  In this paper we study four concrete models, based on no-scale supergravity
with SU(2,1)/SU(2)$\times$ U(1) symmetry. We modify either the K\"ahler
potential or the superpotential, which are related to the no-scale theory with
this symmetry. In this scenario, the induced Gravitational Waves, are
calculated to be detectable by the future space-based observations such as
LISA, BBO and DECIGO. The models under study are interrelated, as they all
yield the Starobinsky effective-like scalar potential in the unmodified case.
We evaluate numerically the scalar power spectrum and the stochastic background
of the Gravitational Waves, satisfying the observational Planck cosmological
constraints for inflation.
