Method for improving the performances of a mobile radiocommunication system using a power control algorithm

1. A method for improving the performances of a mobile radiocommunication system using a power control algorithm, said power control algorithm including an inner-loop power control algorithm for adjusting a transmit power according to received power control commands, said method including:

a step of deciding if the transmit power should be increased according to a received power control command (TPC(k)) requiring a power increase, having regard to a cumulative power variation (Δ sum (k)) already obtained for last received power control commands,

a step of determining the cumulative power variation (Δ sum (k)) to be used by said step of deciding, said step of determining including taking into account, further to power adjustments (P TPC (k)) due to said inner-loop power control algorithm, at least one other factor that may affect said cumulative power variation.

2. A method according to claim 1 , wherein said at least one other factor corresponds to at least one power limitation, said step of determining including taking into account that a power adjustment does not result in any power variation beyond the reaching of a power limit (Maximum_DL_Power, Minimum_DL_Power).

3. A method according to claim 1 , wherein said cumulative power variation is determined based on an adjusted power (P(k)) including different types of power adjustments and said at least one other factor corresponds to at least one other type of power adjustment, other than a power adjustment (P TPC (k)) due to said inner-loop power control algorithm.

4. A method according to claim 3 , wherein said at least one other type of power adjustment corresponds to a correction (P bal (k)) according to a downlink power control procedure for balancing radio link powers towards a common reference power.

5. A method according to claim 3 , wherein one other type of power adjustment corresponds to a power adjustment (P sir (k)) due to a target SIR variation in compressed mode, and is subtracted from said adjusted power (P(k)), for determining said cumulative power variation.

6. A method according to claim 1 , wherein said cumulative power variation is determined based on power adjustments (P TPC (k)) due to said inner-loop power control algorithm.

7. A method according to claim 1 , wherein said step of determining a cumulative power variation includes determining a value Δ sum (k) which is such that:

Δ

sum

⁡

(

k

)

=

∑

i

=

k

-

DL_Power

⁢

_Averaging

⁢

_Window

⁢

_Size

k

-

1

⁢

Q

TPC

⁡

(

i

)

with:

In normal mode:

Q TPC ( k )= P ( k )− P ( k− 1)

In compressed mode:

Q TPC ( k )=( P ( k )− P SIR ( k ) )− P ( k− 1)

where:

DL_Power_Averaging_Window_Size corresponds to the number of said last received power control commands

Maximum_DL_Power and Minimum_DL_Power correspond respectively to a maximum and a minimum power limit

P(k), respectively P(k-1) corresponds to the adjusted power after a k:th, respectively a (k−1):th power adjustment, with:

In normal mode:

P ( k )=min_max_limit( P ( k− 1)+ P TPC ( k )+ P bal ( k ))

where the function “min_max_limit(.)” represents the limiting function to keep P(k) within a maximum and a minimum power limit

In compressed mode:

P ( k )=min_max_limit_cm( P ( k− 1)+ P TPC ( k )+ P bal ( k )+ P sir ( k ) )

where the function “min _max_limit_cm(.)” represents the limiting function to keep P(k) within a maximum and a minimum power limit and where:

P TPC (k) corresponds to a k:th power adjustment due to said inner-loop power control algorithm

P bal (k) corresponds to a correction according to a downlink power control procedure for balancing radio link powers towards a common reference power

P sir (k) corresponds to a power adjustment (P sir (k)) due to a target SIR variation in compressed mode.

8. A method according to claim 1 , wherein said step of determining a cumulative power variation includes determining a value Δ sum (k) which is such that:

Δ

sum

⁡

(

k

)

=

∑

i

=

k

-

DL_Power

⁢

_Averaging

⁢

_Window

⁢

_Size

k

-

1

⁢

Q

TPC

⁡

(

i

)

with:

If P(k)=Maximum_DL_Power+δP curr [with δP curr =0 if the k:th slot is a normal slot or δP curr >0 if the k:th slot is a compressed slot]:

Q TPC ( k )=0

If P(k)=Minimum_DL_Power:

Q TPC ( k )=0

Otherwise: Q TPC (k)=P TPC (k)

where:

DL_Power_Averaging_Window_Size corresponds to the number of said last received power control commands

Maximum_DL_Power and Minimum_DL_Power correspond respectively to a maximum and a minimum power limit,

P TPC (k) corresponds to a k:th power adjustment due to said inner-loop power control algorithm

P(k), respectively P(k−1) corresponds to the adjusted power after a k:th, respectively a (k−1):th power adjustment, with:

In normal mode:

P ( k )=min_max_limit( P ( k− 1)+ P TPC ( k )+ P bal ( k ))

where the function “min_max_limit(.)” represents the limiting function to keep P(k) within a maximum and a minimum power limit

In compressed mode:

P ( k )=min_max_limit_cm( P ( k− 1)+ P TPC ( k )+ P bal ( k )+ P sir ( k ))

where the function “min_max_limit_cm(.)” represents the limiting function to keep P(k) within a maximum and a minimum power limit

and where:

P bal (k) corresponds to a correction according to a downlink power control procedure for balancing radio link powers towards a common reference power

P sir (k) corresponds to a power adjustment (P sir (k)) due to a target SIR variation in compressed mode.

9. A method according to claim 1 , wherein said step of determining a cumulative power variation includes determining a value Δ sum (k) which is such that:

Δ

sum

⁡

(

k

)

=

∑

i

=

k

-

DL_Power

⁢

_Averaging

⁢

_Window

⁢

_Size

k

-

1

⁢

Q

TPC

⁡

(

i

)

with:

If P(k)>Maximum_DL_Power+δP curr [with δP curr =0 if the k:th slot is a normal slot or δP curr >0 if the k:th slot is a compressed slot]

Q TPC ( k )=0

If P(k)<Minimum_DL_Power

Q TPC ( k )=0

Otherwise Q TPC (k)=P TPC (k)

where:

DL_Power_Averaging_Window_Size corresponds to the number of said last received power control commands

Maximum_DL_Power and Minimum_DL_Power correspond respectively to a maximum and a minimum power limit,

P TPC (k) corresponds to a k:th power adjustment due to said inner-loop power control algorithm

P(k) corresponds to the adjusted power after a k:th power adjustment.

10. A method according to claim 1 , wherein the having regard to a cumulative power variation comprises:

measuring the total power variation (Δ sum (k)) already obtained for last received power control commands; and

using the measured total power variation (Δ sum (k)) to decide whether to accept or ignore the received power control command (TPC(k)).

11. An equipment for a mobile radiocommunication system, comprising:

means for deciding if a received power control command (TPC(k)) requiring a power increase should be applied, having regard to a cumulative power variation (Δ sum (k)) already obtained for last applied power control commands,

means for determining a cumulative power variation (Δ sum (k)) to be used by said means for deciding, said means for determining a cumulative power variation including means for taking into account, further to power adjustments due to said inner-loop power control algorithm, at least one other factor that may affect said cumulative power variation.

12. An equipment according to claim 11 , wherein said means for determining a cumulative power variation comprise means for determining a value Δ sum (k) which is such that:

Δ

sum

⁡

(

k

)

=

∑

i

=

k

-

DL_Power

⁢

_Averaging

⁢

_Window

⁢

_Size

k

-

1

⁢

Q

TPC

⁡

(

i

)

with:

In normal mode:

Q TPC ( k )= P ( k )− P ( k− 1)

In compressed mode:

Q TPC ( k )=( P ( k )− P sir ( k ) )− P ( k− 1)

where:

DL_Power_Averaging_Window_Size corresponds to the number of said last received power control commands

Maximum_DL_Power and Minimum_DL_Power correspond respectively to a maximum and a minimum power limit

P(k), respectively P(k−1) corresponds to the adjusted power afler a k:th, respectively a (k−1):th power adjustment, with:

In normal mode:

P ( k )=min_max_limit( P ( k− 1)+ P TPC ( k )+ P bal ( k ))

where the function “min_max_limit(.)” represents the limiting function to keep P(k) within a maximum and a minimum power limit

In compressed mode:

P ( k )=min_max_limit_cm( P ( k− 1)+ P TPC ( k )+ P bal ( k )+ P sir ( k ))

where the function “min_max_limit_cm(.)” represents the limiting function to keep P(k) within a maximum and a minimum power limit and where:

P TPC (k) corresponds to a k:th power adjustment due to said inner-loop power control algorithm

P bal (k) corresponds to a correction according to a downlink power control procedure for balancing radio link powers towards a common reference power

P sir (k) corresponds to a power adjustment (P sir (k)) due to a target SIR variation in compressed mode.

13. An equipment according to claim 11 , wherein said means for determining a cumulative power variation comprise means for determining a value Δ sum (k) which is such that:

Δ

sum

⁡

(

k

)

=

∑

i

=

k

-

DL_Power

⁢

_Averaging

⁢

_Window

⁢

_Size

k

-

1

⁢

Q

TPC

⁡

(

i

)

with:

If P(k)=Maximum_DL_Power+δP curr [with δP curr =0if the k:th slot is a normal slot or δP curr >0 if the k:th slot is a compressed slot]:

Q TPC ( k )=0

If P(k)=Minimum_DL_Power:

Q TPC ( k )=0

Otherwise: Q TPC (k)=P TPC (k)

where:

DL_Power_Averaging_Window_Size corresponds to the number of said last received power control commands

Maximum_DL_Power and Minimum_DL_Power correspond respectively to a maximum and a minimum power limit

P TPC (k) corresponds to a k:th power adjustment due to due to said inner-loop power control algorithm

P(k), respectively P(k−1) corresponds to the adjusted power after a k:th, respectively a (k−1):th power adjustment, with:

In normal mode:

P ( k )=min_max_limit( P ( k− 1)+ P TPC ( k )+ P bal (k))

where the function “min_max_limit(.)” represents the limiting function to keep P(k) within a maximum and a minimum power limit

In compressed mode:

P ( k )=min_max_limit_cm( P ( k− 1)+P TPC ( k )+P bal ( k )+P sir ( k ))

where the function “min_max_limit_cm(.)” represents the limiting function to keep P(k) within a maximum and a minimum power limit and where:

P bal (k) corresponds to a correction according to a downlink power control procedure for balancing radio link powers towards a common reference power

P sir (k) corresponds to a power adjustment (P sir (k)) due to a target SIR variation in compressed mode.

14. An equipment according to claim 11 , wherein said means for determining a cumulative power variation comprise means for determining a value Δ sum (k) which is such that:

Δ

sum

⁡

(

k

)

=

∑

i

=

k

-

DL_Power

⁢

_Averaging

⁢

_Window

⁢

_Size

k

-

1

⁢

Q

TPC

⁡

(

i

)

with:

If P(k)>Maximum_DL_Power+δP curr [with δP curr =0 if the k:th slot is a normal slot or δP curr >0 if the k:th slot is a compressed slot]

Q TPC ( k )=0

If P(k)<Minimum_DL_Power

Q TPC ( k )=0

Otherwise Q TPC (k)=P TPC (k)

where:

DL_Power_Averaging_Window_Size corresponds to the number of said last received power control commands

Maximum_DL_Power and Minimum_DL_Power correspond respectively to a maximum and a minimum power limit,

P TPC (k) corresponds to a k:th power adjustment due to said inner-loop power control algorithm

P(k) corresponds to the adjusted power after a k:th power adjustment.

15. An equipment according to claim 11 , corresponding to a network equipment.

16. An equipment according to claim 15 , corresponding to a base station.

17. An equipment according to claim 11 , corresponding to a mobile terminal.

18. A mobile radiocommunication system, comprising at least one equipment according to claim 11 .