摘要: |
如何提高能量效率是当前认知星地一体化网络研究的热点问题之一,而功率控制是提高能量效率的重要方法。另外,在实际中,由于信道信息评估误差和反馈时延致使所获得信道增益信息是不完美的,从而使得已有基于完美信息的功率算法不能满足系统性能。为此,针对认知星地一体化网络中无线信道信息不确定的情况,进行鲁棒功率控制算法的研究。首先,针对认知用户的瞬时信噪比和对主用户的干扰受信道衰落的影响而具有不确定性的情况,建立了最差情况下的鲁棒优化问题;其次,利用分式规划和拉格朗日对偶分解理论提出了一个低复杂度的鲁棒功率控制算法。仿真分析表明,提出的鲁棒功率控制算法不仅能够严格保证主用户的通信质量,并且与传统的非鲁棒功率控制算法相比能够提高网络能量效率。 |
关键词: 认知星地一体化网络 能量效率 信道不确定性 鲁棒功率控制 |
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A robust energy-efficiency-maximization power control algorithm in cognitive satellite terrestrial networks |
DU Pengfei,SUN Jie,QI Yajiang |
(Southwest China Institute of Electronic Technology,Chengdu 610036,China;China Xi′an Satellite Control Center,Xi′an 710038,China) |
Abstract: |
How to enhance the energy efficiency is a hot research in cognitive satellite terrestrial networks.Power control is one of the most promising approaches.Besides,the obtained channel power gain information is imperfect in reality because of the estimation error and feedback delay.Thus,the existing proposed algorithms cannot satisfy the system requirement.For the uncertainty of the obtained channel power gain,the robust power control algorithm is investigated.For the uncertainty of the cognitive satellite user′s signal-to-noise ratio(SNR) and the primary user′s interference,the worst case robust optimization problem is formulated.By employing the fractional program and Lagrange method, a robust power control algorithm with low complexity is proposed. The simulation results demonstrate that the proposed algorithm not only guarantees the communication quality of the primary user, but also improves the system′s energy efficiency(EE). |
Key words: cognitive satellite terrestrial network energy efficiency channel power gain uncertainty robust power control |