Estimation of Laplacian Symbols for Analog Transmission Over MIMO Channels

© 2015 IEEE. This version of the article has been accepted for publication, after peer review. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works. The Version of Record is available online at: https://doi.org/10.1109/LCOMM.2015.2485216.[Abstract]: The MAP and MMSE estimation of Laplace-distributed symbols transmitted over multiple-input multiple-output channels is studied. This is an important problem in analog joint source channel coding with spiral mappings, where the probability density function of the transmitted symbols approximates a Laplace distribution in the low SNR regime. Simulation results are presented to illustrate the suitability of these estimators in uncoded and coded analog communications.This work was supported by Xunta de Galicia and MINECO of Spain under grants 2012/287 and TEC2013-47141-C4-1-R.Xunta de Galicia; CN 2012/28

Analog joint source-channel coding over MIMO channels

[Abstract]: Analog joint source-channel coding (JSCC) is a communication strategy that does not follow the separation principle of conventional digital systems but has been shown to approach the optimal distortion-cost tradeoff over additive white Gaussian noise channels. In this work, we investigate the feasibility of analog JSCC over multiple-input multiple-output (MIMO) fading channels. Since, due to complexity constraints, directly recovering the analog source information from the MIMO channel output is not possible, we propose the utilization of low-complexity two-stage receivers that separately perform detection and analog JSCC maximum likelihood decoding. We study analog JSCC MIMO receivers that utilize either linear minimum mean square error or decision feedback MIMO detection. Computer experiments show the ability of the proposed analog JSCC receivers to approach the optimal distortion-cost tradeoff both in the low and high channel signal-to-noise ratio regimes. Performance is analyzed over both synthetically computer-generated Rayleigh fading channels and real indoor wireless measured channels.This work has been funded by Xunta de Galicia, MINECO of Spain, and FEDER funds of the EU under grants 2012/287, TEC2010-19545-C04-01, and CSD2008-00010; and by NSF award CIF-0915800.Xunta de Galicia; CN 2012/287United States. National Science Foundation; CIF-091580

Joint Hybrid Precoder and Combiner Design for mmWave Spatial Multiplexing Transmission

Millimeter-wave (mmWave) communications have been considered as a key technology for future 5G wireless networks because of the orders-of-magnitude wider bandwidth than current cellular bands. In this paper, we consider the problem of codebook-based joint analog-digital hybrid precoder and combiner design for spatial multiplexing transmission in a mmWave multiple-input multiple-output (MIMO) system. We propose to jointly select analog precoder and combiner pair for each data stream successively aiming at maximizing the channel gain while suppressing the interference between different data streams. After all analog precoder/combiner pairs have been determined, we can obtain the effective baseband channel. Then, the digital precoder and combiner are computed based on the obtained effective baseband channel to further mitigate the interference and maximize the sum-rate. Simulation results demonstrate that our proposed algorithm exhibits prominent advantages in combating interference between different data streams and offer satisfactory performance improvement compared to the existing codebook-based hybrid beamforming schemes