s configured. It is also expected that there will be new UE categories in the future which do not support full bandwidth (see Chapter 15), and operating with them will be much more efficient when almost contiguous transmission is supported in the UEs. In order not to increase the waveform PAR variations, the feature is defined only for use with OFDM in the uplink. This is anyway the most likely case when the UE has enough power reserves for full-bandwidth transmission (Figure 6.21). The uplink signal generation in Figure 6.19 shows an example with 2 TX antennas and support for two-stream MIMO operation. In the first phase, the UEs based on Release 15 are foreseen to support only 1 TX per technology and frequency band, especially in 6 5G Physical Layer Figure 6.20 Uplink encoding. Transport Block CRC Attachment Code Block Segmentation and CRC Attachment LDPC Encoding Uplink Control Rate Matching Information (UCI) Code Block Channel Encoding Concatenation Multiplexing Operator frequency band allocation Power Not contiguous Frequency UE with small BWP or PUCCH allocation Power Frequency Almost contiguous Figure 6.21 Improvement for uplink allocation flexibility with almost contiguous uplink operation. 6.9 Uplink Signaling Transmission Codeword Modulation Layer Scrambling mapper mapper Transform Resource Block Mapping Signal Precoding generation Antenna Precoding Transform ports Resource Block Mapping Signal Precoding generation Figure 6.22 PUSCH transmitter chain after encoding. connection with LTE-5G dual connectivity. In a later phase, this is foreseen to become more popular, especially when operating with standalone 5G when transmitters on both LTE and 5G will not need to be used simultaneously (Figure 6.22). 6.9 Uplink Signaling Transmission UCI consists of HARQ-ACK feedback, used to provide the HARQ-ACK feedback of the downlink user data. Scheduling Request (SR) is used, as the name indicates, by the UE to request to be scheduled in the uplink due to data arriving at its transmit buffer. CSI is used to support 