User terminal and radio communication method
摘要
說明書
The present invention relates to a user terminal and a radio communication method in next-generation mobile communication systems.
In the UMTS (Universal Mobile Telecommunications System) network, the specifications of long term evolution (LTE) have been drafted for the purpose of further increasing high speed data rates, providing lower latency and so on (see non-patent literature 1). Also, the specifications of LTE-A (also referred to as “LTE-Advanced,” “LTE Rel. 10,” “LTE Rel. 11,” “LTE Rel. 12.” etc.) have been drafted for further broadbandization and increased speed beyond LTE (also referred to as “LTE Rel. 8” or “LTE Rel. 9”), and successor systems of LTE (also referred to as, for example, “FRA (Future Radio Access),” “5G (5th generation mobile communication system).” “5G+(plus),” “NR (New Radio),” “Nx (New radio access),” “FX (Future generation radio access),” “LTE Rel. 13.” “LTE Rel. 14” or “LTE. Rel. 15” and so on) are under study.
Carrier aggregation (CA) to integrate multiple component carriers (CC) is introduced in LTE Rel. 10/11 in order to achieve broadbandization. Each CC is configured with the system band of LTE Rel. 8 as one unit. Furthermore, in CA, a plurality of CCs of the same base station (referred to as an “eNB (evolved Node B),” a “BS (Base Station)” and so on) are configured in a user terminal (UE: User Equipment).
Meanwhile, in LTE Rel. 12, dual connectivity (DC), in which multiple cell groups (CGs) are configured in a UE, is also introduced. Each cell group is comprised of at least one cell (CC). In DC, since multiple CCs of different base stations are integrated, DC is also referred to as “inter-base-station CA (Inter-eNB CA).
