ation Demapping Mapping IDFT-Despreading DFT-Spreading Equalizer Sub-Carrier Mapping Sub-Carrier Demapping IFFT and CP Insertion FFT and CP Removal Multipath Channel Figure 6.7 Layer-1 UTRA LTE uplink link-level simulator. © 2009 by Taylor & Francis Group, LLC Single-Carrier Transmission for UTRA LTE Uplink with the transport format and resource combination (TFRC) information from the link adaptation (LA) module to the transport block generator. The transport block generator generates the packet based on the requested size. Then the cyclic redundancy check (CRC)-based error-detecting code is added to the corresponding packet. According to the packet size and the maximum code block size, the packet is segmented into several blocks. Each block is coded; the coding used for this study is the turbo coding defined in UTRA release 6 [8]. The rate matching block adjusts the output bit rate according to the requirements by puncturing or repeating the coded bits. The rate matching implementation follows the description in UTRA release 6 [8]. Afterward, the output coded bits are interleaved and are passed to the modulator. The modulator is implemented based on the supported modulation schemes defined in technical specification TR 25.814 V7.1.0 [6]: 12 BPSK, QPSK, 8 PSK, and 16 QAM. For QAM modulation, a QAM remapping is performed to set the systematic bits at more reliable constellation points because this improves the decoder performance. Single-carrier transmission is formed by the DFT spreading. The DFT spread- ing block precodes the PSK/QAM data symbols. Thus, all constellation symbols are mixed together to form an SC-FDMA symbol. Afterward, several SC-FDMA symbols are combined with pilot symbols in a time division multiplex (TDM) and mapped to the proper subcarriers. The 3GPP study item report [6] specifies both localized and distributed allocation mapping as discussed in Section 6.3. Finally, the basic OFDM processing discussed in Section 6.3 is performed. The data symbols are placed on orthogonal subcarriers by the 