METHOD AND BASE STATION FOR MU-MIMO TRANSMISSION IN WIRELESS COMMUNICATION SYSTEM

• US 20160212746A1
• Filed: 01/15/2016
• Published: 07/21/2016
• Est. Priority Date: 01/15/2015
• Status: Active Grant

• Current Assignee: NTT Docomo Incorporated (Nippon Telegraph and Telephone Corporation)
• Original Assignee: NTT Docomo Incorporated (Nippon Telegraph and Telephone Corporation)
• Inventors: WANG, Xin, HOU, Xiaolin, JIANG, Huiling
• Granted Patent: US 9,930,666 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H04B 7/0452 Multi-user MIMO systems
• CPC Class Codes: H04L 1/1812 Hybrid protocols; Hybrid automatic repeat request [HARQ]
• CPC Class Codes: H04L 5/0051 of dedicated pilots, i.e. pilots destined for a single user or terminal
• CPC Class Codes: H04L 5/0091 Signaling for the administration of the divided path
• CPC Class Codes: H04W 72/0453 Resources in frequency domain, e.g. a carrier in FDMA
• CPC Class Codes: H04W 72/20 Control channels or signalling for resource management
• CPC Class Codes: H04W 72/23 in the downlink direction of a wireless link, i.e. towards a terminal

Abstract

The present disclosure provides a method and base station for Multiple User-Multiple Input Multiple Output (MU-MIMO) transmission in a wireless communication system. The base station re-allocates frequency resources of a DMRS port which are allocated to N first data flows to M second data flows, wherein M is greater than N, and N first data flows may be used by N first UEs or less than N first UEs. The base station designates a DMRS port for K second UEs involved in joint scheduling according to the re-allocation result of frequency resources of a DMRS port, and sends information of the designated DMRS port via a downlink control signaling to the K second UEs, where K is lower than M or equal to M.

Claims

1. A method for Multiple User-Multiple Input Multiple Output (MU-MIMO) transmission in a wireless communication system, comprising:

re-allocating, by a base station, frequency resources of a DeModulation Reference Signal (DMRS) port which are allocated to N first data flows to M second data flows, wherein M is greater than N, and the N first data flows are used by N first UEs or less than N first UEs; and

designating, by the base station, a DMRS port for K second UEs involved in joint scheduling according to the re-allocation result of frequency resources of a DMRS port, and sending information of the designated DMRS port via a downlink control signaling to the K second UEs, where K is lower than M or equal to M.

2. The method of claim 1, wherein re-allocating frequency resources of a DMRS port which are allocated to N first data flows to M second data flows comprises:

allocating frequency resources of N DMRS ports in at least one resource block uniformly to w*N DMRS ports, wherein w is an integer greater than 1, and M=w*N.

3. The method of claim 1, wherein sending information of the designated DMRS port via the downlink control signaling to the K second UEs comprises:

carrying an antenna port indicator which comprises more than 3 bits in the downlink control signaling to indicate the K second UEs the designated DMRS port.

4. The method of claim 3, wherein the antenna port indicator comprises 4 bits, or 5 bits, or 6 bits.

5. The method of claim 1, further comprising:

adding a wideband mode indicator in the downlink control signaling to indicate the second UE a resource allocation mode, wherein the resource allocation mode is selected from a subband scheduling mode, a broadband scheduling mode, and a fullband scheduling mode;

wherein for the subband scheduling mode, resources are allocated in unit of subband;

for the broadband scheduling mode, resources are allocated in unit of broadband;

for the fullband scheduling mode, resources are allocated in unit of entire frequency resources.

6. The method of claim 5, wherein the downlink control signaling is a Downlink Control Information (DCI) signaling.

7. The method of claim 6, wherein when the resource allocation mode indicated by the base station is the fullband scheduling mode, a resource allocation header field and a resource block allocation field in the DCI are turned off.

8. The method of claim 6, wherein when the resource allocation mode indicated by the base station is the broadband scheduling mode, a resource block allocation field in the DCI is configured according to N_RBG=┌

N_RB^DL/P┐

;

wherein N_RBG denotes bit number of the resource block allocation field, N_RB^DL denotes number of resource blocks corresponding to system bandwidth, P denotes length of a resource block group (RBG), ┌

•

┐

stands for rounding up to the nearest integer, a relationship between N_RB^DL and P is given in the following table;

9. The method of claim 6, wherein when the resource allocation mode indicated by the base station is the broadband scheduling mode, a resource block allocation field in the DCI is configured according to N_RBG=┌

N_RB^DL/P┐

;

wherein N_RBG denotes bit number of the resource block allocation field, N_RB^DL denotes number of resource blocks corresponding to system bandwidth, P denotes length of a Resource Block Group (RBG), ┌

•

┐

stands for rounding up to the nearest integer, a relationship between N_RB^DL and P is given in the following table;

10. The method of claim 8, further comprising:

informing the second UE of the length of RBG via a Radio Resource Control (RRC) signaling.

11. The method of claim 9, further comprising:

informing the second UE of the length of RBG via a Radio Resource Control (RRC) signaling.

12. A base station in a wireless communication system, comprising:

a DeModulation Reference Signal (DMRS)-port frequency resource setting module, configured to re-allocate frequency resources of a DMRS port which are allocated to N first data flows to M second data flows, wherein M is greater than N, and the N first data flows are used by N first UEs or less than N first UEs; and

a DMRS port designating module, configured to designate a DMRS port for K second UEs involved in joint scheduling according to the re-allocation result of frequency resources of a DMRS port, and send information of the designated DMRS port via a downlink control signaling to the K second UEs, where K is lower than M or equal to M.

13. The base station of claim 12, wherein the DMRS-port frequency resource setting module is configured to allocate frequency resources of N DMRS ports in at least one resource block uniformly to w*N DMRS ports, wherein w is an integer greater than 1, and M=w*N.

14. The base station of claim 12, further comprising:

a downlink control signaling configuration module, configured to carry an antenna port indicator which comprises more than 3 bits in the downlink control signaling to indicate the K second UEs the designated DMRS port.

15. The base station of claim 14, wherein the downlink control signaling configuration module is further configured to:

add a wideband mode indicator in the downlink control signaling to indicate the second UE a resource allocation mode, wherein the resource allocation mode is selected from a subband scheduling mode, a broadband scheduling mode, and a fullband scheduling mode;

wherein for the subband scheduling mode, resources are allocated in unit of subband;

for the broadband scheduling mode, resources are allocated in unit of broadband;

for the fullband scheduling mode, resources are allocated in unit of entire frequency resources.

16. A base station, comprising a processor and a memory communicated with the processor;

wherein in the memory, instructions that are executed by the processor are stored, comprising a DMRS-port frequency resource setting instruction and a DMRS port designating instruction, wherein

the DMRS-port frequency resource setting instruction indicates to re-allocate frequency resources of a DMRS port which are allocated to N first data flows to M second data flows, wherein M is greater than N, and the N first data flows are used by N first UEs or less than N first UEs;

the DMRS port designating instruction indicates to designate a DMRS port for K second UEs involved in joint scheduling according to the re-allocation result of frequency resources of a DMRS port, and send information of the designated DMRS port via a downlink control signaling to the K second UEs, where K is lower than M or equal to M.

17. The base station of claim 16, wherein the DMRS-port frequency resource setting instruction indicates to allocate frequency resources of N DMRS ports in at least one resource block uniformly to w*N DMRS ports, wherein w is an integer greater than 1, and M=w*N.

18. The base station of claim 16, where the instructions further comprise a downlink control signaling configuration instruction, wherein

the downlink control signaling configuration instruction indicates to carry an antenna port indicator which comprises more than 3 bits in the downlink control signaling to indicate the K second UEs the designated DMRS port.