  For two-user interference channels, the capacity is known for the case where
interference is stronger than the desired signal. Moreover, it is known that if
the interference is above a certain level, it does not reduce the capacity at
all. To achieve this capacity, the channel inputs need to be Gaussian
distributed. However, Gaussian signals are continuous and unbounded. Thus, they
are not well suited for practical applications. In this paper, we investigate
the achievable rates if the channel inputs are restricted to finite
constellations. Moreover, we will show by numerical simulations that rotating
one of these input alphabets in the complex plane can increase the achievable
rate region. Finally, we show that the threshold at which the single-user rates
are achieved also depends on this rotation.
