Maximization of the weighted sum-rate of secondary users (SUs) possibly equipped with multiantenna transmitters and receivers is considered in the context of cognitive radio (CR) networks with coexisting primary users (PUs). The total interference power received at the primary receiver is constrained to maintain reliable communication for the PU. An interference channel configuration is considered for ad hoc networking, where the receivers treat the interference from undesired transmitters as noise. Without the CR constraint, a convergent distributed algorithm is developed to obtain (at least) a locally optimal solution. With the CR constraint, a semidistributed algorithm is introduced. An alternative centralized algorithm based on geometric programming and network duality is also developed. Numerical results show the efficacy of the proposed algorithms. The novel approach is flexible to accommodate modifications aiming at interference alignment. However, the stand-alone weighted sum-rate optimal schemes proposed here have merits over interference-alignment alternatives especially for practical SNR values.
Bibliographical noteFunding Information:
Manuscript received April 28, 2010; revised January 18, 2011; accepted January 21, 2011. Date of current version April 20, 2011. This work was supported by the National Science Foundation under Grants CCF 0830480, CON 014658, ECCS 0824007, and ECCS 1002180. Part of this work was presented at the 46th Annual Allerton Conference on Communication, Control, and Computing, Monticello, IL, 2008.
- Ad hoc network
- cognitive radio
- interference network