Distributed satellite cluster network is a novel structure in spatial information network. This paper investigates the spectrum-power tradeoff algorithm for distributed satellite cluster (DSC), which enables the master satellite (MS) to offload data traffic to the slave satellite (SS). The SS provides power resource to the master satellite users (MSUs) with bandwidth as compensation. The purpose of the proposed algorithm is to maximize the energy efficiency (EE) of the SS while ensuring the QoS of the DSC. Considering data rate and bandwidth constraints of the MS, the SS jointly allocates bandwidth and power resources based on the served MSU set, meanwhile, data rate and power constraints of the SS should be also satisfied. We first prove that compensating bandwidth of a MSU can only be used by one slave satellite user. Then objective function is simplified to the equivalent subtractive form that can be solved by convex optimization method. Besides, we discuss the MSU selection conditions and employ them to the proposed spectrum-power tradeoff algorithm. The numerical results validate the performance improvement of the proposed algorithm and demonstrate the impact of power, bandwidth and data rate on the EE.

分布式卫星集群网络是空间信息网络中的一种新型结构。本文研究了分布式卫星集群（DSC）的频谱功率折衷算法，该算法使主卫星（MS）能够将数据流量卸载到从属卫星（SS）。SS通过带宽作为补偿向主卫星用户（MSU）提供功率资源。所提出算法的目的是在确保DSC的QoS的同时最大化SS的能量效率（EE）。考虑到MS的数据速率和带宽约束，SS根据服务的MSU集合联合分配带宽和功率资源，同时，还应该满足SS的数据速率和功率约束。我们首先证明，MSU的补偿带宽只能由一个从属卫星用户使用。然后将目标函数简化为可以通过凸优化方法求解的等效减法形式。此外，我们讨论了MSU选择条件，并将其应用于提出的频谱功率折衷算法。数值结果验证了所提算法的性能改进，并证明了功率，带宽和数据速率对EE的影响。