Mobile satellite communication system

Claim 2

A mobile satellite communication system in which a base station is connected with a mobile station via a communication satellite, said mobile station comprising: measuring means for obtaining an actual measuring time T k and an average received signal level Q k (k=1, 2, . . . ) in a predetermined measuring period T; and transmission means for informing said base station of said actual measuring time T k and said average received signal level Q k , and said base station comprising: means for extracting said actual measuring time T k and said average received signal level Q k from a received signal sent from said mobile station; means for calculating a total measuring time t k which is a sum total of said actual measuring time T k ; means for obtaining a measuring error ΔD k of an average received signal level in said total measuring time t k ; storing means for storing a total measuring time t k-1 , a corrected average received signal level R k-1 and a transmission power control amount ΔP k-1 at the end of a preceding measuring period of said mobile station; means for obtaining a corrected average received signal level R k at the end of a present measuring period of said mobile station on the basis of said corrected average received signal level R k-1 , said transmission power control amount ΔP k-1 , said total measuring time t k-1 said average received signal level Q k , said actual measuring time T k and said total measuring time t k ; means for calculating a transmission power control amount ΔP k of said base station on the basis of said measuring error ΔD k and a difference between said corrected average received signal level R k and a predetermined reference value R ref of the received signal level of said mobile station; and means for obtaining present transmission power P k from said transmission power control amount ΔP k and preceding transmission power P k-1 , and for controlling the transmission power of said base station by said present transmission power P k .

Claim 3

The mobile satellite communication system as claimed in claim 1, wherein said base station comprises means for setting an initial value P 0 of said transmission power at a predetermined value.

Claim 4

The mobile satellite communication system as claimed in claim 1, wherein said means for calculating a transmission power control amount obtains said present transmission power control amount ΔP k of said base station by adding said measuring error ΔD k to a difference between said reference value R ref of the received signal level and said corrected average received signal level R k .

Claim 5

The mobile satellite communication system as claimed in claim 1, wherein said means for calculating a transmission power control amount obtains said present transmission power control amount ΔP k of said base station by adding a sum of said measuring error ΔD k and a level setting error ΔS k at said base station to a difference between said reference value R ref of the received signal level and said corrected average received signal level R k .

Claim 6

The mobile satellite communication system as claimed in claim 1, wherein said means for obtaining said measuring error obtains said measuring error ΔD k by dividing a predetermined value C by a square root of said total measuring time t k .

Claim 7

The mobile satellite communication system as claimed in claim 1, wherein said means for obtaining said corrected average received signal level obtains said corrected average received signal level R k by the following equation: R.sub.k ={(R.sub.k-1 +ΔP.sub.k-1)t.sub.k-1 +Q.sub.k T.sub.k }/t.sub.k.

Claim 8

A mobile satellite communication system in which a base station is connected with a mobile station via a communication satellite, said mobile station comprising: measuring means for obtaining an actual measuring time T k and an average received signal level Q k (k=1, 2, . . . ) in a predetermined measuring period T; means for calculating a total measuring time t k which is a sum total of said actual measuring time T k ; means for obtaining a measuring error ΔD k of an average received signal level in said total measuring time t k ; storing means for storing a total measuring time t k-1 and a corrected average received signal level R k-1 at the end of a preceding measuring period of said mobile station; means for extracting a transmission power control amount ΔP k-1 from a signal transmitted from said base station to said mobile station; means for obtaining a corrected average received signal level R k at the end of a present measuring period of said mobile station on the basis of said corrected average received signal level R k-1 , said transmission power control amount ΔP k-1 , said total measuring time t k-1 , said average received signal level Q k , said actual measuring time T k and said total measuring time t k ; and transmission means for informing said base station of said corrected average received signal level R k , and said base station comprising: means for extracting said corrected average received signal level R k from a received signal sent from said mobile station; means for calculating said transmission power control amount ΔP k of said base station on the basis of a prestored level setting error ΔS k and a difference between said corrected average received signal level R k and a predetermined reference value R ref of the received signal level of said mobile station; means for obtaining present transmission power P k from said transmission power control amount ΔP k and preceding transmission power P k-1 , and for controlling the transmission power of said base station by said present transmission power P k ; and means for transmitting information on said present transmission power control amount ΔP k to said mobile station.

Claim 9

A mobile satellite communication system in which a base station is connected with a mobile station via a communication satellite, said mobile station comprising: measuring means for obtaining an actual measuring time T k and an average received signal level Q k (k=1, 2, . . . ) in a predetermined measuring period T; means for calculating a total measuring time t k which is a sum total of said actual measuring time T k ; means for obtaining a measuring error ΔD k of an average received signal level in said total measuring time t k ; storing means for storing a total measuring time t k-1 and a corrected average received signal level R k-1 at the end of a preceding measuring period of said mobile station; means for extracting a transmission power control amount ΔP k-1 from a signal transmitted from said base station to said mobile station; means for obtaining a corrected average received signal level R k at the end of a present measuring period of said mobile station on the basis of said corrected average received signal level R k-1 , said transmission power control amount ΔP k-1 , said total measuring time t k-1 , said average received signal level Q k , said actual measuring time T k and said total measuring time t k ; and transmission means for informing said base station of said corrected average received signal level R k , and said base station comprising: means for extracting said corrected average received signal level R k from a received signal sent from said mobile station; means for calculating said transmission power control amount ΔP k of said base station on the basis of a prestored level setting error ΔS k and a difference between said corrected average received signal level R k and a predetermined reference value R ref of the received signal level of said mobile station; means for obtaining present transmission power P k from said transmission power control amount ΔP k and preceding transmission power P k-1 , and for controlling the transmission power of said base station by said present transmission power P k ; and means for transmitting information on said present transmission power control amount ΔP k to said mobile station.

Claim 10

The mobile satellite communication system as claimed in claim 7, wherein said mobile station further comprises means for setting an initial value P 0 of said transmission power at a predetermined value.

Claim 11

The mobile satellite communication system as claimed in claim 7, wherein said means for calculating a transmission power control amount obtains said present transmission power control amount ΔP k of said base station by adding said level setting error ΔS k to a difference between said reference value R ref of the received signal level and said corrected average received signal level R k .

Claim 12

The mobile satellite communication system as claimed in claim 7, wherein said means for obtaining said measuring error obtains said measuring error ΔD k by dividing a predetermined value C by a square root of said total measuring time t k .

Claim 13

The mobile satellite communication system as claimed in claim 7, wherein said means for obtaining corrected average received signal level obtains said corrected average received signal level R k by the following equation: R.sub.k ={(R.sub.k-1 +ΔP.sub.k-1)t.sub.k-1 +Q.sub.k T.sub.k }/t.sub.k -ΔD.sub.k.

Claim 14

A base station in a mobile satellite communication system in which the base station is connected with a mobile station via a communication satellite, said base station comprising: means for extracting from a received signal an actual measuring time T k and an average received signal level Q k (k=1, 2, . . . ) in a predetermined measuring period T, said actual measuring time T k and said average received signal level Q k being obtained at said mobile station and transmitted from said mobile station to said base station; means for calculating a total measuring time t k which is a sum total of said actual measuring time T k ; means for obtaining a measuring error ΔD k of an average received signal level in said total measuring time t k ; storing means for storing a total measuring time t k-1 , a corrected average received signal level R k-1 and a transmission power control amount ΔP k-1 at the end of a preceding measuring period of said mobile station; means for obtaining a corrected average received signal level R k at the end of a present measuring period of said mobile station on the basis of said corrected average received signal level R k-1 , said transmission power control amount ΔP k-1 , said total measuring time t k-1 , said average received signal level Q k , said actual measuring time T and said total measuring time t k ; means for calculating a transmission power control amount ΔP k of said base station on the basis of said measuring error ΔD k and a difference between said corrected average received signal level R k and a predetermined reference value R ref of the received signal level of said mobile station; and means for obtaining present transmission power P k from said transmission power control amount ΔP k and preceding transmission power P k-1 , and for controlling the transmission power of said base station by said present transmission power P k .

Claim 15

A base station in a mobile satellite communication system in which the base station is connected with a mobile station via a communication satellite, said base station comprising: means for extracting from a received signal an actual measuring time T k and an average received signal level Q k (k=1, 2, . . . ) in a predetermined measuring period T, said actual measuring time T k and said average received signal level Q k being obtained at said mobile station and transmitted from said mobile station to said base station; means for calculating a total measuring time t k which is a sum total of said actual measuring time T k ; means for obtaining a measuring error ΔD k of an average received signal level in said total measuring time t k ; storing means for storing a total measuring time t k-1 , a corrected average received signal level R k-1 and a transmission power control amount ΔP k-1 at the end of a preceding measuring period of said mobile station; means for obtaining a corrected average received signal level R k at the end of a present measuring period of said mobile station on the basis of said corrected average received signal level R k-1 , said transmission power control amount ΔP k-1 , said total measuring time t k-1 , said average received signal level Q k , said actual measuring time T and said total measuring time t k ; means for calculating a transmission power control amount ΔP k of said base station on the basis of said measuring error ΔD k and a difference between said corrected average received signal level R k and a predetermined reference value R ref of the received signal level of said mobile station; and means for obtaining present transmission power P k from said transmission power control amount ΔP k and preceding transmission power P k-1 , and for controlling the transmission power of said base station by said present transmission power P k .

Claim 16

A mobile station in a mobile satellite communication system in which a base station is connected with a mobile station via a communication satellite, said mobile station comprising: measuring means for obtaining an actual measuring time T k and an average received signal level Q k (k=1, 2, . . . ) in a predetermined measuring period T; and transmission means for informing said base station of said actual measuring time T k and said average received signal level Q k .

Claim 17

A mobile station in a mobile satellite communication system in which a base station is connected with a mobile station via a communication satellite, said mobile station comprising: measuring means for obtaining an actual measuring time T k and an average received signal level Q k (k=1, 2, . . . ) in a predetermined measuring period T; and transmission means for informing said base station of said actual measuring time T k and said average received signal level Q k .

Claim 18

A mobile station in a mobile satellite communication system in which a base station is connected with a mobile station via a communication satellite, said mobile station comprising: measuring means for obtaining an actual measuring time T k and an average received signal level Q k (k=1, 2, . . . ) in a predetermined measuring period T; means for calculating a total measuring time t k which is a sum total of said actual measuring time means for obtaining a measuring error ΔD k of an average received signal level in said total measuring time t k ; storing means for storing a total measuring time t k-1 and a corrected average received signal level R k-1 at the end of a preceding measuring period of said mobile station; means for extracting a transmission power control amount ΔP k-1 from a signal transmitted from said base station to said mobile station; means for obtaining a corrected average received signal level R k at the end of a present measuring period of said mobile station on the basis of said corrected average received signal level R k-1 , said transmission power control amount ΔP k-1 , said total measuring time t k-1 , said average received signal level Q k , said actual measuring time T k and said total measuring time t k ; and transmission means for informing said base station of said corrected average received signal level R k .

Claim 19

A mobile station in a mobile satellite communication system in which a base station is connected with a mobile station via a communication satellite, said mobile station comprising: measuring means for obtaining an actual measuring time T k and an average received signal level Q k (k=1, 2, . . . ) in a predetermined measuring period T; means for calculating a total measuring time t k which is a sum total of said actual measuring time means for obtaining a measuring error ΔD k of an average received signal level in said total measuring time t k ; storing means for storing a total measuring time t k-1 and a corrected average received signal level R k-1 at the end of a preceding measuring period of said mobile station; means for extracting a transmission power control amount ΔP k-1 from a signal transmitted from said base station to said mobile station; means for obtaining a corrected average received signal level R k at the end of a present measuring period of said mobile station on the basis of said corrected average received signal level R k-1 , said transmission power control amount ΔP k-1 , said total measuring time t k-1 , said average received signal level Q k , said actual measuring time T k and said total measuring time t k ; and transmission means for informing said base station of said corrected average received signal level R k .

Claim 20

A base station in a mobile station in a mobile satellite communication system in which a base station is connected with a mobile station via a communication satellite, said base station comprising: means for extracting a corrected average received signal level R k from a received signal sent from said mobile station; means for calculating a transmission power control amount ΔP k of said base station on the basis of a prestored level setting error ΔS k and a difference between said corrected average received signal level R k and a predetermined reference value R ref of the received signal level of said mobile station; means for obtaining present transmission power P k from said transmission power control amount ΔP k and preceding transmission power P k-1 , and for controlling the transmission power of said base station by said present transmission power P k ; and means for transmitting information on said present transmission power control amount ΔP k to said mobile station.

Claim 21

A base station in a mobile station in a mobile satellite communication system in which a base station is connected with a mobile station via a communication satellite, said base station comprising: means for extracting a corrected average received signal level R k from a received signal sent from said mobile station; means for calculating a transmission power control amount ΔP k of said base station on the basis of a prestored level setting error ΔS k and a difference between said corrected average received signal level R k and a predetermined reference value R ref of the received signal level of said mobile station; means for obtaining present transmission power P k from said transmission power control amount ΔP k and preceding transmission power P k-1 , and for controlling the transmission power of said base station by said present transmission power P k ; and means for transmitting information on said present transmission power control amount ΔP k to said mobile station.

Claim 22

A mobile satellite communication system in which a base station is connected with a mobile station via a communication satellite, said mobile station comprising: measuring means for obtaining an actual measuring time T k and an average received signal level Q k (k=1, 2, . . . ) in a predetermined measuring period T; and transmission means for informing said base station of said actual measuring time T k and said average received signal level Q k and said base station comprising: means for extracting said actual measuring time T k and said average received signal level Q k from a received signal sent from said mobile station; means for calculating a total measuring time t k which is a sum total of said actual measuring time T k ; means for obtaining a measuring error ΔD k of an average received signal level in said total measuring time t k ; means for obtaining a total error ΔE k by adding said measuring error ΔD k to a predetermined level setting error ΔS k ; storing means for storing a total measuring time t k-1 , a corrected average received signal level R k-1 and a transmission power control amount ΔP k-1 at the end of a preceding measuring period of said mobile station; means for obtaining a corrected average received signal level R k at the end of a present measuring period of said mobile station on the basis of a predetermined reference value R ref of the received signal level of said mobile station, said total error ΔE k , said total measuring time t k-1 , said average received signal level Q k , said actual measuring time T k and said total measuring time t k by the following equation; R.sub.k ={(R.sub.ref +ΔE.sub.k-1)t.sub.k-1 +Q.sub.k T.sub.k }/t.sub.k means for calculating a transmission power control amount ΔP k of said base station on the basis of said total error ΔE k and a difference between said reference value R ref of the received signal level and said corrected average received signal level R k ; and means for obtaining present transmission power P k from said transmission power control amount ΔP k and preceding transmission power P k-1 , and for controlling the transmission power of said base station by said present transmission power P k .

Claim 23

A mobile satellite communication system in which a base station is connected with a mobile station via a communication satellite, said mobile station comprising: measuring means for obtaining an actual measuring time T k and an average received signal level Q k (k=1, 2, . . . ) in a predetermined measuring period T; and transmission means for informing said base station of said actual measuring time T k and said average received signal level Q k and said base station comprising: means for extracting said actual measuring time T k and said average received signal level Q k from a received signal sent from said mobile station; means for calculating a total measuring time t k which is a sum total of said actual measuring time T k ; means for obtaining a measuring error ΔD k of an average received signal level in said total measuring time t k ; means for obtaining a total error ΔE k by adding said measuring error ΔD k to a predetermined level setting error ΔS k ; storing means for storing a total measuring time t k-1 , a corrected average received signal level R k-1 and a transmission power control amount ΔP k-1 at the end of a preceding measuring period of said mobile station; means for obtaining a corrected average received signal level R k at the end of a present measuring period of said mobile station on the basis of a predetermined reference value R ref of the received signal level of said mobile station, said total error ΔE k , said total measuring time t k-1 , said average received signal level Q k , said actual measuring time T k and said total measuring time t k by the following equation; R.sub.k ={(R.sub.ref +ΔE.sub.k-1)t.sub.k-1 +Q.sub.k T.sub.k }/t.sub.k means for calculating a transmission power control amount ΔP k of said base station on the basis of said total error ΔE k and a difference between said reference value R ref of the received signal level and said corrected average received signal level R k ; and means for obtaining present transmission power P k from said transmission power control amount ΔP k and preceding transmission power P k-1 , and for controlling the transmission power of said base station by said present transmission power P k .

Claim 24

A mobile satellite communication system in which a base station is connected with a mobile station via a communication satellite, said mobile station comprising: measuring means for obtaining an actual measuring time T k and an average received signal level Q k (k=1, 2, . . . ) in a predetermined measuring period T; means for calculating a total measuring time t k which is a sum total of said actual measuring time T k ; means for obtaining a measuring error ΔD k of an average received signal level in said total measuring time t k ; storing means for storing a total measuring time t k-1 and a corrected average received signal level R k-1 at the end of a preceding measuring period of said mobile station; means for extracting a transmission power control amount ΔP k-1 from a signal transmitted from said base station to said mobile station; means for obtaining a corrected average received signal level R k at the end of a present measuring period of said mobile station on the basis of a reference value R ref of the received signal level of said mobile station, a predetermined level setting error ΔS k of said base station, said total measuring time t k-1 , said average received signal level Q k , said actual measuring time T k and said total measuring time t k by the following equation; R.sub.k ={(R.sub.ref +ΔS.sub.k-1)t.sub.k-1 +Q.sub.k T.sub.k }/t.sub.k transmission means for informing said base station of said corrected average received signal level R k , and said base station comprising: means for extracting said corrected average received signal level R k from a received signal sent from said mobile station; means for calculating said transmission power control amount ΔP k of said base station on the basis of said level setting error ΔS k and a difference between said corrected average received signal level R k and said predetermined reference value R ref of the received signal level of said mobile station; means for obtaining present transmission power P k from said transmission power control amount ΔP k and preceding transmission power P k-1 , and for controlling the transmission power of said base station by said present transmission power P k ; and means for transmitting information on said present transmission power control amount ΔP k to said mobile station.

Claim 25

A mobile satellite communication system in which a base station is connected with a mobile station via a communication satellite, said mobile station comprising: measuring means for obtaining an actual measuring time T k and an average received signal level Q k (k=1, 2, . . . ) in a predetermined measuring period T; means for calculating a total measuring time t k which is a sum total of said actual measuring time T k ; means for obtaining a measuring error ΔD k of an average received signal level in said total measuring time t k ; storing means for storing a total measuring time t k-1 and a corrected average received signal level R k-1 at the end of a preceding measuring period of said mobile station; means for extracting a transmission power control amount ΔP k-1 from a signal transmitted from said base station to said mobile station; means for obtaining a corrected average received signal level R k at the end of a present measuring period of said mobile station on the basis of a reference value R ref of the received signal level of said mobile station, a predetermined level setting error ΔS k of said base station, said total measuring time t k-1 , said average received signal level Q k , said actual measuring time T k and said total measuring time t k by the following equation; R.sub.k ={(R.sub.ref +ΔS.sub.k-1)t.sub.k-1 +Q.sub.k T.sub.k }/t.sub.k transmission means for informing said base station of said corrected average received signal level R k , and said base station comprising: means for extracting said corrected average received signal level R k from a received signal sent from said mobile station; means for calculating said transmission power control amount ΔP k of said base station on the basis of said level setting error ΔS k and a difference between said corrected average received signal level R k and said predetermined reference value R ref of the received signal level of said mobile station; means for obtaining present transmission power P k from said transmission power control amount ΔP k and preceding transmission power P k-1 , and for controlling the transmission power of said base station by said present transmission power P k ; and means for transmitting information on said present transmission power control amount ΔP k to said mobile station.

Claim 26

A transmission power control method in a mobile satellite communication system in which a base station is connected with a mobile station via a communication satellite, said method comprising the steps of: obtaining an actual measuring time T k and an average received signal level Q k (k=1, 2, . . . ) in a predetermined measuring period T at said mobile station; calculating a total measuring time t k which is a sum total of said actual measuring time T k ; obtaining a measuring error ΔD k of an average received signal level in said total measuring time t k ; storing a total measuring time t k-1 , a corrected average received signal level R k-1 and a transmission power control amount ΔP k-1 at the end of a preceding measuring period of said mobile station; obtaining a corrected average received signal level R k at the end of a present measuring period of said mobile station on the basis of said corrected average received signal level R k-1 , said transmission power control amount ΔP k-1 , said total measuring time t k-1 , said average received signal level Q k , said actual measuring time T k and said total measuring time t k ; calculating a transmission power control amount ΔP k of said base station on the basis of said measuring error ΔD k and a difference between said corrected average received signal level R k and a predetermined reference value R ref of the received signal level of said mobile station; and obtaining present transmission power P k from said transmission power control amount ΔP k and preceding transmission power P k-1 , and for controlling the transmission power of said base station by said present transmission power P k .

Claim 27

A transmission power control method in a mobile satellite communication system in which a base station is connected with a mobile station via a communication satellite, said method comprising the steps of: obtaining an actual measuring time T k and an average received signal level Q k (k=1, 2, . . . ) in a predetermined measuring period T at said mobile station; calculating a total measuring time t k which is a sum total of said actual measuring time T k ; obtaining a measuring error ΔD k of an average received signal level in said total measuring time t k ; storing a total measuring time t k-1 , a corrected average received signal level R k-1 and a transmission power control amount ΔP k-1 at the end of a preceding measuring period of said mobile station; obtaining a corrected average received signal level R k at the end of a present measuring period of said mobile station on the basis of said corrected average received signal level R k-1 , said transmission power control amount ΔP k-1 , said total measuring time t k-1 , said average received signal level Q k , said actual measuring time T k and said total measuring time t k ; calculating a transmission power control amount ΔP k of said base station on the basis of said measuring error ΔD k and a difference between said corrected average received signal level R k and a predetermined reference value R ref of the received signal level of said mobile station; and obtaining present transmission power P k from said transmission power control amount ΔP k and preceding transmission power P k-1 , and for controlling the transmission power of said base station by said present transmission power P k .