QUALCOMM Incorporated
Enhanced power headroom report for feeding back beamformed sounding reference source power scaling

Abstract:

Various aspects are described for an enhanced power headroom report (PHR) for feeding back beamformed sounding reference signal (SRS) power scaling. Beamformed SRS along directions where a user equipment (UE) can best nullify interference/maximize downlink (DL) signal to interference plus noise ratio (SINR) would be very helpful for DL beamforming. SRS beamforming requires additional support, if rank related decisions are being made at eNB. For example, power normalization factors need to be sent or reported on the uplink (UL) to eNB. This disclosure provides examples of how the PHR on the uplink can be used to do such reporting. There are two types of PHR being proposed, one nominal for the UL-oriented SRS, like LTE-style PHR, and one for the DL-oriented SRS where the UE also reports or indicates the power normalization factors of each SRS port.