Degrees of Freedom of Completely-Connected Multi-Way Interference Networks
Namyoon Lee and Robert W. Heath, Jr.
Submitted to IEEE ISIT 2013, Jan. 2013.
This paper considers a fully-connected interference network with a relay in which multiple users equipped with a single antenna want
to exchange multiple unicast messages with other users in the network by sharing the relay equipped with multiple antennas.
For such a network, the optimal degrees of freedom (DoF) are derived by providing both converse and achievability.
Further, considering single-antenna relays in the three-user fully-connected interference network, it is shown that three
distributed relays with a single antenna is sufficient to achieve the optimal DoF. A major implication of the derived DoF results
is that a relay with multiple antennas or distributed relays employing a single antenna increases the capacity scaling law of
the multi-user interference network when multiple directional information flows are considered, even if the networks
are fully-connected and all nodes operate in half-duplex. These results verify an intuition that the relay
is useful in the interference network with practical considerations.
[download full paper]