Adaptive spatial modulation and thresholds optimization for MIMO systems in correlated Rayleigh channels

Visible light communication (VLC) systems are inherently signal-to-noise ratio (SNR) limited due to link budget constraints. One favourable method to overcome this limitation is to focus on the pre-log factors of the channel capacity. Multiple-input multiple-output (MIMO) techniques are therefore a promising avenue of research. However, inter-channel interference in MIMO limits the achievable capacity. Spatial modulation (SM) avoids this limitation. Furthermore, the performance of MIMO systems in VLC is limited by the similarities among spatial channels. This limitation becomes particularly severe in intensity modulation/direct detection (IM/DD) systems because of the lack of phase information. The motivation of this paper is to propose a system that results in a multi-channel transmission system that enables reliable multi-user optical MIMO SM transmission without the need for a precoder, power allocation algorithm or additional optics at the receiver. A general bit error performance model for the SM system is developed for an arbitrary number of light-emitting diodes (LEDs) in conjunction with pulse amplitude modulation. Based on this model, an LED array structure is designed to result in spatially separated multiple channels by manipulating the transmitter geometry. This article is part of the theme issue ‘Optical wireless communication’.

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Hybrid Precoded Spatial Modulation (hPSM) for mmWave Massive MIMO Systems Over Frequency-Selective Channels

IEEE Wireless Communications Letters ◽

10.1109/lwc.2020.2972866 ◽

2020 ◽

Vol 9 (6) ◽

pp. 839-842 ◽

Cited By ~ 1

Author(s):

Jinpeng Li ◽

Shijian Gao ◽

Xiang Cheng ◽

Liuqing Yang

Keyword(s):

Massive Mimo ◽

Mimo Systems ◽

Spatial Modulation ◽

Frequency Selective ◽

Frequency Selective Channels

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Low-Complexity Detection Algorithms for Spatial Modulation MIMO Systems

Journal of Electrical and Computer Engineering ◽

10.1155/2018/4034625 ◽

2018 ◽

Vol 2018 ◽

pp. 1-7 ◽

Cited By ~ 1

Author(s):

Xinhe Zhang ◽

Yuehua Zhang ◽

Chang Liu ◽

Hanzhong Jia

Keyword(s):

Computational Complexity ◽

Mimo Systems ◽

Optimal Solution ◽

Low Complexity ◽

Search Tree ◽

Spatial Modulation ◽

Algorithm Analysis ◽

Detection Algorithms ◽

Search Order ◽

Ber Performance

In this paper, the authors propose three low-complexity detection schemes for spatial modulation (SM) systems based on the modified beam search (MBS) detection. The MBS detector, which splits the search tree into some subtrees, can reduce the computational complexity by decreasing the nodes retained in each layer. However, the MBS detector does not take into account the effect of subtree search order on computational complexity, and it does not consider the effect of layers search order on the bit-error-rate (BER) performance. The ost-MBS detector starts the search from the subtree where the optimal solution is most likely to be located, which can reduce total searches of nodes in the subsequent subtrees. Thus, it can decrease the computational complexity. When the number of the retained nodes is fixed, which nodes are retained is very important. That is, the different search orders of layers have a direct influence on BER. Based on this, we propose the oy-MBS detector. The ost-oy-MBS detector combines the detection order of ost-MBS and oy-MBS together. The algorithm analysis and experimental results show that the proposed detectors outstrip MBS with respect to the BER performance and the computational complexity.

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