3 User interference channel: Degrees of freedom as a function of channel diversity

Abstract

In this paper we characterize, in the context of vector space precoding strategies, the degrees of freedom of the parallel three-user interference channel as a function of the channel diversity L. A channel diversity of L is modeled by L independently fading real-valued parallel channels. Our results also apply to the case of parallel complex-valued channels, where the channel matrices Hij ∊ Cl×l are still diagonal but have complex entries. Here L = 2l is twice the number of parallel channels, and the resulting formulas (as a function of L) for the degrees of freedom are the same as in the real-valued case.