66,609 research outputs found
Outage Probability in Arbitrarily-Shaped Finite Wireless Networks
This paper analyzes the outage performance in finite wireless networks.
Unlike most prior works, which either assumed a specific network shape or
considered a special location of the reference receiver, we propose two general
frameworks for analytically computing the outage probability at any arbitrary
location of an arbitrarily-shaped finite wireless network: (i) a moment
generating function-based framework which is based on the numerical inversion
of the Laplace transform of a cumulative distribution and (ii) a reference link
power gain-based framework which exploits the distribution of the fading power
gain between the reference transmitter and receiver. The outage probability is
spatially averaged over both the fading distribution and the possible locations
of the interferers. The boundary effects are accurately accounted for using the
probability distribution function of the distance of a random node from the
reference receiver. For the case of the node locations modeled by a Binomial
point process and Nakagami- fading channel, we demonstrate the use of the
proposed frameworks to evaluate the outage probability at any location inside
either a disk or polygon region. The analysis illustrates the location
dependent performance in finite wireless networks and highlights the importance
of accurately modeling the boundary effects.Comment: accepted to appear in IEEE Transactions on Communication
Binomial Line Cox Processes: Statistical Characterization and Applications in Wireless Network Analysis
The current analysis of wireless networks whose transceivers are confined to
streets is largely based on Poissonian models, such as Poisson line processes
and Poisson line Cox processes. We demonstrate important scenarios where a
model with a finite and deterministic number of streets, termed binomial line
process, is more accurate. We characterize the statistical properties of the
BLP and the corresponding binomial line Cox process and apply them to analyze
the performance of a network whose access points are deployed along the streets
of a city. Such a deployment scenario will be typical for 5G and future
wireless networks. In order to obtain a fine-grained insight into the network
performance, we derive the meta distribution of the signal-to-interference and
noise ratio. Accordingly, we investigate the mean local delay in transmission
and the density of successful transmission. These metrics, respectively,
characterize the latency and coverage performance of the network and are key
performance indicators of next-generation wireless systems.Comment: Submitted to IEEE Transactions on Wireless Communication
Stochastic Geometry Modeling and Analysis of Single- and Multi-Cluster Wireless Networks
This paper develops a stochastic geometry-based approach for the modeling and
analysis of single- and multi-cluster wireless networks. We first define finite
homogeneous Poisson point processes to model the number and locations of the
transmitters in a confined region as a single-cluster wireless network. We
study the coverage probability for a reference receiver for two strategies;
closest-selection, where the receiver is served by the closest transmitter
among all transmitters, and uniform-selection, where the serving transmitter is
selected randomly with uniform distribution. Second, using Matern cluster
processes, we extend our model and analysis to multi-cluster wireless networks.
Here, the receivers are modeled in two types, namely, closed- and open-access.
Closed-access receivers are distributed around the cluster centers of the
transmitters according to a symmetric normal distribution and can be served
only by the transmitters of their corresponding clusters. Open-access
receivers, on the other hand, are placed independently of the transmitters and
can be served by all transmitters. In all cases, the link distance distribution
and the Laplace transform (LT) of the interference are derived. We also derive
closed-form lower bounds on the LT of the interference for single-cluster
wireless networks. The impact of different parameters on the performance is
also investigated
ALOHA With Collision Resolution(ALOHA-CR): Theory and Software Defined Radio Implementation
A cross-layer scheme, namely ALOHA With Collision Resolution (ALOHA-CR), is
proposed for high throughput wireless communications in a cellular scenario.
Transmissions occur in a time-slotted ALOHA-type fashion but with an important
difference: simultaneous transmissions of two users can be successful. If more
than two users transmit in the same slot the collision cannot be resolved and
retransmission is required. If only one user transmits, the transmitted packet
is recovered with some probability, depending on the state of the channel. If
two users transmit the collision is resolved and the packets are recovered by
first over-sampling the collision signal and then exploiting independent
information about the two users that is contained in the signal polyphase
components. The ALOHA-CR throughput is derived under the infinite backlog
assumption and also under the assumption of finite backlog. The contention
probability is determined under these two assumptions in order to maximize the
network throughput and maintain stability. Queuing delay analysis for network
users is also conducted. The performance of ALOHA-CR is demonstrated on the
Wireless Open Access Research Platform (WARP) test-bed containing five software
defined radio nodes. Analysis and test-bed results indicate that ALOHA-CR leads
to significant increase in throughput and reduction of service delays
On the Design of a Novel Joint Network-Channel Coding Scheme for the Multiple Access Relay Channel
This paper proposes a novel joint non-binary network-channel code for the
Time-Division Decode-and-Forward Multiple Access Relay Channel (TD-DF-MARC),
where the relay linearly combines -- over a non-binary finite field -- the
coded sequences from the source nodes. A method based on an EXIT chart analysis
is derived for selecting the best coefficients of the linear combination.
Moreover, it is shown that for different setups of the system, different
coefficients should be chosen in order to improve the performance. This
conclusion contrasts with previous works where a random selection was
considered. Monte Carlo simulations show that the proposed scheme outperforms,
in terms of its gap to the outage probabilities, the previously published joint
network-channel coding approaches. Besides, this gain is achieved by using very
short-length codewords, which makes the scheme particularly attractive for
low-latency applications.Comment: 28 pages, 9 figures; Submitted to IEEE Journal on Selected Areas in
Communications - Special Issue on Theories and Methods for Advanced Wireless
Relays, 201
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