Abstract: Disclosed is a single process for producing hydrogen, carbon monoxide, and carbon from methane by forming gas products comprising hydrogen and carbon monoxide, and solid products comprising carbon and an iron-based catalyst from methane in a methane-containing feedstock through pyrolysis route involving auto-thermal reduction in a rotary kiln-type reactor in the presence of an iron-based catalyst and separating and recovering respective products.

Abstract: Provided is a pharmaceutical composition comprising as active ingredients: 5 mg of tadalafil or a pharmaceutically acceptable salt thereof; and 0.5 mg of dutasteride or a pharmaceutically acceptable salt thereof, wherein the dissolution rate of tadalafil under the dissolution conditions of a paddle rate of 50 rpm in 500 mL of a dissolution solution having a pH of 1.2 and containing 0.25% of SLS is 60-75% after 5 minutes and 80% or more after 30 minutes, and the dissolution rate of dutasteride under the dissolution conditions of a paddle rate of 50 rpm in 500 mL of a dissolution solution containing water and 0.1% of SLS is 50% or more after 15 minutes and 85% or more after 30 minutes.

Abstract: The present technology provides a system and a method for terminal positioning.

Abstract: There is disclosed a system and method of predicting a location of a user's viewport using location information of a sound source in 360 virtual reality (VR) content. According to the present invention, the spatial representation description (SRD) and the sound source localization information (SLI) of the audio MPD are transmitted with the video MPD being extended, the SRD of the sound source is used to derive the location of the sound source, and the weights of the respective items of the region of interest (ROI), the sound source localization information (SLI), the current viewport, and the pole are allocated differentially according to the bandwidth condition and then multiplied by the reference bitrate to determine the segment bitrate to be provided next, thereby improving the accuracy of predicting the location of the user's viewport and ensuring the quality of experience (QoE) for regeneration speed and regeneration quality.

Abstract: There is disclosed a system and method of predicting a location of a user's viewport using location information of a sound source in 360 virtual reality (VR) content. According to the present invention, the spatial representation description (SRD) and the sound source localization information (SLI) of the audio MPD are transmitted with the video MPD being extended, the SRD of the sound source is used to derive the location of the sound source, and the weights of the respective items of the region of interest (ROI), the sound source localization information (SLI), the current viewport, and the pole are allocated differentially according to the bandwidth condition and then multiplied by the reference bitrate to determine the segment bitrate to be provided next, thereby improving the accuracy of predicting the location of the user's viewport and ensuring the quality of experience (QoE) for regeneration speed and regeneration quality.

Abstract: An apparatus is provided for transmitting a signal in a communication system. Upon receipt of an information vector, the apparatus includes converting the information vector into a plurality of sub-information vectors; performing coding and modulation on each of the sub-information vectors according to a corresponding mode thereby generating a modulation symbol; interleaving the modulation symbol generated for each of the sub-information vectors; allocating power to the interleaved modulation symbol for each individual mode; and beamforming the modulation symbols power-allocated for each individual mode, and transmitting the beamforming symbols.

Abstract: A method is provided for ordering retransmissions in a Multi-Input Multi-Output (MIMO) system using N×M antennas. A transmitter splits a coded data stream into N sub-packets, and transmits the N sub-packets to a receiver via N transmission antennas. The receiver removes interferences of the N sub-packets received via M reception antennas, and independently decodes the interference-removed sub-packets. The receiver transmits an acknowledgement (ACK) or a negative acknowledgement (NACK) to the transmitter based on errors included in the decoded sub-packets. Upon receipt of the NACK, the transmitter retransmits to the receiver a sub-packet retransmission using ordering based on an Alamouti space-time coding scheme.

Abstract: A transmission method based on a Hybrid Automatic Repeat Request (HARQ) scheme for in a communication system. A codeword is generated using a Low Density Parity Check (LDPC) code. Parity bits of the codeword are classified on a basis of a transmission priority. Parity bits with an identical transmission priority are grouped. An information bit group of the codeword and parity bit groups with the identical transmission priority are shuffled in a predefined pattern. A packet is generated from the shuffled information bit group and the shuffled parity bit groups based on the transmission priority. The generated packet is retransmitted in response to a retransmission request. The transmission method can obtain the effect of channel interleaving by setting a transmission priority according to importance of puncturing target blocks, shuffling blocks with the same priority, and shuffling and transmitting bits configuring each block.

Abstract: Practical transmission power adaptation in multicarrier code division multiple access (MC-CDMA) communications is using either a frequency domain technique or a time domain technique or a combined frequency and time domain technique in response to channel variations. With frequency domain power adaptation, the transmission power is allocated over the N? (1?N??N) strongest subcarriers rather than over all possible N subcarriers, where the strongest subcarriers are understood to exhibit the highest channel gains. A substantially optimal N? can be chosen so that the average bit error rate (BER) is minimized. In the time domain power adaptation technique, transmission power is adapted so that the desired signal strength at the receiver output is maintained at a fixed level.

Abstract: A method for puncturing a Low Density Parity Check (LDPC).

Abstract: Provided is a scheduling apparatus and method for allocating resources to individual users in a multiantenna system. The method includes determining a ratio of time slots to be allocated according to a ratio desired by each of the terminals in every specific time slot interval, calculating a channel capacity average and a standard deviation for each terminal according to channel capacity reported from each terminal for a specific time, and determining, based on the determined ratio of time slots, a terminal to which a specific time slot is to be allocated according to the channel capacity average and the standard deviation, calculated for each terminal, and the last reported channel capacity.

Abstract: Practical transmission power adaptation in multicarrier code division multiple access (MC-CDMA) communications is using either a frequency domain technique or a time domain technique or a combined frequency and time domain technique in response to channel variations. With frequency domain power adaptation, the transmission power is allocated over the N? (1?N??N) strongest subcarriers rather than over all possible N subcarriers, where the strongest subcarriers are understood to exhibit the highest channel gains. A substantially optimal N? can be chosen so that the average bit error rate (BER) is minimized. In the time domain power adaptation technique, transmission power is adapted so that the desired signal strength at the receiver output is maintained at a fixed level.

Abstract: Disclosed is a method for estimating the velocity of a mobile station in Rician fading environments in which a direct wave exists. Cellular mobile communication environments include two environments, Rician fading environments in which a direct wave exists and Rayleigh fading environments in which a direct wave does not exist. Generally, many methods for estimating the velocity of a mobile station have been known in Rayleigh fading environments. However, in Rician fading environments in which a direct wave exists, many errors occurs in estimating the velocity of a mobile station due to difficulty in estimation of a Rician coefficient K and an incident angle ?0. According to the invention, a method is provided wherein error is mostly eliminated in estimating the velocity of a mobile station by obtaining a maximum Doppler frequency of the mobile station, even without directly obtaining a Rician coefficient K and an incident angle ?0.

Abstract: Practical transmission power adaptation in multicarrier code division multiple access (MC-CDMA) communications is using either a frequency domain technique or a time domain technique or a combined frequency and time domain technique in response to channel variations. With frequency domain power adaptation, the transmission power is allocated over the N? (1?N??N) strongest subcarriers rather than over all possible N subcarriers, where the strongest subcarriers are understood to exhibit the highest channel gains. A substantially optimal N? can be chosen so that the average bit error rate (BER) is minimized. In the time domain power adaptation technique, transmission power is adapted so that the desired signal strength at the receiver output is maintained at a fixed level.

Abstract: A preamble generating method which includes computing (N) chaotic samples; transforming the (N) chaotic samples into (N) binary values of certain bits, respectively, and computing a chaotic sequence bit successively using the (N) binary values; and generating a preamble based on the chaotic sequence bit. By using the sequence bit from the chaotic samples, a plurality of preambles with optimum auto-correlation and cross-correlation properties is generated.

Abstract: Transmit power adaptation for DS/CDMA systems is disclosed for a CDMA system that utilizes a successive interference cancellation receiver on fading channels. The transmission power is adapted in response to channel variations to achieve an arbitrary power profile for received signal powers at the system base station. That is, the received signal powers are distributed with some factor xi's given as: SRi=SR(1)xi, (i=2, 3, . . . , K and x1=1) where K is the number of users and SR(i) is the received signal power of the user having the ith strength, and wherein user strengths are ranked in the order of estimated channel gains. The factor xi gives a measure of the disparity between the received power levels. The channel is estimated at both the transmitter and receiver. In one embodiment, the factors, xi, for distributing the signal powers are selected such that the average BER for each user is minimized.

Abstract: A method and apparatus for adaptively determining weights for transmission antennas according to a channel condition in a closed-loop transmit diversity system using a plurality of transmission antennas. The antenna weights are determined using variation of channel characteristics based on time and space, to thereby improve bit error rate performance. Parameters for fixing average transmission power per symbol according to the statistical channel characteristics for symbol energy and additive white Gaussian nose energy are previously determined to estimate channel characteristics. The antenna weights are determined using the parameters and channel gains estimated upon reception of data symbols.

Abstract: A signal reception apparatus and method for communication systems. The signal reception apparatus for communication systems according to the present invention is applicable to communication environments in which a plurality of sub-bands having different frequency bands are sequentially used for communications. An embodiment of the invention has a multi-band index generation unit, a multi-band frequency generation unit, a multiplication unit, a correlation signal reception unit, and a buffer unit. The multi-band index generation unit generates a multi-band index corresponding to a sub-band to which a received signal is transmitted in correspondence with the multi-band index. The multiplication unit outputs a signal obtained by multiplying the received signal by the multi-band frequency. The correlation signal reception unit integrates and outputs the signal of the multiplication unit based on an integral time set in correspondence with the multi-band index.

Abstract: A decoding method in a concatenated low-density generator matrix (LDGM) code-based transmission system for detecting a signal using a parity check matrix including a systematic bit part mapped to systematic bits and a parity check part mapped to parity bits. The decoding method includes generating an outer code parity check matrix with a predetermined size using a pseudorandom algorithm; generating an inner code parity check matrix using the outer code parity check matrix; and decoding a received signal using the inner code parity check matrix.

Abstract: A transmission method based on a Hybrid Automatic Repeat Request (HARQ) scheme for in a communication system. A codeword is generated using a Low Density Parity Check (LDPC) code. Parity bits of the codeword are classified on a basis of a transmission priority. Parity bits with an identical transmission priority are grouped. An information bit group of the codeword and parity bit groups with the identical transmission priority are shuffled in a predefined pattern. A packet is generated from the shuffled information bit group and the shuffled parity bit groups based on the transmission priority. The generated packet is retransmitted in response to a retransmission request. The transmission method can obtain the effect of channel interleaving by setting a transmission priority according to importance of puncturing target blocks, shuffling blocks with the same priority, and shuffling and transmitting bits configuring each block.