US Patent No. 10,117,207

OVER-THE-AIR PHASE SYNCHRONIZATION FOR RECIPROCITY-BASED COMP JOINT TRANSMISSION


Patent No. 10,117,207
Issue Date October 30, 2018
Title Over-the-air Phase Synchronization For Reciprocity-based Comp Joint Transmission
Inventorship Zhifei Fan, San Diego, CA (US)
Taesang Yoo, San Diego, CA (US)
Dinkar Vasudevan, New Delhi (IN)
Assignee QUALCOMM Incorporated, San Diego, CA (US)

Claim of US Patent No. 10,117,207

1. A method of wireless communication, comprising:transmitting, by a base station, a first phase synchronization reference signal (PSRS), wherein the base station is one of a plurality of cooperating base stations in a coordinating set of base stations;
receiving, at the base station, a second PSRS;
measuring, at the base station, a receive chain phase drift based on the received second PSRS;
obtaining, at the base station, a transmit chain phase drift based on the first PSRS;
determining, by the base station, a relative phase drift between a downlink channel and an uplink channel using the receive chain phase drift and the transmit chain phase drift;
determining, by the base station, a relative coordinating phase drift among all cooperating base stations in the coordinating set of base stations;
generating, by the base station, an uplink channel estimate based on a sounding reference signal (SRS) received from a user equipment (UE); and
generating, by the base station, a downlink channel estimate based on the uplink channel estimate, the relative phase drift, and the relative coordinating phase drift.