Throughput optimization for cognitive radio under random access ALOHA networks

The cognitive radios (CR) utilize the spectrum resource without interfering the primary users (PU). Spectrum sensing, by which CR users detects the radio environment, is a critical technique in cognitive radios. Various collaborative spectrum sensing schemes are proposed to either improve sensing sensitivity or to reduce the sensing duration. However, most of the previous studies have not investigated the impact of sensing on the network level. Therefore, in this paper we investigate network level performance under ALOHA protocol while using autonomous sensing scheme where independent transmissions of CR users are allowed. We show that the optimal system level access throughput can be achieved by solving an optimization problem in terms of parameters configured for spectrum sensing and we also give the range of optimized throughput and the bound of optimal parameter value.