mis- sion parameters to be used. The gNB scheduler will get feedback information not only on the channel condition (Channel Quality Indicator [CQI]) and power availability in the UE but also on the amount of data in the UE buffers. Power headroom and buffer status reports are covered in the MAC layer signaling as explained in Chapter 7. The PDCCH signaling will also determine if the UE is to use OFDM or DFT-s-OFDM trans- mission. The gNB can use also SRSs to determine which part of the uplink band is best suited for the uplink allocation. The uplink modulation alternatives are QPSK, 16-QAM, 64-QAM, and 256-QAM, and in addition, 2-BPSK is possible when using DFT-S-OFDM. The normal UE is able to reach maximum transmission power with QPSK, and thus 2-BPSK support is optional for the UE side. 2-BPSK is intended to be used with transform precoding only, as the key driver was to minimize the transmitted signal PAR. Use of 2-BPSK was already considered for LTE [1] but it was not adopted at the time as LTE UE requirements require reaching maximum TX power with QPSK. This avoids reducing the uplink data rates when operating at the maximum power level. The uplink encoding chain is similar to the downlink, but with the uplink allocation (grant) in place the UCI is multiplexed with uplink data, as shown in Figure 6.20. The same LDPC coding as in the downlink direction is used also in the uplink. In the uplink direction, an important element is the use of non-contiguous uplink transmission. While on the capability level each UE supports the minimum bandwidth assigned for each frequency band, the use of a bandwidth part (BWP) will temporary limit the part of spectrum that a UE will operate in. If the uplink allocations would always need to be contiguous, this would limit the available data rate greatly if some narrow transmission of uplink control channel were present in between. The benefit of non-contiguous (or almost contiguous) transmission is shown in Figure 6.18, as it allows larger data rates in presence of UEs with BWP