Price-Based Resource Allocation for Spectrum-Sharing Femtocell Networks: A Stackelberg Game Approach

This paper investigates the price-based resource allocation strategies for the uplink transmission of a spectrum-sharing femtocell network, in which a central macrocell is underlaid with distributed femtocells, all operating over the same frequency band as the macrocell. Assuming that the macrocell base station (MBS) protects itself by pricing the interference from the femtocell users, a Stackelberg game is formulated to study the joint utility maximization of the macrocell and the femtocells subject to a maximum tolerable interference power constraint at the MBS. Especially, two practical femtocell channel models: sparsely deployed scenario for rural areas and densely deployed scenario for urban areas, are investigated. For each scenario, two pricing schemes: uniform pricing and non-uniform pricing, are proposed. Then, the Stackelberg equilibriums for these proposed games are studied, and an effective distributed interference price bargaining algorithm with guaranteed convergence is proposed for the uniform-pricing case. Finally, numerical examples are presented to verify the proposed studies. It is shown that the proposed algorithms are effective in resource allocation and macrocell protection requiring minimal network overhead for spectrum-sharing-based two-tier femtocell networks.Comment: 27 pages, 7 figures, Submitted to JSA

Pt (Ⅱ) complexes-based assays for small biomolecules detection in aqueous media

Supramolecular principles such as self-assembly, stimuli-responsiveness, and adaptiveness are widely utilized concepts for developing advanced functional materials. Particularly, they have also significantly impacted analytical science development. In the last two decades, countless supramolecular binders, molecular probes, and chemosensors combined with innovative assays have led to a revolution in molecular sensing and medical diagnostics. Nevertheless, most of these molecular sensing systems are still suffering from either low-binding affinity or low-selectivity or decomposition in complex media such as biofluids, which are the main obstacles limiting their further practical applications. Therefore, the development of new molecular sensing systems that can reach practical requirements is still one of the frontiers in supramolecular chemistry. So far, traditional chromatography-based techniques, e.g., HPLC-MS, are often used for molecular sensing, which are reliable but usually time- and cost-intensive, difficult to do parallel analysis, and require trained personnel. Spectroscopic method-based chemosensors and probes may thus become more suitable for practical applications because of cost-effectiveness, ease of handling, and high-throughput screening ability. Herein, the self-assembling probe (SAP)-based molecular sensing concept is described. By combining molecular reactions and supramolecular interactions, both the high-selective and the high-binding affinity are achieved for the identification and quantification of analytes by utilizing SAP. Beginning with fundamental photophysical knowledge in luminescence, a general introduction of this thesis is given in Chapter 1. As primary candidates for constructing the self-assembling probes (SAPs), transition metal complexes, particularly platinum(II) complexes, are briefly reviewed, including their basic photophysics and applications. In addition, current molecular sensing concepts are introduced and discussed, providing the essential background for the proposed sensing concept in the following text. Small-emitting water-soluble fluorophores are in demand in many application fields, such as fluorescent labels in in-vivo research, indicator dyes in molecular sensing systems, and test cases for theoretical computation studies. In this context, a size-record breaking green-emissive fluorophore 3-hydroxy-isonicotinic aldehyde (HINA, 128 g/mol, λex = 525 nm) is investigated in Chapter 2. Furthermore, HINA also serves as the model case for demonstrating problems that molecular probes face, and it functions as a suitable indicator moiety in the construction of the SAPs. In Chapter 3, the self-assembling probe (SAP)-based molecular sensing concept is described, where time- and spectra-resolved information is observed for the distinction and quantification of target analytes. Due to the combination of the supramolecular and molecular interactions, thirteen tested structural similar analytes can be distinguished by merely using one probe, which overcame the low-selectivity problem of other current molecular sensing concepts. In addition, the potential application of SAPs in human biofluids is explored. As an extension of Chapter 3, Chapter 4 explores the mechanism of the high-selective SAP systems, which is essentially the supramolecular self-assembling of the SAP-analyte conjugates driven by the non-covalent interactions between the adjacent molecules. Therefore, the SAP concept was also applied for chirality sensing as the chiral analyte created a chiral environment and enhanced the chiral signal of the SAP-analyte conjugate. Finally, the conclusion of this thesis is given in Chapter 5. Outlook and suggestions regarding the further investigation of the SAP concepts are included as well

Quantum memory and non-demolition measurement of single phonon state with nitrogen-vacancy centers ensemble

In diamond, the mechanical vibration induced strain can lead to interaction between the mechanical mode and the nitrogen-vecancy (NV) centers. In this work, we propose to utilize the strain induced coupling for the quantum non-demolition (QND) single phonon measurement and memory in diamond. The single phonon in a diamond mechanical resonator can be perfectly absorbed and emitted by the NV centers ensemble (NVE) with adiabatically tuning the microwave driving. An optical laser drives the NVE to the excited states, which have much larger coupling strength to the mechanical mode. By adiabatically eliminating the excited states under large detuning limit, the effective coupling between the mechanical mode and the NVE can be used for QND measurement of the single phonon state. Under realistic experimental conditions, we numerically simulate the scheme. It is found that the fidelity of the absorbing and emitting process can reach a much high value. The overlap between the input and the output phonon shapes can reach $98.57\%$.Comment: 7 pages, 3 figure