Autonomous grouping scheme for selfish DSC introduced spectrum sharing in asynchronous transmit timing conditions

This paper proposes an autonomous grouping in subsystem band for spectrum sharing with the aid of selfish dynamic spectrum control (S-DSC) for asynchronous private wireless networks. When S-DSC, in which each transmitter maps its original spectrum to spectrum with higher channel gain of a system band in a selfish manner, is employed in each link of a shared band, and their transmission timing is asynchronous, there arises mutual interference components in the receiver even at null spectrum positions of the original interference signal, and this causes a so-called near-far problem, which is much severer than the transmit timing synchronous case. To alleviate the critical problem, the proposed scheme introduces an autonomous subsystem band grouping in which each user autonomously selects one of the subsystem band in a system band to maximize its expected average capacity, thereby user links with moderate mutual interference are grouped in the same subsystem band autonomously. Computer simulations confirm that the proposed scheme mitigates the impact of the aforementioned near-far problem. Moreover, the simulations confirm that the frame error rate (FER) performance of the proposed scheme is better than that for the centralized control assumed orthogonal frequency division multiple access (OFDMA).