RADIO STATION, TRANSMITTING STATION, AND FREQUENCY BAND SHARING METHOD

• US 20110009141A1
• Filed: 07/08/2010
• Published: 01/13/2011
• Est. Priority Date: 07/10/2009
• Status: Active Grant

• Current Assignee: NTT Docomo Incorporated (Nippon Telegraph and Telephone Corporation)
• Original Assignee: NTT Docomo Incorporated (Nippon Telegraph and Telephone Corporation)
• Inventors: Oya, Tomoyuki, Harada, Hiroki, Asai, Takahiro, Fujii, Hiromasa
• Granted Patent: US 8,396,498 B2
• Time in Patent Office: Days
• US Class Current: 455/509
• CPC Class Codes: H04W 16/14 Spectrum sharing arrangements between different networks
• CPC Class Codes: H04W 52/243 taking into account interferences
• CPC Class Codes: H04W 88/08 Access point devices

Abstract

The invention has a step where a transmitting station in a second radio communication system determines whether transmission of a second radio communication system signal using a shared frequency band is possible or not based on load information of a first radio communication system broadcast from a base station in the first radio communication system, a step where the transmitting station in the second radio communication system calculates predicted interference power caused in a receiving station in the first radio communication system by the second radio communication system signal transmitted using the shared frequency band, and a step where the base station in the first radio communication system increases an allowable interference level of a first radio communication system signal transmitted using the shared frequency band based on the predicted interference power broadcast from the transmitting station in the second radio communication system.

Claims

1. A radio station for controlling a first radio communication system signal transmitted using a shared frequency band which a first radio communication system uses in priority to a second radio communication system, comprising:

a broadcast section that broadcasts load information of the first radio communication system to a transmitting station in the second radio communication system;

an acquisition section that acquires predicted interference power caused in a receiving station in the first radio communication system by a second radio communication system signal that is transmitted using the shared frequency band from the transmitting station in the second radio communication system; and

an allowable interference level control section that increases an allowable interference level of the first radio communication system signal transmitted using the shared frequency band, based on the predicted interference power acquired in the acquisition section.

2. The radio station according to claim 1, wherein the allowable interference level control section increases transmission power of the first radio communication system signal or decreases a transmission rate of the first radio communication system signal, based on the predicted interference power acquired in the acquisition section.

3. The radio station according to claim 1, further comprising:

a frequency band switching section that switches a frequency band of the first radio communication system signal from the shared frequency band to a dedicated frequency band of the first radio communication system,

wherein the acquisition section acquires priority information of the first radio communication system signal and the second radio communication system signal, and reception quality information of the first radio communication system signal, in addition to the predicted interference power, and

the frequency band switching section switches the frequency band of the first radio communication system signal from the shared frequency band to the dedicated frequency band, based on at least one of the priority information and the reception quality information.

4. The radio station according to claim 3, wherein the acquisition section acquires load information of the second radio communication system, in addition to the predicted interference power, the priority information and the reception quality information, and

the frequency band switching section switches the frequency band of the first radio communication system signal from the shared frequency band to the dedicated frequency band, based on at least one of the priority information, the reception quality information, and the load information of the second radio communication system.

5. The radio station according to claim 1, further comprising:

an adjacent cell interference control section that decreases interference power caused in the receiving station in the first radio communication system by an adjacent cell, based on the predicted interference power acquired in the acquisition section.

6. A transmitting station for transmitting a second radio communication system signal to a receiving station in a second radio communication system, using a shared frequency band which a first radio communication system uses in priority to the second radio communication system, comprising:

an acquisition section that acquires load information of the first radio communication system;

a transmission determining section that determines whether transmission of the second radio communication system signal using the shared frequency band is possible or not, based on the load information acquired in the acquisition section;

a predicted interference power calculating section that calculates predicted interference power caused in a receiving station in the first radio communication system by the second radio communication system signal transmitted using the shared frequency band; and

a broadcast section that broadcasts the predicted interference power calculated in the predicted interference power calculating section to the first radio communication system.

7. The transmitting station according to claim 6, further comprising:

a channel state estimating section that estimates a channel state between the receiving station in the first radio communication system and the transmitting station,

wherein the transmission determining section determines whether transmission of the second radio communication system signal using the shared frequency band is possible or not, based on the load information acquired in the acquisition section and the channel state estimated in the channel state estimating section.

8. The transmitting station according to claim 6, wherein the broadcast section broadcasts priority information of the second radio communication system signal transmitted using the shared frequency band, in addition to the predicted interference power.

9. The transmitting station according to claim 8, wherein the broadcast section broadcasts load information of the second radio communication system, in addition to the predicted interference power and the priority information.

10. A frequency band sharing method in which a first radio communication system and a second radio communication system share a shared frequency band which the first radio communication system uses in priority to the second radio communication system, comprising:

broadcasting, in a radio station in the first radio communication system, load information of the first radio communication system to a transmitting station in the second radio communication system;

determining, in the transmitting station in the second radio communication system, whether transmission of a second radio communication system signal from the transmitting station using the shared frequency band is possible or not, based on the broadcast load information of the first radio communication system;

calculating, in the transmitting station in the second radio communication system, predicted interference power caused in a receiving station in the first radio communication system by the second radio communication system signal transmitted using the shared frequency band;

broadcasting, in the transmitting station in the second radio communication system, the calculated predicted interference power to the radio station in the first radio communication system; and

increasing, in the radio station in the first radio communication system, an allowable interference level of a first radio communication system signal transmitted using the shared frequency band, based on the broadcast predicted interference power.