Precoder Index Modulation

—Index modulation, where information bits are conveyed through antenna indices (spatial modulation) and subcar-rier indices (subcarrier index modulation) in addition to information bits conveyed through conventional modulation symbols, is getting increased research attention. In this paper, we introduce precoder index modulation, where information bits are conveyed through the choice of a precoder matrix at the transmitter from a set of predetermined pseudo-random phase precoder (PRPP) matrices. Combining precoder index modulation (PIM) and spatial modulation (SM), we introduce a PIM-SM scheme which conveys information bits through both antenna index as well as precoder index. Spectral efficiency (in bits per channel use) and bit error performance of these index modulation schemes are presented.random phase precoding.