US Patent 11147034 Carrier grouping in multicarrier communications

Methods, apparatuses, and systems for wireless communications are described. Uplink signals may be time aligned based on different synchronization signals as a timing reference for different carrier groups. A base station may send, to a wireless device, a time alignment command comprising: an indication of a carrier group index, and a time adjustment value. Based on the time alignment command, the wireless device may send second uplink signals.