315 research outputs found
Optimal Energy Allocation For Delay-Constrained Traffic Over Fading Multiple Access Channels
In this paper, we consider a multiple-access fading channel where users
transmit to a single base station (BS) within a limited number of time slots.
We assume that each user has a fixed amount of energy available to be consumed
over the transmission window. We derive the optimal energy allocation policy
for each user that maximizes the total system throughput under two different
assumptions on the channel state information. First, we consider the offline
allocation problem where the channel states are known a priori before
transmission. We solve a convex optimization problem to maximize the
sum-throughput under energy and delay constraints. Next, we consider the online
allocation problem, where the channels are causally known to the BS and obtain
the optimal energy allocation via dynamic programming when the number of users
is small. We also develop a suboptimal resource allocation algorithm whose
performance is close to the optimal one. Numerical results are presented
showing the superiority of the proposed algorithms over baseline algorithms in
various scenarios.Comment: IEEE Global Communications Conference: Wireless Communications
(Globecom2016 WC
Proactive Location-Based Scheduling of Delay-Constrained Traffic Over Fading Channels
In this paper, proactive resource allocation based on user location for
point-to-point communication over fading channels is introduced, whereby the
source must transmit a packet when the user requests it within a deadline of a
single time slot. We introduce a prediction model in which the source predicts
the request arrival slots ahead, where denotes the prediction
window (PW) size. The source allocates energy to transmit some bits proactively
for each time slot of the PW with the objective of reducing the transmission
energy over the non-predictive case. The requests are predicted based on the
user location utilizing the prior statistics about the user requests at each
location. We also assume that the prediction is not perfect. We propose
proactive scheduling policies to minimize the expected energy consumption
required to transmit the requested packets under two different assumptions on
the channel state information at the source. In the first scenario, offline
scheduling, we assume the channel states are known a-priori at the source at
the beginning of the PW. In the second scenario, online scheduling, it is
assumed that the source has causal knowledge of the channel state. Numerical
results are presented showing the gains achieved by using proactive scheduling
policies compared with classical (reactive) networks. Simulation results also
show that increasing the PW size leads to a significant reduction in the
consumed transmission energy even with imperfect prediction.Comment: Conference: VTC2016-Fall, At Montreal-Canad
The Deterministic Capacity of Relay Networks with Relay Private Messages
We study the capacity region of a deterministic 4-node network, where 3 nodes
can only communicate via the fourth one. However, the fourth node is not merely
a relay since it can exchange private messages with all other nodes. This
situation resembles the case where a base station relays messages between users
and delivers messages between the backbone system and the users. We assume an
asymmetric scenario where the channel between any two nodes is not reciprocal.
First, an upper bound on the capacity region is obtained based on the notion of
single sided genie. Subsequently, we construct an achievable scheme that
achieves this upper bound using a superposition of broadcasting node 4 messages
and an achievable "detour" scheme for a reduced 3-user relay network.Comment: 3 figures, accepted at ITW 201
PemanfaatanserbukKayuMerantiMerah{ShoreaparvifatiuDyer)Sebagai 3240 Biosorben lon Logam Cd(II)
Meranti merah sawdus" an abundant and inexpensive material, was used as an adsorbent for the removal of Cd(tr) from wastcr*ater. This research was divided into two tneatnirents, namely: activation of sawdust with toluene and ethanol ( 1 : 1) and without activation of sawdust at variation of contact timg pH, and concentrdion- Ctncentration of Cd(II) ions before and after adsorption were determined by Atomic Adsorption Spectrophotometer (AAS). The results showed that optimum time was 120 minutes for sow'dus qitiout activation and 100 minutes for sawdust with activation, whereas optimum pH for both reatment were 5. Adsorption capacity was studied by both Langmuir isotherm and Freundlich iso&erm. Adsorption capacity value (Qo) was 2;4631\ud
mg/g for sawdust without activation ud 11834 mglg far sawdust with activation. Functional gfoups involved in this biosorption for sawdug without activation and sawdust with activation were-OH
Cache-aided combination networks with interference
Centralized coded caching and delivery isstudied for a radio access combination network (RACN),whereby a set ofHedge nodes (ENs), connected to acloud server via orthogonal fronthaul links with limitedcapacity, serve a total ofKuser equipments (UEs) overwireless links. The cloud server is assumed to hold alibrary ofNfiles, each of sizeFbits; and each user,equipped with a cache of sizeμRNFbits, is connectedto a distinct set ofrENs each of which equipped witha cache of sizeμTNFbits, whereμT,μR∈[0,1]arethe fractional cache capacities of the UEs and the ENs,respectively. The objective is to minimize the normalizeddelivery time (NDT), which refers to the worst case deliverylatency when each user requests a single distinct file fromthe library. Three coded caching and transmission schemesare considered, namely theMDS-IA,soft-transferandzero-forcing (ZF)schemes. MDS-IA utilizes maximum distanceseparable (MDS) codes in the placement phase and realinterference alignment (IA) in the delivery phase. Theachievable NDT for this scheme is presented forr= 2and arbitrary fractional cache sizesμTandμR, and alsofor arbitrary value ofrand fractional cache sizeμTwhen the cache capacity of the UE is above a certainthreshold. The soft-transfer scheme utilizes soft-transferof coded symbols to ENs that implement ZF over the edgelinks. The achievable NDT for this scheme is presentedfor arbitraryrand arbitrary fractional cache sizesμTandμR. The last scheme utilizes ZF between the ENs andthe UEs without the participation of the cloud server inthe delivery phase. The achievable NDT for this scheme is presented for an arbitrary value ofrwhen the totalcache size at a pair of UE and EN is sufficient to store thewhole library, i.e.,μT+μR≥1. The results indicate thatthe fronthaul capacity determines which scheme achievesa better performance in terms of the NDT, and thesoft-transfer scheme becomes favorable as the fronthaulcapacity increases
MOLECULAR CHARACTERIZATION OF GENE 16S rRNA MICRO SYMBIONTS
Molecular characterization studies have been conducted 16S rRNA gene micro symbiont of sponge origin Melawai Beach, Balikpapan in East Kalimantan. Objective analysis of histomorphological research, isolation-purification, molecular characterization of micro-symbiont genes in order to search symbiont bacteria that can live in extreme environments contaminated hydrocarbon waste. The research method that morphological identification, isolation-purification and molecular characterization of the 16S rRNA gene with Chain Reaction Polymerization method. The results of histo-morphological analysis concluded sponge samples with species of Callyspongia sp Isolation and purification mikro symbionts of sponge obtained 2 (two) isolates. Characteristics of Isolates 1; spherical shape, colonize and creamy, while isolates 2; jagged shape, oval and white colonies. Molecular characterization of the 16S rRNA gene by PCR, Bacillus subtilis strain BAB-684 identification for isolates one is the number of nucleotide pairs reached 899 bp and the degree of similarity in GenBank reached 89% homologous, while the second is a Bacillus flexus strain PHCDB20 isolates the number reached 950 bp nucleotide pairs with the degree of similarity in GenBank reached 99% homologous.Keywords: Callyspongia sp, micro-symbionts, characterization, gene Molecule
The Deterministic Multicast Capacity of 4-Node Relay Networks
In this paper, we completely characterize the deterministic capacity region
of a four-node relay network with no direct links between the nodes, where each
node communicates with the three other nodes via a relay. Towards this end, we
develop an upper bound on the deterministic capacity region, based on the
notion of a one-sided genie. To establish achievability, we use the detour
schemes that achieve the upper bound by routing specific bits via indirect
paths instead of sending them directly.Comment: 5 pages, 2 figures, accepted at ISIT'1
- …