Patent ID: 8787216

Claim:
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.