The Approximate Capacity Region of the Symmetric src='/images/tex/20394.gif' alt='K'> -User Gaussian Interference Channel With Strong Interference

摘要

The symmetric -user interference channel (IC) is studied with the goal of characterizing its capacity region in the strong interference regime within a constant gap. The achievable rate region of a scheme combining rate splitting at the transmitters and interference alignment and successive decoding/computation at the receivers is derived. Next, it is shown that this scheme achieves the so-called greedy-max corner points of the capacity region within a constant gap. By combining this result with previous results by Ordentlich on the sum-capacity of the symmetric IC, a constant gap characterization of the capacity region for the strong interference regime is obtained. This leads to the first approximate characterization of the capacity region of the symmetric -user IC. Furthermore, a new scheme that achieves the sum-capacity of the channel in the strong interference regime within a constant gap is also proposed, and the corresponding gap is calculated. The advantage of the new scheme is that it leads to a characterization within a constant gap without leaving an outage set contrary to the scheme by Ordentlich