Adaptive beam-forming antenna (ABA) has been adopted as one of the key techniques of the TDD system. Because of the spatial variation of UE and imprecise digital signal processing (DSP) in the practical system, the system performance is deteriorated by the estimation errors of the direction of arrival (DOA). We evaluate the LTE TDD downlink performance of ABA without DOA estimation errors. Meanwhile, the impact of imperfect ABA on the system performance for the FTP-specific service as well as mixed services including FTP and video is investigated. Also a simple mixed services scheduler with adaptive emergency threshold (AET) is proposed over LTE TDD system to improve the system throughput while guaranteeing the quality of service (QoS) of video service.
['Ruiming Yang', 'Yongyu Chang', 'Shuhui Liu', 'Dacheng Yang']
System Layer Evaluation of Imperfect Adaptive Beam-Forming Antenna for Mixed Services in the LTE TDD System