Abstract: Aiming to solve the problem of energy limitation of relay node and improve the energy efficiency of the system for achieving reliable green communication,the half-duplex relay quantize-and-forward(QF) cooperative system is studied based on simultaneous wireless information and power transfer(SWIPT). Firstly,a SWIPT-based half-duplex relay QF cooperative system model is established. The source node and destination node are powered by external power. The relay node simultaneously implements information transmission and energy harvesting by SWIPT. Then,for the power-splitting protocol,the achievable rate expression of the SWIPT-based QF cooperation is derived. It is proved that the achievable rate is a convex function with respect to the power-splitting factor,and the optimal power-splitting factor is obtained to maximize achievable rate. Furthermore,for slow fading channels,the expected rate of SWIPT-based QF cooperation is further analyzed. Finally,the analysis and simulation shows that the achievable rate or expected rate of SWIPT-based QF cooperation is obviously superior to that of traditional amplify-and-forward and decode-and-forward cooperation,and SWIPT-based QF cooperation achieves similar performance to that of traditional QF cooperation in the absence of external power supply for the relay.

Key words: simultaneous wireless information and power transfer technology, quantize-and-forward cooperation, power-splitting protocol, achievable rate, expected rate