Mobile communication control method and system and mobile station thereof

• US 20020061731A1
• Filed: 11/21/2001
• Published: 05/23/2002
• Est. Priority Date: 11/22/2000
• Status: Active Grant

• Current Assignee: NEC Corporation
• Original Assignee: NEC Corporation
• Inventors: Hamabe, Kojiro, Takano, Nahoko
• Granted Patent: US 7,031,712 B2
• Time in Patent Office: Days
• US Class Current: 455/67.11
• CPC Class Codes: H04B 7/022 Site diversity; Macro-diversity using two or more spaced independent antennas H04B7/04
• CPC Class Codes: H04W 52/40 during macro-diversity or soft handoff

Abstract

In case of making site selection diversity transmit power control, all handover base stations are enabled for transmission depending on a state of the transmission power value of a dedicated data signal from the base stations, thereby preventing a trafic capacity from decreasing due to an increase in the transmission power of a dedicated control signal at a non-transmitting base station, or a received signal quality from degrading at a mobile station because the transmission power value of the transmitting base station reaches a maximum transmission power of base station. A mobile station measures a common pilot signal and a dedicated control signal transmitted from each handover base station by means of a receiving monitor, estimates the transmission power value of the dedicated control signal at each handover base station from a difference thereof, and estimates a difference in the transmission power value of the dedicated control signal between the handover base stations. In the case where this difference is greater than or equal to a predetermined threshold value, a transmitting base station designating section designates all of the handover base stations to be enabled for transmission.

Claims

1. A mobile communication control method in which a mobile station sets a link with one or more base stations, comprising the steps of:

measuring a received signal quality of a pilot signal transmitted from each of said base stations;

determining one or more transmitting base stations from among the base stations with which the mobile station has set the link (hereafter referred to as active set base station) in accordance with the measured results; and

notifying the determined result to said active set base stations,

wherein all of the active set base stations are enabled for transmission depending on a state of the transmission power value from said transmitting base stations.

2. The mobile communication control method according to claim 1, further comprising the steps of:

transmitting a dedicated control signal to said mobile station in said active set base station;

transmitting a dedicated data signal in addition to said dedicated control signal to said mobile station in said transmitting base station; and

estimating a transmission power value of the dedicated control signal transmitted by said active set base station, and making all of the active set base stations the transmitting base station, if an estimated value of the transmission power value of the dedicated control signal transmitted by the active set base station other than said transmitting base stations is greater than or equal to a predetermined threshold value for the estimated value of transmission power value of the dedicated control signal transmitted by said transmitting base station in said mobile station.

3. The mobile communication control method according to claim 1, further comprising the steps of:

transmitting a dedicated data signal to said mobile station in said transmitting base station; and

estimating a transmission power value of the dedicated data signal transmitted by said transmitting base station, and making all of the active set base stations the transmitting base station if a difference between an estimated value of the transmission power value of said transmitting base station and the predetermined maximum transmission power value of base station is smaller than or equal to a predetermined threshold value in said mobile station.

4. The mobile communication control method according to claim 2, further comprising a step of measuring the received powers of a common pilot signal that said active set base station transmits at a predetermined power value and said dedicated control signal or said dedicated data signal transmitted at a power value under the transmission power control in said mobile station, and estimating a power value of said dedicated control signal or said dedicated data signal from a difference between the received power of said common pilot signal and the received power of said dedicated control signal or said dedicated data signal.

5. The mobile communication method according to claim 1, further comprising a step of measuring the received signal quality of the dedicated data signal transmitted from said transmitting base station in said mobile station, and making all of the active set base stations the transmitting base station, in the case where the received signal quality is less than a predetermined signal quality even if said transmitting base station makes the transmission at the predetermined maximum transmission power value.

6. A mobile communication system in which a mobile station sets a link with one or more base stations, measures a received signal quality of a pilot signal transmitted from each of said base stations, determines one or more transmitting base stations from among the base stations with which the mobile station has set the link (hereafter referred to as active set base station) in accordance with the measured results, and notifies the determined result to said active set base stations,

wherein all of the active set base stations are enabled for transmission depending on a state of the transmission power value from said transmitting base stations.

7. The mobile communication system according to claim 6,

wherein said active set base station transmits a dedicated control signal to said mobile station, said transmitting base station transmits a dedicated data signal in addition to the dedicated control signal, and said mobile station estimates a transmission power value of the dedicated control signal transmitted by said active set base station, wherein all of the active set base stations are enabled for transmission, if an estimated value of the transmission power value of the dedicated control signal transmitted by the active set base station other than said transmitting base stations is greater than or equal to a predetermined threshold value for the estimated value of transmission power value of the dedicated control signal transmitted by said transmitting base station.

8. The mobile communication system according to claim 6,

wherein said transmitting base station transmits a dedicated data signal to said mobile station, and said mobile station estimates a transmission power value of the dedicated data signal transmitted by said transmitting base station, and

all of the active set base stations are enabled for transmission, if a difference between an estimated value of the transmission power value of said transmitting base station and the predetermined maximum transmission power value of base station is smaller than or equal to a predetermined threshold value.

9. The mobile communication system according to claim 7,

wherein said mobile station measures the received powers of a common pilot signal that said active set base station transmits at a predetermined power value and said dedicated control signal or said dedicated data signal transmitted at a power value under the transmission power control, and estimates a power value of said dedicated control signal or said dedicated data signal from a difference between the received power of said common pilot signal and the received power of said dedicated control signal or said dedicated data signal.

10. The mobile communication system according to claim 6,

wherein said mobile station measures the received signal quality of a signal transmitted from said transmitting base station, and

all of the active set base stations are enabled for transmission, in the case where the received signal quality is less than a predetermined signal quality even if said transmitting base station makes the transmission at the predetermined maximum transmission power value.

11. A mobile station which sets a link with one or more base stations, comprising means for measuring the received signal quality of a pilot signal transmitted from said base stations;

means for determining one or more transmitting base stations from among the base stations with which the mobile station has set the link (hereafter referred to as active set base station) in accordance with the measured results; and

means for notifying the determined result to said active set base stations,

wherein it is controlled that all of the active set base stations are enabled for transmission depending on a state of the transmission power value of said one or more transmitting base stations.

12. The mobile station according to claim 11,

wherein said mobile station estimates a transmission power value of the dedicated control signal transmitted by said active set base station, and notifies that all of the active set base stations are enabled for transmission in the case where an estimated value of the transmission power value of said dedicated control signal transmitted by the active set base station other than said transmitting base stations is greater than or equal to a predetermined threshold value for the estimated value of transmission power value of the dedicated control signal transmitted by said one or more transmitting base stations.

13. The mobile station according to claim 11,

wherein said mobile stations estimates a transmission power value of the dedicated data signal transmitted by said transmitting base stations, and notifies that all of the active set base stations are enabled for transmission in the case where a difference between an estimated value of the transmission power value of said transmitting base station and the predetermined maximum transmission power value of base station is smaller than or equal to a predetermined threshold value.

14. The mobile station according to claim 12,

wherein said mobile station measures the received powers of a common pilot signal that said active set base station transmits at a predetermined power value and said dedicated control signal or said dedicated data signal transmitted at a power value under the transmission power control, and estimates a power value of said dedicated control signal or said dedicated data signal from a difference between the received power of said pilot signal and the received power of said dedicated control signal or said dedicated data signal.

15. The mobile station according to claim 11,

wherein said mobile station measures the received signal quality of a signal transmitted from said transmitting base station, and notifies that all of the active set base stations are enabled for transmission in the case where the received signal quality is less than a predetermined signal quality even if said transmitting base station makes the transmission at the predetermined maximum transmission power value.