# US 7,609,661 B2 · System and method for controlling uplink traffic load in a cellular wireless mobile communication system

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 7,609,661 B2
- Document ID: US7609661B2
- Status: Granted
- Kind: B2
- Application number: 11/356,821
- Filed: 2006-02-16
- Published: 2006-09-21
- Granted: 2009-10-27
- Earliest claimed: 2005-02-16
- Assignees: Samsung Electronics Co., Ltd.
- Inventors: Heon-Ki Chae; Young-Hoon Kwon
- Web page: https://patentgrep.com/patent/US7609661B2

## CPC

- H04W 52/146: {Uplink power control}
- H04W 52/343: {taking into account loading or congestion level}
- H04W 28/22: Negotiating communication rate
- H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72)

## Abstract

A method is provided for controlling an uplink traffic load in a wireless mobile communication system. A mobile station (MS) receives a reference signal from each of a base station (BS) of its home cell and a BS of a neighbor cell; calculates a power difference between the received reference signals to estimate a path loss value for each individual BS, and reports the estimated path loss value to the BS of the home cell. The BS of the home cell receives the estimated path loss value for each individual BS from the MS; and determines and allocates uplink traffic transmission power and a data rate to the MS taking the estimated path loss value into consideration. The MS transmits an uplink traffic signal taking into account the uplink traffic transmission power and the data rate allocated from the BS of the home cell.

## Claims

### Claim 1

A method for controlling an uplink traffic load by a mobile station (MS) in a wireless mobile communication system having a multi-cell configuration in which a full frequency band is divided into a plurality of sub-frequency bands and a neighbor cell reuses one of the divided sub-frequency bands, the method comprising the steps of:
receiving a reference signal from each of a base station (BS) of a home cell to which the MS belongs and a BS of a neighbor cell;
calculating a power difference between the received reference signals to estimate a path loss value for each individual BS, and reporting the estimated path loss value to the BS of the home cell; and
transmitting an uplink traffic signal, taking into account uplink traffic transmission power and a data rate allocated from the BS of the home cell;
wherein the allocated uplink traffic transmission power satisfies
γ
i
<
L
ii
∑
j
≠
i
⁢
L
ij
and is determined by
P
0
=
(
γ
1
⁢
L
10
+
L
11
)
⁢
γ
0
L
00
⁢
L
11
-
γ
0
⁢
γ
1
⁢
L
10
⁢
L
01
⁢
η
P
1
=
(
γ
0
⁢
L
01
+
L
00
)
⁢
γ
1
L
00
⁢
L
11
-
γ
0
⁢
γ
1
⁢
L
10
⁢
L
01
⁢
η
where γi denotes a carrier-to-interference ratio (CIR) for an MS of an ith BS, Lab denotes a path loss value of an MS located in an ath BS for a bth BS, PA denotes uplink traffic transmission power for an MS of an Ath BS, and η denotes thermal noise power.

### Claim 2 (depends on 1)

The method of claim 1, wherein the MS receives preamble signals from at least two BSs and estimates path loss values according thereto.

### Claim 3

A method for controlling an uplink traffic load by a base station (BS) in a wireless mobile communication system having a multi-cell configuration in which a full frequency band is divided into a plurality of sub-frequency bands and a neighbor cell reuses one of the divided sub-frequency bands, the method comprising the steps of:
receiving an estimated path loss value for each individual BS from a mobile station (MS);
determining uplink traffic transmission power and a data rate to be allocated to the MS, taking the estimated path loss value into consideration; and
allocating the determined uplink traffic transmission power and data rate to the MS;
wherein the uplink traffic transmission power to be allocated to the MS is determined taking into account a data rate determined to be lower than a ratio of an estimated path loss value for each individual BS and an estimated path loss value to a home BS, received from the MS, to a sum of estimated path loss values to neighbor BSs, and is defined as
P
0
=
(
γ
1
⁢
L
10
+
L
11
)
⁢
γ
0
L
00
⁢
L
11
-
γ
0
⁢
γ
1
⁢
L
10
⁢
L
01
⁢
η
P
1
=
(
γ
0
⁢
L
01
+
L
00
)
⁢
γ
1
L
00
⁢
L
11
-
γ
0
⁢
γ
1
⁢
L
10
⁢
L
01
⁢
η
where γi denotes a carrier-to-interference ratio (CIR) for an MS of an ith BS, Lab denotes a path loss value of an MS located in an ath BS for a bth BS, PA denotes uplink traffic transmission power for an MS of an Ath BS, and η denotes thermal noise power.

### Claim 4 (depends on 3)

The method of claim 3, wherein the received estimated path loss value is determined using a power difference between preambles received from a home BS to which the MS belongs and a BS of a neighbor cell.

### Claim 5 (depends on 4)

The method of claim 4, wherein the data rate is defined as
γ
i
<
L
ii
∑
j
≠
i
⁢
L
ij
where γi denotes a carrier-to-interference ratio (CIR) for an MS of ith BS, and Lab denotes a path loss value of an MS located in an ath BS for a bth BS.

### Claim 6

A method for controlling an uplink traffic load in a wireless mobile communication system having a multi-cell configuration in which a full frequency band is divided into a plurality of sub-frequency bands and a neighbor cell reuses one of the divided sub-frequency bands, the method comprising the steps of:
receiving, by a mobile station (MS), a reference signal from each of a base station (BS) of a home cell to which the MS belongs and a BS of a neighbor cell;
calculating a power difference between the received reference signals to estimate a path loss value for each individual BS, and reporting the estimated path loss value to the BS of the home cell;
receiving, by the BS of the home cell, the estimated path loss value for each individual BS from the MS;
determining uplink traffic transmission power and a data rate to be allocated to the MS taking the estimated path loss value into consideration;
allocating the determined uplink traffic transmission power and data rate to the MS; and
transmitting, by the MS, an uplink traffic signal taking into account the uplink traffic transmission power and the data rate allocated from the BS of the home cell;
wherein the uplink traffic transmission power to be allocated to the MS is determined taking into account a data rate determined to be lower than a ratio of an estimated path loss value for each individual BS and an estimated path loss value to a home BS, received from the MS, to a sum of estimated path loss values to neighbor BSs, and is defined as
P
0
=
(
γ
1
⁢
L
10
+
L
11
)
⁢
γ
0
L
00
⁢
L
11
-
γ
0
⁢
γ
1
⁢
L
10
⁢
L
01
⁢
η
P
1
=
(
γ
0
⁢
L
01
+
L
00
)
⁢
γ
1
L
00
⁢
L
11
-
γ
0
⁢
γ
1
⁢
L
10
⁢
L
01
⁢
η
where γi denotes a carrier-to-interference ratio (CIR) for an MS of an ith BS, Lab denotes a path loss value of an MS located in an ath BS for a bth BS, PA denotes uplink traffic transmission power for an MS of an Ath BS, and η denotes thermal noise power.

### Claim 7 (depends on 6)

The method of claim 6, wherein the MS receives preamble signals from at least two BSs and estimates path loss values using a power difference between the preamble signals.

### Claim 8

A system for controlling an uplink traffic load in a wireless mobile communication system having a multi-cell configuration in which a full frequency band is divided into a plurality of sub-frequency bands and a neighbor cell reuses one of the divided sub-frequency bands, the system comprising:
a mobile station (MS) for receiving a reference signal from each of a base station (BS) of a home cell to which the MS belongs and a BS of a neighbor cell, calculating a power difference between the received reference signals to estimate a path loss value for each individual BS, reporting the estimated path loss value to the BS of the home cell, and transmitting an uplink traffic signal taking into account uplink traffic transmission power and a data rate allocated from the BS of the home cell; and
a BS for receiving the estimated path loss value for each individual BS from the MS, determining uplink traffic transmission power and a data rate to be allocated to the MS taking the estimated path loss value into consideration, and allocating the determined uplink traffic transmission power and data rate to the MS;
wherein the BS determines the unlink traffic transmission power to be allocated to the MS taking into account a data rate determined to be lower than a ratio of an estimated path loss value for each individual BS and an estimated path loss value to a home BS, received from the MS, to a sum of estimated path loss values to neighbor BSs, and is defined as
P
0
=
(
γ
1
⁢
L
10
+
L
11
)
⁢
γ
0
L
00
⁢
L
11
-
γ
0
⁢
γ
1
⁢
L
10
⁢
L
01
⁢
η
P
1
=
(
γ
0
⁢
L
01
+
L
00
)
⁢
γ
1
L
00
⁢
L
11
-
γ
0
⁢
γ
1
⁢
L
10
⁢
L
01
⁢
η
where γi denotes a carrier-to-interference ratio (CIR) for an MS of an ith BS, Lab denotes a path loss value of an MS located in an ath BS for a bth BS, PA denotes unlink traffic transmission power for an MS of an Ath BS, and η denotes thermal noise power.

### Claim 9 (depends on 8)

The system of claim 8, wherein the MS receives preamble signals from at least two BSs and estimates path loss values using a power difference between the preamble signals.

### Claim 10 (depends on 8)

The system of claim 8, wherein the data rate is defined as
γ
i
<
L
ii
∑
j
≠
i
⁢
L
ij
where γi denotes a carrier-to-interference ratio (CIR) for an MS of an ith BS, and Lab denotes a path loss value of an MS located in an ath BS for a bth BS.

### Claim 11

A method for controlling an uplink traffic load of a mobile station (MS) located in a cell using a Space Division Multiple Access (SDMA) scheme in a wireless mobile communication system having a multi-cell configuration in which a frill frequency band is divided into a plurality of sub-frequency bands, a neighbor cell reuses one of the divided sub-frequency bands, and any one of a plurality of cells uses SDMA, the method comprising the steps of:
receiving, by the MS, a reference signal from each of a base station (BS) of a home cell to which it belongs and a BS of a neighbor cell;
calculating a power difference between the received reference signals to estimate a path loss value for each individual BS, and reporting the estimated path loss value to the BS of the home cell;
receiving, by the BS of the home cell, the estimated path loss value for each individual BS from the MS;
determining uplink traffic transmission power and a data rate to be allocated to the MS taking into account the estimated path loss value and an antenna gain value;
allocating the determined uplink traffic transmission power and data rate to the MS; and
transmitting, by the MS, an uplink traffic signal taking into account the uplink traffic transmission power and the data rate allocated from the BS of the home cell;
wherein the BS determines the data rate according to a ratio of an antenna gain and an estimated path loss value to an MS in the home cell to a sum of estimated path loss values determined taking into account antenna gains to MSs in all neighbor cells, and is defined as
γ
o
<
p
⁢
G
00
⁢
L
00
∑
G
0
⁢
x
⁢
L
0
⁢
x
γ
1
<
(
1
-
p
)
⁢
G
11
⁢
L
10
∑
G
1
⁢
x
⁢
L
1
⁢
x
where γi denotes a carrier-to-interference ratio (CIR) for an MS of an ith BS, Lab denotes a path loss value of an MS located in an ath BS for a bth BS, p denotes a power weight to be allocated to an MS, and Gij denotes an antenna gain for a jth MS when performing beamforming towards an ith MS.

### Claim 12

A method for controlling an uplink traffic load by a mobile station (MS) located in a cell using a Space Division Multiple Access (SDMA) scheme in a wireless mobile communication system having a multi-cell configuration in which a frill frequency band is divided into a plurality of sub-frequency bands, a neighbor cell reuses one of the divided sub-frequency bands, and any one of a plurality of cells uses SDMA, the method comprising the steps of:
receiving a reference signal from each of a base station (BS) of a home cell to which the MS belongs and a BS of a neighbor cell;
calculating a power difference between the received reference signals to estimate a path loss value for each individual BS, and reporting the estimated path loss value to the BS of the home cell; and
transmitting an uplink traffic signal taking into account uplink traffic transmission power and a data rate allocated from the BS of the home cell;
wherein the allocated uplink traffic transmission power is determined by
P
0
=
(
γ
1
⁢
L
10
+
L
11
)
⁢
γ
0
L
00
⁢
L
11
-
γ
0
⁢
γ
1
⁢
L
10
⁢
L
01
⁢
η
P
1
=
(
γ
0
⁢
L
01
+
L
00
)
⁢
γ
1
L
00
⁢
L
11
-
γ
0
⁢
γ
1
⁢
L
10
⁢
L
01
⁢
η
where γi denotes a carrier-to-interference ratio (CIR) for an MS of an ith BS, Lab denotes a path loss value of an MS located in an ath BS for a bth BS, p denotes a power weight to be allocated to an MS, and Gij denotes an antenna gain for a jth MS when performing beamforming towards an ith MS.

### Claim 13

A method for controlling an uplink traffic load by a base station (BS) located in a cell using a Space Division Multiple Access (SDMA) scheme in a wireless mobile communication system having a multi-cell configuration in which a full frequency band is divided into a plurality of sub-frequency bands, a neighbor cell reuses one of the divided sub-frequency bands, and any one of a plurality of cells uses SDMA, the method comprising the steps of:
receiving an estimated path loss value for each individual BS from a mobile station (MS);
determining uplink traffic transmission power and a data rate to be allocated to the MS taking into account the estimated path loss value and an antenna gain value for each individual transmission antenna; and
allocating the determined uplink traffic transmission power and data rate to the MS;
wherein the BS determines the data rate according to a ratio of an antenna gain and an estimated path loss value to an MS in the home cell to a sum of estimated path loss values determined taking into account antenna gains to MSs in all neighbor cells, and is defined as
γ
o
<
p
⁢
G
00
⁢
L
00
∑
G
0
⁢
x
⁢
L
0
⁢
x
γ
1
<
(
1
-
p
)
⁢
G
11
⁢
L
10
∑
G
1
⁢
x
⁢
L
1
⁢
x
where γi denotes a carrier-to-interference ratio (CIR) for an MS of an ith BS, Lab denotes a path loss value of an MS located in an ath BS for a bth BS, p denotes a power weight to be allocated to an MS, and Gij denotes an antenna gain for a jth MS when performing beamforming towards an ith MS.

### Claim 14 (depends on 13)

The method of claim 13, wherein the received estimated path loss value is determined using a power difference between preambles received from a BS of a home cell to which the MS belongs and a BS of a neighbor cell.

### Claim 15

A system for controlling an uplink traffic load in a wireless mobile communication system having a multi-cell configuration in which a full frequency band is divided into a plurality of sub-frequency bands, a neighbor cell reuses one of the divided sub-frequency bands, and any one of a plurality of cells uses a Space Division Multiple Access (SDMA) scheme, the system comprising:
a mobile station (MS) for receiving a reference signal from each of a base station (BS) of a home cell to which the MS belongs and a BS of a neighbor cell, calculating a power difference between the received reference signals to estimate a path loss value for each individual BS, reporting the estimated path loss value to the BS of the home cell, and transmitting an uplink traffic signal taking into account uplink traffic transmission power and a data rate allocated from the BS of the home cell; and
a BS for receiving the estimated path loss value for each individual BS from the MS, determining uplink traffic transmission power and a data rate to be allocated to the MS taking into account the estimated path loss value and an antenna gain value for each individual transmission antenna, and allocating the determined uplink traffic transmission power and data rate to the MS;
wherein the BS determines the data rate according to a ratio of an antenna gain and an estimated path loss value to an MS in the home cell to a sum of estimated path loss values determined taking into account antenna gains to MSs in all neighbor cells, and is defined as
P
0
=
(
γ
1
⁢
L
10
+
L
11
)
⁢
γ
0
L
00
⁢
L
11
-
γ
0
⁢
γ
1
⁢
L
10
⁢
L
01
⁢
η
P
1
=
(
γ
0
⁢
L
01
+
L
00
)
⁢
γ
1
L
00
⁢
L
11
-
γ
0
⁢
γ
1
⁢
L
10
⁢
L
01
⁢
η
where γi denotes a carrier-to-interference ratio (CIR) for an MS of an ith BS, Lab denotes a path loss value of an MS located in an ath BS for a bth BS, p denotes a power weight to be allocated to an MS, and Gij denotes an antenna gain for a jth MS when performing beamforming towards an ith MS.