Method and apparatus for extending coverage in communication system
摘要
說(shuō)明書(shū)
A set of precoding matrix indicators (PMIs) that a base station can indicate to a terminal may be restricted according to capability of the terminal (i.e., UE capability). For example, the base station may indicate (e.g., set) one or more among fullyAndPartialAndNonCoherent, partialAndNonCoherent, or nonCoherent to the terminal using higher layer signaling. The terminal may identify the information indicated by the higher layer signaling. When fullyAndPartialAndNonCoherent is indicated, the terminal may perform coherent transmission between all antenna ports. When partialAndNonCoherent is indicated, the terminal may not perform coherent transmission between antenna port pairs, but may perform coherent transmission between antenna ports belonging to an antenna port pair. When nonCoherent is indicated, the terminal may not perform coherent transmission for each antenna port. Accordingly, the base station may not allocate a specific PMI depending on capability of the terminal. That is, when the maximum rank that the terminal can support, the maximum number of antenna ports that the terminal can support, and/or UE capability are indicated by RRC signaling, transmitted precoding matrix indicator (TPMI) index(es) indicated to the terminal may be restricted to some of TPMI indexes defined in the technical specification.
For example, the maximum rank indicated to the terminal may be 1, and the number (e.g., the maximum number) of antenna ports indicated to the terminal may be 2. In this case, communication between the terminal and the base station may be performed based on Table 1 below. The TPMI (e.g., TPMI index) used by the terminal may be determined based on a value of a field included in uplink-downlink control information (UL-DCI). The UL-DCI may be a DCI including information element(s) for uplink communication. In exemplary embodiments, the TPMI may refer to a TPMI index.
