Research On Multi-beam Scheduling Technology Method Based On Coverage Enhancement In Millimeter Wave Communication Systems

Mobile communication has developed rapidly.Although 5G has entered the commercial planning stage gradually,the tireless search spirit of researchers has never stopped the future development of mobile communication.In order to further meet the requirements of high speed,low latency and high reliability of future mobile communication,different communication technologies continue to emerge.Millimeter wave communication technology can solve the current problem of spectrum shortage of mobile communication and provide a wider spectrum.Massive MIMO technology and beamforming technology can overcome the more serious path loss under the millimeter wave working frequency band,the use of strong directional narrow beam brings strong directional gain.At this time,multi-beam management has also attracted further research by scholars.At present,the practicality of beam management is still an urgent problem to be studied.This paper studies the beam selection problem during initial access and the beam tracking problem in the connected state.At the same time,millimeter-wave channels are vulnerable to abrupt changes affected by the surrounding environment.Consequently,the works done in this paper also include the channel abrupt change detection so as to enhance the stability of communication.The first work combines beam tracking and channel abrupt change detection,using the information obtained from beam tracking for channel abrupt change detection.The work establishes an angle variation model of millimeter wave channels.Combined with the signal observation model,it uses extended Kalman filtering algorithm to estimate the angles in the current slot,and takes the long-short term memory characteristics of LSTM(Long-short term memory)into consideration,effectively taking full advantages of the CSI(Channel State Information)of much more slots to learn to detect the channel abrupt change.Simulation results show that compared with the reference algorithms,the false detection rate of this algorithm is greatly reduced.For beam selection,the second work’s research is conducted in multi-community and multi-user scenarios in millimeter wave communication system,and ultimately need to assign a service beam to each user.In order to avoid inter-beam interference in the same cell and intra-interference between different cells to the greatest extent,this work adopts a greedy beam selection strategy and selects service beam for each users based on maximization of the current system capacity.Greedy search is a suboptimal scheme.However,simulation results show that this scheme has better performance than several classic beam selection algorithms at present.In a word,this paper focuses on beam tracking,channel abrupt change detection and beam selection.It conducts beam management research on connection state and initial access respectively,and puts forward corresponding algorithms to improve system performance.