面向物理层安全的广义随机空间调制技术

针对窃听信道质量优于合法信道质量时的物理层安全传输问题,提出了一种广义随机空间调制技术。该技术利用合法信道的瞬时状态信息随机扰乱比特到符号的映射关系,实现物理层安全传输。首先给出了广义随机空间调制系统的收发机结构。然后计算了合法接收用户的误码率上界和系统保密容量。从误码率上界的表达式得出,所提广义随机空间调制系统可靠性与传统广义空间调制相同,由此可在不损失系统可靠性的前提下实现安全传输。保密容量的计算表明,安全通信速率不随窃听方天线增多而下降,因此能抵抗具备海量天线的窃听者。最后用仿真验证理论分析的准确性和所提方案的有效性。

Generalized Random Spatial Modulation for Physical-layer Security Transmission

We propose a generalized random spatial modulation(GRSM)to achieve physical-layer security transmission when the wire-tap channel tends to be stronger than the legitimate channel.Specifically,the bit-to-symbol mapping of the GRSM varies corresponding to the instantaneous channel state information between the transmitter and the legitimate user.Since the eavesdropper has no knowledge of the channel,it cannot decode the confidential messages successfully.We first present the transceiver design of the GRSM.Then,the upper bound of the bit error rate(BER)and the ergodic secrecy rate(ESR)are derived.The upper bound of the BER shows that the reliability of the GRSM is identical to that of the conventional generalized spatial modulation,which demonstrates that the security is achieved without sacrificing the system reliability.The analysis on ESR shows that the secrecy performance does not degrade as the number of antennas at the eavesdropper increases.And thus the GRSM can resist eavesdroppers with massive antennas.Finally,numerical results validate the theoretical derivations and demonstrate the effectiveness of the GRSM scheme.