 2nd hop 1 slot 1 slot Figure 6.24 PUCCH intra-slot frequency hopping. Left: Edge-to-edge hopping (LTE). Right: Each hop can be freely placed in frequency, enabling more flexible frequency occupancy (NR). PUCCH transmission (HARQ-ACK, aperiodic CSI report), the size of the triggered payload and well as the PUCCH resource indicator determine the PUCCH configura- tion to use for the PUCCH transmission in a slot, and the slot in which to transmit determined by the slot timing indicated by the DCI. Periodic CSI reports and SRs are configured with the PUCCH resources, formats, and slot timings by the Radio Resource Control (RRC) layer. Uplink beamforming applies to the PUCCH just as to the PUSCH. Each PUCCH resource set is configured with a set of candidate spatial relation signals by the source's RRC, and a MAC control element is used to pick one set out of the configured set to be active at a given time. This source signal is used to determine the uplink beam the UE transmits the PUCCH with. If the source signal is SRS, it is straight forward to transmit the PUCCH using the same beam used to transmit the indicated SRS. If the source signal is a Synchronization Signal Block (SSB) or CSI-RS, the UE needs to be able to transmit the PUCCH using the uplink beam that directionally corresponds with the downlink beam the active spatial relation source signal is received in. Simultaneous PUSCH and PUCCH transmissions are not supported because the independent PUCCH and PUSCH setups lead to a transmission waveform that is not contiguous in frequency. This in turn would yield a very high peak-to-average power ratio to the transmission, and to maintain the peaks within the linear region of the power amplifier the average transmit power would need to be severely reduced, limiting the actual transmitted energy of an OFDM symbol and thus cutting coverage. Thus, simultaneous PUSCH and PUCCH transmissions are not supported, although obviously nothing prevents frequency multiplexing one user's PUSCH with another user's PUCCH. When the