摘要
在认知星地混合网络中,当卫星用户作为次级用户时,为了不影响地面主用户系统的正常工作,在上行链路中要对卫星用户进行必要的功率控制。针对衰落信道场景,选择最大化卫星用户的遍历容量(EC)作为优化的目标函数,分别提出了基于峰值干扰功率约束(PIC)和平均干扰功率约束(AIC)的功率控制方法,并给出了最优发射功率的闭合表达式。仿真结果表明,卫星信道条件越好、地面干扰链路衰减越大,卫星用户的性能越好;除此之外,基于AIC的功率控制方法要优于基于PIC的功率控制方法。
In cognitive satellite terrestrial networks, when the satellite users are secondary users, power control is necessary to guarantee the communication quality of terrestrial primary user in the uplink case. In the context of fading channels, maximizing the Ergodic Capacity( EC) of the satellite user was selected as the objective function, then two optimal power control schemes were proposed based on Peak Interference power Constraint( PIC) and Average Interference power Constraint( AIC), respectively. Meanwhile, the closed expression of the optimal transmit power was given. Simulation results show that the ergodic capacity of satellite user can be increased when the satellite link experiences the weaker shadowing conditions; moreover, under the the specific satellite link condition, the performance of satellite user becomes better with the increasing of the terrestrial interference link fading parameters. In addition, power control method based on AIC is superior to that based on PIC.
出处
《计算机应用》
CSCD
北大核心
2017年第8期2173-2176,2183,共5页
journal of Computer Applications
基金
国家自然科学基金资助项目(61571464
61601511
91338201
91438109
61401507)~~
关键词
认知卫星
遍历容量
峰值干扰功率约束
平均干扰功率约束
功率控制
cognitive satellite
Ergodic Capacity(EC)
Peak Interference power Constraint(PIC)
Average Interference power Constraint(AIC)
power control