Method and apparatus for reference signal sequence mapping in wireless communication

• US 9,432,164 B2
• Filed: 10/13/2010
• Issued: 08/30/2016
• Est. Priority Date: 10/15/2009
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Chen, Wanshi, Gaal, Peter, Montojo, Juan, Luo, Tao
• Primary Examiner(s): MUSA, ABDELNABI O
• Application Number:
  US12/903,659
• Publication Number:
  US 20110249767A1
• Time in Patent Office: 2,148 Days
• Field of Search: 370/322, 370/329, 370/341, 370/348, 370/443, 455/345, 455/263, 455/326, 455/336, 455/442, 455/498
• US Class Current: 1/1
• CPC Class Codes: H04L 5/0023 Time-frequency-space
• CPC Class Codes: H04L 5/0051 of dedicated pilots, i.e. pilots destined for a single user or terminal

Abstract

A wireless communication method implemented in a multi-user, multi-input multi-output MU-MIMO system is disclosed which includes forming one or more antenna port sets, wherein an antenna port set comprises two or more antenna ports and allocating transmission resources to a user equipment reference signal UE-RS, the allocating being based at least in part on an antenna port set index.

Claims

1. A wireless communication method implemented in a multi-input multi-output MIMO system, the system comprising:

forming an antenna port set, wherein the antenna port set comprises a plurality of antenna ports that share a set of transmission resources;

assigning an antenna port set index to a group of antennas of the plurality of antenna ports in the antenna port set;

allocating transmission resources to a user equipment reference signal (UE-RS), the allocating being based at least in part on the antenna port set index, the allocating comprising mapping the UE-RS to the transmission resources, the mapping being a function of the antenna port set index, the UE-RS being scrambled using a pseudorandom UE-RS sequence, and the pseudo-random UE-RS sequence being initialized using an initialization sequence based at least in part on initializing the pseudo-random UE-RS sequence independent of the antenna port set index; and

transmitting, by a base station, the UE-RS from the antenna ports in the antenna port set.

2. The method of claim 1, wherein the UE-RS transmissions from the antenna ports in the antenna port set are frequency domain orthogonally multiplexed.

3. The method of claim 1, wherein the UE-RS transmissions from the antenna ports in the antenna port set are code domain orthogonally multiplexed.

4. The method of claim 1, wherein the MIMO system comprises eight antenna ports;

and

wherein the forming comprises one of;

forming four antenna port sets, each antenna port set comprising a pair of antenna ports, and

forming two antenna port sets, each antenna port set comprising four antenna ports.

5. The method of claim 1, wherein the initializing the pseudo-random UE-RS sequence further comprises initializing the pseudo-random UE-RS sequence using an identification of a serving cell in which the UE-RS is to be transmitted.

6. The method of claim 1, wherein the initializing the pseudo-random UE-RS sequence further comprises initializing the pseudo-random UE-RS sequence using a symbol location index of a symbol in which the UE-RS is to be transmitted.

7. The method of claim 6, wherein the allocated transmission resources are discontiguous across different symbols.

8. The method of claim 1, wherein the mapping is further based at least in part on one or more of a slot number in which the UE-RS is to be transmitted, a physical resource block index, a maximum number of antenna port sets supported by a user equipment receiving the UE-RS transmissions, or a combination thereof.

9. The method of claim 8, wherein the mapping is independent of a bandwidth assigned to a shared data channel over which the UE-RS is to be transmitted.

10. The method of claim 8, wherein the mapping produces at least two different physical resource assignments for two different physical resource block indices.

11. The method of claim 1, wherein the pseudo-random UE-RS sequence is different from an initialization sequence used for allocation of common reference signal transmissions.

12. The method of claim 1, wherein the mapping comprises mapping using

a_k,l^(p)=r_l,ns(m′

),

wherein a_k,l^(p) represent complex-valued modulation symbols corresponding to the transmission resources, r_l,ns(m) represents the pseudo-random UE-RS sequence, n_s is a slot number and l is an index of a symbol in which the UE-RS is to be transmitted, and m′

is calculated using;

m′

=MaxNumAntPortSets*(N(n_s)*n_PRB+N′

)+AntPortSetsIndex

N′

=0,1, . . . ,N(n_s)−

1

wherein MaxNumAntPortSets is a system parameter, N(n_s) is a number of resource elements assigned to the UE-RS transmission per resource block per symbol, n_PRB is an identity of a physical resource block, AntPortSetsIndex is the antenna port set index and N′

is a variable.

13. The method of claim 1, wherein the initializing the pseudo-random UE-RS sequence comprises initializing using:

c_init=2¹⁶·

(7·

(n_s+1)+l+1)·

(2·

N_ID^ServingCell+1)+C+2*N_ID^ServingCell;

wherein c_init is the pseudo-randomUE-RS sequence, n_s is a slot is a slot number and l is an index of a symbol in which the UE-RS is to be transmitted, N_ID^ServingCell is an identification of a serving cell, and C is a constant.

14. A wireless communication method implemented in a multi-input multi-output MIMO system, the method comprising:

receiving an assignment of an antenna port set index associated with a group of antennas of a plurality of antenna ports of an antenna port set, wherein the plurality of antenna ports share a set of transmission resources; and

receiving, by a user equipment (UE), a transmission of a user equipment reference signal (UE-RS), the transmission of the UE-RS being based at least in part on the antenna port set index, the UE-RS being mapped to the transmission resources as a function of the antenna port set index, the UE-RS being scrambled using a pseudo-random UE-RS sequence, and the pseudo-random UE-RS sequence being initialized using an initialization sequence based at least in part on an initialization of the pseudo-random UE-RS sequence independent of the antenna port set index.

15. The method of claim 14, wherein transmissions from the plurality of antenna ports in the antenna port set are:

frequency domain multiplexed orthogonally;

or

code division multiplexed orthogonally.

16. The method of claim 14, wherein initializing the pseudo-random UE-RS sequence further comprises initializing the pseudo-random UE-RS sequence using an identification of a serving cell in which the UE-RS is to be transmitted.

17. A non-transitory computer-readable storage medium having program code recorded thereon, the program code comprising:

program code to receive an assignment of an antenna port set index associated with a group of antennas of a plurality of antenna ports of an antenna port set, wherein the plurality of antenna ports share a set of transmission resources; and

program code to receive a transmission of a user equipment reference signal (UE-RS), the transmission being based at least in part on the antenna port set index, the UE-RS being mapped to the transmission resources as a function of the antenna port set index, the UE-RS being scrambled using a pseudo-random UE-RS sequence, and the pseudo-random UE-RS sequence initialized using an initialization sequence based at least in part on an initialization of the pseudo-random UE-RS sequence independent of the antenna port set index.

18. A wireless communication apparatus for use in a multi-input multi-output MIMO system, the apparatus comprising:

a memory unit; and

at least one processor coupled to the memory unit, the at least one processor being configured;

to receive an assignment of an antenna port set index associated with a group of antennas of a plurality of antenna ports of an antenna port set, wherein the plurality of antenna ports share a set of transmission resources; and

to receive a transmission of a user equipment reference signal (UE-RS), the transmission being based at least in part on the antenna port set index, the UE-RS being mapped to the transmission resources as a function of the antenna port set index, the UE-RS being scrambled using the pseudo-random UE-RS sequence, and the pseudo-random UE-RS sequence being initialized using an initialization sequence based at least in part on an initialization of the pseudo-random UE-RS sequence independent of the antenna port set index.

19. A wireless communication method implemented in a multi-input multi-output MIMO system, the system comprising:

forming an antenna port set, wherein the antenna port set comprises a plurality of antenna ports that share a set of transmission resources;

assigning an antenna port set index to the plurality of antenna ports in the antenna port set;

allocating transmission resources to a user equipment reference signal (UE-RS), the allocating being based at least in part on the antenna port set index, wherein the UE-RS is scrambled using a predetermined pseudo-random UE-RS sequence, the pseudo-random UE-RS sequence initialized using an initialization sequence; and

initializing the pseudo-random UE-RS sequence that is independent of the antenna port set index, wherein the initializing the pseudo-random UE-RS sequence comprises initializing using;

c_init=2¹⁶·

(7·

(n_s+1)+l+1)·

(2·

N_ID^ServingCell+1)+C+2*N_ID^ServingCell;

in which c_init is the pseudo-random UE-RS sequence, n_s is a slot number and l is an index of a symbol in which the UE-RS is to be transmitted, N_ID^ServingCell is an identification of a serving cell, and C is a constant; and

transmitting the UE-RS from the antenna ports in the antenna port set.