An uplink physical channel corresponds to a set of resource atoms carrying information originating from higher layers. The following uplink physical channels are defined (Figure 3.57):
An uplink signal is used by the physical layer but does not carry information originating from higher layers. The following uplink physical signals are defined:
The basic uplink transmission scheme is single-carrier transmission (SC-FDMA) with cyclic prefix to achieve uplink inter-user orthogonality and to enable efficient frequency–domain equalization at the receiver side. Frequency–domain generation of the signal, sometimes known as DFT-SOFDM (Discrete Fourier Transform Spread Orthogonal Frequency Division Multiplex), is assumed and illustrated in Figure 3.58. This allows a relatively high degree of commonality with the downlink OFDM scheme and the same parameters, e.g. clock frequency, can be re-used.
The subcarrier mapping determines which part of the spectrum is used for transmission by inserting a suitable number of zeros at the upper and/or ...