Carriers power allocation algorithm to enhance security of OFDM system transmission
一种提高OFDM系统安全传输的载波功率分配算法

In order to protect OFDM wireless communication systems to transmit information safety major use encryption protocol on high-level, however it has very limited space to improve its safety performance. For this problem, this paper presented a carriers power allocation algorithm to improve the secrecy rate. First, considering each OFDM carrier channel fading coefficient exist differences, based on OFDM wire-tap model it derived the secrecy rate under the authorized receiver and eavesdropper had different average SNR; Then, it used K-T conditions to optimize the carriers power allocation for the target to maximize secrecy rate under the total power limited, thereby enhancing the transmission security performance of OFDM system. Simulation results show that, compared to the average allocation, the secrecy rate of optimal allocation can be enhanced 6.109 bit/s/Hz at most when the system uses 128 carriers. And with the increasing number of carrier the secrecy rate upgrade more obvious.