摘要： 现有多用户正交频分复用(OFDM)无线通信系统的资源分配方案未考虑安全传输问题。为此，提出一种物理层安全约束下的资源分配方案，从信息安全理论的角度构建多用户OFDM系统窃听信道模型，在此基础上，利用子载波与功率的联合优化分配方案，在满足各用户安全服务质量(QoS)需求的条件下，通过对偶分解实现系统保密容量最大化的优化目标。仿真结果表明，当系统选用64个子载波为8个授权用户提供服务时，该分配方案在满足各授权用户安全QoS需求的同时，其保密容量相比参考方案最多可提高2.071 bit/s/Hz。

关键词: 多用户正交频分复用系统, 物理层安全, 窃听信道, 保密容量, 资源分配, 对偶分解

Abstract: Most multiuser Orthogonal Frequency Division Multiplexing(OFDM) wireless communication system resource allocation schemes are poor in secure transmission. This paper presents a method of multiuser OFDM system resource allocation scheme restricted in physical layer security. It constructs a multiuser OFDM wiretap channel model from the perspective of information security theory. Based on this model, the scheme utilizes joint optimization of subcarrier and power allocation, via dual decomposition method to achieve the system security rate maximization optimization target in conditions to fulfill the needs of each user’s security QoS. Simulation results show that when the system selects 64 sub-carrier to serve 8 authorized users, the secrecy capacity of the proposed scheme can be increased by 2.071 bit/s/Hz than the traditional schemes at most, and security QoS requirements of authorized users can be met at the same time.

Key words: multiuser Orthogonal Frequency Division Multiplexing(OFDM) system, physical layer security, wire-tap channel, secrecy capacity, resource allocation, dual decomposition

中图分类号: 

• TP391