Empowering Reconfigurable Intelligent Surfaces for Security of Downlink NOMA

Table 1

Main notations.

Symbol	Description
	Probability
	The cumulative distribution function (CDF) of a random variable
	The probability density function (PDF) of a random variable
	The normalized transmission powers
	The signal for ,
	The corresponding power allocation coefficients
	The additive white Gaussian noise (AWGN) at that is modeled as a zero-mean complex Gaussian distribution with variance
	The amplitude reflection coefficient with
	The RIS adjustable phase applied by the -th reflecting element
	The path loss exponent
	The target rate at the user
	The complex channel coefficient for the link RIS
	The complex channel coefficient for the link RIS
	The complex channel coefficient for the link RIS
	The complex channel coefficient for the link RIS