On Feasibility of Interference Alignment in MIMO Interference Networks
Abstract
The degrees of freedom of MIMO interference networks with constant channel coefficients are not known in general. Determining the feasibility of a linear interference alignment solution is a key step toward solving this open problem. Our approach in this paper is to view the alignment problem as a system of bilinear equations and determine its solvability by comparing the number of equations and the number of variables. To this end, we divide interference alignment problems into two classes - proper and improper. An interference alignment problem is called proper if the number of equations does not exceed the number of variables. Otherwise, it is called improper. Examples are presented to support the intuition that for generic channel matrices, proper systems are almost surely feasible and improper systems are almost surely infeasible.
- Publication:
-
IEEE Transactions on Signal Processing
- Pub Date:
- September 2010
- DOI:
- 10.1109/TSP.2010.2050480
- arXiv:
- arXiv:0904.4526
- Bibcode:
- 2010ITSP...58.4771Y
- Keywords:
-
- Computer Science - Information Theory;
- Computer Science - Hardware Architecture
- E-Print:
- 6 pages. Submitted to IEEE Globecom March 31 2009