研究了多用户场景下多载波码分多址系统(MC—CDMA)的下行信道和功率分配,并将吞吐最大化问题建模成一个混合整数优化问题.为了简化分析,将问题分成2个低复杂度的子问题:功率分配和信道分配.这2个子问题可分别被一个次最优自适应功率分配算法(APA)和一个最优自适应信道分配算法(ACA)解决.通过联合APA和ACA算法,进一步提出了一个自适应信道和功率的分配方案.仿真结果表明:与传统的均匀功率分配算法相比,提出的APA算法更加适用于MC—CDMA系统;此外,提出的自适应信道和功率分配方案可以显著地提高系统吞吐量性能.
The joint channel and power allocation in the downlink transmission of multi-user multi-carrier code division multiple access(MC-CDMA) systems are investigated and the throughput maximization problem is considered as a mixed integer optimization problem. For simplicity of analysis, the problem is divided into two less complex sub-problems: power allocation and channel allocation, which can be solved by a suboptimal adaptive power allocation (APA)algorithm and an optimal adaptive channel allocation (ACA) algorithm, respectively. By combining APA and ACA algorithms, an adaptive channel and power allocation scheme is proposed. The numerical results show that the proposed APA algorithm is more suitable for MC-CDMA systems than the conventional equal power allocation algorithm, and that the proposed channel and power allocation scheme can significantly improve the system throughout performance.