Abstract:
A method to generate a beamforming vector by a terminal includes receiving information on a first precoding matrix and a second precoding matrix from a serving base station; and generating a beamforming vector by linearly combining the first precoding matrix and the second precoding matrix.
Abstract:
In an inter-cell interference relief method, a plurality of terminals are grouped into a plurality of groups. A base station transmits data to a first terminal belonging to a first group among the plurality of groups, without the help of a neighbouring base station. Additionally, the base station transmits data to a second terminal belonging to a second group among the plurality of groups, with the help of a neighbouring base station.
Abstract:
In a communication system including a plurality of base stations and a plurality of terminals belonging to each of the base stations, the base station receives information on subcarriers allocated to a terminal that belongs to an adjacent base station from the adjacent base station. Thereafter, the base station generates power control information on the basis of the subcarrier information and transmits the power control information to the terminal, and the terminal controls uplink power on the basis of the received power control information. At this time, the power control information, as information based on estimating hitting between subcarriers used by the terminal that belongs to the base station and subcarriers used by the adjacent base station, may be a ratio found by dividing the total number of subcarriers used by each terminal that belongs to the adjacent base station by the entire number of subcarriers that can be used by the base station.
Abstract:
The present invention relates to an apparatus and a method for selection of a precoding matrix. In the present invention, a precoding matrix to enable an effective signal-to-noise ratio (ESNR) to have a maximum value with respect to a signal vector that requires retransmission is selected in a codebook and fed back to a transmitter. Accordingly, since the effective signal-to-noise ratio has the maximum value after the signal vector is retransmitted, it is possible to minimize a reception error probability of retransmission.
Abstract:
In a symbol mapping method, transmission data is encoded to output information bits and re¬ dundancy bits. The information bits and the redundancy bits are mapped to a symbol according to a first mapping scheme at a first transmission, and the information bits and the redundancy bits are mapped to a symbol according to a second mapping scheme at a second transmission.
Abstract:
A device for generating a transmission codebook in a communication system including a multi-input multi-output (MIMO) antenna according to an embodiment of the present invention includes: a frequency determiner that determines a frequency to allow the transmission codebook to have an optimal characteristic; a precoding matrix generator that generates a precoding matrix on the basis of the frequency; and a codebook generator that generates a retransmission codebook to be used for retransmission on the basis of the precoding matrix and generates the transmission codebook on the basis of the retransmission codebook.
Abstract:
PURPOSE: A synchronization acquisition method between nodes in a wireless network and apparatus thereof are provided to effectively acquire synchronization between nodes by estimating a radio wave delaying phenomenon. CONSTITUTION: A first node transmits a first signal including the transmission time information of the first signal to a second node(S500). The first node receives a second signal including the transmission time information and reception time information of the first signal from the second node(S510). A radio wave delaying phenomenon is established between the first and the second node by using the information(S520). Synchronization is acquired between the first and the second node by using the radio wave delaying phenomenon(S550).
Abstract:
In an orthogonal frequency division multiple access (OFDMA) communication system, a transmission apparatus connects multiple tiles, which have a 4×3 structure, along a time or frequency axis in an uplink 4-layer partial usage of subchannels (PUSC) mode, and designs pilots corresponding to one layer at one of multiple symbol positions adjacent to a first corner of the tiles and one of multiple symbol positions adjacent to a second corner of the tiles that face the first corner in a diagonal direction. In this case, null symbols are designed at the rest of the symbol positions adjacent to the first corner or the second corner where the pilots are not designed. Accordingly, a receiving apparatus can obtain n channel values from n tiles. Further, n estimated channel values are applied to a linear interpolation method, so that it is possible to estimate the entire channel value of n tiles.
Abstract:
A method to generate a beamforming vector by a terminal includes receiving information on a first precoding matrix and a second precoding matrix from a serving base station; and generating a beamforming vector by linearly combining the first precoding matrix and the second precoding matrix.