Exploiting Spatial and Frequency Diversity in Spatially Correlated MU-MIMO Downlink Channels

Table 2

Codebook size for unitary precoding, 𝐿=4.

	𝐄0=1√2111−1
	𝐄1=1√2111√21(1+𝑗)√2(−1−𝑗)
	𝐄2=1√211𝑗−𝑗
	𝐄3=1√2111√21(−1+𝑗)√2(1−𝑗)