Hierarchical DWT based optimal diversity power allocation for video transmission in 4G OFDMA wireless systems
Hierarchical DWT based optimal diversity power allocation for video transmission in 4G OFDMA wireless systems
复制标题
4G OFDMA 无线系统中视频传输基于分层 DWT 的最佳分集功率分配
DOI：
10.1109/ist.2011.5962178
复制
发表时间：
2011
期刊：
影响因子：
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通讯作者：
A. Jagannatham
中科院分区：
文献类型：
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作者：
Sohil Mahajan;A. Jagannatham
在本文中，我们提出了新的算法，最佳子载波功率分配对视频传输正交频分多址（OFDMA）为基础的4G无线系统。所提出的方案的一个独特的特点是，它们采用依赖于基于离散小波变换（DWT）的分层视频分解的分集相关的子载波功率分布。这些方案的另一个关键方面是，它们基于OFDMA系统中分配的子载波的顺序统计，专门采用部分信道状态信息（CSI）反馈。这显著减少了反向链路上所需的通信开销，从而降低了复杂性并提高了吞吐量。它表明，基于有序子载波分集的视频失真最小化的范例可以制定为一个约束凸成本最小化问题。此外，我们说明，这种成本最小化减少到一个多项式根计算下一个合适的近似。推导了基于分集的最优功率分配方案的封闭形式表达式。采用多个视频序列的OFDMA系统的仿真结果表明，所提出的最优子载波功率分配方案优于等功率分配方案的上级性能。
In this paper we propose novel algorithms for optimal subcarrier power allocation towards video transmission in Orthogonal Frequency Division Multiple Access (OFDMA) based 4G wireless systems. A unique feature of the proposed schemes is that they employ diversity dependent subcarrier power distribution relying on a discrete wavelet transform (DWT) based hierarchical video decomposition. Another key aspect of the schemes is that they exclusively employ partial channel state information (CSI) feedback based on the order statistics of the allotted subcarriers in the OFDMA system. This significantly reduces the communication overhead required on the reverse link, thus reducing complexity and enhancing throughput. It is demonstrated that the paradigm of ordered subcarrier diversity based video distortion minimization can be formulated as a constrained convex cost minimization problem. Further, we illustrate that this cost minimization reduces to a polynomial root computation under a suitable approximation. Closed form expressions are derived for the diversity based optimal power allocation scheme. Simulation results employing several video sequences for an OFDMA system demonstrate superior performance of the proposed optimal subcarrier power allocation schemes over equal power allocation.
DOI：
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发表时间：
1999-12
期刊：
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影响因子：
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作者：
R. V. Nee;R. Prasad
通讯作者：
R. V. Nee;R. Prasad