Three-Dimensional Beam Tracking for Wireless Communication Systems

The narrow millimetre wave beam in future 5G networks is easily interrupted by the movement of mobile handsets. In this thesis, a novel three dimensional (3-D) beam tracking method is proposed to achieve beam alignment between the access node (AN) and the user node (UN). The algorithm is achieved through rotation tracking and location tracking of the UN relative to AN's beam angle and location. The rotation tracking algorithm is operating within the location tracking algorithm to track the UN's rotation and the rotation data is used to update the location information as the UN moves. For rotation tracking, a gradient descent algorithm is employed for self-rotation tracking based on measurements obtained by the three smartphone sensors (gyroscope, accelerometer and magnetometer) embedded in the micro-electro-mechanical system (MEMS). For location tracking, an extended Kalman Fltering (EKF) based location tracking algorithm is also incorporated into the design by combining the data from the direction of arrival (DoA) and time of arrival (ToA) estimation results of the user node (UN) since accurate UN location information is also crucial in the beam tracking process. Moreover, an operation protocol is provided for the tracking process and tested in three different scenarios: self-rotation with a fixed UN position and one AN, self-rotation with the straight-line movement of the UN with one AN and self-rotation with the straight-line movement of six ANs.