116,204 research outputs found
Lossless Source Coding in the Point-to-Point, Multiple Access, and Random Access Scenarios
This paper treats point-to-point, multiple access and random access lossless source coding in the finite-blocklength regime. A random coding technique is developed, and its power in analyzing the third-order coding performance is demonstrated in all three scenarios. Results include a third-order-optimal characterization of the Slepian-Wolf rate region and a proof showing that for dependent sources, the independent encoders used by Slepian-Wolf codes can achieve the same third-order- optimal performance as a single joint encoder. The concept of random access source coding, which generalizes the multiple access scenario to allow for a subset of participating encoders that is unknown a priori to both the encoders and the decoder, is introduced. Contributions include a new definition of the probabilistic model for a random access-discrete multiple source, a general random access source coding scheme that employs a rateless code with sporadic feedback, and an analysis demonstrating via a random coding argument that there exists a deterministic code of the proposed structure that simultaneously achieves the third- order-optimal performance of Slepian-Wolf codes for all possible subsets of encoders
Lossless Source Coding in the Point-to-Point, Multiple Access, and Random Access Scenarios
This paper treats point-to-point, multiple access and random access lossless
source coding in the finite-blocklength regime. A random coding technique is
developed, and its power in analyzing the third-order coding performance is
demonstrated in all three scenarios. Via a connection to composite hypothesis
testing, a new converse that tightens previously known converses for
Slepian-Wolf source coding is established. Asymptotic results include a
third-order characterization of the Slepian-Wolf rate region and a proof
showing that for dependent sources, the independent encoders used by
Slepian-Wolf codes can achieve the same third-order-optimal performance as a
single joint encoder. The concept of random access source coding, which
generalizes the multiple access scenario to allow for a subset of participating
encoders that is unknown a priori to both the encoders and the decoder, is
introduced. Contributions include a new definition of the probabilistic model
for a random access source, a general random access source coding scheme that
employs a rateless code with sporadic feedback, and an analysis demonstrating
via a random coding argument that there exists a deterministic code of the
proposed structure that simultaneously achieves the third-order-optimal
performance of Slepian-Wolf codes for all possible subsets of encoders.Comment: 42 pages, 10 figures. Part of this work was presented at ISIT'1
Partition Information and its Transmission over Boolean Multi-Access Channels
In this paper, we propose a novel partition reservation system to study the
partition information and its transmission over a noise-free Boolean
multi-access channel. The objective of transmission is not message restoration,
but to partition active users into distinct groups so that they can,
subsequently, transmit their messages without collision. We first calculate (by
mutual information) the amount of information needed for the partitioning
without channel effects, and then propose two different coding schemes to
obtain achievable transmission rates over the channel. The first one is the
brute force method, where the codebook design is based on centralized source
coding; the second method uses random coding where the codebook is generated
randomly and optimal Bayesian decoding is employed to reconstruct the
partition. Both methods shed light on the internal structure of the partition
problem. A novel hypergraph formulation is proposed for the random coding
scheme, which intuitively describes the information in terms of a strong
coloring of a hypergraph induced by a sequence of channel operations and
interactions between active users. An extended Fibonacci structure is found for
a simple, but non-trivial, case with two active users. A comparison between
these methods and group testing is conducted to demonstrate the uniqueness of
our problem.Comment: Submitted to IEEE Transactions on Information Theory, major revisio
Sign-Compute-Resolve for Tree Splitting Random Access
We present a framework for random access that is based on three elements:
physical-layer network coding (PLNC), signature codes and tree splitting. In
presence of a collision, physical-layer network coding enables the receiver to
decode, i.e. compute, the sum of the packets that were transmitted by the
individual users. For each user, the packet consists of the user's signature,
as well as the data that the user wants to communicate. As long as no more than
K users collide, their identities can be recovered from the sum of their
signatures. This framework for creating and transmitting packets can be used as
a fundamental building block in random access algorithms, since it helps to
deal efficiently with the uncertainty of the set of contending terminals. In
this paper we show how to apply the framework in conjunction with a
tree-splitting algorithm, which is required to deal with the case that more
than K users collide. We demonstrate that our approach achieves throughput that
tends to 1 rapidly as K increases. We also present results on net data-rate of
the system, showing the impact of the overheads of the constituent elements of
the proposed protocol. We compare the performance of our scheme with an upper
bound that is obtained under the assumption that the active users are a priori
known. Also, we consider an upper bound on the net data-rate for any PLNC based
strategy in which one linear equation per slot is decoded. We show that already
at modest packet lengths, the net data-rate of our scheme becomes close to the
second upper bound, i.e. the overhead of the contention resolution algorithm
and the signature codes vanishes.Comment: This is an extended version of arXiv:1409.6902. Accepted for
publication in the IEEE Transactions on Information Theor
Space-time coding techniques with bit-interleaved coded modulations for MIMO block-fading channels
The space-time bit-interleaved coded modulation (ST-BICM) is an efficient
technique to obtain high diversity and coding gain on a block-fading MIMO
channel. Its maximum-likelihood (ML) performance is computed under ideal
interleaving conditions, which enables a global optimization taking into
account channel coding. Thanks to a diversity upperbound derived from the
Singleton bound, an appropriate choice of the time dimension of the space-time
coding is possible, which maximizes diversity while minimizing complexity.
Based on the analysis, an optimized interleaver and a set of linear precoders,
called dispersive nucleo algebraic (DNA) precoders are proposed. The proposed
precoders have good performance with respect to the state of the art and exist
for any number of transmit antennas and any time dimension. With turbo codes,
they exhibit a frame error rate which does not increase with frame length.Comment: Submitted to IEEE Trans. on Information Theory, Submission: January
2006 - First review: June 200
Nash Region of the Linear Deterministic Interference Channel with Noisy Output Feedback
In this paper, the -Nash equilibrium (-NE) region of the two-user
linear deterministic interference channel (IC) with noisy channel-output
feedback is characterized for all . The -NE region, a subset of
the capacity region, contains the set of all achievable information rate pairs
that are stable in the sense of an -NE. More specifically, given an
-NE coding scheme, there does not exist an alternative coding scheme for
either transmitter-receiver pair that increases the individual rate by more
than bits per channel use. Existing results such as the -NE region
of the linear deterministic IC without feedback and with perfect output
feedback are obtained as particular cases of the result presented in this
paper.Comment: 5 pages, 2 figures, to appear in ISIT 201
Polar codes for the two-user multiple-access channel
Arikan's polar coding method is extended to two-user multiple-access
channels. It is shown that if the two users of the channel use the Arikan
construction, the resulting channels will polarize to one of five possible
extremals, on each of which uncoded transmission is optimal. The sum rate
achieved by this coding technique is the one that correponds to uniform input
distributions. The encoding and decoding complexities and the error performance
of these codes are as in the single-user case: for encoding and
decoding, and for block error probability, where
is the block length.Comment: 12 pages. Submitted to the IEEE Transactions on Information Theor
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