Interaction of Pilot Reuse and Channel State Feedback under Coherence Disparity
Interaction of Pilot Reuse and Channel State Feedback under Coherence Disparity
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DOI：
10.1109/itw54588.2022.9965758
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发表时间：
2022-11
期刊：
影响因子：
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通讯作者：
Mehdi Karbalayghareh;Aria Nosratinia
中科院分区：
文献类型：
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作者：
Mehdi Karbalayghareh;Aria Nosratinia
以往的研究表明，当下行信道中的单个链路具有不同的相干间隔时，导频复用不仅可以获得速率增益，还可以获得自由度增益。信道状态反馈是另一个增益来源，但是将波束形成与导频复用相结合会提出新的有趣的设计问题。在一致性不一致的情况下，这种方案的性能一直是一个悬而未决的问题，在一致性不一致的情况下，试点重用是最有希望的。我们提出了一种新的导频和数据的非正交传输方案，该方案可以与完全或不完全信道状态反馈和谐结合。该方案在同一框架内采用了积叠加和零强迫波束形成，并提高了最终的可实现率。研究进展包括在多用户下行信道中谨慎的导频放置和在信道状态反馈下有效的导频复用策略。数值结果证实了我们的发现。
When the individual links in a downlink channel have different coherence intervals, previous studies have shown that pilot reuse can achieve not only rate gains, but also gains in degrees of freedom (DoF). Channel state feedback is another source of gains, but combining beamforming with pilot reuse presents new and interesting design questions. The performance of such a scheme has been an open problem under coherence disparity, the regime in which pilot reuse is most promising. We propose a new non-orthogonal transmission scheme for pilots and data that harmoniously combines with either perfect or imperfect channel state feedback. The proposed scheme employs both product superposition and zero-forcing beamforming within the same framework, and improves the resulting achievable rates. The developments include careful pilot placement and an efficient pilot reuse strategy under channel state feedback in a multi-user downlink channel. Numerical results are presented to corroborate our findings.