Figure 2

Transmit gain. (a) A column-reduced DFT matrix ${\mathbf{E}}_1^{\left(3\right)}$ and its column vectors e_1,1, e_1,2, and (b) the desired precoding matrix N₁(30°) and its column vectors n_1,1, n_1,2. We assume the number of precoding matrices G=2, the number of transmit antennas N=3, and $\frac{\lambda }{d}=0.5$.