53 research outputs found
Joint Radio Resource Management and Power Control in a Multi Cell Cellular Distributed Antenna System with Jain Fairness
No full text
Under feedback and interference constraints uplink power control in two-tier networks
No full textThis paper considers optimum uplink power control policy that maximizes total sum-rate without any interference cancellation techniques under interference and feedback constraints at next generation communication systems. System model has two tier and it is assumed that the feedback channel between these tiers has finite capacity. Second tier users (STU) cause interference on first tier users (FTU) and base station (FTB) while communicating with second tier base station (STB). In proposed scenario, this interference power on first tier network is limited at a certain level. To this end, two different feedback policies are proposed. The first one is determining the K smallest interference channel coefficients of STUs by FTU and sending them to STB. The other policy is that STB requests the interference channel information of K users that have the best direct channel state from FTB. Due to proposed scenario is not a convex problem, it is solved with DC programming well-studied in literature before and performances of proposed feedback policies are compared
Effects of leukemia inhibitory receptor gene mutations on human hypothalamo-pituitary-adrenal function
No full textStuve-Wiedemann syndrome (STWS) (MIM #601559) is a rare autosomal recessive disorder caused by mutations in the leukemia inhibitory factor receptor (LIFR) gene. STWS has a diverse range of clinical features involving hematopoietic, skeletal, neuronal and immune systems. STWS manifests a high mortality due to increased risk of sudden death. Heterodimerization of the LIFR mediates leukemia inhibitory factor (LIF) signalling through the intracellular Janus kinase (JAK)/STAT3 signalling cascade. The LIF/LIFR system is highly expressed in and regulates the hypothalamo-pituitary-adrenal (HPA) axis. HPA function was investigated in three STWS patients to characterise consequences of impaired LIF/LIFR signalling on adrenal function. Six genetically proven STWS patients from four unrelated Turkish families were included in the study. Sudden death occurred in three before 2 years of age. Basal adrenal function tests were performed by measurement of early morning serum cortisol and plasma ACTH concentrations on at least two different occasions. Low dose synacthen stimulation test and glucagon stimulation tests were performed to explore adrenal function in three patients who survived. All patients carried the same LIFR (p.Arg692X) mutation. Our oldest patient had attenuated morning serum cortisol and plasma ACTH levels at repeated measurements. Two of three patients had attenuated cortisol response (< 18 mu g/dl) to glucagon, one of whom also had borderline cortisol response to low dose (1 mu g) ACTH stimulation consistent with central adrenal insufficiency. STWS patients may develop central adrenal insufficiency due to impaired LIF/LIFR signalling. LIF/LIFR system plays a role in human HPA axis regulation
MOLECULAR CHARACTERIZATION OF MUTATION REGIONS IN HERBICIDE-RESISTANT QUINOA (Chenopodium quinoa Willd.) MUTANT LINES
No full textQuinoa can be considered as an alternative plant with its features being compatible with unfavorable climate and soil conditions. Moreover, the nutrient content of its seed is great. But there is not a selective herbicide for weeds in quinoa fields. This is a significant problem in the quinoa cultivation. Therefore, it is necessary to develop herbicide-resistant quinoa lines In the study, Tititcaca, a variety of quinoa was used. Sodium azide was used 1.5 mM for mutagenesis. Herbicide-resistant plants were determined by applying herbicide belonging to the IMI group in the M3 generation. These were named ET-6, ET-7, OT-11 and T-103. The 4 mutant lines obtained as a result of seed mutagenesis, and mutant line OT-11 plants occurred in the form of replacement of the cytosine nucleotide with the adenine nucleotide (C -> A) in the ALS gene. Line ET-6 plants, the thymine nucleotide was replaced with a guanine nucleotide (T -> G). The mutation occurring in the OT-11 and ET-6 genotypes was evaluated as a transversion-type mutation. A transition type mutation occurred in mutant line T-103 plants as well, and this mutation occurred in the form of substitution of thymine nucleotide with cytosine nucleotide (T -> C) at nucleotide 1114. The findings suggest that effective weed control in quinoa cultivation can be done effectively by developing varieties resistant to IMI group herbicides in quinoa plants. Herbicide resistance studies should be continued in the next generations with the ET-6, OT-11, and T-103 lines
Distributed MIMO Precoding with Routing Constraints in Segmented Fronthaul
No full textDistributed Multiple-Input and Multiple-Output (D-MIMO) is envisioned to play
a significant role in future wireless communication systems as an effective
means to improve coverage and capacity. In this paper, we have studied the
impact of a practical two-level data routing scheme on radio performance in a
downlink D-MIMO scenario with segmented fronthaul. At the first level, a
Distributed Unit (DU) is connected to the Aggregating Radio Units (ARUs) that
behave as cluster heads for the selected serving RU groups. At the second
level, the selected ARUs connect with the additional serving RUs. At each route
discovery level, RUs and/or ARUs share information with each other. The aim of
the proposed framework is to efficiently select serving RUs and ARUs so that
the practical data routing impact for each User Equipment (UE) connection is
minimal. The resulting post-routing Signal-to-Interference plus Noise Ratio
(SINR) among all UEs is analyzed after the routing constraints have been
applied. The results show that limited fronthaul segment capacity causes
connection failures with the serving RUs of individual UEs, especially when
long routing path lengths are required. Depending on whether the failures occur
at the first or the second routing level, a UE may be dropped or its SINR may
be reduced. To minimize the DU-ARU connection failures, the segment capacity of
the segments closest to the DU is set as double as the remaining segments. When
the number of active co-scheduled UEs is kept low enough, practical segment
capacities suffice to achieve a zero UE dropping rate. Besides, the proper
choice of maximum path length setting should take into account segment capacity
and its utilization due to the relation between the two.Comment: This is the accepted version of a paper published in 2023 IEEE 34th
Annual International Symposium on Personal, Indoor and Mobile Radio
Communications (PIMRC). The final version is available at
https://ieeexplore.ieee.org/document/1029378
Interference-aware Distributed Precoding in Coherent Large-scale Distributed MIMO
No full textLarge-scale Distributed Multiple-Input Multiple-Output (D-MIMO) is one of the key radio technologies to support ubiquitous radio access by enabling the User Equipment (UE) having simultaneous connectivity to many highly coordinated network transmission points called Access Points (APs). In this work, coherent large-scale D-MIMO has been investigated in an industrial indoor scenario considering the frequency range from 3.5 GHz to 100 GHz assuming synchronized APs. The UE-centric AP selection has been studied to determine the subset of APs jointly serving to the UEs. Thereafter, interference aware distributed precoding is formulated and compared with centralized precoding. The simulation results show that more coordinated APs in clusters increases coherent precoding gain and enhances interference management, eventually provides more gain in spectral efficiency. Moreover, distributed, partially distributed and collocated deployment models have been compared, and trade-off between implementation complexity and deployment complexity has been shown.This work was supported by The Scientific and Technological Research Council of Turkey (TUBITAK) through the 1515
Frontier Research and Development Laboratories Support Program under Project 5169902, and has been partly funded by
the European Commission through the H2020 project Hexa-X (Grant Agreement no. 101015956
- …
