Cooperative Spectrum Sharing with Distributed Secondary User Selection
Yinghua Han, See Ho Ting, Ashish Pandharipande · 2010
In this paper, we propose a two-phase protocol based on cooperative relaying for a secondary system to achieve spectrum access along with a primary system. The primary system comprises of a transmitter-receiver pair PT-PR, and the secondary system comprises of M transmitter-receiver pairs STi-SRi, i ∈ {1,2,⋯M}. The secondary pair STb-SRbwhich is able to provide the best performance for the primary system, is selected to access the spectrum, with STbserving as a cooperative relay for the primary system. In the first transmission phase, PT transmits the primary signal to PR, which is also received by STband SRb, where it is decoded. At STb, the primary signal is regenerated and linearly combined with the secondary signal by assigning fractions α and (1-α) of the available power to the primary and secondary signals respectively. This combined signal is then broadcasted by STbin the second transmission phase, and PR combines the signal it received in the two phases to decode for the primary signal. Theoretical and simulation results confirm that the outage performance for both primary and secondary systems are improved with a larger M by using the proposed scheme.