Entropy Loading Design for the MIMO-OFDM Visible Light Communication System Using the OCT Precoding Technique

Figure 3

Experimental verification when the modulation order is 32-QAM: (a) GMI as a function of subcarrier index, (b) NGMI as a function of subcarrier index, (c) corresponding constellation density of the scheme without precoding, and (d) corresponding constellation density of the proposed scheme with OCT precoding.

(a)

(b)

(c)

(d)