Coexistence Evaluation of LTE with Active Antenna System

Due to the new radio architecture of Active Antenna System (AAS), the LTE BS equipped with AAS will have more flexible RF planning than that equipped with passive antenna. However, the new RF characteristic of AAS will have potential impacts on the existing BS RF requirements, which is imperative to be evaluated. In this paper, general antenna pattern and spatial Adjacent Channel Leakage Ratio (ACLR) are introduced considering the new RF features of AAS, and the impacts of AAS on BS performance are analyzed based on the AAS fundamental applications. System-level coexistence simulation is conducted to evaluate the RF features of transmitter and receiver of AAS on BS performance. Simulation results show that RF feature of spatial ACLR of AAS transmitter has little impact on throughput loss in victim system and ACLR of 45 dB per transmitter of AAS can fully meet the coexistence requirement; RF feature of in-band blocking level of individual receiver of AAS is higher than that of receiver of BS equipped with passive antenna around 1-4 dB, which imposes harder requirement to design the channel selection filter in the individual receiver of AAS, thus in-band blocking requirement needs to be redefined for AAS BS in the existing 3GPP specification.