Simultaneous Information and Power Transfer for Broadband Wireless Systems
Simultaneous Information and Power Transfer for Broadband Wireless Systems
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DOI：
10.1109/tsp.2013.2281026
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发表时间：
2013-12-01
影响因子：
5.4
通讯作者：
Larsson, Erik
中科院分区：
文献类型：
--
作者：
Huang, Kaibin;Larsson, Erik
远场微波功率传输（MPT）将使无线传感器和其他移动设备摆脱有限电池容量所带来的限制。将MPT与无线通信相结合以支持同时进行无线信息与功率传输（SWIPT），可在不影响服务质量的情况下将同一频谱用于双重目的。本文提出了一种在宽带系统中实现SWIPT的新方法，该系统采用正交频分复用和发射波束成形来创建一组用于SWIPT的并行子信道，从而简化了资源分配。基于一种所提出的可重构移动架构，通过组合单用户/多用户系统、下行链路/上行链路信息传输以及可变/固定编码率来考虑不同的系统配置。针对这些配置优化功率控制会产生一类新的多用户功率控制问题，其具有电路功率约束，即传输的功率必须足够大以支持接收器电路的运行。解决这些问题可得到一组功率控制算法，这些算法利用频率上的信道多样性来同时提高吞吐量和MPT效率。对于具有可变编码率的系统配置，这些算法是考虑电路功率约束的注水算法的变体。对于那些具有固定编码率的配置，其最优算法是按升序依次为移动设备分配其解码所需的功率，直到用完整个预算功率。移动设备所需的功率可推导为正确解码的最小信噪比、电路功率和子信道增益的简单函数。
Far-field microwave power transfer (MPT) will free wireless sensors and other mobile devices from the constraints imposed by finite battery capacities. Integrating MPT with wireless communications to support simultaneous wireless information and power transfer (SWIPT) allows the same spectrum to be used for dual purposes without compromising the quality of service. A novel approach is presented in this paper for realizing SWIPT in a broadband system where orthogonal frequency division multiplexing and transmit beamforming are deployed to create a set of parallel sub-channels for SWIPT, which simplifies resource allocation. Based on a proposed reconfigurable mobile architecture, different system configurations are considered by combining single-user/multi-user systems, downlink/uplink information transfer, and variable/fixed coding rates. Optimizing the power control for these configurations results in a new class of multi-user power-control problems featuring the circuit-power constraints, specifying that the transferred power must be sufficiently large to support the operation of the receiver circuitry. Solving these problems gives a set of power-control algorithms that exploit channel diversity in frequency for simultaneously enhancing the throughput and the MPT efficiency. For the system configurations with variable coding rates, the algorithms are variants of water-filling that account for the circuit-power constraints. The optimal algorithms for those configurations with fixed coding rates are shown to sequentially allocate mobiles their required power for decoding in ascending order until the entire budgeted power is spent. The required power for a mobile is derived as simple functions of the minimum signal-to-noise ratio for correct decoding, the circuit power and sub-channel gains.