d to PUSCH transmission. The PT-RS is mapped to resource elements according BPT-RsW[rPT-Rs(po,2n+k') TPT-RS(Pv-1,2n+k)) where k + 2k' for configura- tion Type 1 or k=6n+k'+ A for configuration Type 2, if l is within the OFDM symbols allocated for the PUSCH transmission, the resource element (k,l) is not used for DM-RS. parameters as well as the precoding matrix W are given in [6]. The configuration type is provided by the higher layer parameter DMRS-UplinkConfig. In the preceding expression, scaling factor BPT-RS is used to adjust the transmit power. The set of time indices l is defined relative to the start of the PUSCH allocation is defined by max(lref+(i- 1)LPT-RS + 1, lref) lref + iLPT-RS ALPT-RS 6 {1,2,4} where any symbol in this interval which overlaps with a DM-RS symbol is skipped. 600 Chapter 4 Table 4.24: Time-domain/frequency-domain density of phase tracking reference signal as a function of scheduled modulation coding scheme/ bandwidth [9]. Scheduled MCS Time-Domain Density LPT-RS 0 < MCS < MCS1 No PT-RS MCS < MCS < MCS2 Every OFDM symbol MCS2 < MCS < MCS3 Every second OFDM symbol MCS3 < MCS < MCS4 Every fourth OFDM symbol Scheduled Bandwidth Frequency Domain Density KPT-RS <NRB NRB1 No PT-RS NRB1 VI NRB <NRB Every second RB NRB2 VI NRB Every fourth RB PUSCH_(data/ PUSCH_(data/ PUSCH_(data/ control control control) PT-RS on every OFDM symbol PT-RS on every second OFDM symbol PT-RS on every fourth OFDM symbol PT-RS on every second resource block PT-RS on every fourth resource block Scheduled bandwidth Figure 4.75 Example CP-OFDM uplink time-frequency resource mappings. The resource blocks allocated for PUSCH transmission are numbered from 0 to NRB-1 rela- tive to the lowest scheduled resource block for the purpose of PT-RS transmission. The subcarriers associated with these resource blocks are numbered in increasing order from 0 to NRBNRB starting with the lowest frequency. The PT-RS is mapped to subcarriers k=kref where KPT-RS &{2,4} (see Table 4.24). The parameter KRB=NRNTI mod KPT-RS, if NRB mod KPT