TECHNICAL FIELD

The disclosed embodiments relate generally to wireless communication, and, more particularly, to methods and apparatus for power-efficient radio resource management (RRM) for new radio (NR) network.

BACKGROUND

Mobile networks communication continues to grow rapidly. The mobile data usage will continue skyrocketing. New data applications and services will require higher speed and more efficient. Large data bandwidth application continues to attract more consumers. New technologies are developed to meet the growth such as carrier aggregation (CA), which enables operators, vendors, content providers and the other mobile users to meet the increasing requirement for the data bandwidth. 5G wireless network implements NR technologies can improve the network capacity.

In an LTE network, the measurement gap is used for inter-frequency measurement. In NR, the measurement gap is used for inter-frequency measurement, intra-frequency measurement with gap, and intra-frequency measurement without gap when all the measurement resource are overlapped by the measurement gap. For RRM measurement in NR, UE can be configured to measure synchronization signal (SS) blocks and/or channel state information reference signal (CSI-RS). The transaction of SS block is confined in 5 ms time window while the transmission of the CSI-RS could have moved with more flexibility. This adds the complexity of the RRM measurement for the SS blocks and the CSI-RS.

Improvements and enhancements are required to configure and perform RRM measurement for the NR network more efficiently.

SUMMARY

Apparatus and methods are provided for RRM measurement in the NR network. In one novel aspect, the RRM measurement is configured with one measurement gap for SS block and CSI-RS. In one embodiment, an extended MGL (eMGL) is configured such that the SS block and CSI-RS is measurement within one measurement gap. In another embodiment, the shorter MGL (sMGL) that is shorter than the standard MGL is configured. In yet another embodiment, a single common measurement duration and a single common timing offset are configured for different CSI-RS resources. In one embodiment, the RRM measurement configuration configures both an SS block measurement and a CSI-RS measurement when the UE performs an initial synchronization, and wherein the measurement gap is configured with an extended measurement gap length (eMGL) larger than a standard MGL such that both the SS block and the CSI-RS are measured within the eMGL. In another embodiment, the RRM measurement configuration configures only a CSI-RS measurement after the UE performs an initial synchronization, and wherein the measurement gap is configured with short measurement gap length (sMGL) smaller than a standard MGL. In yet another embodiment, the RRM configuration and the measurement gap configuration are configured by dedicated signaling.

In another novel aspect, the CSI-RS is allocated adjacent to the SS blocks such that one measurement gap is configured for both the SS block and CSI-RS measurement. In one embodiment, the CSI-RS is allocated in a physical downlink shared channel (PDSCH) symbol before the SS block. In another embodiment, the CSI-RS is allocated in a physical downlink shared channel (PDSCH) symbol after the SS block. In yet another embodiment, the SS block is an SS burst block across multiple analog beams, and wherein CSI-RS is allocated in a physical downlink shared channel (PDSCH) symbol after the SS block. In one embodiment, the same analog beamforming applies to both the SS burst block and the CSI-RS burst block.

In another novel aspect, the CSI-RS measurement is conditionally configured. In one embodiment, the UE receives a RRM measurement configuration that includes a conditional measurement configuration for CSI-RS measurement. The conditional measurement configuration for CSI-RS is based on one of triggering conditions comprising: a measurement result for beam management from a serving cell, a synchronization signal (SS)-block measurement result, and no triggering condition.

In yet another novel aspect, the UE decodes the time index of the SS block conditionally. The UE performs RRM measurement by the UE in a CONNECTED state based on the received RRM measurement configuration, wherein the UE only decodes a time index of configured SS block when one or more time-index triggering conditions are detected. In one embodiment, the UE performs RRM measurement on SS block of a serving cell and one or more neighboring cells to derive SS-block measurement. In one embodiment, the time-index triggering conditions comprising: a channel condition, a random-access channel (RACH) optimization is disabled, and a NBR CSI-RS is configured and is sufficient for RACH optimization. In one embodiment, the RRM measurement configuration includes a conditional measurement configuration for CSI-RS measurement based on one of triggering conditions comprising: a measurement result for beam management from a serving cell, a SS block measurement result, and no triggering condition.

Other embodiments and advantages are described in the detailed description below. This summary does not purport to define the invention. The invention is defined by the claims.

