Abstract—This paper considers a cognitive radio (CR) net-work, in which the unlicensed (secondary) users (SUs) are allowed to concurrently access the spectrum allocated to the licensed (primary) users provided that their interference to the primary users (PUs) satisfies certain constraints. It is more general and owns stronger challenge to ensure the quality of service (QoS) of the PUs as well as to maximize the weighted sum-rate of the SUs. By choosing the weighted coefficients, we can find any optimal boundary point of the capacity region. On the other hand, single-antenna mobile users are quite common due to the size and cost limitations of mobile terminals. Thus, we simply term this setting as single input multiple output multiple access channels (SIMO-MAC) in the CR Networks. Subject to the interference constraints of the SUs as well as peak power constraints of the SUs, the weighted sum-rate maximization problem is solved. To effectively and efficiently maximize the achievable weighted sum-rate of the SUs, a tight pair of upper and lower bounds, as an interval, of the optimal Lagrange multiplier is proposed. It can avoid ineffectiveness or inefficiency when the dual decomposition is used. Therefore, not only is convergence of the proposed algorithm guaranteed, but efficient computation is also provided by the proposed algorithm.
Index Terms—Wireless communications, coganative radio(CR) network, weighted sum-rate, multiple acess channels (MAC), optimization methods.
The authors are with the department of electrical and computer engineering, Ryerson university, Ontario, Canada, M5B 2K3 (e-mail: email@example.com, lzhao@ ee.ryerson.ca).
Cite: Peter He and Lian Zhao, "Efficient Maximum Sum-Rate Computation for Multiple Access Channels in CR Networks," International Journal of Computer Theory and Engineering vol. 4, no. 4, pp. 646-650, 2012.