Energy-Efficient Hybrid Precoding Scheme Based on Antenna Selection Technology in Massive Multiple-Input Multiple-Output Systems

Algorithm 2

Analog precoding scheme.

Input: Channel matrix H, analog beamforming codebook , the number of RF chains

Initialization:

 1: for do

 2:   while do

 3:   User feed back the index of codebook vector r_i to BS. BS finds corresponding vector from codebook and setting as the ith column of F_RF, that is

 4:   

 5:   end while

 6:   

 7: end for