Constant interference methods for power allocation in orthogonal frequency division multiplexing-based cognitive radio networks

Abstract

The capacity maximisation problem of the secondary user subject to an interference constraint in orthogonal frequency division multiplexing-based cognitive radio systems is studied in this paper. A novel constant interference strategy to allocate power to subcarriers is derived, where all selected subcarriers are subject to the same interference constraint. It means all subcarriers have the same interference power. This strategy ensures the original interference constraint satisfied. The capacity loss of the proposed methods compared with the optimal solution is also analysed. An upper bound of the capacity loss is derived. Its value can determine the potential benefit of the proposed methods even if the optimal solution is not obtained. Therefore an advanced strategy to select subcarriers to allocate power becomes important, which affects the performance of the proposed methods and the upper bound. By using a proposed indicator, two novel power allocation methods were presented with a lower complexity to select subcarriers for allocating power, which outperforms the existing methods. Performances of the proposed methods are very near that of the optimal solution.

New multiple‐input multiple‐output‐based filter bank multicarrier structure for cognitive radio networks

“…In addition, resource allocation for SUs in the CR scenario has received considerable attention. In [19, 20], the authors presented a scheme to maximise the capacity per sub‐channel. They considered only the power constraints while the effect of side lobes of neighbouring subcarriers was omitted.…”

“…One of the fundamental problems to be addressed in CR systems is the management of interference to avoid the problem of PUs and SUs coexistence. In past decades, resource management in terms of subcarrier allocation, power, and interference control for CR systems has been considerably investigated [19–21]. Therefore, resource management for multicarrier‐based CR systems is an important matter that needs to be prudently addressed.…”

Minimum BER Power Allocation for OFDM-based Cognitive Radio Networks

“…[6] studied the power allocation problem to maximize the SU sum rates under the PU protection criterion expressed through a utility function. In [7], a constant interference strategy was proposed to allocate power to subcarriers such that the subcarriers are subject to the same interference. In [8], a fast and efficient power allocation algorithm for the OFDM-based CR network was proposed based on the parallel-shift property of water-filling.…”