Apparatus and method for allocating channel state information-reference signal in wireless communication system

• US 8,787,216 B2
• Filed: 05/31/2011
• Issued: 07/22/2014
• Est. Priority Date: 06/01/2010
• Status: Active Grant

• Current Assignee: Pantech Corporation (Ideahub, Inc.)
• Original Assignee: Pantech Corporation (Ideahub, Inc.)
• Inventors: Kim, Kitae, YOON, Sungjun, PARK, Kyoung-min
• Primary Examiner(s): Nguyen, Hanh N
• Application Number:
  US13/149,225
• Publication Number:
  US 20110292847A1
• Time in Patent Office: 1,148 Days
• Field of Search: 370/203, 370207-210, 370/468, 370/294, 370/273, 370/276, 370/280, 370/344, 370/329, 370/330, 370/332, 375/295, 375/340, 375/267, 375/316, 375/324
• US Class Current: 370/281
• CPC Class Codes: H04B 7/0413 MIMO systems
• CPC Class Codes: H04B 7/0626 Channel coefficients, e.g. channel state information [CSI]
• CPC Class Codes: H04L 2025/03426 transmission using multiple-input and multiple-output channels
• CPC Class Codes: H04L 2025/03802 Signalling on the reverse channel
• CPC Class Codes: H04L 25/0226 sounding signals per se
• CPC Class Codes: H04L 27/2607 Cyclic extensions
• CPC Class Codes: H04L 5/0007 the frequencies being orthogonal, e.g. OFDM(A), DMT
• CPC Class Codes: H04L 5/0026 Division using four or more dimensions
• CPC Class Codes: H04L 5/0039 Frequency-contiguous, i.e. with no allocation of frequencies for one user or terminal between the frequencies allocated to another
• CPC Class Codes: H04L 5/0048 Allocation of pilot signals, i.e. of signals known to the receiver
• CPC Class Codes: H04L 5/005 of common pilots, i.e. pilots destined for multiple users or terminals
• CPC Class Codes: H04L 5/0057 Physical resource allocation for CQI
• CPC Class Codes: H04L 5/0073 Allocation arrangements that take into account other cell interferences for intercell interference mitigation or co-ordination in orthogonal multiplex systems H04J11/005
• CPC Class Codes: H04L 5/0082 at predetermined intervals
• CPC Class Codes: H04L 5/14 Two-way operation using the same type of signal, i.e. duplex
• CPC Class Codes: H04L 5/1469 using time-sharing

Abstract

Embodiments of the present invention relate to a wireless communication system, and more particularly, to a technology for allocating a Channel State Information-Reference Signal (CSI-RS) in a wireless communication system. Embodiments of the present invention provides an apparatus and method for allocating CSI-RSs to resource areas, in which, under the condition of a subframe in which the CP is an extended CP, and the duplex scheme is TDD, if CSI-RSs for maximum 8 antenna ports are allocated, the CSI-RSs are allocated to the 8th and 9th symbols (symbol No. l=7 and 8), wherein each CSI-RS for every two antenna ports is allocated to the same RE while being discriminated from each other by an orthogonal code and neighbor CSI-RS allocated REs in the frequency axis are spaced by an interval of three REs.

Claims

1. An apparatus, comprising:

a processor configured to allocate Channel State Information-Reference Signals (CSI-RSs) for maximum 8 antenna ports to resource areas including a plurality of Resource Elements (REs) under a condition of a subframe in which an extended Cyclic Prefix (CP) is employed as a CP and a Time Division Duplex (TDD) scheme is employed as a duplex scheme,

wherein CSI-RSs for a pair of antenna ports are allocated to REs corresponding to one sub-carrier at every 12 sub-carriers in a frequency band and corresponding to 8^th and 9^th symbols in a subframe, one subframe having a total of 12 symbols for the extended CP,

CSI-RSs for the pair of antenna ports are allocated to identical REs, the CSI-RS for a first antenna port in the pair of antenna ports and the CSI-RS for a second antenna port in the pair of antenna ports being discriminated from each other by different orthogonal codes, and

CSI-RSs for a first pair of two neighboring pairs of antenna ports are allocated in first REs and CSI-RSs for a second pair of the two neighboring pairs are allocated in second REs, the first REs and the second REs being spaced apart by having two REs between the first REs and the second REs along a frequency axis.

2. The apparatus of claim 1, wherein CSI-RSs of a higher antenna port number are allocated to an RE having a lower subcarrier index in the frequency axis.

3. The apparatus of claim 1, wherein CSI-RSs of the (7^th, 8^th), (5^th, 6^th), (3^rd, 4^th), (1^st, 2^nd) antenna ports for CSI-RS transmission are allocated to two REs having subcarrier indexes within an Resource Block of 0, 3, 6, and 9 (1^st, 4^th, 7^th and 10^th subcarriers within an Resource Block, respectively), respectively.

4. A method for an apparatus comprising a processor for allocating Channel State Information-Reference Signals (CSI-RSs) for maximum 8 antenna ports to resource areas including a plurality of Resource Elements (REs) under a condition of a subframe in which an extended Cyclic Prefix (CP) is employed as a CP and a Time Division Duplex (TDD) scheme is employed as a duplex scheme, the method comprising:

allocating, by the processor, CSI-RSs for a pair of antenna ports to REs corresponding to one sub-carrier at every 12 sub-carriers in a frequency band and corresponding to 8^th and 9^th symbols in a subframe, one subframe having a total of 12 symbols for the extended CP,

wherein CSI-RSs for the pair of antenna ports are allocated to identical REs, the CSI-RS for a first antenna port in the pair of antenna ports and the CSI-RS for a second antenna port in the pair of antenna ports being discriminated from each other by different orthogonal codes, and

CSI-RSs for a first pair of two neighboring pairs of antenna ports are allocated in first REs and CSI-RSs for a second pair of the two neighboring pairs are allocated in second REs, the first REs and the second REs being spaced apart by having two REs between the first REs and the second REs along a frequency axis.

5. The method of claim 4, wherein CSI-RSs of a higher antenna port number are allocated to an RE having a lower subcarrier index in the frequency axis.

6. The method of claim 4, wherein CSI-RSs of the (7^th, 8^th), (5^th, 6^th), (3^rd, 4^th) (1^st, 2^nd) antenna ports for CSI-RS transmission are allocated to two REs having subcarrier indexes within an Resource Block of 0, 3, 6, and 9 (1^st, 4^th, 7^th and 10^th subcarriers within an Resource Block, respectively), respectively.

7. An apparatus to receive Channel State Information-Reference Signals (CSI-RSs), the apparatus comprising:

a signal receiver to receive an Orthogonal Frequency Division Multiplexing (OFDM) signal, which is generated through allocation of CSI-RSs for maximum 8 antenna ports under a condition of a subframe in which an extended Cyclic Prefix (CP) is employed as a CP and a Time Division Duplex (TDD) scheme is employed as a duplex scheme;

a CSI-RS extractor to extract CSI-RSs for antenna ports allocated to particular REs from a signal received by the signal receiver; and

a channel state measurer to acquire Channel State Information (CSI) based on the extracted CSI-RSs,

wherein CSI-RSs for a pair of antenna ports are allocated to REs corresponding to one sub-carrier at every 12 sub-carriers in a frequency band and corresponding to 8^th and 9^th symbols in a subframe, one subframe having a total of 12 symbols for the extended CP,

CSI-RSs for the pair of antenna ports are allocated to identical REs, the CSI-RS for a first antenna port in the pair of antenna ports and the CSI-RS for a second antenna port in the pair of antenna ports being discriminated from each other by different orthogonal codes, and

CSI-RSs for a first pair of two neighboring pairs of antenna ports are allocated in first REs and CSI-RSs for a second pair of the two neighboring pairs are allocated in second REs, the first REs and the second REs being spaced apart by having two REs between the first REs and the second REs along a frequency axis.

8. The apparatus of claim 7, wherein CSI-RSs of a higher antenna port number are allocated to an RE having a lower subcarrier index in the frequency axis.

9. The apparatus of claim 7, wherein CSI-RSs of the (7^th, 8^th), (5^th, 6^th), (3^rd, 4^th), (1^st, 2^nd) antenna ports for CSI-RS transmission are allocated to two REs having subcarrier indexes within an Resource Block of 0, 3, 6, and 9 (1^st, 4^th, 7^th and 10^th subcarriers within an Resource Block, respectively), respectively.

10. A method for an apparatus comprising a signal receiver to receive Channel State Information-Reference Signals (CSI-RSs), the method comprising:

receiving, by the signal receiver, an Orthogonal Frequency Division Multiplexing (OFDM) signal, which is generated through allocation of CSI-RSs for maximum 8 antenna ports under a condition of a subframe in which an extended Cyclic Prefix (CP) is employed as a CP and a Time Division Duplex (TDD) scheme is employed as a duplex scheme;

extracting CSI-RSs for antenna ports allocated to particular REs from the received signal; and

acquiring Channel State Information (CSI) based on the extracted CSI-RSs,

wherein CSI-RSs for a pair of antenna ports are allocated to REs corresponding to one sub-carrier at every 12 sub-carriers in a frequency band and corresponding to 8^th and 9^th symbols in a subframe, one subframe having a total of 12 symbols for the extended CP,

CSI-RSs for the pair of antenna ports are allocated to identical REs, the CSI-RS for a first antenna port in the pair of antenna ports and the CSI-RS for a second antenna port in the pair of antenna ports being discriminated from each other by different orthogonal codes, and

CSI-RSs for a first pair of two neighboring pairs of antenna ports are allocated in first REs and CSI-RSs for a second pair of the two neighboring pairs are allocated in second REs, the first REs and the second REs being spaced apart by having two REs between the first REs and the second REs along a frequency axis.

11. The method of claim 10, wherein CSI-RSs of a higher antenna port number are allocated to an RE having a lower subcarrier index in the frequency axis.

12. The method of claim 10, wherein CSI-RSs of the (7^th, 8^th), (5^th, 6^th), (3^rd, 4^th) (1^st, 2^nd) antenna ports for CSI-RS transmission are allocated to two REs having subcarrier indexes within an Resource Block of 0, 3, 6, and 9 (1^st, 4^th, 7^th and 10^th subcarriers within an Resource Block, respectively), respectively.