摘要:
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.
摘要:
There is provided an antenna including (a) a first micro-strip antenna, (b) a second micro-strip antenna spaced away from and facing the first micro-strip antenna, (c) a ground plate located between the first and second micro-strip antennas, the ground plate being formed with an opening overlapping both the first and second micro-strip antennas, (d) a first dielectric material sandwiched between the first micro-strip antenna and the ground plate, (e) a second dielectric material sandwiched between the second micro-strip antenna and the ground plate, and (f) a micro-strip line formed on a surface of the first dielectric material and connected to the first micro-strip antenna. In accordance with the antenna, when electromagnetic wave is supplied to the first micro-strip antenna, the first micro-strip antenna resonates and radiates electromagnetic waves to atmosphere therearound. The second micro-strip antenna is electromagnetically coupled to the first micro-strip antenna through the opening formed at the ground plate. As a result, the second micro-strip antenna resonates to the first micro-strip antenna to thereby radiate electromagnetic waves to atmosphere similarly to the first micro-strip antenna. Hence, the antenna is able to have bi-directional or non-directional characteristic. In addition, since electric power is supplied only to the first micro-strip antenna, it is no longer necessary for the antenna to include a three-dimensional power distributor unlike a conventional antenna, ensuring that the antenna can be fabricated in a smaller size.
摘要:
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.
摘要:
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. A system for providing this service includes a cellular phone base station that borrows partial or all communication resources of communication lines in a prescribed area from a cellular phone service provider that lends communication resources of lines, to perform communications through a public IP network, the cellular phone base station being disposed within the area, a terminal registration authenticating device for base station authenticates whether the cellular phone terminals are registered with the cellular phone base station, and only when they are authenticated to be registered, transmits information specific to the area of the base station to the cellular phone terminal, a terminal registration authenticating device for the cellular phone service provider determines whether the cellular phone terminals having not been authenticated to be registered are registered with the cellular phone service provider; and transmits the result. Communication services are performed using communication resources lent to only the cellular phone terminals having been authenticated to be registered, cellular phone terminals having not been authenticated to be registered are enabled to perform communications using surplus communication resources of the cellular phone base station.
摘要:
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.
摘要:
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. The calibration apparatus further includes 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.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
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.