Sounding Reference Signal Transmission Control in Wireless Carrier Aggregation

The patent applies preliminary action by requiring the UE to obtain timing advance information for a secondary cell before transmitting sounding reference signals on that cell. The network configures the UE with timing advance values through RRC signaling or MAC CE commands during the cell activation process, ensuring synchronization is established in advance. This prevents timing misalignment and interference while enabling channel quality measurements, as the UE transmits SRS only after the timing advance configuration is received and applied.

The patent applies universality by enabling a single timing advance value to serve multiple secondary cells that share the same uplink timing relationship with the primary cell. When multiple SCells have identical timing advance requirements, the network can configure them to use a common timing advance value rather than providing separate timing advance commands for each cell. This reduces signaling overhead and UE processing complexity while maintaining synchronization accuracy, as the same timing advance value correctly synchronizes transmissions on all cells within the same timing group.

The patent resolves this contradiction by performing preliminary timing advance configuration during the SCell activation process. The network sends timing advance values to the UE via RRC signaling or MAC CE commands before the UE begins data transmission or SRS transmission on the SCell. This ensures the UE has valid timing information in advance, allowing it to transmit SRS on activated SCells without causing interference, while the network receives accurate channel quality measurements for scheduling decisions.