Power estimation method
View Patent ↗The invention is related to control of transmissions in spread spectrum radio systems, more accurately to estimating transmission power increases caused by new transactions in the system. According to the invention, the estimate or interference power increase due to a new transaction is calculated at least partly on the basis of the current fractional load, the current received interference power level, and a load factor εL, which is calculated essentially on the basis of the chiprate, the bitrate of the new transaction, and the estimated required signal-to-interference ratio for the service type of the new transaction.
1. A method for estimating an interference power increase in an uplink direction due to a transaction in a spread spectrum cellular telecommunication system, comprising calculating the interference power increase estimate at least partly on a basis of:
current fractional load,
current received interference power level, and
a load factor ΔL, which is calculated in accordance with the relationship
Δ
L
=
1
1
+
W
SIR
·
R
,
where W is a chiprate, R is a bitrate of a new transaction, and SIR is an estimated required signal-to-interference ratio for a service type of the new transaction.
2. The method of claim 1 , wherein the interference power increase estimate ΔP rx — total is calculated in accordance with the relationship
Δ
P
rx_total
=
Δ
L
1
-
η
-
Δ
L
P
rx_total
,
where η is a current fractional load.
3. The method of claim 1 , wherein the interference power increase estimate ΔP rx — total is calculated in accordance with the relationship
Δ
P
rx_total
=
Δ
L
1
-
η
P
rx_total
,
where η is a current fractional load.
4. The method of claim 1 , wherein the transaction is a new connection.
5. The method of claim 1 , wherein the transaction is a transmission of a data packet.
6. An admission control method in a spread spectrum cellular telecommunication system, the method comprising the steps of:
measuring a current interference power received at a receiver,
estimating an interference power increase due to a new requested connection is estimated at least partly on a basis of current fractional load, current received interference power level, and a load factor ΔL, which is calculated in accordance with the relationship
Δ
L
=
1
1
+
W
SIR
·
R
,
where W is a chiprate, R is a bitrate of the new requested connection, and SIR is an estimated required signal-to-interference ratio for a service type of the new requested connection,
comparing a sum of said current received interference power and said interference power increase to a threshold, and
allocating resources for the new requested connection, if said sum is smaller than said threshold.
7. The method of claim 6 , wherein the interference power increase estimate ΔP rx — total is calculated in accordance with the relationship
Δ
P
rx_total
=
Δ
L
1
-
η
-
Δ
L
P
rx_total
,
where η is the current fractional load.
8. The method of claim 6 , wherein the interference power increase estimate ΔP rx — total is calculated in accordance with the relationship
Δ
P
rx_total
=
Δ
L
1
-
η
P
rx_total
,
where η is the current fractional load.
9. A method for scheduling data packets in a spread spectrum cellular telecommunication system, the method comprising the steps of:
measuring a current interference power received at a receiver,
estimating the interference power increase due to a transmission of a new packet at least partly on a basis of current fractional load, current received interference power level, and a load factor ΔL, which is calculated in accordance with the relationship
Δ
L
=
1
1
+
W
SIR
·
R
,
where W is a chiprate, R is a bitrate which will be used in transmission of the packet, and SIR is an estimated required signal-to-interference ratio for the successful transmission and reception of the packet,
comparing a sum of said current received interference power and said interference power increase to a threshold, and
allocating resources for the transmission of the packet, if said sum is smaller than said threshold.
10. The method of claim 9 , wherein the interference power increase estimate ΔP rx — total is calculated in accordance with the relationship
Δ
P
rx_total
=
Δ
L
1
-
η
-
Δ
L
P
rx_total
,
where η is the current fractional load.
11. The method of claim 9 , wherein the interference power increase estimate ΔP rx — total is calculated in accordance with the relationship
Δ
P
rx_total
=
Δ
L
1
-
η
P
rx_total
,
where η is the current fractional load.
12. A system for estimating the interference power increase in an uplink direction due to a new transaction in a spread spectrum cellular telecommunication system, the system comprising:
means for calculating the interference power increase estimate at least partly on a basis of
current fractional load,
current received interference power level, and
a load factor ΔL, and
means for calculating said load factor ΔL in accordance with the relationship
Δ
L
=
1
1
+
W
SIR
·
R
,
where W is a chiprate, R is a bitrate of the new transaction, and SIR is an estimated required signal-to-interference ratio for a service type of the new requested transaction.
13. A network element of a cellular telecommunications network, the network element comprising:
means for calculating an interference power increase estimate due to a new transaction at least partly on a basis of
current fractional load,
current received interference power level, and
a load factor ΔL, and
means for calculating said load factor in accordance with the relationship
Δ
L
=
1
1
+
W
SIR
·
R
,
where W is a chiprate, R is a bitrate of the new transaction, and SIR is an estimated required signal-to-interference ratio for the service type of the new transaction.
14. The network element of claim 13 , wherein the network element is a radio network controller.
15. The network element of claim 13 , wherein the network element is a radio network controller of a UMTS cellular system.