QUALCOMM Incorporated
Reference signal multiplexing in shortened transmission time intervals

Abstract:

Methods, systems, and devices for wireless communications are described for mapping demodulation reference signal (DMRS) data to resource elements (REs) within a shortened transmission time interval (sTTI) so as to avoid collision with other reference signal data that the sTTI may be configured to include, such as channel state information reference signal (CSI-RS) data, cell-specific reference signal (CRS) data, or the like. A base station may select a DMRS mapping pattern for an sTTI based on one or more factors, including a CSI-RS configuration, a CRS configuration of the sTTI, an antenna port configuration for CRS (e.g., a number of CRS ports and associated number of layers configured for CRS, such as a one port CRS having a two-layer configuration, or a two port CRS having a four-layer configuration), or a type of subframe that includes the sTTI.