of VHb using carbon monoxide difference spectra. In addition, because of inherently high solubility of VHb, the fusion can increase the solubility of sparingly soluble target proteins. Target proteins can be easily separated from His-tagged VHb due to the presence of a thrombin cleavage site between them.
摘要:
A method for fabricating a counter electrode for a dye-sensitized solar cell includes co-sputtering platinum and a metal oxide as target materials to deposit nanocrystalline platinum and an amorphous metal oxide on the substrate. The counter electrode exhibits improved performances as an electro-catalyst to assist in the reduction of I3− during operation of a dye-sensitized solar cell.
摘要:
A voice mailing system and a service method for additionally processing fax mail while intactly maintaining the voice mail in order to save memory requirement and simplify the mail management structure. The voice mail system where a corresponding profile box is accessed by a profile number to perform a voice mail service, contains a memory having a plurality of data cells for storing fax data, transactions for storing index of the data cells, a storing date and time, a storing mail format, and page classifying information for each fax mail; and a plurality of mailboxes for storing index information of the fax mail.