A Heuristic Optimal Discrete Bit Allocation Algorithm for Margin Maximization in DMT Systems
A Heuristic Optimal Discrete Bit Allocation Algorithm for Margin Maximization in DMT Systems
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DOI：
10.1155/2007/12140
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发表时间：
2007
影响因子：
1.9
通讯作者：
Li-ping Zhu;Yao Ping Yan;Shidong Zhou;Shi-wei Dong
中科院分区：
文献类型：
--
作者：
Li-ping Zhu;Yao Ping Yan;Shidong Zhou;Shi-wei Dong
针对离散多音（DMT）系统的余量最大化问题，提出了一种启发式离散最优位分配算法。该算法从初始等功率分配比特分配出发，采用多阶段比特率分配方案来满足目标比特率。如果总比特率远低于目标比特率，则使用多比特加载过程来获得接近目标比特率的比特分配。当接近目标速率时，采用并行的位加载过程来达到目标速率，这比传统的贪婪位加载算法计算效率更高。最后，检查目标比特率分布，如果是有效的，那么它也是最优解；否则，只需少量的位交换即可获得最优的位分布。采用标准非对称数字用户线路（ADSL）测试环路进行的仿真结果表明，该算法在实际DMT传输中是有效的。
A heuristic optimal discrete bit allocation algorithm is proposed for solving the margin maximization problem in discrete multitone (DMT) systems. Starting from an initial equal power assignment bit distribution, the proposed algorithm employs a multistaged bit rate allocation scheme to meet the target rate. If the total bit rate is far from the target rate, a multiple-bits loading procedure is used to obtain a bit allocation close to the target rate. When close to the target rate, a parallel bit-loading procedure is used to achieve the target rate and this is computationally more efficient than conventional greedy bit-loading algorithm. Finally, the target bit rate distribution is checked, if it is efficient, then it is also the optimal solution; else, optimal bit distribution can be obtained only by few bit swaps. Simulation results using the standard asymmetric digital subscriber line (ADSL) test loops show that the proposed algorithm is efficient for practical DMT transmissions.