Performing Coordinated Multipoint Transmission and Reception (CoMP) in a Wireless Communication Network

• US 20140011531A1
• Filed: 03/22/2011
• Published: 01/09/2014
• Est. Priority Date: 03/22/2011
• Status: Active Grant

• Current Assignee: Telefonaktiebolaget LM Ericsson
• Original Assignee: Telefonaktiebolaget LM Ericsson
• Inventors: Burstrm, Per, De Bruin, Peter, Hagerman, Bo, Simonsson, Arne, Skillermark, Per
• Granted Patent: US 9,281,876 B2
• Time in Patent Office: Days
• US Class Current: 455/509
• CPC Class Codes: 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
• CPC Class Codes: H04L 5/0035 Resource allocation in a cooperative multipoint environment
• CPC Class Codes: H04W 16/24 Cell structures
• CPC Class Codes: H04W 24/00 Supervisory, monitoring or testing arrangements
• CPC Class Codes: H04W 72/121 for groups of terminals or users
• CPC Class Codes: H04W 8/186 Processing of subscriber group data

Abstract

The present invention relates to the field of coordinated multipoint transmission and reception (CoMP) in wireless communication networks, in particular to methods, an apparatus, and a network node for use in performing coordinated data transmissions in a wireless communication network. A method for use in a network node for coordinating data transmission to user equipments in a wireless communication network, wherein the wireless communication network comprising at least two access nodes each access node having one or more antennas and being arranged to perform coordinated data transmissions to user equipments is provided. The method comprising: obtaining signal strength values associated with the one or more antennas of the at least two access nodes for a number of user equipments; arranging the number of user equipments into one or more groups of user equipments and associating each of the one or more groups of user equipments with a sub-set of the one or more antennas of the at least two access nodes based on the obtained signal strength values; and coordinating data transmission performed by the at least two access nodes to each of the one or more groups of user equipments based on the subset of the one or more antennas of the at least two access nodes associated with each group of user equipments, respectively.

Claims

1-19. -19. (canceled)

20. A method for use in a network node for coordinating data transmissions to user equipments in a wireless communication network, said wireless communication network comprising at least two access nodes each having one or more antennas and being arranged to perform coordinated data transmissions to user equipments, comprising:

obtaining signal strength values associated with the one or more antennas of the at least two access nodes for a number of user equipments;

arranging the number of user equipments into one or more groups of user equipments and associating each of the one or more groups of user equipments with a sub-set of the one or more antennas of the at least two access nodes based on the obtained signal strength values; and

coordinating data transmissions performed by the at least two access nodes to each of the one or more groups of user equipments based on the sub-set of the one or more antennas of the at least two access nodes associated with each group of user equipments, respectively.

21. The method according to claim 20, wherein arranging the number of user equipments and associating the one or more groups of user equipments, further comprises:

calculating antenna relationship values for each of the number of user equipments based on the obtained signal strength values, and

arranging the number of user equipments into one or more groups of user equipments and associating each of the one or more groups of user equipments with a sub-set of the one or more antennas of the at least two access nodes based on the calculated antenna relationship values.

22. The method according to claim 21, wherein arranging the number of user equipments and associating the one or more groups of user equipments based on the calculated antenna signal relationship values, further comprises:

comparing one or more of the calculated antenna relationship values of each of the number of user equipments, and

arranging the number of user equipments into one or more groups of user equipments and associating each of the one or more groups of user equipments with a sub-set of the one or more antennas of the at least two access nodes based on the antenna relationship value comparison.

23. The method according to claim 20, further comprising:

combining a first group of user equipments with a second group of user equipments to form a combined third group of user equipments based on jointly associated antennas in the sub-sets of the one or more antennas of the at least two access nodes associated with the first and second group of user equipments, respectively.

24. The method according to claim 23, further comprising:

dividing a first group of user equipments into a second and third group of user equipments based on jointly associated antennas in the sub-sets of the one or more antennas of the at least two access nodes associated with the second and third group of user equipments, respectively.

25. The method according to claim 24, wherein the combination of groups of user equipments is stopped or the division of a group of user equipments is initiated based on one or more of:

when one or more predetermined threshold number of antennas is comprised in the sub-set of the one or more antennas of the at least two access nodes associated with the group of user equipments,

when one or more predetermined threshold number of user equipments have been associated with the group of user equipments,

when one or more predetermined CoMP transmission multi-user limits has been reached for the group of user equipments,

when one or more predetermined channel limitations is reached for the group of user equipments,

when one or more predetermined transmission power limits are reached,

when one or more predetermined backhaul load thresholds are reached,

when one or more predetermined uplink radio channel load thresholds are reached.

26. The method according to claim 20, wherein coordinating data transmissions performed by the at least two access nodes to each of the one or more groups of user equipments, further comprises:

scheduling each group of user equipments for downlink transmission separately from each other in frequency and/or time, or on orthogonal resource blocks; and

scheduling each user equipment within a group of user equipments for downlink transmission together in frequency and/or time, or on non-orthogonal resource blocks.

27. The method according to claim 20, further comprising:

obtaining channel information for a group of user equipments to the sub-set of the one or more antennas of the access nodes associated with the group of user equipments; and

coordinating data transmission to the group of user equipments based on the obtained channel information.

28. The method according to claim 20, wherein obtaining signal strength values associated with the one or more antennas of the at least two access nodes for a number of user equipments comprises:

receiving signal strength values measured at the access nodes from the access nodes, or

receiving signal strength values measured at the user equipments from the user equipments via the access nodes.

29. The method according to claim 20, wherein the method is performed repetitively with a periodicity based on capturing slow fading.

30. An apparatus for use in a network node for coordinating data transmissions to user equipments in a wireless communication network, said wireless communication network comprising at least two access nodes each access node having one or more antennas and being arranged to perform coordinated data transmissions to user equipments, said apparatus comprising:

a retrieving unit configured to obtain signal strength values associated with the one or more antennas of the at least two access nodes for a number of user equipments;

a cooperating cell group unit configured to arrange the number of user equipments into one or more groups of user equipments and associate each of the one or more groups of user equipments with a sub-set of the one or more antennas of the at least two access nodes based on the signal strength values obtained by the retrieving unit; and

a cooperation scheduling unit configured to coordinate data transmissions performed by the at least two access nodes to each of the one or more groups of user equipments based on the sub-set of the one or more antennas of the at least two access nodes associated with each group of user equipments, respectively.

31. The apparatus according to claim 30, wherein the cooperating cell group unit is further configured to calculate antenna relationship values for each of the number of user equipments based on the obtained signal strength values, and arrange the number of user equipments into one or more groups of user equipments and associate each of the one or more groups of user equipments with a sub-set of the one or more antennas of the at least two access nodes based on the calculated antenna relationship values.

32. The apparatus according to claim 31, wherein the cooperating cell group unit is further configured to compare one or more of the calculated antenna relationship values of each of the number of user equipments, and arrange the number of user equipments into one or more groups of user equipments and associate each of the one or more groups of user equipments with a sub-set of the one or more antennas of the at least two access nodes based on the antenna relationship value comparison.

33. The apparatus according to claim 30, wherein the cooperating cell group unit is further configured to combine a first group of user equipments with a second group of user equipments to form a combined third group of user equipments based on jointly associated antennas in the sub-sets of the one or more antennas of the at least two access nodes associated with the first and second group of user equipments, respectively.

34. The apparatus according to claim 33, wherein the cooperating cell group unit is further configured to divide a first group of user equipments into a second and third group of user equipments based on jointly associated antennas in the sub-sets of the one or more antennas of the at least two access nodes associated with the second and third group of user equipments, respectively.

35. The apparatus according to claim 34, wherein the cooperating cell group unit is further configured to stop the combination of groups of user equipments or initiate the division of a group of user equipments based on one or more of:

when one or more predetermined threshold number of antennas is comprised in the sub-set of the one or more antennas of the at least two access nodes associated with the group of user equipments,

when one or more predetermined threshold number of user equipments have been associated with the group of user equipments,

when one or more predetermined CoMP transmission multi-user limits has been reached for the group of user equipments,

when one or more predetermined channel limitations is reached for the group of user equipments,

when one or more predetermined transmission power limits are reached,

when one or more predetermined backhaul load thresholds are reached,

when one or more predetermined uplink radio channel load thresholds are reached.

36. The apparatus according to claim 30, wherein the cooperation scheduling unit is further configured to schedule each group of user equipments for downlink transmission separately from each other in frequency and/or time, or on orthogonal resource blocks, and schedule each user equipment within a group of user equipments for downlink transmission together in frequency and/or time, or on non-orthogonal resource blocks.

37. The apparatus according to claim 30, wherein the cooperation scheduling unit is further configured to obtain channel information for a group of user equipments to the sub-set of the one or more antennas of the at least two access nodes associated with the group of user equipments, and to coordinate data transmission to the group of user equipments based on the obtained channel information.