Maucksch, Thomas; Falconetti, Laetitia; Dusza, Bjoern (Rohde & Schwarz, Munich, Germany)
The development of the new radio communication system called Long Term Evolution (LTE) is part of Universal Mobile Telecommunications System (UMTS) Release 8. It includes not only the design of the new system in terms of architecture, protocols and main features but also the standardization of Radio Frequency (RF) and performance requirements that a User Equipment (UE) shall meet to be certified LTE standard conform. This paper analyses the particularities of LTE and outlines their impact on the UE Transmitter (Tx) RF requirements and the UE Receiver (Rx) performance requirements. Whereas some Tx RF requirements of the previous UMTS releases like the Adjacent Channel Leakage power Ratio (ACLR) can be adapted to LTE, some of them like the Error Vector Magnitude (EVM) requirement, even adapted, can not guarantee a good LTE UE Tx signal quality. The need for new measurements taking into account the flexibility of the LTE Uplink (UL) signal is shown in this paper. The evaluation of LTE Rx performance requires a more complex emulation of the propagation channel and the selection of relevant test cases that will be implemented in Test Equipment (TE) becomes complicated considering the many degrees of freedom of the LTE transmission parameters. Finally, this paper emphasizes the new challenges a TE must face to be used in LTE RF conformance testing.