3D Localization for Launch Vehicle Using Virtual TOA and AOA of Ground Stations

Wireless Personal Communications - Generally, a ground telemetry station for a launch vehicle (LV) includes a tracking function only; therefore, position measurements for LV depend on received...     

Performance Analysis of 3D Localization for a Launch Vehicle Using TOA,AOA, and TDOA

Wireless Personal Communications - In general, a ground telemetry station for a launch vehicle (LV) includes a tracking function only; therefore, position measurements for LV depend on received...     

Adaptive Channel Estimation Scheme Based on LTE Uplink in V2V Environments

Wireless Personal Communications - Vehicle communication can facilitate efficient coordination among vehicles on the road and enable future vehicular applications such as vehicle safety...     

Design and Performance Analysis of Soft Decision-Based Network-Assisted Interference Cancellation and Suppression Scheme

Recently, 3rd Generation Partnership Project (3GPP) has developed a network-assisted interference cancellation and suppression scheme to reduce the effect of interference. In this paper, we propose an advanced receiver based on soft decision to reduce the interference from the neighbor cells. The proposed receiver can suppress and cancel the interference by calculating the unbiased estimation value of the interference signal using the minimum mean square error or the interference rejection combining receiver. The interference signal is updated using soft information expressed by the log-likelihood ratio. We perform the system-level simulation based on 20 MHz bandwidth of a 3GPP LTE-Advanced sidelink system. The simulation results show that the proposed receiver can improve the signal-to-noise-plus-interference ratio, throughput, and spectral efficiency of a conventional system.

     

Bee Venom Activates the Nrf2/HO-1 and TrkB/CREB/BDNF Pathways in Neuronal Cell Responses against Oxidative Stress Induced by Aβ1–42

Honeybee venom has recently been considered an anti-neurodegenerative agent, primarily due to its anti-inflammatory effects. The natural accumulation of amyloid-beta (Aβ) in the brain is reported to be the natural cause of aging neural ability downfall, and oxidative stress is the main route by which Aβ ignites its neural toxicity. Anti-neural oxidative stress is considered an effective approach for neurodegenerative therapy. To date, it is unclear how bee venom ameliorates neuronal cells in oxidative stress induced by Aβ. Here, we evaluated the neuroprotective effect of bee venom on Aβ-induced neural oxidative stress in both HT22 cells and an animal model. Our results indicate that bee venom protected HT22 cells against apoptosis induced by Aβ_1–42. This protective effect was explained by the increased nuclear translocation of nuclear factor erythroid 2-like 2 (Nrf2), consequently upregulating the production of heme oxygenase-1 (HO-1), a critical cellular instinct antioxidant enzyme that neutralizes excessive oxidative stress. Furthermore, bee venom treatment activated the tropomyosin-related kinase receptor B (TrkB)/cAMP response element-binding (CREB)/brain-derived neurotrophic factor (BDNF), which is closely related to the promotion of cellular antioxidant defense and neuronal functions. A mouse model with cognitive deficits induced by Aβ_1–42 intracerebroventricular (ICV) injections was also used. Bee venom enhanced animal cognitive ability and enhanced neural cell genesis in the hippocampal dentate gyrus region in a dose-dependent manner. Further analysis of animal brain tissue and serum confirmed that bee venom reduced oxidative stress, cholinergic system activity, and intercellular neurotrophic factor regulation, which were all adversely affected by Aβ_1–42. Our study demonstrates that bee venom exerts antioxidant and neuroprotective actions against neural oxidative stress caused by Aβ_1–42, thereby promoting its use as a therapeutic agent for neurodegenerative disorders.     

Novel Interference Cancellation of Channel Estimation Scheme Based on LTE in V2V Communications

Transportation infrastructures integrate advanced Information Technology to enable the operations and management of transportation systems. Advanced vehicle and road systems of a comprehensive concept that improve the efficiency and safety of road traffic are being built and will be commercially available through Intelligent Transport Systems (ITS) technology and services. To support ITS technology, Vehicle-To-Everything (V2X) is needed, and in the 3rd Generation Partnership Project, many studies have focused on Long Term Evolution (LTE)-based vehicle communications. In order to realize reliable and optimized communications performance in vehicle communications, which move in propagation environments at high speed, in this study, we propose a novel channel estimation scheme suited for LTE sidelink-based Vehicle-To-Vehicle systems. Conventional channel estimation schemes can be categorized as Decision-Directed Channel Estimation, spectral temporal averaging, and smoothing methods. In this study, unlike conventional channel estimation schemes, we propose a Novel Interference Cancellation of Channel Estimation (NICCE) using Quadratic Smoothing of the pilot symbols, which estimates a channel with greater accuracy, and a novel interference cancellation of channel estimation in data symbols. In simulation results, the proposed NICCE scheme shows improved overall performance in terms of the Normalized Mean Square Error and uncoded Bit Error Rate relative to conventional schemes.     

Advanced Receiver for Interference Suppression and Cancellation in Sidelink System of LTE-Advanced

Recently, the 3rd Generation Partnership Project (3GPP) has developed a sidelink system to compensate for the explosive increase in mobile data traffic. However, there are numerous challenging technical problems that must be overcome. One major problem is inter-cell interference management. 3GPP has considered network-assisted interference cancellation and suppression to improve both the signal-to-noise-plus-interference ratio (SINR) and receiver performance by suppression or cancellation of inter-cell interference signals. In this paper, we propose a novel advanced receiver to reduce the interference from neighbor cell in sidelink systems. The proposed receiver can suppress and cancel the interference by combining interference rejection combining with successive interference cancellation. We perform a system-level simulation based on 20 MHz bandwidth of 3GPP LTE-Advanced system. Simulation results show that the proposed receiver can improve the SINR, throughput, and spectral efficiency, relative to a conventional system.