By adressing various scenarios, the analysis provides an interesting insight into the effect of the primary user position, the relays position, and the interference limit on the end-to-end performance and, more generally, opens a new direction in the design of multihop cognitive relay systems.
Firstly, based on the transmit power of the CBS and the interference limits of PU receivers, a joint power control and interference avoidance method has been analyzed to simplify the constraints and guarantee the performance in the PS with priority.
The factor I shows the ITPU on the given channel while Imax is the maximum interference limit to the PU.
Based on the spectrum sensing results, the SUs can access the spectrum bands under the interference limit to the PUs.
We consider a dynamic spectrum sharing system consisting of a primary user, whose licensed spectrum is allowed to be accessed by a secondary user as long as it does not violate the prescribed interference limit inflicted on the primary user.
First, a primary base station (PBS) determines the interference limits that can be accepted at each PU receiver based on its target performance, such as predefined signal to interference plus noise ratio (SINR), system outage probability, and so on.
Marraffini, L.A. & Sontheimer, E.J. CRISPR interference limits horizontal gene transfer in staphylococci by targeting DNA.
However, political interference limits the effectiveness of these provisions.
On the other hand, the presence of the OFDM transmission induces interference limited performance of the secondary system.
A 15-yard pass interference limit: Committee members might propose a 15-yard maximum for defensive pass interference penalties.
