e configured for one of the two uplink carriers in the cell. The initial access is supported on each uplink carrier. The mapping of the UCI to PUSCH resources is such that more (operationally) important bits (HARQ-ACK) are mapped to the first OFDM symbol after the first DM-RS, and less (operationally) important bits (CSI reports) are mapped to the subsequent symbols. Unlike the data part, which relies on rate adaptation to overcome the effects of radio propagation, the L1/L2 control signaling part cannot be rate-adapted. Power control may theoretically be used, but it would imply fast power variations in the time 634 Chapter 4 domain, which negatively impact the RF properties. Therefore, the transmission power is maintained constant over the PUSCH duration and the amount of resource elements allo- cated to L1/L2 control signaling is changed by changing the code rate of the control signal- ing. In addition to a semi-static value controlling the amount of PUSCH resources used for UCI, it is also possible to signal this information as part of a DCI. The bit sequence from the output of code block concatena- tion and multiplexing, where is the number of bits in codeword q transmitted on the physical shared channel, are scrambled prior to modulation, resulting in a block of scram- bled bits (N(9) - such that the UL-SCH bits (except the UCI place- holder bits) are scrambled with pseudo-random sequence c(n) that is initialized with the 16- bit RNTI bits as follows 6(9) (i) = where Cinit = NRNTI215 + NID and nIDE{0,1, ., 1023} is set equal to the RRC parameter dataScramblingIdentityPUSCH oth- erwise, = Ncell The parameter NRNTI corresponds to the RNTI associated with the PUSCH transmission, if the input bits corresponding to UCI place-holder bits are set to one or the previous scrambled bit, depending on the value of the bits [6]. The block of scrambled bits are modulated using 2-BPSK (with transform precoding only), QPSK, 16QAM, 64QAM, or 256QAM modulation schemes, resulting in a block of complex-valued modulation symbol