Spread-spectrum cognitive networking: Distributed channelization and routing

We study a framework that captures the interdependencies between spreading channelization and routing for a secondary multi-hop cognitive radio network that operates cognitively to coexist with primary users. We consider interactions between dynamic routing and code-division channelization functionalities for cognitive radio networks. With this respect, we study the effect of joint routing, spreading code and power allocation on the network throughput. A solution for joint routing and spread-spectrum channelization is proposed as a localized approximation of the throughput-maximizing problem. Specifically, power and spreading code are allocated to guarantee the quality of service of the on-going primary and secondary transmissions, while the routing algorithm dynamically selects relays based on the network traffic dynamics and on the achievable data rates on different secondary links.