# US 9,520,922 B2 · Downlink channel quality information acquisition method and device

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- Number: US 9,520,922 B2
- Document ID: US9520922B2
- Status: Granted
- Kind: B2
- Application number: 14/491,590
- Filed: 2014-09-19
- Published: 2015-01-08
- Granted: 2016-12-13
- Earliest claimed: 2012-03-20
- Assignees: Huawei Technologies Co., Ltd.
- Applicants: Huawei Technologies Co., Ltd.
- Inventors: Dageng Chen; Xiaoyan Bi; Jiayin Zhang
- Web page: https://patentgrep.com/patent/US9520922B2

## CPC

- H04B 7/024: Co-operative use of antennas of several sites, e.g. in co-ordinated multipoint or co-operative multiple-input multiple-output [MIMO] systems
- H04B 7/0632: {Channel quality parameters, e.g. channel quality indicator [CQI]}
- Y02D 30/70: in wireless communication networks
- H04B: TRANSMISSION
- Y02D: CLIMATE CHANGE MITIGATION TECHNOLOGIES IN INFORMATION AND COMMUNICATION TECHNOLOGIES [ICT], I.E. INFORMATION AND COMMUNICATION TECHNOLOGIES AIMING AT THE REDUCTION OF THEIR OWN ENERGY USE

## Abstract

A downlink channel quality information acquisition method includes: a transmission node in a coordinated node set acquires the noise receiving power of a user equipment (UE11) and the interference power on the UE11 of a node in a non-coordinated set; the transmission node in the coordinated node set acquires, via the transmission node in the coordinated node set, an inter-user interference power during the multi-user scheduling and the effective signal receiving power of the UE11; the transmission node in the coordinated node set acquires the interference power on the UE11 of a non-transmission node in the coordinated set; calculating the ratio between the effective signal receiving power and the sum of an interference source power and the noise receiving power of the UE11, and using the ratio as the value of the downlink CQI between the transmission node and the UE11.

## Claims

### Claim 1

A method for obtaining downlink channel quality information, the method comprising:
obtaining, by a transmission node in a cooperative node set, a received noise power of a user equipment, and obtaining, by the transmission node in the cooperative node set, a power of interference to the user equipment from a node in a non-cooperative node set;
obtaining, by the transmission node in the cooperative node set, an inter-user interference power during a multi-user scheduling of the transmission node in the cooperative node set, and a power of useful signal received at the user equipment;
obtaining, by the transmission node in the cooperative node set, a power of interference to the user equipment from a non-transmission node in the cooperative node set, by interacting with the non-transmission node in the cooperative node set; and
calculating a ratio of the power of received useful signal to a sum of an interference source power and the received noise power of the user equipment, the ratio being taken as a value of the downlink channel quality information (CQI) of a downlink channel between the transmission node and the user equipment, wherein the interference source power comprises the inter-user interference power during the multi-user scheduling of the transmission node in the cooperative node set, the power of interference to the user equipment from the node in the non-cooperative node set, and the power of interference to the user equipment from the non-transmission node in the cooperative node set.

### Claim 2 (depends on 1)

The method according to claim 1, wherein the obtaining, by the transmission node in the cooperative node set, the received noise power of the user equipment and the power of interference to the user equipment from the node in the non-cooperative node set comprises:
receiving power of interference to the user equipment from P nodes in the non-cooperative node set, and the received noise power nUE11nUE11H of the user equipment, wherein both of the power of interference to the user equipment from P nodes in the non-cooperative node set and the received noise power of the user equipment are fed back by the user equipment,
wherein the obtained power of interference to the user equipment from the node in the non-cooperative node set is
∑
p
=
1
P
⁢
⁢
∑
q
=
1
Q
p
⁢
⁢
P
Non_s
⁢
_pq
⁢

w
UE
⁢
⁢
11
H
⁡
(
H
Non_p
⁢
P
Non_pq
)

2
,
wUE11H is a conjugate transpose of a receiver vector wUE11 of the user equipment, HNon_p is a channel matrix of an arbitrary node NNon_p in the P nodes of the non-cooperative node set and the user equipment, PNon_pq is a pre-coding vector employed in beamforming for another user equipment UENon13pq which is served by the arbitrary node NNon13p in the P nodes of the non-cooperative node set, PNon_s_pq is a power assigned to the another user equipment UE Non13 pq by the arbitrary node NNon_p in the P nodes of the non-cooperative node set, and
∑
q
=
1
Q
p
⁢
⁢
P
Non_s
⁢
_pq
⁢

w
UE
⁢
⁢
11
H
⁡
(
H
Non_p
⁢
P
Non_pq
)

2
is a power of interference to the user equipment from the arbitrary node N Non_p in the P nodes of the non-cooperative node set, wherein q is in a range of 1, 2, . . . , Qp.

### Claim 3 (depends on 1)

The method according to claim 1, wherein the obtaining, by the transmission node in the cooperative node set, the received noise power of user equipment and the power of interference to the user equipment from the node in the non-cooperative node set comprises:
receiving a corrected value
P
s
⁢
⁢
11
′
(
∑
p
=
1
P
⁢
⁢
∑
q
=
1
Q
p
⁢
⁢
P
Non_s
⁢
_pq
⁢

w
UE
⁢
⁢
11
H
⁡
(
H
Non_p
⁢
P
Non_pq
)

2
+
n
UE
⁢
⁢
11
⁢
n
UE
⁢
⁢
11
H
)
of a sum
∑
p
=
1
P
⁢
⁢
∑
q
=
1
Q
p
⁢
⁢
P
Non_s
⁢
_pq
⁢

w
UE
⁢
⁢
11
H
⁡
(
H
Non_p
⁢
P
Non_pq
)

2
+
n
UE
⁢
⁢
11
⁢
n
UE
⁢
⁢
11
H
of an obtained power of interference
∑
p
=
1
P
⁢
⁢
∑
q
=
1
Q
p
⁢
⁢
P
Non_s
⁢
_pq
⁢

w
UE
⁢
⁢
11
H
⁡
(
H
Non_p
⁢
P
Non_pq
)

2
to the user equipment from P nodes in the non-cooperative node set, and the received noise power nUE11nUE11H of the user equipment, wherein both of the power of interference to the user equipment from the P nodes in the non-cooperative node set and the received noise power of the user equipment are fed back by the user equipment; and
wherein PNon_s_pq is a power assigned to another user equipment UENon_pq by an arbitrary node N Non _p in the P nodes of the non-cooperative node set;
∑
q
=
1
Q
p
⁢
⁢
P
Non_s
⁢
_pq
⁢

w
UE
⁢
⁢
11
H
⁡
(
H
Non_p
⁢
P
Non_pq
)

2
is a power of interference to the user equipment from the arbitrary node N Non _p in the P nodes of the non- cooperative node set, Ps11′ is a power of a signal which is sent by the user equipment and used to measure an uplink channel at the network side; H Non _p is a channel matrix of the arbitrary node N Non _p in the P nodes of the non-cooperative node set and the user equipment; PNon_p is a pre-coding vector employed in beamforming for the another user equipment UENon_pq which is served by the arbitrary node NNon _p in the P nodes of the non-cooperative node set; wherein q is in a range of 1, 2, . . . , Qp.

### Claim 4 (depends on 1)

The method according to claim 1, wherein the obtaining, by the transmission node in the cooperative node set, the received noise power of the user equipment and the power of interference to the user equipment from the node in the non-cooperative node set comprises:
receiving Ps11′ and a sum
∑
p
=
1
P
⁢
⁢
∑
q
=
1
Q
p
⁢
⁢
P
Non_s
⁢
_pq
⁢

w
UE
⁢
⁢
11
H
⁡
(
H
Non_p
⁢
P
Non_pq
)

2
+
n
UE
⁢
⁢
11
⁢
n
UE
⁢
⁢
11
H
of an obtained power of interference
∑
p
=
1
P
⁢
⁢
∑
q
=
1
Q
p
⁢
⁢
P
Non_s
⁢
_pq
⁢

w
UE
⁢
⁢
11
H
⁡
(
H
Non_p
⁢
P
Non_pq
)

2
to the user equipment from P nodes in the non-cooperative node set and the received noise power nUE11nUE11H of the user equipment, where both of the power of interference to the user equipment from the P nodes in the non-cooperative node set and the received noise power of the user equipment are fed back by the user equipment; wherein
∑
q
=
1
Q
p
⁢
⁢
P
Non_s
⁢
_pq
⁢

w
UE
⁢
⁢
11
H
⁡
(
H
Non_p
⁢
P
Non_pq
)

2
is a power of interference to the user equipment from an arbitrary node NNon_p in the P nodes of the non-cooperative node set, PNon_s_pq is a power assigned to another user equipment UENon_pq by the arbitrary node NNon_p in the P nodes of the non-cooperative node set; Ps11 ′ is a power of a signal which is sent by the user equipment and used to measure an uplink channel at the network side; HNon_p is a channel matrix of the arbitrary node NNon_p in the P nodes of the non-cooperative node set and the user equipment; PNon_pq is a pre-coding vector employed in beamforming for the another user equipment UENon_pq which is served by the arbitrary node NNon_p in the P nodes of the non-cooperative node set; and wherein q is in a range of 1, 2, . . . Qp; and
correcting
∑
p
=
1
P
⁢
⁢
∑
q
=
1
Q
p
⁢
⁢
P
Non_s
⁢
_pq
⁢

w
UE
⁢
⁢
11
H
⁡
(
H
Non_p
⁢
P
Non_pq
)

2
+
n
UE
⁢
⁢
11
⁢
n
UE
⁢
⁢
11
H
with Ps11′ to obtain a corrected value
P
s
⁢
⁢
11
′
(
∑
p
=
1
P
⁢
⁢
∑
q
=
1
Q
p
⁢
⁢
P
Non_s
⁢
_pq
⁢

w
UE
⁢
⁢
11
H
⁡
(
H
Non_p
⁢
P
Non_pq
)

2
+
n
UE
⁢
⁢
11
⁢
n
UE
⁢
⁢
11
H
)
.

### Claim 5 (depends on 1)

The method according to claim 1, wherein the obtaining, by the transmission node in the cooperative node set, the inter-user interference power during the multi-user scheduling of the transmission node in the cooperative node set and the power of useful signal received at the user equipment comprises.
obtaining, by a scheduler, PS11, HUE11, nUE11, PS1j, PUE1j and PUE11l, wherein Ps11 is a power assigned to the user equipment by the transmission node, HUE11 is a channel matrix between the user equipment and the transmission node, nUE11 is a reception noise signal of the user equipment, PS1j is a power assigned to user equipment UE1j by the transmission node, PUE1j is a pre-coding vector employed when the transmission node performs beamforming on the user equipment UE1j, and PUE11 is a pre-coding vector employed when the transmission node performs beamforming on the user equipment, wherein the user equipment differs from the user equipment UE1j; and
calculating values of Ps11|WUE11 H(HUE11PUE11)|2 and
∑
j
=
2
J
⁢
⁢
P
s
⁢
⁢
1
⁢
j
⁢

w
UE
⁢
⁢
11
H
⁡
(
H
UE
⁢
⁢
11
⁢
P
UE
⁢
⁢
1
⁢
j
)

2
,
wherein Ps11|WUE11H(HUE11PUE11)|2 represents the power of received useful signal of the user equipment and
∑
j
=
2
J
⁢
⁢
P
s
⁢
⁢
1
⁢
j
⁢

w
UE
⁢
⁢
11
H
⁡
(
H
UE
⁢
⁢
11
⁢
P
UE
⁢
⁢
1
⁢
j
)

2
represents the inter-user interference power during the multi-user scheduling of the transmission node in the cooperative node set, and WUE11H is a conjugate transpose of a receiver vector wUE11 of the user equipment.

### Claim 6 (depends on 1)

The method according to claim 1, wherein the obtaining, by the transmission node in the cooperative node set, the power of interference to the user equipment from the non-transmission node in the cooperative node set, by interacting with the non-transmission node in the cooperative node set comprises:
obtaining Ps_km, Hk and Pkm by interacting with K non- transmission nodes in the cooperative node set, wherein Ps_km is a power assigned to another user equipment UEco_km by an arbitrary non-transmission node Nk in the K non-transmission nodes of the cooperative node set, Hk is a channel matrix of the arbitrary non-transmission node Nk in the K non-transmission nodes of the cooperative node set and the user equipment, Pkm is a pre-coding vector employed in beamforming for the another user equipment UEco_km which is served by one of the K non-transmission nodes in the cooperative node set, and m is in a range of 1, 2, . . . , Mk; and
calculating
∑
k
=
1
K
⁢
⁢
∑
m
=
1
M
k
⁢
⁢
P
s_Ian
⁢

w
UE
⁢
⁢
11
H
⁡
(
H
k
⁢
P
km
)

2
as a power of interference to the user equipment from the K non-transmission nodes in the cooperative node set, wherein
∑
m
=
1
M
k
⁢
⁢
P
s_km
⁢

w
UE
⁢
⁢
11
H
⁡
(
H
k
⁢
P
km
)

2
is a power of interference to the user equipment from the arbitrary non-transmission node Nk in the K non-transmission nodes of the cooperative node set.

### Claim 7

A device for obtaining downlink channel quality information, the device comprising:
one or more processors; and
a memory storing program instructions that, when executed by the one or more processors, configure the device to:
obtain a received noise power of a user equipment, and obtain a power of interference to the user equipment from a node in a non-cooperative node set;
obtain an inter-user interference power during a multi-user scheduling of a transmission node in a cooperative node set, and obtain a power of useful signal received at the user equipment;
obtain a power of interference to the user equipment from a non-transmission node in the cooperative node set, by interacting with the non-transmission node in the cooperative node set; and
calculate a ratio of the power of received useful signal to a sum of an interference source power and the received noise power of the user equipment, the ratio being taken as a value of the downlink channel quality information (CQI) of a downlink channel between the transmission node and the user equipment; wherein the interference source power comprises the inter-user interference power during the multi-user scheduling of the transmission node in the cooperative node set, the power of interference to the user equipment from the node in the non-cooperative node set, and the power of interference to the user equipment from the non-transmission node in the cooperative node set.

### Claim 8 (depends on 7)

The device according to claim 7, wherein the obtaining the received noise power of the user equipment, and the obtaining the power of interference to the user equipment from the node in the non-cooperative node set comprises:
receiving a power of interference to the user equipment from P nodes in the non-cooperative node set, and the received noise power nUE11nUE11H of the user equipment, wherein both of the power of interference to the user equipment from P nodes in the non-cooperative node set and the received noise power of the user equipment are fed back by the user equipment, wherein the power of interference to the user equipment from the node in the non-cooperative node set is
∑
p
=
1
P
⁢
⁢
∑
q
=
1
Q
p
⁢
⁢
P
Non_s
⁢
_pq
⁢

w
UE
⁢
⁢
11
H
⁡
(
H
Non_p
⁢
P
Non_pq
)

2
,
WUE11H is a conjugate transpose of a receiver vector wUE11 of the user equipment, HNon_p is a channel matrix of an arbitrary node NNon_p in the P nodes of the non-cooperative node set and the user equipment, PNon _pq is a pre-coding vector employed in beamforming for another user equipment UENon13 pq which is served by the arbitrary node NNon_p in the P nodes of the non-cooperative node set, PNon_s_pq is a power assigned to the another user equipment UENon_pq by the arbitrary node NNon_p in the P nodes of the non-cooperative node set, and
∑
q
=
1
Q
p
⁢
⁢
P
Non_s
⁢
_pq
⁢

w
UE
⁢
⁢
11
H
⁡
(
H
Non_p
⁢
P
Non_pq
)

2
is a power of interference to the user equipment from the arbitrary node NNon_p in the P nodes of the non-cooperative node set, wherein q is in a range of 1, 2, . . . , Qp.

### Claim 9 (depends on 7)

The device according to claim 7, wherein the obtaining the received noise power of the user equipment, and the obtaining the power of interference to the user equipment from the node in the non-cooperative node set comprises:
receiving a corrected value
P
s
⁢
⁢
11
′
⁡
(
∑
p
=
1
P
⁢
⁢
∑
q
=
1
Q
p
⁢
⁢
P
Non_s
⁢
_pq
⁢

w
UE
⁢
⁢
11
H
⁡
(
H
Non_p
⁢
P
Non_pq
)

2
+
n
UE
⁢
⁢
11
⁢
n
UE
⁢
⁢
11
H
)
of a sum
∑
p
=
1
P
⁢
⁢
∑
q
=
1
Q
p
⁢
⁢
P
Non_s
⁢
_pq
⁢

w
UE
⁢
⁢
11
H
⁡
(
H
Non_p
⁢
P
Non_pq
)

2
+
n
UE
⁢
⁢
11
⁢
n
UE
⁢
⁢
11
H
of an obtained power of interference
∑
p
=
1
P
⁢
⁢
∑
q
=
1
Q
p
⁢
⁢
P
Non_s
⁢
_pq
⁢

w
UE
⁢
⁢
11
H
⁡
(
H
Non_p
⁢
P
Non_pq
)

2
to the user equipment from P nodes in the non-cooperative node set, and the received noise power nUE11nUE11H of the user equipment, wherein both of the power of interference to the user equipment from the P nodes in the non-cooperative node set and the received noise power of the user equipment are fed back by the user equipment; and whereinPNon_s_pq is a power assigned to another user equipment UENon_pq by an arbitrary node NNon_p in the non-cooperative node set;
∑
q
=
1
Q
p
⁢
⁢
P
Non_s
⁢
_pq
⁢

w
UE
⁢
⁢
11
H
⁡
(
H
Non_p
⁢
P
Non_pq
)

2
is a power of interference to the user equipment from the arbitrary node NNon_p in the P nodes of the non-cooperative node set, Ps1140 is a power of a signal which is sent by the user equipment and used to measure an uplink channel at the network side; HNon_p is a channel matrix of the arbitrary node in the P nodes of the non-cooperative node set and the user equipment; PNon_pq is a pre-coding vector employed in beamforming for the another user equipment UENon_pq which is served by the arbitrary node NNon_p in the P nodes of the non-cooperative node set; wherein q is in a range of 1, 2, . . . , Qp.

### Claim 10 (depends on 7)

The device according to claim 7, wherein the obtaining the received noise power of the user equipment, and the obtaining the power of interference to the user equipment from the node in the non-cooperative node set comprises:
receiving Ps11′ and a sum
∑
p
=
1
P
⁢
⁢
∑
q
=
1
Q
p
⁢
⁢
P
Non_s
⁢
_pq
⁢

w
UE
⁢
⁢
11
H
⁡
(
H
Non_p
⁢
P
Non_pq
)

2
+
n
UE
⁢
⁢
11
⁢
n
UE
⁢
⁢
11
H
of an obtained power of interference
∑
p
=
1
P
⁢
⁢
∑
q
=
1
Q
p
⁢
⁢
P
Non_s
⁢
_pq
⁢

w
UE
⁢
⁢
11
H
⁡
(
H
Non_p
⁢
P
Non_pq
)

2
to the user equipment from P nodes in the non-cooperative node set and the received noise power nUE11nUE11H of the user equipment, where both of the power of interference to the user equipment from the P nodes in the non-cooperative node set and the received noise power of the user equipment are fed back by the user equipment; wherein
∑
q
=
1
Q
p
⁢
⁢
P
Non_s
⁢
_pq
⁢

w
UE
⁢
⁢
11
H
⁡
(
H
Non_p
⁢
P
Non_pq
)

2
is a power of interference to the user equipment from an arbitrary node NNon_p in the P nodes of the non-cooperative node set, PNon_s_pq is a power assigned to another user equipment UENon_pq by the arbitrary node NNon_p in the P nodes of the non-cooperative node set; Ps11′ is a power of a signal which is sent by the user equipment and used to measure an uplink channel at the network side; HNon_p is a channel matrix of the arbitrary node NNon_p in the P nodes of the non-cooperative node set and the user equipment; PNon_pq is a pre-coding vector employed in beamforming for the another user equipment UENon_pq which is served by the arbitrary node NNon_p in the P nodes of the non-cooperative node set; and wherein q is in a range of 1, 2, . . . Qp; and
correcting
∑
p
=
1
P
⁢
⁢
∑
q
=
1
Q
p
⁢
⁢
P
Non_s
⁢
_pq
⁢

w
UE
⁢
⁢
11
H
⁡
(
H
Non_p
⁢
P
Non_pq
)

2
+
n
UE
⁢
⁢
11
⁢
n
UE
⁢
⁢
11
H
with Ps11′ to obtain a corrected value
P
s
⁢
⁢
11
′
⁡
(
∑
p
=
1
P
⁢
⁢
∑
q
=
1
Q
p
⁢
⁢
P
Non_s
⁢
_pq
⁢

w
UE
⁢
⁢
11
H
⁡
(
H
Non_p
⁢
P
Non_pq
)

2
+
n
UE
⁢
⁢
11
⁢
n
UE
⁢
⁢
11
H
)
.

### Claim 11 (depends on 7)

The device according to claim 7, wherein the obtaining the inter-user interference power during the multi-user scheduling of the transmission node in the cooperative node set, and the obtaining the power of useful signal received at the user equipment comprises:
obtaining Ps11, HUE 11, nUE11, PS1j, PUE1j and PUE11 by a scheduler, wherein Ps11 is a power assigned to the user equipment by the transmission node, HUE11 is a channel matrix of the user equipment and the transmission node, nUE11 is a reception noise signal of the user equipment, PS1j is a power assigned to user equipment UE1j by the transmission node, PUE1j is a pre-coding vector employed when the transmission node performs beamforming on the user equipment UE1j, and PUE11 is a pre-coding vector employed when the transmission node performs the beamforming on the user equipment, wherein the user equipment differs from the user equipment UE1j; and
calculating values of Ps11|wUE11H(HUE11PUE11)|2 and
∑
j
=
2
J
⁢
⁢
P
s
⁢
⁢
1
⁢
⁢
j
⁢

w
UE
⁢
⁢
11
H
⁡
(
H
UE
⁢
⁢
11
⁢
P
UE
⁢
⁢
1
⁢
⁢
j
)

2
,
wherein Ps11|wUE11H(HUE11PUE11)|2 represents the power of received useful signal of the user equipment and
∑
j
=
2
J
⁢
⁢
P
s
⁢
⁢
1
⁢
⁢
j
⁢

w
UE
⁢
⁢
11
H
⁡
(
H
UE
⁢
⁢
11
⁢
P
UE
⁢
⁢
1
⁢
⁢
j
)

2
represents the inter-user interference power during the multi-user scheduling of the transmission node in the cooperative node set, and wUE11H is a conjugate transpose of a receiver vector wUE of the user equipment.

### Claim 12 (depends on 7)

The device according to claim 7, wherein the obtaining the power of interference to the user equipment from the non-transmission node in the cooperative node set, by interacting with the non-transmission node in the cooperative node set comprises:
obtaining Ps_km, Hk and Pkm by interacting with K non-transmission nodes in the cooperative node set, wherein Ps_km is a power assigned to another user equipment UEco_km by an arbitrary non-transmission node Nk in the K non-transmission nodes of the cooperative node set, Hk is a channel matrix of the arbitrary non- transmission node Nk in the K non-transmission nodes of the cooperative node set and the user equipment, Pkm is a pre-coding vector employed in beamforming for the another user equipment UEco_km which is served by one of the K non-transmission nodes in the cooperative node set, and m is in a range of 1,2, . . . , Mk; and
calculating
∑
k
=
1
K
⁢
⁢
∑
m
=
1
M
k
⁢
⁢
P
s_km
⁢

w
UE
⁢
⁢
11
H
⁡
(
H
k
⁢
P
km
)

2
as a power of interference to the user equipment from the K non-transmission nodes in the cooperative node set, wherein
∑
m
=
1
M
k
⁢
⁢
P
s_km
⁢

w
UE
⁢
⁢
11
H
⁡
(
H
k
⁢
P
km
)

2
is a power of interference to the user equipment from the arbitrary non-transmission node Nk in the K non-transmission nodes of the cooperative node set.