Non-cooperative power control for large-scale antenna systems
View Patent ↗A base station servicing a cell of a cellular network provides power control of a cell independent of any other cell in the network. For downlink power control, the base station transmits information at its full power and applies a downlink power control factor to each downlink channel to equalize downlink throughputs of the mobile terminals in the cell. For uplink power control, the base station transmits instructions to have the uplink channel with the worst channel condition to transmit at its full power and the other uplink channels to transmit at that same full power. Each transmission is scaled by a corresponding uplink power control factor such that uplink throughputs for the mobile terminals in the cell are equalized. The base station applies an approximation of a rigorous capacity lower bound algorithm using propagation channel conditions and channel parameters to calculate the uplink and downlink power control factors.
1. A method comprising:
transmitting, by a base station servicing a cell of a cellular communication network, information over one or more downlink channels of the cell, the base station transmitting the information at full power scaled by a downlink power control factor for each of the downlink channels, each of the downlink power control factors being calculated by the base station using an open loop power control factor calculation in which propagation channel conditions and channel parameters of each corresponding downlink channel is applied to an approximation of a rigorous capacity lower bound algorithm, the transmission being performed by the base station independent of any other cell of the cellular communication network, the calculation for the open loop downlink power control factor for a k th mobile terminal being based on
ρ
mobile
,
k
(
1
+
τ
u
ρ
u
β
k
)
β
k
-
2
∑
i
=
1
K
ρ
mobile
,
l
(
1
+
τ
u
ρ
u
β
l
)
β
l
-
2
with k=1, . . . , K in which,
k and K are integers equal to or greater than 2,
ρ mobile,k is a normalized received power for the k th mobile terminal,
ρ mobile,l is a normalized received power for an l th mobile,
ρ u is an uplink normalized SNR,
β k is a slow fading coefficient for the kth mobile,
β l is a slow fading coefficient for an l th mobile, and
τ u represents a duration of a pilot signal.
2. The method of claim 1 , wherein the downlink power control factors add to a sum equal to 1 or less.
3. The method of claim 1 , wherein the base station has an LSAS comprising M antenna elements where M is an integer equal to 2 or greater.
4. A method comprising:
transmitting, by a base station servicing a cell of a cellular communication network, uplink power control factors over each of one or more downlink channels of the cell for corresponding uplink channels, the uplink power control factors being calculated by the base station using an open loop uplink power control factor calculation and propagation channel conditions and channel parameters of each of the corresponding uplink channels, the transmission of the uplink power control factors by the base station being performed independent of any other cell of the cellular communication network, the calculation for the open loop uplink power control factor for a k th mobile terminal being based on (1+ρ u ρ u β l )β k −2 /φ ol with k=1, . . . , K, in which,
k and K are integers equal to or greater 2,
φ ol =max{(1+τ u ρ u β l )β l −2 , l=1, . . . , K},
a normalized received power for the k th mobile terminal, ρ mobile,l is a normalized received power for an l th mobile,
β k is a slow fading coefficient for the k th mobile,
β l is a slow fading coefficient for an l th mobile, and
ρ u represents a duration of a pilot signal; and
receiving, by the base station, information from the uplink channels all of which transmit information at a full power of one of the uplink channels scaled by the corresponding calculated uplink power control factors.
5. The method of claim 4 , wherein the transmitting by the base station transmits a command over the downlink channels instructing the uplink channels to transmit information at a full power of one of the uplink channels.
6. The method of claim 4 , wherein the base station applies the propagation channel conditions and channel parameters to an approximation of a rigorous capacity lower bound algorithm to calculate the uplink power control factors.
7. The method of claim 4 , wherein each of the calculated uplink power control factors is less than or equal to 1.
8. A method comprising:
transmitting, by a base station servicing a cell of a cellular communication network, information over one or more downlink channels of the cell, the base station transmitting the information at full power scaled by a downlink power control factor for each of the downlink channels, each of the downlink power control factors being calculated by the base station using a closed loop downlink power control calculation in which propagation channel conditions and channel parameters of each corresponding downlink channel is applied to an approximation of a rigorous capacity lower bound algorithm, the transmission being performed by the base station independent of any other cell of the cellular communication network, the calculation for the closed downlink power control factors for a kth mobile being based on
λ
d
,
k
,
0
/
SINR
mobile
,
k
,
0
∑
l
=
1
K
λ
d
,
l
,
0
/
SINR
mobile
,
l
,
0
with k=1, . . . , K in which,
k and K are integers equal to or greater than 2,
SINR mobile,k,0 and SINR mobile,l,0 are the Signal to Interference Ratio for a k th and an l th mobile respectively,
and λ d,k,0 , and λ d,l,0 are downlink power control factors from a previous transmission for a k th and an l th mobile terminal respectively.
9. The method of claim 8 , wherein the downlink power control factors add to a sum equal to 1 or less.
10. The method of claim 8 , wherein the base station has an LSAS comprising M antenna elements where M is an integer equal to 2 or greater.
11. A method comprising:
transmitting, by a base station servicing a cell of a cellular communication network, uplink power control factors over each of one or more downlink channels of the cell for corresponding uplink channels, the uplink power control factors being calculated by the base station using a closed loop uplink power control factor calculation and propagation channel conditions and channel parameters of each of the corresponding uplink channels, the transmission of the uplink power control factors by the base station being performed independent of any other cell of the cellular communication network, the calculation for the closed loop uplink power control factor for a k th mobile terminal being based on
ϕ
cl
(
M
-
1
+
SINR
BS
,
k
,
0
)
λ
u
,
k
,
0
(
M
-
1
)
SINR
BS
,
k
,
0
with k=1, . . . , K in which,
k and K where
ϕ
cl
=
min
{
(
M
-
1
)
SINR
BS
,
l
,
0
(
M
-
1
+
SINR
BS
,
l
,
0
)
λ
u
,
l
,
0
,
l
=
1
,
…
,
K
}
are integers equal to or greater than 2,
ρ mobile,k is a normalized received power for the k th mobile terminal,
ρ mobile,l is a normalized received power for an l th mobile,
β k is a slow fading coefficient for the k th mobile,
β l is a slow fading coefficient for an l th mobile,
ρ u represents a duration of a pilot signal,
SINR BS,l,0 is signal to interference noise ratio measured at the base station for a previous transmission,
λ u,l,0 is a calculated uplink power control factor for an l th mobile for a previous transmission and
M represents a number of antenna elements of an LSAS of the base station where M is an integer equal to 2 or greater; and
receiving, by the base station, information from the uplink channels all of which transmit information at a full power of one of the uplink channels scaled by the corresponding calculated uplink power control factors.
12. The method of claim 11 , wherein the transmitting by the base station transmits a command over the downlink channels instructing the uplink channels to transmit information at a full power of one of the uplink channels.
13. The method of claim 11 , wherein the base station applies the propagation channel conditions and channel parameters to an approximation of a rigorous capacity lower bound algorithm to calculate the uplink power control factors.
14. The method of claim 11 , wherein each of the calculated uplink power control factors is less than or equal to 1.