Downlink Resource Allocation in Multi-Carrier Systems: Frequency-Selective vs. Equal Power Allocation
Downlink Resource Allocation in Multi-Carrier Systems: Frequency-Selective vs. Equal Power Allocation
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DOI：
10.1109/t-wc.2008.061110
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发表时间：
2007-06
期刊：
影响因子：
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通讯作者：
Hyang-Won Lee;S. Chong
中科院分区：
文献类型：
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作者：
Hyang-Won Lee;S. Chong
本文在渐近效用最大化的背景下研究了多载波系统中的动态子载波和功率分配问题。利用基于梯度的资源分配，我们制定了一个优化问题，包括子载波和发射功率分配为每个时隙，并提出了一个最优算法解决这个问题。由于最优算法的复杂性使其不切实际，基于广义Benders分解，提出了一种简单的次优算法。此外，我们通过证明在一般效用最大化问题中等功率分配并不总是接近最优，并刻画了等功率分配的最优性条件，来确定等功率分配策略的性能。这一结果不仅证明了我们的动态功率分配的使用，但也推广了性能的等功率分配，这是众所周知的是近似最优的总和容量最大化问题在高信噪比（信噪比）制度。我们的算法和分析通过大量的模拟验证。
In this paper, dynamic subcarrier and power allocation problem is considered in the context of asymptotic utility maximization in multi-carrier systems. Using gradient-based resource allocation, we formulate an optimization problem involving subcarrier and transmit power allocation for each time slot, and propose an optimal algorithm solving the problem. Since the optimal algorithm is impractical due to its complexity, a simple suboptimal algorithm is also proposed based on generalized Benders decomposition. Furthermore, we identify the performance of equal power allocation policy by showing that equal power allocation is not always near optimal in general utility maximization problem and characterizing the optimality condition of equal power allocation. This result not only justifies the use of our dynamic power allocation, but also generalizes the performance of equal power allocation, which is well-known to be approximately optimal to the sum capacity maximization problem in high SNR (signal-to-noise ratio) regime. Our algorithms and analysis are verified through extensive simulations.