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This paper addresses a unified approach towards communication in decentralized wireless networks of separate transmitter-receiver pairs. In general, users are unaware of each other's codebooks and there is no central controller to assign…

Information Theory · Computer Science 2016-09-08 Kamyar Moshksar , Amir K. Khandani

Using analytical methods of statistical mechanics, we analyse the typical behaviour of a multiple-input multiple-output (MIMO) Gaussian channel with binary inputs under LDPC network coding and joint decoding. The saddle point equations for…

Statistical Mechanics · Physics 2009-11-13 Roberto C. Alamino , David Saad

We consider communication over the Gaussian multiple-access channel in the regime where the number of users grows linearly with the codelength. In this regime, schemes based on sparse superposition coding can achieve a near-optimal tradeoff…

Information Theory · Computer Science 2025-06-04 Xiaoqi Liu , Kuan Hsieh , Ramji Venkataramanan

This article introduces a novel communication paradigm for the unsourced, uncoordinated Gaussian multiple access problem. The major components of the envisioned framework are as follows. The encoded bits of every message are partitioned…

Information Theory · Computer Science 2020-11-23 Asit Pradhan , Vamsi Amalladinne , Avinash Vem , Krishna R. Narayanan , Jean-Francois Chamberland

We analyze an uplink of a fast flat fading MIMO-CDMA channel in the case where the data symbol vector for each user follows an arbitrary distribution. The spectral efficiency of the channel with CSI at the receiver is evaluated analytically…

Information Theory · Computer Science 2007-07-13 Keigo Takeuchi , Toshiyuki Tanaka

An efficient Bayesian inference method for problems that can be mapped onto dense graphs is presented. The approach is based on message passing where messages are averaged over a large number of replicated variable systems exposed to the…

Disordered Systems and Neural Networks · Physics 2009-11-13 Juan P Neirotti , David Saad

Statistical mechanics approach is useful not only in analyzing macroscopic system performance of wireless communication systems, but also in discussing design problems of wireless communication systems. In this paper, we discuss a design…

Information Theory · Computer Science 2008-10-02 Koichiro Kitagawa , Toshiyuki Tanaka

In this paper, we explore the mystery of synchronous CDMA as applied to wireless and optical communication systems under very general settings for the user symbols and the signature matrix entries. The channel is modeled with real/complex…

Information Theory · Computer Science 2015-03-17 K. Alishahi , S. Dashmiz , P. Pad , F. Marvasti , M. H. Shafinia , M. Mansouri

We consider unsourced random access (uRA) in a cell-free (CF) user-centric wireless network, where a large number of potential users compete for a random access slot, while only a finite subset is active. The random access users transmit…

Information Theory · Computer Science 2025-05-01 Burak Çakmak , Eleni Gkiouzepi , Manfred Opper , Giuseppe Caire

We investigate the detection dynamics of the parallel interference canceller (PIC) for code-division multiple-access (CDMA) multiuser detection, applied to a randomly spread, fully syncronous base-band uncoded CDMA channel model with…

Statistical Mechanics · Physics 2007-05-23 Kazushi Mimura , Masato Okada

In this paper, we propose a new method of channel estimation for asynchronous additive white Gaussian noise channels in satellite communications. This method is based on signals correlation and multiuser interference cancellation which…

Networking and Internet Architecture · Computer Science 2010-12-02 Helmi Chaouech , Ridha Bouallegue

In this work, we develop a pair of rate-diverse encoder and decoder for a two-user Gaussian multiple access channel (GMAC). The proposed scheme enables the users to transmit with the same codeword length but different coding rates under…

Information Theory · Computer Science 2021-03-23 Pingping Chen , Long Shi , Yi Fang , Francis C. M. Lau , Jun Cheng

Kudekar et al. proved that the belief-propagation (BP) performance for low-density parity check (LDPC) codes can be boosted up to the maximum-a-posteriori (MAP) performance by spatial coupling. In this paper, spatial coupling is applied to…

Information Theory · Computer Science 2016-11-18 Keigo Takeuchi , Toshiyuki Tanaka , Tsutomu Kawabata

In this paper, a class of nonlinear MMSE multiuser detectors are derived based on a multivariate Gaussian approximation of the multiple access interference. This approach leads to expressions identical to those describing the probabilistic…

Information Theory · Computer Science 2007-07-13 Peng Hui Tan , Lars K. Rasmussen

In this paper, we investigate a joint device activity detection (DAD), channel estimation (CE), and data decoding (DD) algorithm for multiple-input multiple-output (MIMO) massive unsourced random access (URA). Different from the…

Information Theory · Computer Science 2021-12-20 Tianya Li , Yongpeng Wu , Mengfan Zheng , Wenjun Zhang , Chengwen Xing , Jianping An , Xiang-Gen Xia , Chengshan Xiao

Asymptotic spectral distribution (ASD) of the crosscorrelation matrix is investigated for a random spreading short/long-code asynchronous direct sequence-code division multiple access (DS-CDMA) system. The discrete-time decision statistics…

Information Theory · Computer Science 2008-10-06 Chien-Hwa Hwang

We investigate the detection dynamics of the Gibbs sampler for code-division multiple access (CDMA) multiuser detection. Our approach is based upon dynamical replica theory which allows an analytic approximation to the dynamics. We use this…

Disordered Systems and Neural Networks · Physics 2009-11-11 J. P. L. Hatchett , M. Okada

We analyze multiuser detection under the assumption that the number of users accessing the channel is unknown by the receiver. In this environment, users' activity must be estimated along with any other parameters such as data, power, and…

Information Theory · Computer Science 2016-11-15 Adrià Tauste Campo , Albert Guillén i Fàbregas , Ezio Biglieri

Precise characterization of the mutual information of MIMO systems is required to assess the throughput of wireless communication channels in the presence of Rician fading and spatial correlation. Here, we present an asymptotic approach…

Information Theory · Computer Science 2016-11-17 Giorgio Taricco

This paper studies the design of a decentralized multiuser multi-antenna (MIMO) system for spectrum sharing over a fixed narrow band, where the coexisting users independently update their transmit covariance matrices for individual…

Information Theory · Computer Science 2009-05-22 Rui Zhang , John M. Cioffi