A Secure Simultaneous Wireless Information and Power Transmission System Based on CDMA Architecture

In view of the security issue of the simultaneous wireless information and power transmission (SWIPT), this paper presents a secrecy SWIPT communication system based on code division multiple access (CDMA) architecture. The transmitter uses different spread spectrum polynomials to spread spectrum information and superimposes a narrow band energy signal. Then the transmitter sends information and energy to the legitimate user terminals. Each legitimate user terminal collects energy and despread the received information by using its own spread spectrum polynomial. Although the eavesdroppers can receive all the information sent by the transmitter, they are unable to correctly despread or decrypt information without spreading polynomials of legitimate users. Secure information transmission is thereby achieved. Moreover, a modified adaptive allocation algorithm of orthogonal-variable-spreading-factor (OVSF) code is proposed for the new system.