非理想信道状态信息下调制方式切换阈值最优化算法  

Modulation mode switching threshold optimization algorithm with imperfect channel state information

作　　者：赵志信[1] 周泓岑 

机构地区：[1]黑龙江科技大学电子与信息工程学院,哈尔滨150022 [2]大连海事大学信息科学技术学院,辽宁大连116026

出　　处：《黑龙江科技大学学报》2015年第1期104-109,114,共7页Journal of Heilongjiang University of Science And Technology

基　　金：国家自然科学基金项目(61201143)

摘　　要：针对自适应资源调度OFDM系统,在非理想信道状态信息下(ICSI)最大化系统频谱效率问题,提出了平均BER约束下调制方式切换阈值最优化(MSTO)算法。利用拉格朗日乘数法将此J-1维的调制方式切换阈值最优化问题转化为一维优化问题,并证明了问题最优解必在平均BER约束条件的边界(目标平均BER)上取得,从而得到该问题的最优解。仿真结果表明,MSTO算法能在满足用户目标平均BER条件下自适应用户ICSI准确度参数的变化,最大化系统频谱效率。该算法性能优于改进的Ma’s算法和AM-PCSI算法,其复杂度符合实际自适应OFDM系统实时性设计要求,可方便地应用到实际系统中。This paper introduces an optimization （MSTO） algorithm, an algorithm designed for modu- lation mode switching threshold with average BER constrains, in an effort to maximize system spectral ef- ficiency in adaptive OFDM system in the case of imperfect channel state information （ICSI）. This algo- rithm is obtained by using Lagrange multiplier method to transform J-ldimensional optimization problem for modulation mode threshold switching into one-dimensional optimization problem, and verifying the de- velopment of the optimal solution on the border of the average BER constraints, and thereby arriving at an optimal solution to the problem. Simulation result shows that MSTO algorithm is sufficiently adaptable for the variation of the ICSI accuracy parameter to maximize spectral efficiency while meeting the target aver- age BER for users. It follows that this algorithm holds a promise as a convenient application in actual sys- tem, thanks to its demonstrated superiority over improved Ma＇ s and AM-PCSI algorithm and the resulting complexity geared to the requirements of the design of actual real-time adaptive OFDM system.

关 键 词：OFDM 非理想信道状态信息 调制方式 切换阈值 平均BER 

分 类 号：TN914.5[电子电信—通信与信息系统]