Mobility measurement using CSI-RS in additional carrier
View Patent ↗A system and a method for a mobility measurement in a wireless network comprises determining at a wireless terminal a channel power estimation E S for a carrier signal based on Channel State Information Reference Signals (CSI-RS), and determining at the wireless terminal a noise plus interference I+N for the carrier signal based on a muted CSI-RS. The carrier signal is an additional carrier without the presence of a Cell-specific Reference Signal. In one exemplary embodiment, the periodicity of the CSI-RS is selected to be 1, 2 or 3 subframes.
1. A wireless terminal, comprising:
a receiver coupled to one or more antennas; and
a processor coupled to the receiver, the processor being configured to:
determine a channel power estimation E s for a carrier signal based on Channel State Information Reference Signals (CSI-RS) received by the receiver, the carrier signal being an additional carrier without the presence of a Cell-specific Reference Signal transmitted in a wireless network by a node providing wireless access to the wireless network, wherein the channel power estimation is determined by averaging a channel power from the one or more antennas, by using random precoding, or by using a subset of CSI-RS ports, or combinations thereof,
determine a noise plus interference I+N for the carrier signal based on a muted CSI-RS, and
calculate a Reference Signal Received Power (RSRP) measurement or a Reference Signal Received Quality (RSRQ) measurement, or a combination thereof, based at least in part on the channel power estimation and the noise plus interference.
2. The wireless terminal according to claim 1 , further comprising a transmitter coupled to the processor, the transmitter being capable of transmitting to the node providing wireless access to the wireless network the determined channel power estimation E s and the determined noise plus interference I+N.
3. The wireless terminal according to claim 1 , wherein a periodicity of the CSI-RS is 1, 2 or 3 subframes.
4. The wireless terminal according to claim 1 , wherein the processor is further configured to determine signal power estimation E s as
E
S
=
1
N
t
∑
i
=
1
N
r
∑
j
=
1
N
t
H
i
,
j
2
in which N is the number of resource blocks (RBs) of the E-UTRA carrier RSSI measurement bandwidth, H is the channel response between j th transmit antenna and i th receive antenna, N r is the total number of receive antennas at UE, N t is the total number of transmit antennas at the node providing wireless access to the wireless network i is the receive antenna index, and j is the transmit antenna index.
5. The method according to claim 4 , wherein the processor is further configured to determine the noise plus interference I+N for the carrier signal based on the muted CSI-RS as
I
+
N
=
1
N
r
x
N
t
∑
i
=
1
N
r
∑
j
=
1
N
t
H
i
,
j
2
in which N t is the number of muted CSI-RS ports, N r is the receive antenna number, H i,j is the estimated channel, and i and j are indices.
6. The wireless terminal according to claim 5 , wherein a periodicity of the CSI-RS is 1, 2 or 3 subframes.
7. The wireless terminal according to claim 1 , wherein the processor is further configured to determine the signal power estimation E S as
E
S
=
∑
i
=
i
N
r
H
i
V
2
,
in which H, is the column vector corresponding to each receive antenna, V is the N t ×1 random precoder and i is the receive antenna index.
8. The wireless terminal according to claim 7 , wherein the processor is further configured to determine the noise plus interference I+N for the carrier signal based on the muted CSI-RS as
I
+
N
=
1
N
r
x
N
t
∑
i
=
1
N
r
∑
j
=
1
N
t
H
i
,
j
2
in which N t is the number of muted CSI-RS ports, N r is the receive antenna number, H i,j is the estimated channel, and i and j are indices.
9. The wireless terminal according to claim 7 , wherein a periodicity of the CSI-RS is 1, 2 or 3 subframes.
10. The wireless terminal according to claim 1 , wherein the processor is further configured to determine the noise plus interference I+N for the carrier signal based on the muted CSI-RS as
I
+
N
=
1
N
r
x
N
t
∑
i
=
1
N
r
∑
j
=
1
N
t
H
i
,
j
2
in which N t is the number of muted CSI-RS ports, N r is the receive antenna number, H i,j is the estimated channel, and i and j are indices.
11. The wireless terminal according to claim 1 , wherein the wireless network comprises one of an IEEE-802.11-based protocol wireless network, a 3GPP-based protocol wireless network, a WiMax-based protocol wireless network, an UMTS-based protocol wireless network, a CDMA2000-based protocol wireless network, a GSM-based protocol wireless network, a cellular-digital-packet-data-based (CDPD-based) protocol wireless network, or a Mobitex-based protocol wireless network.
12. The wireless terminal according to claim 1 , further comprising a touchscreen display capable of receiving input from a touch of a user or a stylus to control the processor.
13. A mobility measurement method in a wireless network, the method comprising:
determining at a wireless terminal a channel power estimation E s for a carrier signal based on Channel State Information Reference Signals (CSI-RS), the carrier signal being an additional carrier without the presence of a Cell-specific Reference Signal, wherein the channel power estimation is determined by averaging a channel power from one or more antennas, by using random precoding, or by using a subset of CSI-RS ports, or combinations thereof;
determining at the wireless terminal a noise plus interference I+N for the carrier signal based on a muted CSI-RS having a minimum periodicity less than 5 subframes; and
calculating a Reference Signal Received Power (RSRP) measurement or a Reference Signal Received Quality (RSRQ) measurement, or a combination thereof, based at least in part on the channel power estimation and the noise plus interference.
14. The method according to claim 13 , wherein the periodicity of the CSI-RS is 1, 2 or 3 subframes.
15. The method according to claim 13 , wherein determining at the wireless terminal the signal power estimation comprises determining E S as
E
S
=
1
N
∑
i
=
1
N
r
∑
j
=
1
N
t
H
i
,
j
2
in which N is the number of resource blocks (RBs) of the E-UTRA carrier RSSI measurement bandwidth, H is the channel response between j th transmit antenna and i th receive antenna, N r is the total number of receive antennas at UE, N t is the total number of transmit antennas at a node providing wireless access to the wireless network, i is the receive antenna index, and j is the transmit antenna index.
16. The method according to claim 15 , wherein determining at the wireless terminal the noise plus interference I+N for the carrier signal based on the muted CSI-RS comprises
I
+
N
=
1
N
r
x
N
t
∑
i
=
1
N
r
∑
j
=
1
N
t
H
i
,
j
2
in which N t is the number of muted CSI-RS ports, N r is the receive antenna number, H i,j is the estimated channel, and i and j are indices.
17. The method according to claim 16 , wherein the periodicity of the CSI-RS is 1, 2 or 3 subframes.
18. The method according to claim 13 , wherein determining at the wireless terminal the signal power estimation comprises determining E S as
E
S
=
∑
i
=
i
N
r
H
i
V
2
,
in which H i is the column vector corresponding to each receive antenna, V is the N t ×1 random precoder and i is the receive antenna index.
19. The method according to claim 18 , wherein determining at the wireless terminal the noise plus interference I+N for the carrier signal based on the muted CSI-RS comprises
I
+
N
=
1
N
r
x
N
t
∑
i
=
1
N
r
∑
j
=
1
N
t
H
i
,
j
2
in which N t is the number of muted CSI-RS ports, N r is the receive antenna number, H i,j is the estimated channel, and i and j are indices.
20. The method according to claim 18 , wherein the periodicity of the CSI-RS is 1, 2 or 3 subframes.
21. The method according to claim 13 , wherein determining at the wireless terminal the noise plus interference I+N for the carrier signal based on the muted CSI-RS comprises
I
+
N
=
1
N
r
x
N
t
∑
i
=
1
N
r
∑
j
=
1
N
t
H
i
,
j
2
in which N, is the number of muted CSI-RS ports, N r is the receive antenna number, H i,j is the estimated channel, and i and j are indices.
22. The method according to claim 13 , wherein the wireless network comprises one of an IEEE-802.11-based protocol wireless network, a 3GPP-based protocol wireless network, a WiMax-based protocol wireless network, an UMTS-based protocol wireless network, a CDMA2000-based protocol wireless network, a GSM-based protocol wireless network, a cellular-digital-packet-data-based (CDPD-based) protocol wireless network, or a Mobitex-based protocol wireless network.
23. The method according to claim 13 , wherein the wireless terminal comprises a touchscreen display capable of receiving input from a touch of a user or a stylus.
24. A wireless terminal, comprising:
a receiver capable of determining a channel power estimation E s for a carrier signal based on Channel State Information Reference Signals (CSI-RS), wherein the channel power estimation is determined by averaging a channel power from one or more antennas, by using random precoding, or by using a subset of CSI-RS ports, or combinations thereof, the carrier signal being an additional carrier without the presence of a Cell-specific Reference Signal transmitted in a wireless network by a node providing wireless access to the wireless network, capable of determining at the mobile station a noise plus interference I+N for the carrier signal based on a muted CSI-RS having a periodicity of the CSI-RS is 1, 2 or 3 subframes, and capable of calculating a Reference Signal Received Power (RSRP) measurement or a Reference Signal Received Quality (RSRQ) measurement, or a combination thereof, based at least in part on the channel power estimation and the noise plus interference; and
a transmitter capable of transmitting to the node providing wireless access to the wireless network the determined channel power estimation E s and the determined noise plus interference I+N .
25. The wireless terminal according to claim 24 , wherein the signal power estimation E S is determined as
E
S
=
1
N
∑
i
=
1
N
r
∑
j
=
1
N
t
H
i
,
j
2
in which N is the number of resource blocks (RBs) of the E-UTRA carrier RSSI measurement bandwidth, H is the channel response between j th transmit antenna and i th receive antenna, N r is the total number of receive antennas at UE, N t is the total number of transmit antennas at the node providing wireless access to the wireless network, i is the receive antenna index, and j is the transmit antenna index,
or
E
S
=
∑
i
=
i
N
r
H
i
V
2
;
in which H i is the column vector corresponding to each receive antenna, V is the N t ×1 random precoder and i is the receive antenna index,
wherein the noise plus interference I+N for the carrier signal based on the muted CSI-RS is determined as
I
+
N
=
1
N
r
x
N
t
∑
i
=
1
N
r
∑
j
=
1
N
t
H
i
,
j
2
in which N t is the number of muted CSI-RS ports, N r is the receive antenna number, H i,j is the estimated channel, and i and j are indices; and
wherein a periodicity of the CSI-RS is 1, 2 or 3 subframes.
26. The wireless terminal according to claim 24 , wherein the wireless network comprises one of an IEEE-802.11-based protocol wireless network, a 3GPP-based protocol wireless network, a WiMax-based protocol wireless network, an UMTS-based protocol wireless network, a CDMA2000-based protocol wireless network, a GSM-based protocol wireless network, a cellular-digital-packet-data-based (CDPD-based) protocol wireless network, or a Mobitex-based protocol wireless network.
27. The wireless terminal according to claim 24 , further comprising a touchscreen display capable of receiving input from a touch of a user or a stylus to control the processor.
28. An article comprising: a non-transitory computer-readable medium having stored thereon instructions that, if executed, result in at least the following:
determining at a wireless terminal a channel power estimation E s for a carrier signal based on Channel State Information Reference Signals (CSI-RS), the carrier signal being an additional carrier in a wireless network without the presence of a Cell-specific Reference Signal,
the signal power estimation E s being determined as
E
S
=
1
N
∑
i
=
1
N
r
∑
j
=
1
N
t
H
i
,
j
2
in which N is the number of resource blocks (RBs) of the E-UTRA carrier RSSI measurement bandwidth, H is the channel response between j th transmit antenna and i th receive antenna, N r is the total number of receive antennas at UE, N t is the total number of transmit antennas at a node providing wireless access to the wireless network, i is the receive antenna index, and j is the transmit antenna index,
or
E
S
=
∑
i
=
i
N
r
H
i
V
2
;
in which H i is the column vector corresponding to each receive antenna, V is the N t ×1 random precoder and i is the receive antenna index; and
determining at the wireless terminal a noise plus interference I+N for the carrier signal based on a muted CSI-RS, wherein the noise plus interference I+N for the carrier signal based on the muted CSI-RS is determined as
I
+
N
=
1
N
r
x
N
t
∑
i
=
1
N
r
∑
j
=
1
N
t
H
i
,
j
2
in which N t is the number of muted CSI-RS ports, N r is the receive antenna number, H i,j is the estimated channel, and i and j are indices; and
wherein a periodicity of the CSI-RS comprises 1, 2 or 3 subframes.
29. The article according to claim 28 , wherein the wireless network comprises one of an IEEE-802.11-based protocol wireless network, a 3GPP-based protocol wireless network, a WiMax-based protocol wireless network, an UMTS-based protocol wireless network, a CDMA2000-based protocol wireless network, a GSM-based protocol wireless network, a cellular-digital-packet-data-based (CDPD-based) protocol wireless network, or a Mobitex-based protocol wireless network.
30. The article according to claim 28 , wherein the wireless terminal comprises a touchscreen display capable of receiving input from a touch of a user or a stylus.