Coverage Probability Analysis for mmWave Communication Network With ABSF-Based Interference Management by Stochastic Geometry

Millimeter wave (mmWave) communication technology has been widely discussed as a promising part to be used in 5th Generation (5G) fig: interference networks. However, mmWave signals are sensitive to blockage compared with traditional spectrums used for cellular networks, which proposes new challenges. In addition, 5G networks will support Time-Division Duplex (TDD) mode, which is able to provide flexible and dynamic uplink-downlink (UL-DL) configurations. However, dynamic adjustment will then introduce UL-DL interference and will further influence system performance. This paper will focus on the coverage probability of mmWave communication network with dynamic TDD configuration based on stochastic geometry analysis. Both the Line-of-Sight (LoS) link and Non-Line-of-Sight (NLoS) link are modeled, since the transmissions of mmWave signals will be greatly influenced by different link types. Coverage probabilities for downlink and uplink are analyzed, respectively. Furthermore, in order to mitigate the UL-DL interference introduced by dynamic TDD, the Almost-Blank-SubFrame (ABSF) scheme is studied in this work. In ABSF scheme, a base station with DL transmission will mute temporarily to avoid severe DL-UL interference to nearby base stations with LoS links and UL transmissions. Possible improvement after introducing ABSF is studied by updating downlink and uplink coverage probability expressions. Numerical results under different configurations are obtained and discussed. It is shown that uplink coverage probability is greatly influenced by downlink interference, which provides basis for applying ABSF. Improvements by ABSF are validated by corresponding results.