nterface - MIMO and Beamforming The coding configurations are defined in Table 6.4 for single-panel mode and Table 6.5 for multi-panel mode. Number of CSI-RS ports N1,N2 01,02 (2,1) (4,-) (2,2) (4,4) (4,1) (4,-) (3,2) (4,4) (6,1) (4,-) (4,2) (4,4) (8,1) (4,-) (6,2), (4,3) (4,4) (12,1) (4,-) (8,2), (4,4) (4,4) (16,1) (4,-) Table 6.4. Codebook for type 1/type 2 single-panel Number of CSI-RS ports Ng,N1,N2 01,02 (2,2,1) (4,-) (2,2,2) (4,4) (2,4,1), (4,2,1) (4,-) (2,4,2), (4,2,2) (4,4) (2,8,1), (4,4,1) (4,-) Table 6.5. Codebook for type 1 multi-panel The mobile owns a codebook, which can be defined with the antenna architecture of the base station. The gNb transmits to the mobile the antenna model via an RRC message in the CodebookConfig data structure. The type 1 codebook corresponds to the case of a single user (SU-MIMO) up to eight spatial layers. Due to the architecture of the antennas, type 1 offers two subtypes: type 1 single-panel CSI and type 1 multi-panel CSI. NG-RAN and 5G-NR The type 2 codebook is dedicated to MU-MIMO transmissions with at most two spatial layers per user. 6.5. PUSCH transmission Uplink transmission uses either the OFDM signal (Orthogonal Frequency Division Multiplexing) or the DFT-S-OFDM signal (Discrete Fourier Transform Spread OFDM). Only the OFDM signal allows the MIMO mechanism to operate up to four spatial layers or the beamforming mechanism by digital precoding. MIMO is possible only for mobiles that are able to check the consistency of the signals on the two or four antenna ports. The MIMO mechanism or the beamforming mechanism for the uplink requires the capacity of the mobile to control the relative phase of the signals transmitted on the different antennas (coherence between antennas). The phase difference between a signal transmitted on a pair of antennas or on the four antennas must be constant (for a wideband signal). The antenna capacities of the mobile are defined by the following characteristics: - full coherence: all antenna ports can transmit broadband signals coherently