Spread Spectrum-Based Coordination Design for Multi-Hop Spectrum-Agile Wireless Networks

In this paper, we propose a reliable direct- sequence spread-spectrum (DSSS)-based underlay control channel (CC) design for exchanging control information in cognitive radio networks (CRNs). The proposed design allows both narrow-band data and wide-band control transmissions to simultaneously proceed while protecting the performance of primary radio (PR) users. To achieve this, we derive a closed-form expression for the minimum required transmit power for control transmissions such that predefined CRN connectivity requirements are realized. Given the derived expression, we compute the maximum permissible power for CR data transmissions such that an enforced power mask constrain over the PR channels is not violated. Simulation results indicate that our CC design enables efficient CR communications without relying on a dedicated CC.