Abstract: An antenna orientation adjustment device (200) include a camera (210), nut runners (220 and 230), and a motion controller (400). The nut runners (220 and 230) can be mounted on an azimuth adjustment bolt (160) and an elevation adjustment bolt (180), respectively. The nut runners (220 and 230) change the orientation of an antenna unit by applying motor power to the azimuth adjustment bolt (160) and the elevation adjustment bolt (180). The motion controller (400) calculates an angle position of the antenna unit (110) where a reception strength is maximum based on an image taken by the camera (210) and a reception strength of radio waves received by the antenna unit (110), and then adjusts the antenna unit (110) to the angle position where the reception strength is maximum by supplying a drive signal to the azimuth adjustment bolt (160) and the elevation adjustment bolt (180).

Abstract: The antenna device includes an antenna unit (110) mounted so that its direction is adjustable, a motor-driven unit (124, 125) that changes a direction of the antenna unit (110), a camera (130) fixed so that its direction relative to the antenna unit (110) does not change, and a direction adjustment control unit (200) that supplies a drive signal to the motor-driven unit (124, 125) and adjusts the direction of the antenna unit (110). The direction adjustment control unit (200) performs feedback control to return the direction of the antenna unit (110) back to an initial direction based on an image taken by the camera (130). It is thereby possible to maintain the communication quality even when a mechanical vibration occurs in a structure on which an antenna device is mounted.

Abstract: When wireless communication is performed, a signal can be formed into a spiral beam (H), the spiral pitch of the signal can be changed, and a plurality of spiral beams (H) with different spiral pitches can be transmitted and received. A wireless signal transmitting antenna (10) includes a signal emitting means (A) having N number of antenna elements (A1, . . . , AN) (where N is an integer satisfying N?2) equally spaced on a circumference of circle, and a signal distribution means (B) for generating, from an input first signal (S), N number of second signals (G1, . . . , GN) having a phase difference from one another and outputting the N number of second signals (G1, . . . , GN) to the N number of antenna elements (A1, . . . , AN), respectively, so that a spiral beam (H) with the equiphase surface inclined spirally is output from the signal emitting means (A).

Abstract: An antenna orientation adjustment device (200) include a camera (210), nut runners (220 and 230), and a motion controller (400). The nut runners (220 and 230) can be mounted on an azimuth adjustment bolt (160) and an elevation adjustment bolt (180), respectively. The nut runners (220 and 230) change the orientation of an antenna unit by applying motor power to the azimuth adjustment bolt (160) and the elevation adjustment bolt (180). The motion controller (400) calculates an angle position of the antenna unit (110) where a reception strength is maximum based on an image taken by the camera (210) and a reception strength of radio waves received by the antenna unit (110), and then adjusts the antenna unit (110) to the angle position where the reception strength is maximum by supplying a drive signal to the azimuth adjustment bolt (160) and the elevation adjustment bolt (180).

Abstract: The antenna device includes an antenna unit (110) mounted so that its direction is adjustable, a motor-driven unit (124, 125) that changes a direction of the antenna unit (110), a camera (130) fixed so that its direction relative to the antenna unit (110) does not change, and a direction adjustment control unit (200) that supplies a drive signal to the motor-driven unit (124, 125) and adjusts the direction of the antenna unit (110). The direction adjustment control unit (200) performs feedback control to return the direction of the antenna unit (110) back to an initial direction based on an image taken by the camera (130). It is thereby possible to maintain the communication quality even when a mechanical vibration occurs in a structure on which an antenna device is mounted.

Abstract: An antenna orientation adjustment assistance device that allows any worker to quickly and accurately install an antenna device is provided. An antenna device (100) is temporarily installed. Further, a camera (200) is mounted on the antenna device (100). Then, the antenna orientation adjustment assistance device includes a reception strength detection unit (420) that detects a reception strength of radio waves received by an antenna unit (110), a position calculation unit (414) that calculates a relative angle position of the antenna unit (110) by using an image taken by a camera (200) fixed relative to the antenna unit (110), and a reception strength recording unit (430) that records the relative angle position of the antenna unit (110) and the reception strength at the relative angle position in association with each other.

Abstract: The base station includes: a first combiner which weights the BB signals received by first and second antenna elements by first and second weight coefficients and adds them; a second combiner which weights the BB signals received by third and fourth antenna elements by first and second weight coefficients and adds them; a third combiner which weights the BB signals added by the first and second combiners by third and fourth weight coefficients and adds them; a first processor which calculates such first and second weight coefficients that a combined polarization of the received signals of each antenna is orthogonal to a polarization of an interfering signal existing in the same direction as a desired signal; and a second processor which calculates such third and fourth coefficients that a null is formed in a direction different from the desired signal and in which an interfering signal exists.

Abstract: A base station of the present invention includes: first and second antenna elements that have polarization characteristics orthogonal to each other; a first converter that converts a received signal of the first antenna element into a baseband signal; a first multiplier that weights the baseband signal converted by the first converter by multiplying a first weight coefficient; a second converter that converts a received signal of the second antenna element into a baseband signal; a second multiplier that weights the baseband signal converted by the second converter by multiplying a second weight coefficient; an adder that adds the baseband signals weighted by the first and second multipliers and outputs the sum; and, a signal processor that calculates the first and second coefficients by MMSE such that the combined polarization of the received signals of the first and second antenna elements will be orthogonal to the polarization of an interference signal.

Abstract: The base station includes: a first combiner which weights the BB signals received by first and second antenna elements by first and second weight coefficients and adds them; a second combiner which weights the BB signals received by third and fourth antenna elements by first and second weight coefficients and adds them; a third combiner which weights the BB signals added by the first and second combiners by third and fourth weight coefficients and adds them; a first processor which calculates such first and second weight coefficients that a combined polarization of the received signals of each antenna is orthogonal to a polarization of an interfering signal existing in the same direction as a desired signal; and a second processor which calculates such third and fourth coefficients that a null is formed in a direction different from the desired signal and in which an interfering signal exists.

Abstract: A base station of the present invention includes: first and second antenna elements that have polarization characteristics orthogonal to each other; a first converter that converts a received signal of the first antenna element into a baseband signal; a first multiplier that weights the baseband signal converted by the first converter by multiplying a first weight coefficient; a second converter that converts a received signal of the second antenna element into a baseband signal; a second multiplier that weights the baseband signal converted by the second converter by multiplying a second weight coefficient; an adder that adds the baseband signals weighted by the first and second multipliers and outputs the sum; and, a signal processor that calculates the first and second coefficients by MMSE such that the combined polarization of the received signals of the first and second antenna elements will be orthogonal to the polarization of an interference signal.

Abstract: Disclosed is a radio communication system for performing MIMO transmission including: a first radio communication apparatus including an array antenna in which a plurality of first antennas each having two orthogonally polarized wave characteristics are arranged in an array configuration at predetermined intervals; and a second radio communication apparatus including a plurality of second antennas each having a polarized wave characteristic which are intermediate in angle between the two orthogonally polarized wave characteristics, the plurality of second antennas being arranged at predetermined interval, wherein the first radio communication apparatus forms a directional beam using the array antenna and performs the MIMO transmission using the two orthogonally polarized wave characteristics. The array antenna may be formed by using a plurality of antennas having a right-handed circularly polarized wave characteristic and a left-handed circularly polarized wave characteristic.

Abstract: A cellular phone base station rental service allows a communication service provider, without using the costs of installing base stations on its own, to expand communication service areas to any places desired by users.

Abstract: A reception unit receives signals from a plurality of radio terminals. A transmission unit transmits signals to the radio terminals. A direction determination unit determines the directions of the radio terminals viewed from the transmission unit on the basis of the signals received by the reception unit. A group selection unit distributes, by using a threshold, the transmission powers or downlink data transmission rates of radio terminals which transmit signals in a time-overlapping manner, thereby classifying the radio terminals into two groups. Then, the group selection unit selects a group having a smaller total number of radio terminals. A directivity pattern control unit controls a directivity pattern on the basis of the directions of the radio terminals determined by the direction determination unit.

Abstract: A calibration apparatus for an array of antenna elements. The apparatus includes a plurality of first antenna elements in the array of antenna elements, and a calibration signal supplier for supplying a calibration signal to a second antenna element near at least two first antenna elements, or a coupler connected to the first antenna element. The calibration apparatus further includes a section which obtains a relative phase fluctuation between the antenna elements based on the calibration signal received by the plurality of antenna elements and user signals received respectively by the antenna elements.

Abstract: An array antenna calibration apparatus simple in configuration and inexpensive while ensuring an accurate calibration of an array antenna is provided.

Abstract: A null direction control method allows optimum antenna weights forming designated null beam directions without calculating an inverse matrix. In an N-element array antenna, a designated null beam antenna pattern is obtained by processing a 2-element antenna weight vector forming a null in a sequentially selected one of M designated null directions and a (N−M)-element antenna weight vector forming a beam in a designated beam direction to produce an antenna weight vector for the N-element array antenna. The final antenna weight vector is calculated by incrementing the number of elements of a work antenna weight vector each time a null is formed in a sequentially selected one of the M designated null directions.

Abstract: An array antenna calibration apparatus simple in configuration and inexpensive while ensuring an accurate calibration of an array antenna is provided.

Abstract: A method for estimating an arrival direction of a desired wave in which the arrival direction of the desired wave can be estimated even in case of existence of a multiple reflection wave. An identical signal series is repetitively transmitted two or more times from a transmitting side. The transmitted signal series is received by an array antenna having a plurality of element antennas on a receiving side. When the signal is received by each of the element antennas, cross-correlation is calculated between the signal series corresponding to the different repetition of the signal transmission from the transmitting side. Then, a MUSIC algorithm or an ESPRIT algorithm using the cross-correlation matrix is applied to estimate the arrival direction of the desired wave.

Abstract: The apparatus of the present invention includes: a plurality of first antenna elements in said antenna elements for calibration; a calibration signal supplier for supplying a calibration signal to a second antenna element near at least two first antenna elements, or a coupler connected to said first antenna element; a section which obtains a relative phase fluctuation between the antenna elements based on the calibration signal received by the plurality of antenna elements and user signals received respectively by the antenna elements; a calibration factor supplier which obtains a relative amplitude fluctuation between the antenna elements of the array antenna based on the calibration signals received by at least first antenna elements and the user signals received respectively by the antenna elements; and a beam former which calibrates the user signals received respectively by the antenna elements using the relative phase fluctuation and the relative amplitude fluctuation.

Abstract: A null direction control method allows optimum antenna weights forming designated null beam directions without calculating an inverse matrix. In an N-element array antenna, a designated null beam antenna pattern is obtained by processing a 2-element antenna weight vector forming a null in a sequentially selected one of M designated null directions and a (N−M) -element antenna weight vector forming a beam in a designated beam direction to produce an antenna weight vector for the N-element array antenna. The final antenna weight vector is calculated by incrementing the number of elements of a work antenna weight vector each time a null is formed in a sequentially selected one of the M designated null directions.