Sounding reference signals with collisions in asymmetric carrier aggregation
摘要
說明書
Thus, the UE may use the inactive uplink portions of a downlink CC, e.g. CC2, to transmit SRS to the eNB. Although examples are described using the term “eNB,” an eNB is only one example of a base station. The aspects described herein may also be applied with a 5G base station, e.g., a gNB. The carrier aggregation configuration for CC2 includes downlink portions and excludes, or does not configure, uplink portions of CC2 for use by UE. For example, CC2 may not be configured for data transmission on PUSCH. Thus, CC2 may also be referred to as a downlink only CC, because the UE has been configured for downlink on CC2 without being configured for uplink data transmissions on CC2. However, the UE may additionally be configured to use at least a portion of the inactive, or unconfigured, uplink portions of CC2 to transmit SRS. The UE may use this inactive uplink portion of CC2, e.g., for SRS transmissions without transmitting PUSCH, CSI, etc. on CC2. Such additional transmissions might place an undue burden on the available resources. Transmitting the SRS may provide an eNB information about the channel using a minimal amount of overhead. The SRS may be only a few symbols wide in an area defined for the UE by the eNB.
The SRS transmission on CC2 may cause an interruption in another uplink CC. For example, the SRS transmission on the inactive portion of CC2 may at least partially overlap another scheduled uplink transmission on a different CC. This may be called a collision. The UE might only be capable of transmitting or receiving using one CC at a time.
