Optimum number of secondary users in collaborative spectrum sensing considering resources usage efficiency

The optimum number of secondary users in collaborative spectrum sensing is derived for lognormal shadowing channels, static additive white Gaussian noise channels and Rayleigh fading channels, when the efficiency of resources usage is considered in the system design. By weighting the detection performance and the usage efficiency in a target function that is maximized with respect to the number of secondary users, it is shown that the optimum number of secondary users decreases when the weighting coefficient of the usage efficiency increases, the sample correlation increases, or the SNR increases.