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Vahid Aref

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Publications associées (10)

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A Compressed Sensing Approach for Distribution Matching

Vahid Aref, Mohamad Baker Dia

In this work, we formulate the fixed-length distribution matching as a Bayesian inference problem. Our proposed solution is inspired from the compressed sensing paradigm and the sparse superposition (SS) codes. First, we introduce sparsity in the binary so ...

IEEE2018

Approaching the Rate-Distortion Limit With Spatial Coupling, Belief Propagation, and Decimation

Nicolas Macris, Vahid Aref, Marc Vuffray

We investigate an encoding scheme for lossy compression of a binary symmetric source based on simple spatially coupled low-density generator-matrix codes. The degree of the check nodes is regular and the one of code-bits is Poisson distributed with an aver ...

Institute of Electrical and Electronics Engineers2015

Approaching the Rate-Distortion Limit by spatial Coupling with Belief Propagation and Decimation

Nicolas Macris, Vahid Aref, Marc Vuffray

We investigate an encoding scheme for lossy compression based on spatially coupled Low-Density Generator-Matrix codes. The degree distributions are regular, or are Poisson on the code-bit side and check-regular which allows use for any compression rate. Th ...

2013

On the Convergence Speed of Spatially Coupled LDPC Ensembles

Vahid Aref

Spatially coupled low-density parity-check codes show an outstanding performance under the low-complexity belief propagation (BP) decoding algorithm. They exhibit a peculiar convergence phenomenon above the BP threshold of the underlying non-coupled ensemb ...

2013

Lossy source coding via spatially coupled LDGM ensembles

Rüdiger Urbanke, Nicolas Macris, Vahid Aref, Marc Vuffray

We study a new encoding scheme for lossy source compression based on spatially coupled low-density generatormatrix codes. We develop a belief-propagation guided-decimation algorithm, and show that this algorithm allows to approach the optimal distortion of ...

Ieee2012

Universal Rateless Codes From Coupled LT Codes

Rüdiger Urbanke, Vahid Aref

It was recently shown that spatial coupling of individual low-density parity-check codes improves the belief-propagation threshold of the coupled ensemble essentially to the maximum a posteriori threshold of the underlying ensemble. We study the performanc ...

Ieee Service Center, 445 Hoes Lane, Po Box 1331, Piscataway, Nj 08855-1331 Usa2011

Performance of Rateless Codes under Spatial Coupling

Vahid Aref

Spatial coupling of individual LDPC codes improves the BP threshold of the coupled ensemble to the MAP threshold of the underlying ensemble. In this report, we investigate the performance of spatial coupling on LDGM codes which might lead to constructing a ...

2010

Partial cognitive relay channel

Masih Nilchian, Vahid Aref

We define partial cognitive relay channel as a two-transmitter, two-receiver interference channel with a relay node such that one of the transmitters is a cognitive transmitter. As a more feasible assumption we assume that the cognitive transmitter has non ...

IEEE2009

Bounds on the Sum Capacity of Synchronous Binary CDMA Channels

Pedram Pad, Vahid Aref

In this paper, we obtain a family of lower bounds for the sum capacity of code-division multiple-access (CDMA) channels assuming binary inputs and binary signature codes in the presence of additive noise with an arbitrary distribution. The envelope of this ...

Institute of Electrical and Electronics Engineers2009

Approaching the Rate-Distortion Limit with Spatial Coupling, Belief propagation and Decimation

Nicolas Macris, Vahid Aref, Marc Vuffray

We investigate an encoding scheme for lossy compression of a binary symmetric source based on simple spatially coupled Low-Density Generator-Matrix codes. The degree of the check nodes is regular and the one of code-bits is Poisson distributed with an aver ...

Institute of Electrical and Electronics Engineers0