摘要:
Disclosed is a data transmission system that transmits data using a relay. During a first time slot, a base station may transmit base station data to the relay, and a mobile station may transmit mobile station data to the relay. During a second time slot, the relay may transmit the mobile station data to the base station, and transmit the base station data to the mobile station.
摘要:
A method and apparatus for transmitting and receiving data by performing an iterative multi-user detection is provided. The apparatus includes: a receives a transmission signal and generates a received signal, the transmission signal being generated by modulating a single carrier signal via a modulation process, specialized for each user, in a wireless communication system; an interference canceled signal generator which generates an interference canceled signal by canceling a signal interference using a demodulated signal with respect to the received signal, the signal interference being caused by an other user; and a demodulated signal generator which generates the demodulated signal by demodulating the received signal via a demodulation process using the interference canceled signal, the demodulation process being specialized for each user, wherein the demodulated signal, which is generated by performing the generating of the interference canceled signal and the generating of the demodulated signal at least once, is adopted as a final demodulated signal.
摘要:
A communication network applying an interference alignment scheme with a low or reduced complexity is provided. The communication network may include a plurality of transmit nodes and a plurality of receive nodes. A plurality of combinations of transmit-receive pairs may exist between the plurality of transmit nodes and the plurality of receive nodes. A communication apparatus for the communication network may select, from candidate combinations of transmit-receive pairs, a target combination to be applied with the interference alignment scheme. In particular, the communication apparatus may sequentially decrease a number of candidate combinations to select the target combination with a low complexity.
摘要:
A method and apparatus for compensating a distortion due to a clipped amplitude when an amplitude of a signal is clipped to reduce a peak to average power ratio (PAPR) in a wireless communication system using an orthogonal frequency division multiplexing (OFDM) scheme and a transmit diversity method using an orthogonal coding.A wireless data transmission apparatus which transmits a data stream via a plurality of antennas, the apparatus including: a coding unit which Space-Time block codes a first data stream into a plurality of second data streams, the plurality of second data streams being orthogonal to each other; an inverse Fourier transform unit which performs an inverse Fourier transform of each of the Space-Time block coded second data stream and generates a plurality of time domain signals; and a plurality of amplitude clipping units which clips an amplitude of each of the plurality of generated time domain signals.
摘要:
A method of controlling data transmission mode in an orthogonal frequency division multiple access (OFDMA) wireless relay system and an apparatus using the method are provided. The method of controlling data transmission mode includes: dividing all frequency bands of an OFDM signal into a frequency band group including at least one subcarrier band; estimating a plurality of channels of wireless links which respectively link a base station (BS), at least one relay station (RS), and a mobile station (MS) with respect to the at least one subcarrier band; selecting any one of a plurality of data transmission modes based on a feature of the estimated plurality of channels of wireless links with respect to the frequency band group; and applying the selected data transmission mode to all of the at least one subcarrier bands in the frequency band group to transmit data.
摘要:
A communication system may include a serving base station and neighboring base stations. Each of the serving base station and the neighboring base stations may have a corresponding user group. Terminals belonging to a particular user group may feed back information associated with interference channels, and reasonably generate a precoding matrix. Through this, it is possible to perform an accurate interference alignment and to enhance a throughput. In this instance, terminals belonging to the other user groups may feed back information associated with a throughput, and a corresponding base station may perform the interference alignment using a user selection resulting in decreased overhead.
摘要:
A method of determining an optimal transmission mode and a data frame structure for determining an optimal transmission mode in a data transmission system using a relay, are provided. Any one of a base station, a relay, and a mobile station determines an optimal transmission mode from among a plurality of transmission modes, and the base station transmits the determined optimal transmission mode by enabling the determined optimal transmission mode to be included in the system information duration of the data frame, so that the overall relay system can transmit data according to the optimal transmission mode.
摘要:
Provided is a communication system using various types of random beamforming technologies. Each of terminals that belong to a user group may generate a decoding matrix, based on interference caused by a neighboring base station of a serving base station. Each of the terminals may transmit, to the serving base station or the neighboring base station, information associated with a signal-to-interference plus noise ratio (SINR) or throughput based on the decoding matrix. The serving base station may select, from the terminals, at least one target terminal to communicate with the serving base station.
摘要:
A method and apparatus for controlling power in a decode-and-forward (DF) relay system is provided. The method of controlling power in a DF relay system includes: acquiring first channel information of a first link between a source node and a destination node, second channel information of a second link between the source node and a relay node, and third channel information of a third link between the relay node and the destination node, by using a pilot signal; determining a power level of the source node from the acquired first through third channel information; and feeding back the determined power level to the source node and the relay node.
摘要:
A base station with multiple antennas including a relay scheduler to select a serving relay from a plurality of candidate relays. Each candidate relay may have a user group including at least one user. The selection may be based on an achievable transmission capacity of each candidate relay with respect to its user group and a state of channels formed between the plurality of candidate relays and the base station. The base station also includes a transmission signal generator to generate a transmission signal for the user group corresponding to the serving relay.