  Simultaneous wireless information and power transfer (SWIPT) technique is a
popular strategy to convey both information and RF energy for harvesting at
receivers. In this regard, we consider a relay employing SWIPT strategy, where
splitting the received signal leads to a rate-energy trade-off. In literature,
the works on transceiver design have been studied using computationally
intensive and suboptimal convex relaxation based schemes. In this paper, we
study the balanced precoder design using chordal distance (CD) decomposition to
provide a better rate-energy trade-off, which incurs much lower complexity and
flexible to dynamic energy requirements. It is analyzed that given a
non-negative value of CD, the achieved harvested energy for the proposed
balanced precoder is higher than that for the perfect interference alignment
(IA) precoder, while verifying the analyzed loss in sum rates. Simulation
results verify the analysis and add that the IA schemes based on mean-squared
error are better suited for the SWIPT maximization than the subspace
alignment-based methods.
