EP0822672A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Downlink transmission power control scheme for mobile communication system using site diversity
Assignee: NTT Docomo Inc
•
Filing: 1997-07-29
•
Granted: —
•
Expires: 2017-07-29
Abstract
Abstract A downlink transmission power control scheme for a mobile communication system using the site diversity, which carries out a primary downlink transmission power control using a primary control signal which is transmitted from the mobile station and terminated at each base station, and an additional downlink transmission power control using additional control signals which are transmitted from the base station control station to the base stations. The additional downlink transmission power control may also use a secondary control signal which is transmitted from the mobile station and terminated at the base station control station. The primary downlink transmission power control can be carried out during a non-site diversity period while the additional downlink transmission power control is carried out during the site diversity period, or the primary downlink transmission power control and the additional downlink transmission power control can be both carried out during the site diversity period.
Inventors
- 👤 Etsuhiro Nakano
- 👤 Takehiro Nakamura
- 👤 Koji Ohno
- 👤 Takaaki Sato
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-27 06:56
CPC Classifications
H; H04; H04W; H04W52/00; H04W52/04; H04W52/38; H04W52/40; H04W52/30; H04W52/36; H04W52/367
Claims Analysis
Total Claims: 50
Claim 1
Independent Claim
148 words
A method of downlink transmission power control in a
mobile communication system formed by a plurality of base
stations, a mobile station to be connected with the base
stations via radio channels, and a base station control
station for controlling the base stations, wherein the
mobile communication system uses a site diversity in which
the mobile station is simultaneously connected with more
than one base stations and a diversity combining among said
more than one base stations is carried out, the method
comprising the steps of: carrying out a primary downlink transmission power
control using a primary control signal which is transmitted
from the mobile station and terminated at each base station
and not to be combined during a site diversity period; and carrying out an additional downlink transmission power
control using additional control signals which are
transmitted from the base station control station to the
base stations.
Claim 2
Dependent Claim
26 words
The method of claim 1, wherein the primary downlink
transmission power control is carried out at shorter time
intervals than the additional downlink transmission power
control.
Claim 3
Dependent Claim
15 words
The method of claim 1, wherein the primary control
signal is a layer-1 control signal.
Claim 4
Dependent Claim
42 words
The method of claim 1, wherein the additional downlink
transmission power control also uses a secondary control
signal which is transmitted from the mobile station and
terminated at the base station control station and to be
combined during the site diversity period.
Claim 5
Dependent Claim
15 words
The method of claim 4, wherein the secondary control
signal is a layer-3 control signal.
Claim 6
Dependent Claim
35 words
The method of claim 4, wherein the primary downlink
transmission power control is carried out during a non-site
diversity period, while the additional downlink
transmission power control is carried out during the site
diversity period.
Claim 7
Dependent Claim
53 words
The method of claim 6, wherein the primary downlink
transmission power control is based on a receiving SIR of a
communication channel at the mobile station, while the
additional downlink transmission power control is based on
a bit error rate or a frame error rate of the communication
channel at the mobile station.
Claim 8
Dependent Claim
47 words
The method of claim 6, wherein the primary downlink
transmission power control is based on a receiving SIR of a
communication channel at the mobile station, while the
additional downlink transmission power control is based on
a receiving SIR of a perch channel at the mobile station.
Claim 9
Dependent Claim
40 words
The method of claim 6, wherein the primary downlink
transmission power control and the additional downlink
transmission power control are both based on a bit error
rate or a frame error rate of a communication channel at
the mobile station.
Claim 10
Dependent Claim
26 words
The method of claim 6, wherein the mobile station
stops a transmission of a bit corresponding to the primary
control signal during the site diversity period.
Claim 11
Dependent Claim
28 words
The method of claim 4, wherein the primary downlink
transmission power control and the additional downlink
transmission power control are both carried out during the
site diversity period.
Claim 12
Dependent Claim
58 words
The method of claim 11, wherein the primary downlink
transmission power control controls a transmission power of
each base station, while the additional downlink
transmission power control sets upper and lower limits for
the transmission power of each base station according to a
receiving SIR at the mobile station of a perch channel
transmitted from each base station.
Claim 13
Dependent Claim
65 words
The method of claim 12, wherein the upper and lower
limits for the transmission power of each base station are
determined from a perch channel receiving SIR at the mobile
station of a perch channel transmitted from said each base
station, a perch channel transmission power at said each
base station, and a target receiving SIR for a downlink
communication channel at the mobile station.
Claim 14
Dependent Claim
81 words
The method of claim 13, wherein the secondary control
signal notifies the perch channel receiving SIRs from the
mobile station to the base station control station, the
base station control station determines the upper and lower
limits for the transmission power of each base station
according to the secondary control signal, and the
additional control signals notify the upper and lower
limits for the transmission power of each base station from
the base station control station to said each base station.
Claim 15
Dependent Claim
71 words
The method of claim 13, wherein the secondary control
signal notifies the perch channel receiving SIRs from the
mobile station to the base station control station, the
additional control signals notify the perch channel
receiving SIRs from the base station control station to
each base station, and each base station determines the
upper and lower limits for the transmission power of said
each base station according to the additional control
signals.
Claim 16
Dependent Claim
74 words
The method of claim 12, wherein the upper and lower
limits for the transmission power of each base station are
determined from a receiving SIR at the mobile station of a
perch channel transmitted from one base station which has a
smallest propagation loss with respect to the mobile
station, a perch channel transmission power at said one
base station, and a target receiving SIR for a downlink
communication channel at the mobile station.
Claim 17
Dependent Claim
61 words
The method of claim 11, wherein the primary downlink
transmission power control controls a transmission power of
each base station, while the additional downlink
transmission power control specifies a correction to the
transmission power of at least one base station according
to receiving SIRs at the mobile station of a perch channel
and a communication channel transmitted from each base
station.
Claim 18
Dependent Claim
58 words
The method of claim 17, wherein the secondary control
signal notifies the correction for said at least one base
station from the mobile station to the base station control
station, and the additional control signals notify the
correction for said at least one base station from the base
station control station to said at least one base station.
Claim 19
Dependent Claim
33 words
The method of claim 17, wherein the correction
corrects the transmission power of said at least one base
station so as to make transmission powers of the base
stations equal to each other.
Claim 20
Dependent Claim
52 words
The method of claim 17, wherein the correction
corrects the transmission power of said at least one base
station so as to make a desired transmission power ratio
among the base stations according to a ratio of the
receiving SIRs at the mobile station of perch channels
transmitted from the base stations.
Claim 21
Dependent Claim
44 words
The method of claim 1, wherein the primary downlink
transmission power control controls a transmission power of
each base station independently, while the additional
downlink transmission power control controls the
transmission powers of the base stations to be identical
during the site diversity period.
Claim 22
Dependent Claim
120 words
The method of claim 21, wherein each base station
periodically reports to the base station control station a
transmission power control amount due to the primary
downlink transmission power control and a receiving
reliability at said each base station during a prescribed
period of time, the base station control station notifies
one transmission power control amount reported from one
base station which has a highest receiving reliability
among the base stations to other base stations, and each
other base station controls a transmission power at said
each other base station by using said one transmission
power control amount notified from the base station control
station, so that the transmission powers of the base
stations are controlled to be identical periodically.
Claim 23
Dependent Claim
73 words
The method of claim 21, wherein each base station
periodically reports a transmission power value at said
each base station to the base station control station, the
base station control station notifies one transmission
power value reported from one base station to other base
stations, and each other base station controls a
transmission power at said each other base station to said
one transmission power value notified from the base station
control station.
Claim 24
Dependent Claim
22 words
The method of claim 23, wherein said one transmission
power value is largest among transmission power values
reported from the base stations.
Claim 25
Dependent Claim
22 words
The method of claim 23, wherein said one transmission
power value is smallest among transmission power values
reported from the base stations.
Claim 26
Dependent Claim
147 words
A mobile communication system, comprising: a plurality of base stations; a mobile station to be connected with the base
stations via radio channels, which transmits a primary
control signal which is to be terminated at each base
station and not to be combined during a site diversity
period so as to carry out a primary downlink transmission
power control at each base station according to the primary
control signal; and a base station control station for controlling the
base stations, which transmits additional control signals
to the base stations so as to carry out an additional
downlink transmission power control at the base stations
according to the additional control signals; wherein the mobile communication system uses a site
diversity in which the mobile station is simultaneously
connected with more than one base stations and a diversity
combining among said more than one base stations is carried
out.
Claim 27
Dependent Claim
28 words
The mobile communication system of claim 26, wherein
the primary downlink transmission power control is carried
out at shorter time intervals than the additional downlink
transmission power control.
Claim 28
Dependent Claim
17 words
The mobile communication system of claim 26, wherein
the primary control signal is a layer-1 control signal.
Claim 29
Dependent Claim
48 words
The mobile communication system of claim 26, wherein
the mobile station also transmits a secondary control
signal which is to be terminated at the base station
control station and to be combined during the site
diversity period, in order to carry out the additional
downlink transmission power control.
Claim 30
Dependent Claim
17 words
The mobile communication system of claim 29, wherein
the secondary control signal is a layer-3 control signal.
Claim 31
Dependent Claim
37 words
The mobile communication system of claim 29, wherein
the primary downlink transmission power control is carried
out during a non-site diversity period, while the
additional downlink transmission power control is carried
out during the site diversity period.
Claim 32
Dependent Claim
53 words
The mobile communication system of claim 31, wherein
the mobile station transmits the primary control signal
based on a receiving SIR of a communication channel at the
mobile station, and the secondary control signal based on a
bit error rate or a frame error rate of the communication
channel at the mobile station.
Claim 33
Dependent Claim
47 words
The mobile communication system of claim 31, wherein
the mobile station transmits the primary control signal
based on a receiving SIR of a communication channel at the
mobile station, and the secondary control signal based on a
receiving SIR of a perch channel at the mobile station.
Claim 34
Dependent Claim
43 words
The mobile communication system of claim 31, wherein
the mobile station transmits the primary control signal and
the secondary control signal which are both based on a bit
error rate or a frame error rate of a communication channel
at the mobile station.
Claim 35
Dependent Claim
28 words
The mobile communication system of claim 31, wherein
the mobile station stops a transmission of a bit
corresponding to the primary control signal during the site
diversity period.
Claim 36
Dependent Claim
30 words
The mobile communication system of claim 29, wherein
the primary downlink transmission power control and the
additional downlink transmission power control are both
carried out during the site diversity period.
Claim 37
Dependent Claim
60 words
The mobile communication system of claim 36, wherein
the primary downlink transmission power control controls a
transmission power of each base station, while the
additional downlink transmission power control sets upper
and lower limits for the transmission power of each base
station according to a receiving SIR at the mobile station
of a perch channel transmitted from each base station.
Claim 38
Dependent Claim
67 words
The mobile communication system of claim 37, wherein
the upper and lower limits for the transmission power of
each base station are determined from a perch channel
receiving SIR at the mobile station of a perch channel
transmitted from said each base station, a perch channel
transmission power at said each base station, and a target
receiving SIR for a downlink communication channel at the
mobile station.
Claim 39
Dependent Claim
83 words
The mobile communication system of claim 38, wherein
the secondary control signal notifies the perch channel
receiving SIRs from the mobile station to the base station
control station, the base station control station
determines the upper and lower limits for the transmission
power of each base station according to the secondary
control signal, and the additional control signals notify
the upper and lower limits for the transmission power of
each base station from the base station control station to
said each base station.
Claim 40
Dependent Claim
73 words
The mobile communication system of claim 38, wherein
the secondary control signal notifies the perch channel
receiving SIRs from the mobile station to the base station
control station, the additional control signals notify the
perch channel receiving SIRs from the base station control
station to each base station, and each base station
determines the upper and lower limits for the transmission
power of said each base station according to the additional
control signals.
Claim 41
Dependent Claim
76 words
The mobile communication system of claim 37, wherein
the upper and lower limits for the transmission power of
each base station are determined from a receiving SIR at
the mobile station of a perch channel transmitted from one
base station which has a smallest propagation loss with
respect to the mobile station, a perch channel transmission
power at said one base station, and a target receiving SIR
for a downlink communication channel at the mobile station.
Claim 42
Dependent Claim
63 words
The mobile communication system of claim 36, wherein
the primary downlink transmission power control controls a
transmission power of each base station, while the
additional downlink transmission power control specifies a
correction to the transmission power of at least one base
station according to receiving SIRs at the mobile station
of a perch channel and a communication channel transmitted
from each base station.
Claim 43
Dependent Claim
60 words
The mobile communication system of claim 42, wherein
the secondary control signal notifies the correction for
said at least one base station from the mobile station to
the base station control station, and the additional
control signals notify the correction for said at least one
base station from the base station control station to said
at least one base station.
Claim 44
Dependent Claim
35 words
The mobile communication system of claim 42, wherein
the correction corrects the transmission power of said at
least one base station so as to make transmission powers of
the base stations equal to each other.
Claim 45
Dependent Claim
54 words
The mobile communication system of claim 42, wherein
the correction corrects the transmission power of said at
least one base station so as to make a desired transmission
power ratio among the base stations according to a ratio of
the receiving SIRs at the mobile station of perch channels
transmitted from the base stations.
Claim 46
Dependent Claim
46 words
The mobile communication system of claim 26, wherein
the primary downlink transmission power control controls a
transmission power of each base station independently,
while the additional downlink transmission power control
controls the transmission powers of the base stations to be
identical during the site diversity period.
Claim 47
Dependent Claim
122 words
The mobile communication system of claim 46, wherein
each base station periodically reports to the base station
control station a transmission power control amount due to
the primary downlink transmission power control and a
receiving reliability at said each base station during a
prescribed period of time, the base station control station
notifies one transmission power control amount reported
from one base station which has a highest receiving
reliability among the base stations to other base stations,
and each other base station controls a transmission power
at said each other base station by using said one
transmission power control amount notified from the base
station control station, so that the transmission powers of
the base stations are controlled to be identical
periodically.
Claim 48
Dependent Claim
75 words
The mobile communication system of claim 46, wherein
each base station periodically reports a transmission power
value at said each base station to the base station control
station, the base station control station notifies one
transmission power value reported from one base station to
other base stations, and each other base station controls a
transmission power at said each other base station to said
one transmission power value notified from the base station
control station.
Claim 49
Dependent Claim
24 words
The mobile communication system of claim 48, wherein
said one transmission power value is largest among
transmission power values reported from the base stations.
Claim 50
Dependent Claim
24 words
The mobile communication system of claim 48, wherein
said one transmission power value is smallest among
transmission power values reported from the base stations.
References Cited (Backward Citations)
No citation records indexed.
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