Nec Corporation

Ryuji Zenkyu

Eisaku Sasaki

The OAM mode multiplexing transmission apparatus includes a UCA antenna, a correction circuit, a correction value calculation circuit that calculates correction values, and a correction value feedback part that regularly feeds back the correction values from a receiving end to a transmitting end. The correction value calculation circuit is connected to a database that stores information about an ideal MIMO channel matrix, which is calculated by using an array diameter of the UCA antenna, a number of antenna elements, an RF frequency, and a link distance as parameters, in a state in which transmission and reception UCA antennas face each other, or is connected to a calculation apparatus that calculates the information. The correction value calculation circuit regularly calculates the correction values relating to signal phase rotation by using a MIMO channel matrix estimated with known signals embedded in received transmission frames and the ideal MIMO channel matrix.

OAM mode multiplexing transmission apparatus, OAM mode multiplexing radio transmission system, method for correcting OAM mode multiplexing transmission apparatus, and computer-readable non-transient recording medium

An OAM reception apparatus () includes an OAM reception unit () and an interference compensation unit (C) that are independent of each other. The OAM reception unit () and the interference compensation unit (C) execute 'OAM reception processing' and 'interference compensation processing', respectively, based on a plurality of vertical component signals and a plurality of horizontal component signals obtained by performing polarization separating and down-conversion on a plurality of reception radio signals received by a plurality of reception antenna elements (-to-).

OAM reception apparatus, OAM reception method, and OAM transmission system

An antenna device includes a plurality of antenna elements. Each of the plurality of antenna elements outputs radio signals transmitted to another antenna device arranged so as to be opposed to the antenna device. At least one of the plurality of antenna elements is configured in such a way that a polarization direction of the radio signals to be output can be switched between a first direction and a second direction that is orthogonal to the first direction.

Antenna device, wireless transmitter, wireless receiver, and wireless communication system

A control device causes a first transmission system in a MIMO transmission device to transmit a first transmitting-end clock transmission signal (first transmission signal), causes a second transmission system to transmit a second transmission signal, and causes the first transmission system to transmit a third transmission signal. The control device acquires a first phase value and a second phase value. The first phase value is a phase value of the second transmission signal received in the second reception system operating based on a receiving-end clock signal synchronous with a transmitting-end clock signal by the first transmission signal. The second phase value is a phase value of the third transmission signal received in the second reception system in synchronous operation. The control device calculates a first correction value for correcting a first delay amount set value of a delay adjustment processing unit based on the first and second phase values.

Control device, delay difference adjustment method, and non-transitory computer readable medium for storing delay difference adjustment program

Provided is a radio transmission device, a baseband processing device, a radio transmission method, and a radio reception device that can reduce the peak to average power ratio in multiplex transmission using the OAM transmission system. In a baseband processing device (), a signal formation unit () forms N number of multiplex signals corresponding to N number of antenna devices () by multiplying M number (M is a natural number equal to or larger than 2) of data symbols that are different from and parallel to each other by a 'corrected weighting matrix'. The 'corrected weighting matrix' is obtained by adding the phase rotation matrix for suppressing the peak to a fixed OAM basic weighting matrix.

Radio transmission device, baseband processing device, radio transmission method, and radio reception device

An equalizer can connect with N receiving antennas that receive single carrier transmission signals transmitted from M transmitting antenna(s) in the same frequency band at the same time, and receives as input L signals sampled in a sampling period T from each of the N receiving antennas, the equalizer comprising, a first selection part that selects K signal(s) from the L signals for each of the N receiving antennas as signals to be multiplied by a first tap coefficient(s), and a second selection part selects L-K signal(s) to be multiplied by a second tap coefficient(s), from the L signals obtained by multiplying signals in the same sampling period for each of the N receiving antennas by the tap coefficient(s) and performing addition thereof.

Equalizer, receiving apparatus and receiving method

An interference compensation unit in an OAM reception apparatus removes the interference component caused by horizontally polarized waves relative to vertically polarized waves from a first mode vertical component reception signal obtained by an OAM reception unit using both a first mode horizontal component reception signal and a second mode horizontal component reception signal.

A radio communication system is provided with: a transmission apparatus that responds to OAM radio communication, a receiving apparatus that responds to OAM radio communication, and a correction apparatus. The correction apparatus corrects antenna axes of the transmission apparatus and the receiving apparatus, based on correlation information that associates: information related to the antennas of the transmission apparatus and the receiving apparatus, and an inter-mode interference pattern that characterizes interference by a transmission mode when the transmission apparatus transmits a signal, on a receiving mode when the receiving apparatus receives a signal.

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Tokyo, Japan

Ryuji Zenkyu