Rate-splitting (RS) has recently been recognized as a promising physical-layer technique for multi-antenna broadcast channels (BC). Due to its ability to partially decode the interference and partially treat the remaining interference as noise, RS is an enabler for a powerful multiple access, namely rate-splitting multiple access (RSMA), that has been shown to achieve higher spectral efficiency (SE) and energy efficiency (EE) than both space division multiple access (SDMA) and non-orthogonal multiple access (NOMA) in a wide range of user deployments and network loads. As SE maximization and EE maximization are two conflicting objectives, the study of the tradeoff between the two criteria is of particular interest. In this work, we address the SE-EE tradeoff by studying the joint SE and EE maximization problem of RSMA in multiple input single output (MISO) BC with rate-dependent circuit power consumption at the transmitter. To tackle the challenges coming from multiple objective functions and rate-dependent circuit power consumption, we first propose two methods to transform the original problem into a single-objective problem, namely, weighted-sum method and weighted-power method. A successive convex approximation (SCA)-based algorithm is then proposed to jointly optimize the precoders and RS message split of the transformed problem. Numerical results show that our algorithm converges much faster than existing algorithms. In addition, the performance of RS is superior to or equal to non-RS strategy in terms of both SE and EE and their tradeoff.

翻译：分离率(RS)最近被公认为是多antenna广播频道(BC)中充满希望的物理级技术。 由于其能够部分解码干扰,部分将其余干扰作为噪音处理,RS是强大的多重接入的促进因素,即分率多重接入(RSMA),这证明比空间分区多重接入(SDMA)和非横向多重接入(NOMA)在广泛的用户部署和网络负荷中都提高了光谱效率和能源效率(EEE)。由于优化和EE最大化是两个相互冲突的目标,因此对两种标准之间的权衡研究特别有意义。在这项工作中,我们研究SE-EE交换率(SEMA)和E(E)的多重多重接入(SMA)和E(E)交易效率(EE)的最大化联合问题,在传输器的多个输入单项输出(MISO)中以取决于费率的电流能消耗率(SDM)实现更高的光谱效率(EE-E-E-E-E-E-E-E-E-E-E-E-E-E-E-E-E-E-E-E-E-E-E-E-E-E-E-E-E-E-E-E-E-E-E-E-E-E-E-E-E-E-E-E-E-E-E-E-E-E-E-E-E-E-E-E-E-E-E-E-E-E-E-E-E-E-E-E-E-E-E-E-E-E-E-E-E-E-E-E-E-E-E-E-E-E-E-E-E-E-E-E-E-E-E-E-E-E-A-E-A-A-A-A-A-A-A-A-A-A-E-E-E-E-E-E-E-E-E-E-E-E-A-A-A-A-E-E-A-A-A-A-A-E-A-A-A-A-E-A-A-E-A-A-E-E-A-A-A-A-A-