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arXiv 0910.1871cs.ITmath.IT
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统计约束下的MIMO无线通信

MIMO Wireless Communications under Statistical Queueing Constraints

Mustafa Cenk Gursoy

摘要:

研究了在统计随机约束条件下多输入多输出无线通信系统的性能。缓冲区违反概率的限制,施加的约束。在这种限制下的业绩是通过有效的能力规划获得的。在低功率,宽带,高信噪比(SNR)制度的有效容量进行了详细的分析。在低功率分析中,在各种假设下,在发射机处的信道状态信息的程度上,获得了在SNR= 0时有效容量相对于SNR的一阶和二阶导数的表达式。确定了在实现一阶和二阶导数的意义上最优的传输策略。结果表明,虽然一阶导数不受约束条件的影响,但二阶导数会随着约束条件的严格而变小。通过能量效率分析,这表明意味着最小比特能量要求不随更严格的限制而改变,但宽带斜率减小。如果经历丰富的多径衰落,则在宽带区域中获得类似的结果。另一方面,稀疏多径衰落与有界数量的自由度示出增加的最小比特能量的要求,在存在的约束。在低信噪比研究的基础上,通过分析瑞利衰落信道中的高信噪比斜率和功率偏移,量化了缓冲区限制对高信噪比性能的影响。最后,数值结果来说明理论研究结果。

英文摘要:

The performance of multiple-input multiple-output wireless systems is investigated in the presence of statistical queueing constraints. Queuing constraints are imposed as limitations on buffer violation probabilities. The performance under such constraints is captured through the effective capacity formulation. A detailed analysis of the effective capacity is carried out in the low-power, wideband, and high--signal-to-noise ratio (SNR) regimes. In the low-power analysis, expressions for the first and second derivatives of the effective capacity with respect to SNR at SNR= 0 are obtained under various assumptions on the degree of channel state information at the transmitter. Transmission strategies that are optimal in the sense of achieving the first and second derivatives are identified. It is shown that while the first derivative does not get affected by the presence of queueing constraints, the second derivative gets smaller as the constraints become more stringent. Through the energy efficiency analysis, this is shown to imply that the minimum bit energy requirements do not change with more strict limitations but the wideband slope diminishes. Similar results are obtained in the wideband regime if rich multipath fading is being experienced. On the other hand, sparse multipath fading with bounded number of degrees of freedom is shown to increase the minimum bit energy requirements in the presence of queueing constraints. Following the low-SNR study, the impact of buffer limitations on the high-SNR performance is quantified by analyzing the high-SNR slope and the power offset in Rayleigh fading channels. Finally, numerical results are provided to illustrate the theoretical findings.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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