- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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Energy Harvesting Wireless Communications || Power Allocation for Point-to-Point Energy Harvesting Channels
摘要： This chapter considers a point-to-point EH wireless channel when the transmitter and the receiver are powered by EH. Under this setup, we first maximize various system utilities (such as the end-to-end throughput and the non-outage probability) via adaptive power allocation over time subject to the EH constraints at the transmitter, where the accumulatively consumed energy should not exceed that accumulatively harvested at any time. Under various CSIT and ESIT assumptions, we discuss the respective optimal designs. For example, in the noncausal CSIT and ESIT case, the optimal offline power allocation is shown to follow a non-decreasing and piecewise-constant (or staircase-like) pattern for the Gaussian channel case, and the optimal transmit power corresponds to a staircase water-filling power allocation for the fading channel case. In the causal ESIT and CSIT case, applicable online optimization strategies include dynamic programming-based and heuristically designed power allocation strategies. We also point out several open problems under different ESIT and CSIT considerations. For example, the throughput maximization problems under the case with causal CSIT and noncausal ESIT and the case with no CSIT and noncausal/causal ESIT remain unsolved in general, while the outage probability minimization problems under causal CSIT and noncausal/causal ESIT are also open problems at large. Furthermore, we extend the power allocation policies to other scenarios by considering other practical constraints such as limited battery capacity and imperfect circuits. We show that in the noncausal CSIT and ESIT case, the staircase power allocation with Gaussian channel and the staircase water-filling power allocation with fading channels can be modified to take these new practical constraints into account. With imperfect circuits, the EH transmitter should employ an on-off power allocation, which turns the transmitter into a sleep mode to save power in order to transmit more energy efficiently in the wake-up mode to tradeoff between the transmit energy consumption versus the circuit energy consumption. These new offline power allocation strategies motivate new online power allocation approaches with only causal CSIT and ESIT. Finally, we provide discussions on the transmit and receive power allocations in the case with EH transmitter and EH receiver, where in addition to the transmitter, the receiver's power consumption is also subject to an EH constraint. Under such a scenario, it is essential for the transmitter and the receiver to jointly optimize the transmit power and the code rate (hence, control the receive power consumption) to improve the end-to-end utility. Note that the case of EH receiver has not been widely investigated in the literature and there are rich open problems (e.g. under causal CSIT and ESIT) worth being pursued in future work.
关键词： power allocation,outage probability minimization,battery capacity,EH receiver,imperfect circuits,ESIT,wireless communications,throughput maximization,CSIT,Energy harvesting
更新于2025-09-23 15:22:29
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Flexible Multi-Group Single-Carrier Modulation: Subcarrier Mapping and Power Allocation Optimization
摘要： Orthogonal frequency division multiplexing (OFDM) and single-carrier frequency domain equalization (SC-FDE) are two commonly adopted modulation schemes for frequency-selective channels. Compared to SC-FDE, OFDM generally achieves higher data rates, but at the cost of higher transmit signal peak-to-average power ratio (PAPR) that leads to lower power amplifier efficiency. This paper studies a multi-group single-carrier modulation scheme, termed flexible multi-group single-carrier (FMG-SC), which encapsulates both OFDM and SC-FDE as special cases, thus achieving more flexible rate-PAPR trade-offs between them. Specifically, in FMG-SC, the total bandwidth is divided into a set of orthogonal subcarriers, which, based on the channel gains, are flexibly mapped to multiple non-overlapping groups, and SC-FDE is applied over each group independently to send multiple data streams in parallel. We investigate the joint subcarrier grouping and power allocation optimization problem to maximize the achievable rate of our proposed FMG-SC scheme for both the cases with Gaussian signaling and with practical modulation constellation (e.g., quadrature amplitude modulation (QAM)), respectively. For both cases, the optimization problem is non-convex in general, for which we propose a two-step approach for finding a high-quality approximate solution efficiently. First, with any given subcarrier grouping, we show that the optimal power allocation can be obtained via convex optimization techniques. Second, with fixed power allocation, we propose low-complexity algorithms for the subcarrier grouping design catering to the SC-FDE receiver. Numerical results show that our proposed algorithms perform close to the optimal solution obtained via exhaustive search over all subcarrier groupings, yet with substantially reduced complexity. Moreover, the achievable rate of our proposed FMG-SC scheme with Gaussian signaling approaches the OFDM channel capacity and significantly outperforms that of SC-FDE. Furthermore, with practical modulation constellation, numerical results show that our proposed FMG-SC scheme greatly outperforms the existing single-carrier frequency division multiple access (SC-FDMA) in terms of achievable rate, but with moderately increased PAPR.
关键词： frequency-domain equalization,single-carrier modulation,subcarrier grouping,peak-to-average power ratio,Multicarrier modulation,power allocation
更新于2025-09-23 15:21:01
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[IEEE 2018 International Conference on Information and Telecommunication Technologies and Radio Electronics (UkrMiCo) - Odessa, Ukraine (2018.9.10-2018.9.14)] 2018 International Conference on Information and Telecommunication Technologies and Radio Electronics (UkrMiCo) - Spatial-Energy Characteristics of Focused Modes of Metallic Terahertz Laser Resonator
摘要： Cellular networks are currently experiencing a tremendous growth of data traffic. To cope with this demand, a close cooperation between academic researchers and industry/standardization experts is necessary, which hardly exists in practice. In this paper, we try to bridge this gap between researchers and engineers by providing a review of current standard-related research efforts in wireless communication systems. Furthermore, we give an overview about our attempt in facilitating the exchange of information and results between researchers and engineers, via a common simulation platform for 3GPP long term evolution (LTE) and a corresponding webforum for discussion. Often, especially in signal processing, reproducing results of other researcher is a tedious task, because assumptions and parameters are not clearly specified, which hamper the consideration of the state-of-the-art research in the standardization process. Also, practical constraints, impairments imposed by technological restrictions and well-known physical phenomena, e.g., signaling overhead, synchronization issues, channel fading, are often disregarded by researchers, because of simplicity and mathematical tractability. Hence, evaluating the relevance of research results under practical conditions is often difficult. To circumvent these problems, we developed a standard-compliant open-source simulation platform for LTE that enables reproducible research in a well-defined environment. We demonstrate that innovative research under the confined framework of a real-world standard is possible, sometimes even encouraged. With examples of our research work, we investigate on the potential of several important research areas under typical practical conditions, and highlight consistencies as well as differences between theory and practice.
关键词： MIMO,pilot power allocation,LTE,Heterogeneous networks,distributed antenna systems,reproducible research,frequency synchronization,multiuser gains
更新于2025-09-23 15:21:01
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[IEEE 2019 PhotonIcs & Electromagnetics Research Symposium - Spring (PIERS-Spring) - Rome, Italy (2019.6.17-2019.6.20)] 2019 PhotonIcs & Electromagnetics Research Symposium - Spring (PIERS-Spring) - Characterization of Plasmonic Effects in AuNP+rGO Composite as a Sensing Layer for a Low-cost Lab-on-chip Biosensor
摘要： In this paper, we study the joint pilot assignment and resource allocation for system energy efficiency (SEE) maximization in the multi-user and multi-cell massive multi-input multi-output network. We explicitly consider the pilot contamination effect during the channel estimation in the SEE maximization problem, which aims to optimize the power allocation, the number of activated antennas, and the pilot assignment. To tackle the SEE maximization problem, we transform it into a subtractive form, which can be solved more efficiently. In particular, we develop an iterative algorithm to solve the transformed problem where optimization of power allocation and number of antennas is performed, and then pilot assignment optimization is conducted sequentially in each iteration. To tackle the first sub-problem, we employ a successive convex approximation (SCA) technique to attain a solvable convex optimization problem. Moreover, we propose a novel iterative low-complexity algorithm based on the Hungarian method to solve the pilot assignment sub-problem. We also describe how the proposed solution approach can be useful to address the sum rate (SR) maximization problem. In addition to the algorithmic developments, we characterize the optimal structure of both SEE and SR maximization problems. The numerical studies are conducted to illustrate the convergence of the proposed algorithms, impacts of different parameters on the SR and SEE, and significant performance gains of the proposed solution compared the conventional design.
关键词： Energy efficiency,multi-cell,massive MIMO,power allocation,pilot contamination,pilot assignment
更新于2025-09-23 15:21:01
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Quality of Transmission Aware Optical Networking using Enhanced Gaussian Noise Model
摘要： We present a new joint routing, wavelength, and power allocation method for optical network planning. The introduced gradient-based convex optimization approach has a lower computational complexity, compared to common linear programming techniques, suitable for both static as well as time-critical dynamic network planning with fast convergence requirement. The proposed scheme takes physical-layer impairments into account, using the enhanced Gaussian noise nonlinear model. In contrast to methods exploiting the theoretical full link spectrum utilization assumption (fully occupied fiber-optic C-band spectrum), we focus on maximizing the network achievable rate (AR) and minimum signal-to-noise ratio (SNR) margin of networks with partial spectrum utilization in their links, relevant to the majority of empirical metro network scenarios. According to numerical results, the network achievable rate can be improved around 17% by performing power optimization over the individual launch power of network lightpaths compared to optimizing a single flat (equal) launch power for all the lightpaths. Moreover, the minimum SNR margin of the simulated network is improved by about 2.3 dB. Finally, it is observed that maximizing the network minimum SNR margin needs the launch power of each lightpath to be proportional to the total nonlinear interference noise efficiency influencing the lightpath.
关键词： non-linear effects,routing and wavelength assignment,optical network optimization,network planning,Enhanced Gaussian noise model,power allocation,coherent transmission
更新于2025-09-23 15:21:01
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[IEEE 2019 IEEE CHILEAN Conference on Electrical, Electronics Engineering, Information and Communication Technologies (CHILECON) - Valparaiso, Chile (2019.11.13-2019.11.27)] 2019 IEEE CHILEAN Conference on Electrical, Electronics Engineering, Information and Communication Technologies (CHILECON) - A sustainability-based comparison between Photovoltaics and Concentrating Solar Power in Chile
摘要： This paper investigates the downlink of a single-cell base station (BS) equipped with a large-scale antenna array system while considering a non-negligible transmit circuit power consumption. This consumption involves that activating all RF chains does not always necessarily achieve the maximum sum-rate when the total BS transmit power is limited. This paper formulates a sum-rate maximization problem when a low complexity linear precoder, such as conjugate beamforming or zero forcing beamforming, is used. The problem is first relaxed by assuming arbitrary antenna selection. In this case, we derive analytically the optimal number of activated RF chains that maximizes the sum-rate under either optimal power allocation or equal received power constraint for all users. Also, user scheduling algorithms are proposed when users require a minimum received signal-to-interference-plus-noise ratio. Two iterative user scheduling algorithms are designed. The first one is efficient in terms of fairness and the second one achieves the optimal performance. Next, the antenna selection is investigated and we propose iterative antenna selection algorithms that are efficient in terms of instantaneous sum-rate. Simulation results corroborate our analytical results and demonstrate the efficiency of the proposed algorithms compared with arbitrary and optimal brute force search antenna selection.
关键词： circuit power consumption,Large-scale MIMO,power allocation,user scheduling,antenna selection
更新于2025-09-23 15:19:57
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[IEEE 2019 European Space Power Conference (ESPC) - Juan-les-Pins, France (2019.9.30-2019.10.4)] 2019 European Space Power Conference (ESPC) - Potential of the three-terminal heterojunction bipolar transistor solar cell for space applications
摘要： Cooperative communication suffers from multiplexing loss and low spectral efficiency due to the half duplex constraint of relays. To improve the multiplexing gain, successive relaying, which allows concurrent transmission of the source and relays, has been proposed. However, the severe inter-relay interference becomes a key challenge. In this paper, we propose a channel aware successive relaying protocol, also referred to as CAO-SIR, which is capable of thoroughly mitigating inter-relay interference by carefully adapting relays’ transmission order and rate. In particular, a relay having a poorer link to the source is scheduled first to forward a message, the data rate of which is adapted to the link quality of the source-relay and relay-destination channels. By this means, each relay may decode the messages intended for the preceding relays, and then cancel these relays’ interference in a low complexity which is equal to that of Decision Feedback Equalizer (DFE). To further optimize and analyze CAO-SIR, we present its equivalent parallel relay channel model, based upon which the adaptive relay selection and power allocation schemes are proposed. By employing M half duplex relays, CAO-SIR is capable of achieving an diversity-multiplexing tradeoff (DMT) given by 1 ? M +2 and r denote the diversity and multiplexing gains, respectively. Its DMT asymptotically approaches the DMT upper bound achieved by (M + 1) × 1 MISO systems or M full duplex relays, when M is large.
关键词： diversity-multiplexing tradeoff,rate adaptation,Successive relaying,relay selection,interference cancellation,power allocation,water filling,opportunistic communications,relay ordering
更新于2025-09-23 15:19:57
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[IEEE 2018 4th IEEE International Conference on Emerging Electronics (ICEE) - Bengaluru, India (2018.12.17-2018.12.19)] 2018 4th IEEE International Conference on Emerging Electronics (ICEE) - Optimizing device efficiency of P3HT/P3HT:PCBM interlayer organic solar cell: Annealing dependent study
摘要： We address a robust beamforming design and power allocation problem for a one-way multi-antenna relay network, where the multi-antenna source implements communication with the multi-antenna destination via a decode-and-forward (DF) relay in the presence of the multiple single-antenna eavesdroppers. The eavesdroppers can only overhear the information flowed from the relay to the destination in the second hop. We aim to maximize the worst-case secrecy rate in the condition that the global channel state information (CSI) is imperfect. To this end, we propose the joint beamforming and power allocation design for the worst-case secrecy rate maximization. However, our proposed design constitutes a non-convex problem, which involves an infinite number of constraints because of the imperfect CSI. To make the problem more tractable, we approximate the problem into several tractable semidefinite programs by semidefinite relaxation, successive convex approximation, and S-procedure techniques, and we propose an iterative algorithm to solve the problem. Furthermore, we show that the proposed algorithm is also applicable for the case the Gaussian wiretap model, where only the eavesdroppers’ CSI is imperfect. Simulation results validate the effectiveness of the proposed algorithm.
关键词： Security,robust beamforming,cooperative network,power allocation
更新于2025-09-23 15:19:57
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[IEEE 2017 IEEE Workshop on Recent Advances in Photonics (WRAP) - Hyderabad (2017.12.18-2017.12.19)] 2017 IEEE Workshop on Recent Advances in Photonics (WRAP) - Detection of Fibre Laser Instability Using a Constant Fraction Discriminator
摘要： Cellular networks are currently experiencing a tremendous growth of data traffic. To cope with this demand, a close cooperation between academic researchers and industry/standardization experts is necessary, which hardly exists in practice. In this paper, we try to bridge this gap between researchers and engineers by providing a review of current standard-related research efforts in wireless communication systems. Furthermore, we give an overview about our attempt in facilitating the exchange of information and results between researchers and engineers, via a common simulation platform for 3GPP long term evolution (LTE) and a corresponding webforum for discussion. Often, especially in signal processing, reproducing results of other researcher is a tedious task, because assumptions and parameters are not clearly specified, which hamper the consideration of the state-of-the-art research in the standardization process. Also, practical constraints, impairments imposed by technological restrictions and well-known physical phenomena, e.g., signaling overhead, synchronization issues, channel fading, are often disregarded by researchers, because of simplicity and mathematical tractability. Hence, evaluating the relevance of research results under practical conditions is often difficult. To circumvent these problems, we developed a standard-compliant open-source simulation platform for LTE that enables reproducible research in a well-defined environment. We demonstrate that innovative research under the confined framework of a real-world standard is possible, sometimes even encouraged. With examples of our research work, we investigate on the potential of several important research areas under typical practical conditions, and highlight consistencies as well as differences between theory and practice.
关键词： MIMO,pilot power allocation,LTE,Heterogeneous networks,distributed antenna systems,reproducible research,frequency synchronization,multiuser gains
更新于2025-09-23 15:19:57
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[IEEE 2017 IEEE 17th International Conference on Communication Technology (ICCT) - Chengdu (2017.10.27-2017.10.30)] 2017 IEEE 17th International Conference on Communication Technology (ICCT) - Power allocation for multiple targets localization in distributed MIMO radar system
摘要： To improve the resource utilization for MIMO radar system in multiple tasks model, a power allocation algorithm is proposed for multiple targets localization. The Cramer-Rao bound (CRB) is used to be the measurement metric for location estimation. The minimal transmit power budget is used as the cost function. Restricted by different localization mean square error (MSE) requirements, a power allocation model is established, and the corresponding optimization problem is solved by Sequential Parametric Convex Approximation (SPCA) algorithm. The simulation results indicate that under different system layout and target Radar Cross Section (RCS), the proposed allocation algorithm can improve the resource utilization by using much less power budget than uniform allocation.
关键词： power allocation,distributed MIMO radar,target localization
更新于2025-09-19 17:15:36