Per Burström

Uplink Control Channel in E-UTRA, Radio Link and Radio Network Evaluation

Evolved UTRA (E-UTRA) is specified by the Third generation partnership project, 3GPP. E-UTRA is designed to efficiently and flexibly utilize different spectrum bands supporting high physical bit rate and short radio link delay. A reliable control channel is a key component for short delay and high bit rate on higher layers. For user peak bit rate, a low HARQ NACK error ratio is crucial. HARQ ACK/NACK for downlink is sent on the Physical Uplink Control Channel (PUCCH). In this paper the PUCCH performance is evaluated by means of simulations. Results on both link and network level in a multi-cell environment show that the PUCCH is robust and designed for 1-reuse frequency plans. Good performance is shown for different channel types and for high speed mobiles. For up to 12 scheduled users per sub-frame the NACK error rate is maintained well below le-4.

System performance challenges of IMT-Advanced test environments

The test environments for system level evaluations of IMT-A (International Mobile Telecommunications-Advanced) candidate technologies are analyzed. Compared to the evaluation criteria for previous IMT standards, the IMT-A test environments provide significantly more realistic settings for evaluating system-level performance. The models include line-of-sight probability in all scenarios, different groups of users in terms of propagation and speed, as well as indoor and outdoor deployments. This contribution scrutinizes the evaluation conditions and presents resulting performance for a basic Long-Term Evolution (LTE) candidate system. Each environment contains challenging characteristics. Examples include a mix of indoor and outdoor users, a mix of line-of-sight and non-line-of-sight conditions, and terminal speeds making accurate tracking of channel quality difficult. Together, these characteristics suggest that a radio transmission technology fulfilling the ITU IMT-A requirements is well suited for meeting a variety of challenges of real deployment scenarios.