Simultaneous wireless information and power transfer can be achieved using an integrated receiver, where the incoming signal is rectified, and both the energy harvesting (EH) and the information detection (ID) operate on this rectified signal. Because phase information is lost at the input of the ID, commonly-used modulation techniques cannot be straightforwardly applied and biased MM -ASK is used instead. We consider downstream communication over a Rician block-fading channel, from a multi–antenna basestation to a number of single-antenna users. Multi-user interference is eliminated by applying zero-forcing precoding. Using a realistic rectifier model, we compare EH and ID performances of linear precoding (LP) and modified Tomlinson-Harashima precoding (THP). We add low-complexity algorithms to these precoders that optimize the user ordering and the constellation rotations. Moreover, we investigate the effect of the amplitude ratio ρASK\rho _{\mathrm {ASK}} of the constellation on the energy-rate trade-off. Compared to the same precoders without optimization, optimizing the user ordering, rotations and ρASK\rho _{\mathrm {ASK}} considerably reduces the transmit power required to achieve a harvested power of −30 dBm or an average mutual information of (log2M)/2(\log _{2}M)/2 . Both with and without optimizations, THP outperforms LP in terms of EH and ID, but THP exhibits much larger gains when optimizations are applied.

中文翻译：

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具有集成接收器的多用户 SWIPT 中偏置 ASK 调制的优化线性和非线性预编码


使用集成接收器可以同时实现无线信息和电力传输，其中输入信号经过整流，能量收集 (EH) 和信息检测 (ID) 均对该整流信号进行操作。由于相位信息在 ID 的输入处丢失，因此不能直接应用常用的调制技术，而是使用偏置 MM-ASK。我们考虑通过莱斯块衰落信道的下行通信，从多天线基站到多个单天线用户。通过应用迫零预编码来消除多用户干扰。使用真实的整流器模型，我们比较了线性预编码 (LP) 和改进的 Tomlinson-Harashima 预编码 (THP) 的 EH 和 ID 性能。我们向这些预编码器添加了低复杂度算法，以优化用户排序和星座旋转。此外，我们研究了星座的振幅比 ρASK\rho _{\mathrm {ASK}} 对能量速率权衡的影响。与未经优化的相同预编码器相比，优化用户排序、旋转和 ρASK\rho _{\mathrm {ASK}} 显着降低了实现 −30 dBm 的收获功率或 (log2M) 平均互信息所需的发射功率/2(\log _{2}M)/2 。无论有没有优化，THP 在 EH 和 ID 方面都优于 LP，但在应用优化时，THP 表现出更大的增益。