1,116 research outputs found
q-Identities from Lagrange and Newton Interpolation
Combining Newton and Lagrange interpolation, we give -identities which
generalize results of Van Hamme, Uchimura, Dilcher and Prodinger
Partition Analysis and Symmetrizing Operators
Using a symmetrizing operator, we give a new expression for the Omega
operator used by MacMahon in Partition Analysis, and given a new life by
Andrews and his coworkers. Our result is stated in terms of Schur functions.Comment: 5 page
Beyond the Min-Cut Bound: Deterministic Network Coding for Asynchronous Multirate Broadcast
In a single hop broadcast packet erasure network, we demonstrate that it is
possible to provide multirate packet delivery outside of what is given by the
network min-cut. This is achieved by using a deterministic non-block-based
network coding scheme, which allows us to sidestep some of the limitations put
in place by the block coding model used to determine the network capacity.
Under the network coding scheme we outline, the sender is able to transmit
network coded packets above the channel rate of some receivers, while ensuring
that they still experience nonzero delivery rates. Interestingly, in this
generalised form of asynchronous network coded broadcast, receivers are not
required to obtain knowledge of all packets transmitted so far. Instead, causal
feedback from the receivers about packet erasures is used by the sender to
determine a network coded transmission that will allow at least one, but often
multiple receivers, to deliver their next needed packet.
Although the analysis of deterministic coding schemes is generally a
difficult problem, by making some approximations we are able to obtain
tractable estimates of the receivers' delivery rates, which are shown to match
reasonably well with simulation. Using these estimates, we design a fairness
algorithm that allocates the sender's resources so all receivers will
experience fair delivery rate performance
Dynamic Rate Adaptation for Improved Throughput and Delay in Wireless Network Coded Broadcast
In this paper we provide theoretical and simulation-based study of the
delivery delay performance of a number of existing throughput optimal coding
schemes and use the results to design a new dynamic rate adaptation scheme that
achieves improved overall throughput-delay performance.
Under a baseline rate control scheme, the receivers' delay performance is
examined. Based on their Markov states, the knowledge difference between the
sender and receiver, three distinct methods for packet delivery are identified:
zero state, leader state and coefficient-based delivery. We provide analyses of
each of these and show that, in many cases, zero state delivery alone presents
a tractable approximation of the expected packet delivery behaviour.
Interestingly, while coefficient-based delivery has so far been treated as a
secondary effect in the literature, we find that the choice of coefficients is
extremely important in determining the delay, and a well chosen encoding scheme
can, in fact, contribute a significant improvement to the delivery delay.
Based on our delivery delay model, we develop a dynamic rate adaptation
scheme which uses performance prediction models to determine the sender
transmission rate. Surprisingly, taking this approach leads us to the simple
conclusion that the sender should regulate its addition rate based on the total
number of undelivered packets stored at the receivers. We show that despite its
simplicity, our proposed dynamic rate adaptation scheme results in noticeably
improved throughput-delay performance over existing schemes in the literature.Comment: 14 pages, 15 figure
Semi-Finite Forms of Bilateral Basic Hypergeometric Series
We show that several classical bilateral summation and transformation
formulas have semi-finite forms. We obtain these semi-finite forms from
unilateral summation and transformation formulas. Our method can be applied to
derive Ramanujan's summation, Bailey's transformations,
and Bailey's summation.Comment: 8 pages. accepted by Proc. Amer. Math. So
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