arXiv subjects

Yuchi Wu

Publications and source records attributed to Yuchi Wu.

22 records · Page 2Linked to original sources

arXiv2021

Optimal Unbiased Linear Sensor Fusion over Multiple Lossy Channels with Collective Observability

In this paper, we consider optimal linear sensor fusion for obtaining a remote state estimate of a linear process based on the sensor data transmitted over lossy channels. There is no local observability guarantee for any of the sensors. It is assumed that the state of the linear process is collectively observable. We transform the problem of finding the optimal linear sensor fusion coefficients as a convex optimization problem which can be efficiently solved. Moreover, the closed-form expression is also derived for the optimal coefficients. Simulation results are presented to illustrate the performance of the developed algorithm.

eess.SY↗

arXiv2020

Mean-Field Transmission Power Control in Dense Networks

We consider uplink power control in wireless communication when a large number of users compete over the channel resources. The CDMA protocol, as a supporting technology of 3G networks accommodating signal from different sources over the code domain, represents the orthogonal multiple access (OMA) techniques. With the development of 5G wireless networks, non-orthogonal multiple access (NOMA) is introduced to improve the efficiency of channel allocation. Our goal is to investigate whether the power-domain NOMA protocol can introduce performance improvement when the users interact with each other in a non-cooperative manner. It is compared with the CDMA protocol, where the fierce competition among users jeopardizes the efficiency of channel usage. In this work, we conduct analysis with an aggregative game model, and show the existence and uniqueness of an equilibrium strategy. Next, we adopt the social welfare of the population as the performance metric, which is the average utility achieved by the user population. It is shown that under the corresponding equilibrium strategies, NOMA outperforms CDMA by higher efficiency of channel access for uplink communications.

eess.SY↗

arXiv2020

Mean-Field Transmission Power Control in Dense Networks, Part II -- Social Welfare Evaluation

We consider uplink power control in wireless communication when massive users compete over the channel resources. In Part I, we have formulated massive transmission power control contest in a mean-field game framework. In this part, our goal is to investigate whether the power-domain non-orthogonal multiple access (NOMA) protocol can regulate the non-cooperative channel access behaviors, i.e., steering the competition among the non-cooperative users in a direction with improved efficiency and fairness. It is compared with the CDMA protocol, which drives each user to fiercely compete against the population, hence the efficiency of channel usage is sacrificed. The existence and uniqueness of an equilibrium strategy under CDMA and NOMA have already been characterized in Part I. In this paper, we adopt the social welfare of the population as the performance metric, which is defined as the expectation of utility over the distribution of different types of channel users. It is shown that under the corresponding equilibrium strategies, NOMA outperforms CDMA in the social welfare achieved, which is illustrated through simulation with different unit price for power consumption. Moreover, it can be observed from numerical results that NOMA can improve the fairness of the achieved data rates among different users.

eess.SY↗

arXiv2020

Varied fusion reaction probability induced by ion stopping modification in laser-driven plasma with different temperature

The dynamics of nuclear reaction in plasma is a fundamental issue in many high energy density researches, such as the astrophysical reactions and the inertial confinement fusion. The effective reaction cross-sections and ion stopping power in plasma need to be taken into account to analyze the reactivity. In this research, we have experimentally investigated the from D-D reactions from interactions between deuteron beams and deuterated polystyrene (CD) plasma, driven by two laser pulses respectively. The neutron yields, plasma density and deuteron energy loss in plasma have been measured, and the plasma temperature and deuteron stopping power have been analyzed from simulations. It is shown that, compared with a cold target, the reaction probability in plasma conditions can be enhanced or suppressed, which is ascribed to the deuteron stopping power modifications in plasma. In hotter CD plasma, the energy loss of moderate energetic deuterons reduces, which leads to higher D-D reaction probability, while the contrary happens in colder plasma. This work provides new understanding of fusion reactions in plasma environment.

physics.plasm-ph↗