采用串行干扰消除的DS-CDMA系统中速率分配与译码顺序调整的联合优化

在采用串行干扰消除的DS-CDMA系统中，可能的速率模式与译码顺序随着用户数的增长而指数增长。如何分配速率使得系统效用最大化是一个NP问题，这涉及到速率分配与译码顺序调整的联合优化。该文针对此问题提出两种次优贪婪算法。算法的主要思想是逐步贪婪地更新速率模式，再针对每步更新后的速率模式调整译码顺序，根据调整后的译码顺序快速检验对应速率模式的可行性。提出的算法具有较低的计算复杂度，可用于速率的快速有效分配。仿真实验证实了分析结果并展示了算法的有效性。

Joint Optimization of Rate Allocation and Decoding Order Adjustment in DS-CDMA Systems with Successive Interference Cancellation

In DS-CDMA systems with Successive Interference Cancellation (SIC), the numbers of possible rate modes and decoding orders grow exponentially with the number of users. How to allocate rates in order to maximize the system utility is an NP problem, which involves the joint optimization of rate allocation and decoding order adjustment. This paper proposes two suboptimal greedy algorithms for addressing this NP problem. The main idea of the algorithms is that the rate mode is greedily updated step by step, then the decoding order is adjusted for the updated rate mode in every step and the feasibility of the corresponding rate mode is quickly examined according to the adjusted decoding order. The proposed algorithms have very low computational complexity and can be used to implement the quick and efficient allocation of rates. Simulation experiments validate this analysis and demonstrate the effectiveness of the algorithms.