Priority Based Channel Searching Sequence Allocation for Rendezvous of Cognitive Radio

This paper proposes a scheme for a cognitive radio system that differentiates user rendezvous performance based on priority. We categorize users into primary CR users (PCUs) and secondary CR users (SCUs) and assign them distinct channel searching sequences. The proposed scheme is based on the method introduced by Paul, Choi, Jang, and Kim, where PCUs utilize a p-ary m-sequence of period p2−1, and SCUs use a p-ary m-sequence of period p4−1. A key advantage of this approach is its ability to transition a legacy system, which does not consider priority, into a priority-based system simply by adding a low-priority SCU group and assigning them a dedicated channel searching sequence. Furthermore, we demonstrate the effectiveness of the proposed scheme through computer simulations that show a clear difference in rendezvous performance between PCUs and SCUs. Additionally, we verify the distinction between our scheme and methods that restrict channel allocation with primary sequence for SCUs, also through simulation.