Radio communication method and radio base transmission station

Abstract

An antenna pattern assigning method capable of avoiding interference between a plurality of base transmission stations constituting a radio system in a cellular type broad band communication. In the radio system, when assigning a fixed beam pattern different for each frequency, each of the radio base transmission station devices transmits a radio wave having a directivity pattern having a peak in the same direction in two or more different frequencies, and between adjacent radio base transmission station devices, radio transmission is performed by using different directivity patterns in the two or more frequencies.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a conventional example of allocation of an antenna pattern for a signal base transmission station (narrow band).

FIG. 2 shows an example of an antenna pattern.

FIG. 3A and FIG. 3B show examples of an antenna pattern when SDMA is executed (6-SDMA case).

FIG. 4A to FIG. 4D show examples of an antenna pattern when SDMA is executed (3-SDMA case).

FIG. 5 shows a conventional example of allocation of an antenna pattern for a signal base transmission station (broad band).

FIG. 6 shows a conventional example of allocation of an antenna pattern for a plurality of base transmission stations (broad band).

FIG. 7 shows an example of allocation of an antenna pattern for a plurality of base transmission stations (broad band) according to the present invention.

FIG. 8 shows an example of allocation of an antenna pattern for a plurality of base transmission stations (6-SDMA case) according to the present invention.

FIG. 9 shows an example of allocation of an antenna pattern for a plurality of base transmission stations (3-SDMA case) according to the present invention.

FIG. 10 shows a configuration of a radio base transmission station device according to the present invention.

FIG. 11 shows an example of frequency characteristic of C/I when the present invention is executed.

FIG. 12 shows a conventional down link SDMA beam transmission device (narrow band).

FIG. 13 shows a conventional down link SDMA beam transmission device (broad band).

FIG. 14 shows a flow diagram for channel allocation.

FIG. 15 shows a configuration of an entire system.

Claims

1. A radio communication method using two or more radio base transmission station devices having a function to transmit or receive a radio signal by a fixed directivity pattern and capable of selecting the directivity pattern according to the frequency, wherein each of the radio base transmission station devices transmits or receives a signal by a radio wave having a directivity pattern having a peak in the same direction in two or more different frequencies and, between adjacent radio base transmission station devices, a signal is transmitted or received with the two or more different frequencies each combined with a directivity pattern in different correspondence patterns.

2. The radio communication method as claimed in claim 1, wherein the radio base transmission station device has a function for temporally switching the directivity pattern and transmits or receives a signal by a radio wave having the directivity pattern having a peak in the same direction in two or more different channels, each of which is a unit for setting a directivity pattern formed by a matrix of frequency and time, and between adjacent radio base transmission station devices, a signal is transmitted or received with the two or more different channels being combined with the directivity pattern in different correspondence patterns.

3. The radio communication method as claimed in claim 1, wherein at least seven adjacent radio base transmission station devices are combined as a set, in which each of the radio base transmission station devices transmits or receives a signal by a radio wave having a directivity pattern having a peak in the same direction in two or more different frequencies and, between different radio base transmission station devices, a signal is transmitted or received with the two or more different frequencies each being combined with the directivity pattern in different correspondence patterns, and wherein a set formed by at least seven adjacent radio base transmission station devices is cyclically repeated.

4. The radio communication method as claimed in claim 1, wherein the Walsh function is used for generating a correspondence pattern for combining the frequency with the directivity pattern between adjacent radio base transmission station devices.

5. A radio base transmission station device comprising a memory for storing a plurality of directivity patterns different according to frequencies, a beam forming block for forming a beam for each of the frequencies by applying an array weight to a down link signal according to the directivities stored in the memory, an IFFT block for subjecting an output of the beam forming block to inverse fast Fourier transform, and an analog front end block for converting an output of the IFFT block into an analog signal and transmitting it from an antenna; wherein the array weight stored in the memory generates a directivity pattern having a peak in the same direction in two or more different frequencies and combines the two or more different frequencies each with a directivity pattern in different correspondence patterns between adjacent radio base transmission station devices.

6. The radio base transmission station device as claimed in claim 5, wherein the beam forming block has a function of temporally switching the directivity pattern, the array weight stored in the memory generates a directivity having a peak in the same direction in two or more different channels, each channel being formed by a matrix of frequency and time as a unit for setting the directivity pattern and said array weight combines the two or more different channels each with a directivity pattern in a different correlation pattern from an adjacent radio base transmission station device.

7. The radio base transmission station device as claimed in claim 5, wherein the radio base transmission station device belongs to a radio communication system in which at least seven adjacent radio base transmission station devices are combined as a set and an array weight stored in a memory of each radio base transmission station device in the set generates a directivity pattern having a peak in the same direction in two or more different frequencies and combines the two or more different frequencies each with a directivity pattern in a different correspondence pattern from a different radio base transmission station device in the set.

8. The radio base transmission station device as claimed in claim 5, wherein the Walsh function is used to define a combination of a frequency and a directivity pattern in order to generate a different correspondence pattern from an adjacent radio base transmission station device.

9. A radio communication system comprising at least two radio base transmission station devices having a function of transmitting or receiving a radio signal by a fixed directivity pattern and capable of selecting the directivity pattern according to a frequency, wherein each of the radio base transmission station devices transmits or receives a signal by a radio wave having a directivity pattern having a peak in the same direction in two or more different frequencies and, between adjacent radio base transmission station devices, a signal is transmitted or received with the two or more different frequencies each combined with a directivity pattern in different correspondence patterns.

10. The radio communication system as claimed in claim 9, wherein the radio base transmission station device has a function of temporally switching the directivity pattern and transmits or receives a signal by a radio wave having the directivity pattern having a peak in the same direction in two or more different channels, each channel being a unit for setting a directivity pattern formed by a matrix of frequency and time, and between adjacent radio base transmission station devices, a signal is transmitted or received with the two or more different channels each combined with a directivity pattern in different correspondence patterns.

11. The radio communication system as claimed in claim 9, wherein at least seven adjacent radio base transmission station devices are combined as a set, in which each of the radio base transmission station devices transmits or receives a signal by a radio wave having a directivity pattern having a peak in the same direction in two or more different frequencies and, between different radio base transmission station devices, a signal is transmitted or received in the two or more different frequencies each combined with a directivity pattern in different correspondence patterns, and wherein a set formed by at least seven adjacent radio base transmission station devices is cyclically repeated.

12. The radio communication system as claimed in claim 9, wherein the Walsh function is used for generating a correspondence pattern for combining the frequency with the directivity pattern between adjacent radio base transmission station devices.