The physical layer of UTRA TDD

The third generation mobile radio system UTRA that has been specified in the Third Generation Partnership Project (3GPP) consists of an FDD and a TDD mode. This paper presents the physical layer of the UTRA TDD mode, which is based on TD-CDMA. Important system features are explained in detail. The physical layer is responsible for the transmission of transport blocks over the air interface. This includes forward error correction, multiplexing of different transport channels on the same physical resources, rate matching, modulation, spreading and RF processing.