公开(公告)号：US10129770B2

公开(公告)日：2018-11-13

申请号：US15453736

申请日：2017-03-08

Applicant: QUALCOMM Incorporated

Inventor： Taesang Yoo ,  Dinkar Vasudevan ,  Jing Sun ,  Juan Montojo

IPC: H04W24/02 ,  H04L1/00 ,  H04L5/00 ,  H04W72/04 ,  H04W72/14

Abstract: Methods, systems, and devices for broadcast transmissions in wireless communication are described. A base station may transmit a control reference signal (CRS), a UE-specific reference signal (UERS), and broadcast data (e.g., broadcast physical downlink shared channel (PDSCH) data) in a broadcast downlink transmission. A UE may identify that the CRS and UERS are associated with the broadcast downlink data, and demodulate the broadcast downlink data in the broadcast downlink transmission based at least in part on the CRS and UERS. A UE may estimate a frequency offset based on a phase difference between the CRS and UERS, combine the CRS and UERS for use in a channel estimation, and demodulate the broadcast data based at least in part on the estimated frequency offset and channel estimation. The base station may provide signaling, such as dynamic or semi-static signaling, that indicates presence of both CRS and UERS.

公开(公告)号：US10117207B2

公开(公告)日：2018-10-30

申请号：US15830821

申请日：2017-12-04

Applicant: QUALCOMM Incorporated

Inventor： Zhifei Fan ,  Taesang Yoo ,  Dinkar Vasudevan

IPC: H04B7/005 ,  H04B7/01 ,  H04B7/015 ,  H04B15/00 ,  H04W56/00 ,  H04B1/403 ,  H04B7/024 ,  H04L25/02 ,  H04L5/00

Abstract: Over-the-air (OTA) phase synchronization for reciprocity-based coordinated multipoint (CoMP) joint transmission is disclosed. Phase synchronization reference signals (PSRS) are transmitted within a CoMP operation that can be used to determine the phase drifts of the transmit and receive chains of the base stations. These phase drifts can then be used to obtain a relative phase drift between the uplink and downlink channels. When estimating the uplink channel from the sounding reference signals (SRS), the relative phase drift may be applied to estimate the downlink channel as well. The OTA phase synchronization may be performed with a user equipment (UE)-assisted or inter-base station procedures.