ink, a user may be assigned to one or more resource blocks. Subchannelization defines subchannels that can be allocated to mobile stations depending on their channel conditions and service requirements. Using subchannelization, within the same time slot (i.e., an integer number of OFDM symbols) an OFDMA system can allocate more transmitting power to user devices with lower SNR and less power to user devices with higher SNR. Subchannelization also enables the BS to allocate higher power to sub-channels assigned to indoor mobile terminals, resulting in better indoor coverage. The basic uplink transmission technique in 3GPP LTE is single-carrier transmission (SC-FDMA) with a cyclic prefix to achieve uplink inter-user orthogonality and to enable efficient frequency-domain equalization at the receiver side. DFT-Spread OFDM (DFT-S OFDM) a form of single-carrier transmission technique where the signal is generated in the frequency-domain similar to OFDMA, and is illustrated in Figure 9-10. In Figure 9-10, the common processing units in OFDMA and SC-FDMA are distinguished from those that are specific to SC-FDMA. This allows for a relatively high degree of commonality with the downlink OFDMA baseband processing using the same parameters, e.g., clock frequency, sub-carrier spacing, FFT/IFFT size, etc. The use of SC-FDMA in the uplink is mainly due to the relatively inferior PAPR properties of OFDMA that result in worse uplink coverage compared to 9.3 SC-FDMA and OFDMA principles OFDMA User B User E User A User C User D Resource Element (One Sub-carrier over One OFDM Symbol) FIGURE 9-9 An illustration of the difference between OFDM and OFDMA SC-FDMA. The PAPR characteristics are important for cost-effective design of a mobile station's power amplifiers. The ith transmitted symbol in an SC-FDMA system without a cyclic prefix in a single transmit/ receive antenna case can be expressed as a vector of length NFFT samples defined by y = FTDx where X = (x1, x2, XM)T is an M X 1 vector with M QAM modulated symbols (the superscript