Power Resource Optimization for Backscatter-Aided Symbiotic Full-Duplex Secondary Transmission with Hardware Impairments in a Cognitive Radio Framework

This paper investigates the power resource optimization problem for a new cognitive radio framework with a symbiotic backscatter-aided full-duplex secondary link under imperfect interference cancellation and other hardware impairments. The problem is formulated using two approaches, namely, maximization of the sum rate and maximization of the primary link rate, subject to rate constraints on the secondary link, and the solution for each approach is derived. The problem of a half-duplex secondary link is also solved. Simulation results show that the sum rate and exploitation of the full-duplex capability of the secondary link are strongly affected by both the problem objective and hardware impairments.

Kinematic Analysis of a Gear-Driven Rotary Planting Mechanism for a Six-Row Self-Propelled Onion Transplanter

The purpose of this study was to develop a kinematic model of a gear-driven rotary planting mechanism for a self-propelled onion transplanter. The kinematic model was simulated using a commercial mechanical design and a simulation software package, and was validated through an on-site performance test. Torque and acceleration sensors were installed with an input power shaft and hopper jaws, respectively. Through kinematic analysis and simulation, the appropriate length combinations for primary, connecting, and planting arm were determined as 90, 70, and 190 mm, respectively. The diameters of the driver, driven, and idler gears in the primary arm were 56, 48, and 28 mm, respectively. For the secondary link, the diameters of the driver, idler, and driven gears were 28, 28, and 56 mm, respectively. The length of the planting hopper was selected as 190 mm and remained constant during the kinematic analysis. The maximum magnitude of the velocity and acceleration of the planting mechanism were determined as 1032 mm/s and 6501 mm/s2, respectively. The power consumption was measured as 35.4 W at 60 rpm. The single- and double-unit assembly of the studied rotary planting mechanism can transplant 60 and 120 seedlings/min, respectively.

Development of the zooplankton community in the growing ponds of the Novosibirsk region when growing carp fingerlings using the probiotic “Sibmos-PRO”

Quantitative characteristics of the zooplankton community in cyprinid growth ponds were studied. As a method of stimulating the growth and development of hydrobionts, the introduction of probiotic into water and feed was used. It was taken into account that zooplankton is the main and significant part of the natural food base for young carp grown in ponds. At the early stages of ontogenesis, the activity of digestive enzymes in carp is extremely low, the larva practically does not assimilate high-molecular compounds [7]. At the same time, zooplankton is a secondary link in the food chain of aquatic ecosystems, and plays an important role in their functioning and structure. Changes in plankton fauna can lead to modification of the aquatic ecosystem [18]. The development and existence of zooplankton pond communities during the growing season is influenced by a combination of abiotic and biotic factors, in particular: the composition and abundance of ichthyofauna, fluctuations in the water level in the reservoir, temperature, «flowering» of water, etc. Due to a set of indicators, and the strengthening or weakening of certain factors, it is possible to observe changes in the seasonal dynamics of zooplankton communities, which are more uneven than progressive. In the conducted research on the use of the probiotic Sibmos-Pro-antimicrobial feed concentrate based on mananoligosaccharides (obtained from yeast cell walls) in combination with the bacteria Bacillus Subtilis and Bacillus Licheniformis. Its introduction was carried out both in feed and in feed and water. Studies have shown that, judging by the productivity of carp and zooplankton biomass, the probiotic is absorbed by hydrobionts and affects the increase in the number and productivity of crustaceans. The level of development of the natural food supply increases, which ensures an increase in fish production. The structure of the zooplankton community changes under the influence of probiotics.

A Low-Cost Software Defined Radio Based Cognitive Radio Test-Bed for LTE Networks

In this work, we present a low-cost implementation of a Cognitive Radio (CR) test-bed for LTE and LTE-Advanced (LTE-A) Networks. The test-bed setup is implemented using highly integrated Software Defined Radio (SDR) platforms which are well suited for wireless communication. Each transceiver can be configured to work as a primary (resp. secondary) eNodeB or a primary (resp. secondary) user in a Heterogeneous Cognitive Radio framework. In this context, we study the problem of spectrum management in an LTE based heterogeneous network and propose simple distributed algorithms which the secondary eNodeB can employ to efficiently manage the spectral opportunities that arise in such a network. Experimental validation show significant improvement in the secondary link throughput.

On the Practical Implementation of VFDM-based Opportunistic Systems: Issues and Challenges

Vandermonde-subspace frequency division multiplexing (VFDM) is a physical layer technique for cognitive two-tiered networks, allowing for the coexistence of an orthogonal frequency division multiplexing (OFDM) legacy system and a cognitive secondary system in a time division duplex mode. It consists of a linear null-space precoder used by the secondary transmitter to effectively cancel the interference towards one or more primary receivers, while guaranteeing a non-negligible rate to a served secondary receiver. In this work, we propose an implementation of an experimental test-bed using the new SDR4All platform developed at the Alcatel-Lucent Chair on Flexible Radio (SUPELEC) to take a step towards a proof of concept of a VFDM-based system. We focus on the secondary link, where an opportunistic transmitter/receiver pair communicates over moderately frequency selective channels, characterized by very short root mean square (r.m.s.) delay spreads and non uniform power delay profiles (PDP). The obtained results show the practical feasibility of a VFDM transmission over a secondary link. However, a significant bit error rate (BER) loss with respect to the previously shown achievable theoretical performance is evident. A thorough analysis of the structure of the VFDM precoder is carried out and the impact of the channel characteristics on the performance of the opportunistic system is discussed. Numerical findings demonstrate that the potential BER drop can be addressed by designing a suitable flexible receiver able to deal with the effect induced by non uniform PDP and short r.m.s. delay spread channels.