The Precoder Design with Covariance Feedback for Simultaneous Information and Energy Transmission Systems

Table 1

Overhead of computing the precoders.

Precoding method	Overhead
the proposed two methods	Tx obtains the channel covariance matrices and noise power , by measure- ment over a period of time.
isotropic transmission	No overhead is needed.
the precoder with hybrid CSI feedback [31]	Tx obtains the energy channel covariance matrices and noise power , by measurement over a period of time; Tx also requires the instant CSI of the information channel.
time switching method	It is the same with the proposed methods.