Capacity and Optimal Power Allocation for Spectrum-Sharing with Primary Transmission Consideration in Fading Channels

We study the capacity and optimal power allocation problem for spectrum sharing with the primary transmission consideration in fading channels. In contrast to the existing power allocation schemes designed for spectrum sharing, the proposed optimal power allocation scheme can not only exploit the channel state information of the primary user to maximize the secondary capacity, but also ensure that the primary transmission is not interrupted by the maximization of the secondary capacity, which is of great significance for some applications, especially for real-time application.