  The multi-channel blind rendezvous problem in distributed cognitive radio
networks (DCRNs) refers to how users in the network can hop to the same channel
at the same time slot without any prior knowledge (i.e., each user is unaware
of other users' information). The channel hopping (CH) technique is a typical
solution to this blind rendezvous problem. In this paper, we propose a quinary
coding and matrix structure-based CH algorithm called QCMS-CH. The QCMS-CH
algorithm can guarantee the rendezvous of users using only one cognitive radio
in the scenario of the asynchronous clock (i.e., arbitrary time drift between
the users), heterogeneous channels (i.e., the available channel sets of users
are distinct), and symmetric role (i.e., all users play a same role). The
QCMS-CH algorithm first represents a randomly selected channel (denoted by R)
as a fixed-length quaternary number. Then it encodes the quaternary number into
a quinary bootstrapping sequence according to a carefully designed
quaternary-quinary coding table with the prefix "R00". Finally, it builds a CH
matrix column by column according to the bootstrapping sequence and six
different types of elaborately generated subsequences. The user can access the
CH matrix row by row and accordingly perform its channel hopping to attempt to
rendezvous with other users. We prove the correctness of QCMS-CH and derive an
upper bound on its Maximum Time-to-Rendezvous (MTTR). Simulation results show
that the QCMS-CH algorithm outperforms the state-of-the-art in terms of the
MTTR and the Expected Time-to-Rendezvous (ETTR).
