Numerical results about the design of precoding matrix including four different methods to segment the complete set of basic beams and the multiuser transmission scheme are presented in this section.
Then, calculate the distances between v1 and all the basic beams, and select the nearest one c i and the farthest one c j, i = arg max i ∈ [ 1, 2, …, N v N h ] v 1 H c i v 1 · c i, j = arg min i ∈ [ 1, 2, …, N v N h ] v 1 H c j v 1 · c j. (13).
Then, we introduce a set of 3D beams which possess good discrimination in horizontal and vertical domains to be the basic beam set and adopt a topology describing the 3D beam set to illustrate the angle information in an intuitive way.
To discuss the design of inner precoding matrix W1, we first introduce the selection of basic beam set and then explain the design of inner precoding and outer precoding matrix in detail.
A set of 3D beams which has good discrimination in horizontal and vertical domains is selected to be the basic beam set, and a UPA topology is introduced to demonstrate the angle relations among these 3D beams.
Basic beam set and precoding method based on double codebook are described in Section 3. In Section 4, the CSI feedback scheme, user scheduling criteria, and fast codebook searching method are illustrated.
In S-RINA and conventional BSA, users have only a basic beam pattern switching rate of Ω u =1, and thus, the average sum rates are constant in all cases.
Then, in order to investigate the reliability of the ACK, static and dynamic simulations of both approaches were compared with each other and with analytical calculations on basic beam models.
This have several reasons: The need for 3-D treatment planning is not recognized; there is no confidence in the calculation algorithm; Monte-Carlo algorithms are too time-consuming; and the effort necessary to measure basic beam data for 3-D planning is considered disproportionate.
Figure8 gives an example of X k and illustrates its position in the complete basic beam set as the dotted line surrounds.
