Base station transmission power control system mobile station and base station
First Claim
1. A base station transmission power control system in a code division multi access cellular mobile radio communication system comprising a plurality of base stations respectively announcing unique pilot signals and a mobile station which is capable of simultaneously establishing connection with a soft hand over base station group consisted of some base stations out of said base stations in the system, whereinsaid mobile station detecting a communication reception quality and a primary base station among sad base stations, reception level of pilot signal of which becomes maximum among pilot signals received from respective base stations in said soft hand over base station group, notifying a base station number of said primary base station as a transmission power control signal for respective of said base stations in said soft hand over base station group when said communication reception quality is lower than a desired quality, and notifying a number other than the base station number of the base stations in said soft hand over bases group when said communication reception quality is in excess of said desired quality;
- and each base station in said soft hand over base station group receiving said transmission power control signal and being restricted a transmission power when a content of said transmission power control signal identifies number other than own base station number;
wherein each base station in said soft hand over base station group manages two transmission power values including a first transmission power value and a second transmission power value, deceases said first transmission power value when the content of said transmission power control signal identifies number other than said base station number in said soft hand over base station group, increases said first transmission power value when the content of said transmission power control signal identifies any one of said base station number in said soft hand over base station group, selectively sets one of said first transmission power value and a minimum transmission power value as said second transmission power value, sets said first transmission power value as said second transmission power value when the content of said transmission power control signal identifies own base station number, sets said minimum transmission power value as said second transmission power value when the content of said transmission power control signal identifies said base station number in said soft hand over base station group other than own base station number, sets said first transmission power value as said second transmission power value when the content of said transmission power control signal identifies other than base station number in said soft hand over base station group and when said first transmission power value is set as said second transmission power value in the preceding time, sets said minimum power value as said second transmission power value when the content of said transmission power control signal identifies base station number other than the base station number in said soft hand over base station group and said minimum transmission power value is set as said second transmission power value in the preceding time, and takes said second transmission power value as an output value of a transmission amplifier device.
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Accused Products
Abstract
In soft hand over in a code division multi access mobile radio communication system, interference in a down link caused by transmission from a plurality of base stations for one mobile station, can be restricted. Control of transmission power is performed according to command from the mobile station only in the base station serving as a primary base station which has minimum propagation loss with the mobile station during soft hand over, and the base stations other than the primary base station perform transmission with restricting output. In comparison with the transmission power control performed by the conventional plural base station transmission, interference for the peripheral mobile station can be reduced to achieve higher down link capacity. Also, upon restricting transmission power of the base station other than the base stations having small propagation loss with the mobile station among base station group in soft hand over, by moderately attenuating the transmission power instead of restricting abruptly, degradation of the reception quality can be prevented when error is caused in selection of the base station.
37 Citations
12 Claims
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1. A base station transmission power control system in a code division multi access cellular mobile radio communication system comprising a plurality of base stations respectively announcing unique pilot signals and a mobile station which is capable of simultaneously establishing connection with a soft hand over base station group consisted of some base stations out of said base stations in the system, wherein
said mobile station detecting a communication reception quality and a primary base station among sad base stations, reception level of pilot signal of which becomes maximum among pilot signals received from respective base stations in said soft hand over base station group, notifying a base station number of said primary base station as a transmission power control signal for respective of said base stations in said soft hand over base station group when said communication reception quality is lower than a desired quality, and notifying a number other than the base station number of the base stations in said soft hand over bases group when said communication reception quality is in excess of said desired quality; - and
each base station in said soft hand over base station group receiving said transmission power control signal and being restricted a transmission power when a content of said transmission power control signal identifies number other than own base station number;
wherein each base station in said soft hand over base station group manages two transmission power values including a first transmission power value and a second transmission power value, deceases said first transmission power value when the content of said transmission power control signal identifies number other than said base station number in said soft hand over base station group, increases said first transmission power value when the content of said transmission power control signal identifies any one of said base station number in said soft hand over base station group, selectively sets one of said first transmission power value and a minimum transmission power value as said second transmission power value, sets said first transmission power value as said second transmission power value when the content of said transmission power control signal identifies own base station number, sets said minimum transmission power value as said second transmission power value when the content of said transmission power control signal identifies said base station number in said soft hand over base station group other than own base station number, sets said first transmission power value as said second transmission power value when the content of said transmission power control signal identifies other than base station number in said soft hand over base station group and when said first transmission power value is set as said second transmission power value in the preceding time, sets said minimum power value as said second transmission power value when the content of said transmission power control signal identifies base station number other than the base station number in said soft hand over base station group and said minimum transmission power value is set as said second transmission power value in the preceding time, and takes said second transmission power value as an output value of a transmission amplifier device.
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2. A base station transmission power control system in a code division multi access cellular mobile radio communication system comprising a plurality of base stations respectively announcing unique pilot signals and a mobile station which is capable of simultaneously establishing connection with a soft hand over base station group consisted of some base stations out of said base stations in the system, wherein
said mobile station detecting a communication reception quality and a primary base station among said base stations, reception level of pilot signal of which becomes maximum among pilot signals received from respective base stations in said soft hand over base station group, notifying a base station number of said primary base station as a transmission power control signal for respective of said base stations in said soft hand over base station group when said communication reception quality is lower than a desired quality, and notifying a number other than the base station number of the base stations in said soft hand over base station group when said communication reception quality is in excess of said desired quality; - and
each base station in said soft hand over base station group receiving said transmission power control signal and being restricted a transmission power when a content of said transmission power control signal identifies number other than own base station number;
wherein each base station of said soft hand over base station group increases the transmission power when said transmission power control signal expresses the base station number of own base station and decreases said transmission power when said transmission power control signal does not express the base station number of own base station.
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3. A base station transmission power control system in a code division multiple access cellular mobile radio communication system comprising:
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a plurality of base stations respectively announcing unique pilot signals and a mobile station which is capable of simultaneously establishing connection wit a soft hand over base station on group including some of base stations out of said base stations in the system, wherein said mobile station detects a communication reception quality and a primary base station among said base stations, reception level of pilot signal of which becomes maximum among pilot signals received from respective base stations in said soft hand over base station group, sets a power increasing symbol in a transmission power control bit when said communication reception quality dose not exceed a desired quality, sets a power decreasing symbol in the transmission power control bit when said communication reception quality exceeds said desired quality, transmits said transmission power control bit to said soft hand over base station group and intermittently transmits said primary base station number, and each base station in said soft hand over base station group receives said transmission power control signal which includes a primary base station number, and restricts a transmission power of own station following to the current timing when said primary base station number is not consistent with own base station, and wherein each base station in said soft hand over base station group manages at least two transmission power values including a first transmission power value and a second transmission power value, increases and decreases said first transmission power value according to said transmission power control bit contained in said transmission power control signal, sets said first transmission power value as said second transmission power value when the primary base station number is received and the received primary base station number is consistent with own base station number, sets a minimum transmission power as said second transmission power value when said primary base station number is received and the received primary base station number is not consistent with own base station number, and uses said second transmission power value as an output value of a transmission amplifier device.
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4. A base station transmission power control system in a code division multiple access cellular mobile radio communication system comprising:
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a plurality of base stations respectively announcing unique pilot signals and a mobile station which is capable of simultaneously establishing connection with a soft hand over base station on group including some of base stations out of said base stations in the system, wherein said mobile station detects a communication reception quality and a primary base station among said base stations, reception level of pilot signal of which becomes maximum among pilot signals received from respective base stations in said soft hand over base station group, sets a power increasing symbol in a transmission power control bit when said communication reception quality dose not exceed a desired quality, sets a power decreasing symbolin the transmission power control bit when said communication reception quality exceeds said desired quality, transmits said transmission power control bit to said hand over base station group and intermittently transmits said primary base station number, and each base station in said soft hand over base station group receives said transmission power control signal which includes a primary base station number, and restricts a transmission power of own station following to the current timing when said primary base station number is not consistent with own base station, and wherein in each base station of said soft hand over base station group increases and decreases transmission power according to said transmission power control bit contained in said transmission power control signal when said primary base station number is received and the received primary base station number is consistent with own base station number and decreases said transmission power irrespective of said transmission power control bit when the primary base station number is received and the received primary base station number is not consistent with own base station number.
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5. A base station transmission power control system in a code division multiple access cellular mobile radio communication system comprising a plurality of base stations respectively announcing unique pilot signals and a mobile station which is capable of simultaneously establishing connection with a soft hand over base station on group including some of base stations out of said base stations in the system, wherein
said mobile station detects a communication reception quality and a primary base station among said base stations, reception level of pilot signal of which becomes maximum among pilot signals received from respective base stations in said soft hand over base station group, sets a power increasing symbol in a transmission power control bit when said communication reception quality dose not exceed a desired quality, sets a power decreasing symbol in the transmission power control bit when said communication reception quality exceeds said desired quality, transmits said transmission power control signal including at least one of said transmission power control bit and said primary base station number to said soft hand over base station group, and each base station in said soft hand over base station group receives said transmission power control signal, and restricts a transmission power of own station when said primary base station number is not consistent with own base station number, and wherein in each base station in said soft hand over base station group manages at least two transmission power values including a first transmission power value and a second transmission power value, increases and decreases said first transmission power value according to said transmission power control bit contained in said transmission power control signal, sets said first transmission power value as said second transmission power value when the primary base station number is received and the received primary base station number is consistent with own base station number, sets a minimum transmission power as said second transmission power value when said primary base station number is received and the received primary base station number is not consistent with own base station number, and uses said second transmission power value as an output value of a transmission amplifier device.
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6. A base station transmission power control system in a code division multiple access cellular mobile radio communication system comprising a plurality of base stations respectively announcing unique pilot signals and a mobile station which is capable of simultaneously establishing connection with a soft hand over base station group including some of base stations out of said base stations in the system, wherein
said mobile station detects a communication reception quality and a primary base station among said base stations, reception level of pilot signal of which becomes maximum among pilot signals received from respective base stations in said soft hand over base stations group, sets a power increasing symbol in a transmission power control bit when said communication reception quality dose not exceed a desired quality, sets a power decreasing symbol in the transmission power control bit when said communication reception quality exceeds said desired quality, transmits a transmission power control signal including at least one of said transmission power control bit and said primary base station number to said soft hand over base station group, and each base station in said soft hand over base station group receives said transmission power control signal, and restricts a transmission power of own station when said primary base station number is not consistent with own base station number, and wherein each base station of said soft hand over base station group increases and decreases transmission power according to said transmission power control bit contained in said transmission power control signal when said primary base station number is received and the received primary base station number is consistent with own base station number and decreases said transmission power irrespective of said transmission power control bit when the primary base station number is received and the received primary base station number is not consistent with own base station number.
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7. A cellular mobile communication system including a plurality of base stations and mobile station, comprising:
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base station number assigning means for temporarily assigning base station numbers for a plurality of base stations in soft hand over with said mobile station;
base station selecting means for selecting the base station which transmits a pilot signal received by said mobile station at a maximum reception intensity among pilot signals transmitted from said base station in soft hand over;
transmission power control signal transmitting means for using a base station number of the selected base station as a transmission power control signal to be transmitted to said base station group in soft hand over from said mobile station; and
transmission power control means for controlling the transmission power of said base station on the basis of said transmission power control signal, the transmission power of the base station other than the selected base station being controlled for sequentially attenuating toward a predetermined minimum power with a given attenuation amount;
wherein said transmission power control means includes virtual power management means for managing a virtual transmission power value premised for the case where the base station is constantly selected irrespective of selection of said base station and transmission power determining means for using said virtual transmission power value as said transmission power value of the base station. - View Dependent Claims (8)
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9. A communication control method in a cellular mobile communication system including a plurality of base stations and mobile station, comprising:
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base station number assigning step of temporarily assigning base station numbers for a plurality of base stations in soft hand over with said mobile station;
base station selecting step of selecting the base station which transmits a pilot signal received by said mobile station at a maximum reception intensity among pilot signals transmitted from said base station in soft hand over;
transmission power control signal transmitting step of using a base station number of the selected base station as a transmission power control signal to be transmitted to said base station group in soft hand over from said mobile station; and
transmission power control step of controlling the transmission power of said base station on the basis of said transmission power control signal, the transmission power of the base station other than the selected base station being controlled for sequentially attenuating toward a predetermined minimum power with a given attenuation amount;
wherein said transmission power control step includes virtual power management step for managing a virtual transmission power value premised for the case where the base station is constantly selected irrespective of selection of said base station and transmission power determining step fro using said vitual transmission power value as said transmission power value of the base station. - View Dependent Claims (10)
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11. A base station in a cellular mobile communication system temporarily assigned the base station number by a mobile station in soft hand over with said mobile station, comprising:
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means for transmitting a pilot signal;
judgment means for receiving a transmission power control signal including a base station number selected as base station which ants a pilot signal received by said mobile station at a maximum reception intensity among pilot signals transmitted from said base station in soft hand over and making judgment whether said base station number is consistent with a number assigned to own station or not; and
transmission power control means for performing sequential attenuation control of the transmission power with a given attenuation amount when said base station number and said number of own station are inconsistent with each other;
wherein said transmission power control means includes virtual power managing means for managing a virtual transmission power value in consideraton of the case where the base station is constantly selected irrespective of judgment made by said judgment means and transmission power determining means for using said virtual transmission power value as the transmission power value of the relevant base station when a certain base station is seleted. - View Dependent Claims (12)
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Specification