The 5G New Radio (NR) cell search and system acquisition procedure is an essential step that allows a user equipment (UE) to synchronize with and connect to a 5G network. It involves the UE searching for available cells, synchronizing with the strongest cell, and acquiring system information to establish a connection. Here is a high-level overview of the cell search and system acquisition procedure in 5G NR:
1) Initial cell search: The UE performs an initial cell search to identify potential cells in the vicinity. It scans for synchronization signals called Primary Synchronization Signal (PSS) and Secondary Synchronization Signal (SSS) to detect the presence of 5G NR cells.
2) Synchronization: Once the PSS and SSS are detected, the UE uses them to synchronize with the strongest cell. The PSS and SSS provide information such as cell identity and frame timing, which allows the UE to align its timing and frequency with the cell.
3) Physical cell identity (PCI) determination: After synchronization, the UE decodes the Cell-specific Reference Signal (CRS) to determine the Physical Cell Identity (PCI) of the synchronized cell. The PCI uniquely identifies the cell within the network.
4) System information acquisition: Once the PCI is determined, the UE reads the System Information Block Type 1 (SIB1) from the synchronized cell. SIB1 contains essential information about the cell and the network, such as system bandwidth, cell identity, and initial access parameters.
5) Higher-layer parameter acquisition: After acquiring SIB1, the UE may need to obtain higher-layer system information by reading additional System Information Blocks (SIBs). These blocks provide information about the cell’s operational parameters, mobility management, security, and other network-related details.
6) Random access: Once the necessary system information is acquired, the UE can initiate a random access procedure to establish a connection with the network. The random access procedure involves transmitting a random access preamble to the cell and awaiting a random access response from the network.
7) Connection establishment: Upon successful random access, the UE receives a random access response from the network, which includes a Temporary C-RNTI (Cell Radio Network Temporary Identifier). The UE uses the Temporary C-RNTI to complete the connection establishment procedure, including the assignment of a permanent C-RNTI and acquiring additional configuration parameters.