Multimedia communication in cognitive radio networks based on sample division multiplexing

In this paper, we address the problem of channel sensing, channel allocation and transmission of multimedia signals in a cognitive radio network, while maintaining the required quality of service (QoS) constraints. Depending on the type of signal and QoS requirements, different types of multimedia signals need different bandwidths for communication. In typical wireless systems, unless a contiguous frequency band in the spectrum with width at least equal to the required bandwidth is obtained, multimedia communication can not occur with the desired QoS. We propose here a novel technique based on sample division multiplexing (SDM) to overcome this issue. Our proposed approach is based on utilizing several frequency bands, each of smaller width than the required bandwidth but whose sum total equals at least the required bandwidth. Towards this end, we present algorithms for channel reservation, channel sensing and allocation along with protocols for transmission and reception. Our approach also ensures preemption of secondary users by the primary users as typically demanded in a cognitive radio based communication environment.