Abstract: A communication device includes: a wireless transceiver configured to communicate with another communication device through a wireless channel; and at least one processor configured to execute instructions to: a) estimate at least one first channel response of the wireless channel based on a predetermined signal received from the another communication device; and b) predict a second channel response based on the at least one first channel response by an extrapolation method for signal transmission to the another communication device at a time instant where no channel estimation is performed.

Abstract: A base station, a method for a base station, and a program capable of appropriately selecting radio terminals for which spatial multiplexing is performed and an MCS, and thereby increasing throughput in multi-user MIMO are provided. A base station 11 according to the present disclosure includes: a correction parameter storage unit 1141 configured to store a plurality of correction parameters for each of a plurality of radio terminals 12, the plurality of correction parameters being provided for each of the radio terminals 12; a correction parameter selection unit 1131 configured to select a predetermined correction parameter from among the plurality of correction parameters based on a combination of radio terminals 12 that are spatially multiplexed in the same radio resource; a correction value calculation unit 1132 configured to calculate a correction value of the radio terminal 12 based on the predetermined correction parameter.

Abstract: A control apparatus controls a communication with a plurality of wireless terminals using a plurality of beams. The control apparatus calculates an index indicating a relationship between the plurality of beams, on the basis of a first information about a success/failure of a communication with at least two of the plurality of wireless terminals, and a second information indicating a combination pattern of at least two of the plurality of beams that are used a communication whose success/failure is indicated by the first information; and selects, from among the plurality of wireless terminals and the plurality of beams, a combination of at least one wireless terminal serving as a communication target and at least one beam used to communicate with the at least one wireless terminal, on the basis of the index.

Abstract: An eigenvalue decomposition apparatus includes: first generation means for inputting a first matrix and generating a 2×2-dimensional third matrix using a plurality of elements included in a second matrix based on the first matrix; first calculation means for calculating a two-dimensional eigenvector that corresponds to a maximum eigenvalue of the third matrix; first update means for generating a fourth matrix obtained by reducing the dimension of the second matrix by using the two-dimensional eigenvector, updating the second matrix based on the fourth matrix, and determining, when the number of elements included in the fourth matrix is one, the element included in the fourth matrix to be an eigenvalue of the first matrix; and second calculation means for determining the eigenvector of the first matrix using the two-dimensional eigenvectors calculated before the number of elements included in the fourth matrix becomes one.

Abstract: Provided is a control apparatus configured to acquire a measurement result including information on reception qualities of a plurality of beams, update a database including information representing a relationship between the plurality of beams for each of a plurality of propagation environments, based on the measurement result, and perform selection processing for selecting a beam using the database.

Abstract: A radio communication apparatus includes a distortion calculation unit and an assignment unit. The distortion calculation unit calculates the degree of distortion of the frequency response of the channel between the radio communication apparatus and the radio terminal. Further, the assignment unit assigns the reference signal to the radio terminal based on the degree of distortion calculated by the distortion calculation unit.

Abstract: A radio apparatus capable of reducing the amount of calculation required to suppress an interference signal is provided. A radio apparatus (1) includes a spatial transformation unit (2) configured to perform a spatial transformation on a received signal including a desired signal and an interference signal received by a plurality of antennas, and thereby calculate a first beam-space received signal vector, a beam selecting unit (3) configured to select at least two elements from the first beam-space received signal vector and generate a second beam-space received signal vector, and an interference suppression synthesis unit (4) configured to estimate a covariance matrix of an interference noise signal including a noise signal and the interference signal included in the second beam-space received signal vector, generate a reception weight by using this covariance matrix, and detect the desired signal based on the reception weight and the second beam-space received signal vector.

Abstract: A wireless apparatus includes a channel estimation part that acquires an estimated impulse response which is an estimate value of an impulse response of a channel between a wireless terminal and the wireless apparatus, a tap location error detection part that detects a tap location error between estimated impulse responses at different time points out of the estimated impulse responses, and a channel prediction part that calculates a predicted impulse response which is an impulse response of the channel at a future time point by using the estimated impulse responses and the tap location error.

Abstract: A control apparatus includes a determination unit configured to determine first and second reception weight matrixes by using first and second channel matrixes between first and second radio apparatuses and the first and second terminals, a first calculation unit configured to calculate a data channel matrix of a data signal transmitted from the first radio apparatus to the first terminal by using the first channel matrix and the first reception weight matrix, a second calculation unit configured to calculate an interference channel matrix of interference to the second terminal caused by the first radio apparatus by using a third channel matrix between the first radio apparatus and the second terminal and the second reception weight matrix, and a third calculation unit configured to calculate a transmission weight matrix for transmitting a data signal so that the interference is suppressed by using the data channel matrix and the interference channel matrix.

Abstract: A radio apparatus capable of reducing the amount of calculation required to suppress an interference signal is provided. A radio apparatus (1) includes a spatial transformation unit (2) configured to perform a spatial transformation on a received signal including a desired signal and an interference signal received by a plurality of antennas, and thereby calculate a first beam-space received signal vector, a beam selecting unit (3) configured to select at least two elements from the first beam-space received signal vector and generate a second beam-space received signal vector, and an interference suppression synthesis unit (4) configured to estimate a covariance matrix of an interference noise signal including a noise signal and the interference signal included in the second beam-space received signal vector, generate a reception weight by using this covariance matrix, and detect the desired signal based on the reception weight and the second beam-space received signal vector.

Abstract: A control apparatus includes a calculation unit configured to calculate, for each of radio apparatuses, a combination of a pre-coding weight and a post-coding weight using a first channel information matrix based on estimated values of channel responses between each of the radio apparatuses and each of terminals, a selection unit configured to select one combination from the combinations calculated using the first channel information matrices as a first combination, and an orthogonalization unit configured to generate a second channel information matrix for each of the radio apparatuses by projecting each first channel information matrix onto the subspace that is orthogonal to the post-coding weight included in the first combination. The calculation unit calculates a combination for each of the radio apparatuses using a second channel information matrix, and the selection unit selects one combination from the combinations calculated using the second channel information matrix as a second combination.

Abstract: A wireless apparatus includes a channel estimation part that acquires an estimated impulse response which is an estimate value of an impulse response of a channel between a wireless terminal and the wireless apparatus, a tap location error detection part that detects a tap location error between estimated impulse responses at different time points out of the estimated impulse responses, and a channel prediction part that calculates a predicted impulse response which is an impulse response of the channel at a future time point by using the estimated impulse responses and the tap location error.

Abstract: A control apparatus includes a determination unit configured to determine first and second reception weight matrixes by using first and second channel matrixes between first and second radio apparatuses and the first and second terminals, a first calculation unit configured to calculate a data channel matrix of a data signal transmitted from the first radio apparatus to the first terminal by using the first channel matrix and the first reception weight matrix, a second calculation unit configured to calculate an interference channel matrix of interference to the second terminal caused by the first radio apparatus by using a third channel matrix between the first radio apparatus and the second terminal and the second reception weight matrix, and a third calculation unit configured to calculate a transmission weight matrix for transmitting a data signal so that the interference is suppressed by using the data channel matrix and the interference channel matrix.

Abstract: A control apparatus includes a calculation unit configured to calculate, for each of radio apparatuses, a combination of a pre-coding weight and a post-coding weight using a first channel information matrix based on estimated values of channel responses between each of the radio apparatuses and each of terminals, a selection unit configured to select one combination from the combinations calculated using the first channel information matrices as a first combination, and an orthogonalization unit configured to generate a second channel information matrix for each of the radio apparatuses by projecting each first channel information matrix onto the subspace that is orthogonal to the post-coding weight included in the first combination. The calculation unit calculates a combination for each of the radio apparatuses using a second channel information matrix, and the selection unit selects one combination from the combinations calculated using the second channel information matrix as a second combination.

Abstract: A radio apparatus (10) includes an estimation unit (2) configured to calculate an estimated value of a channel response for each of a plurality of antennas, a padding unit (3) configured to generate a first antenna-space channel vector having dimensions larger than the number of the antennas by combining the estimated value with a padding value, a spatial transformation unit (4) configured to calculate a first beam-space channel vector by spatial transforming the first antenna-space channel vector, a noise suppression unit (5) configured to generate a second beam-space channel vector by suppressing at least one element of the first beam-space channel vector, an inverse spatial transformation unit (6) configured to calculate a second antenna-space channel vector by inversely and spatial transforming the second beam-space channel vector, and an extraction unit (7) configured to determine an estimated value of each channel based on the second antenna-space channel vector.

Abstract: A radio apparatus (10) includes an estimation unit (2) configured to calculate an estimated value of a channel response for each of a plurality of antennas, a padding unit (3) configured to generate a first antenna-space channel vector having dimensions larger than the number of the antennas by combining the estimated value with a padding value, a spatial transformation unit (4) configured to calculate a first beam-space channel vector by spatial transforming the first antenna-space channel vector, a noise suppression unit (5) configured to generate a second beam-space channel vector by suppressing at least one element of the first beam-space channel vector, an inverse spatial transformation unit (6) configured to calculate a second antenna-space channel vector by inversely and spatial transforming the second beam-space channel vector, and an extraction unit (7) configured to determine an estimated value of each channel based on the second antenna-space channel vector.

Abstract: A wireless apparatus includes a first weight multiplication part, a channel estimation part, a channel response conversion part, and a second weight generation part. The first weight multiplication part includes first weights, each of which corresponds to an individual one of a plurality of beams, and multiplies a signal(s) corresponding to a reference signal(s) transmitted from a wireless terminal(s) by the first weights. The channel estimation part estimates first channel responses for the respective beams by using the signals obtained by the multiplication by the first weights. The channel response conversion part converts the first channel responses into second channel responses by using the first weights. The second weight generation part generates second weights used for wireless communication with the wireless terminal(s) by using the second channel responses.

Abstract: A wireless apparatus includes a first weight multiplication part, a channel estimation part, a channel response conversion part, and a second weight generation part. The first weight multiplication part includes first weights, each of which corresponds to an individual one of a plurality of beams, and multiplies a signal(s) corresponding to a reference signal(s) transmitted from a wireless terminal(s) by the first weights. The channel estimation part estimates first channel responses for the respective beams by using the signals obtained by the multiplication by the first weights. The channel response conversion part converts the first channel responses into second channel responses by using the first weights. The second weight generation part generates second weights used for wireless communication with the wireless terminal(s) by using the second channel responses.

Abstract: A radio apparatus is provided with: a channel estimation part that estimates a channel response between a radio terminal and the radio apparatus; a channel information generation part that generates channel information from the estimated channel response; and a transmission part that transmits the generated channel information to a control apparatus.

Abstract: A method and a device for estimating a communication load, as well as a radio station and an upper-level apparatus in a radio communication system, are provided that can estimate a communication load in a target network with high accuracy by using received quality information. A communication load estimation function (1) for estimating a communication load in a network (NW) estimates the communication load in the network by using at least a first quality indicator (Q1), which is a quality measurement value including entire received power, and a second quality indicator (Q2), which is a quality measurement value including the signal-to-noise-and-interference ratio of a reference signal.