scholarly journals Performance Evaluation of MPPM-Coded Wireless Optical MIMO System with Combined Effects over Correlated Fading Channel

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Yue Zhang ◽  
Huiqin Wang ◽  
Minghua Cao ◽  
Zhongxian Bao
Keyword(s):  
Fading Channel ◽  
Influence Factor ◽  
Mimo System ◽  
Combined Effects ◽  
Channel Correlation ◽  
Pointing Error ◽  
Correlated Fading ◽  
Correlated Channel ◽  
Pat System ◽  
Approximate Expressions

The performance of wireless optical MIMO system with multiple pulse position modulation (MPPM) over correlated fading channel is investigated. The combined effects of atmospheric attenuation, atmospheric turbulence, and pointing error are taken into consideration. The bit error rate (BER) and the ergodic channel capacity are analyzed by utilizing the Poisson counting model and the exponential correlation model. Moreover, their approximate expressions are derived. The simulation results demonstrate that the pointing error is the most prominent influence factor over weak correlated channel. The performance degradation caused by a high channel correlation coefficient is more than that of pointing error in strong correlated channel. Therefore, the use of pointing, acquisition, and tracking (PAT) system and reasonable arrangement of the number and spacing of antennas at the transceiver are the keys to improve system performance.

A Novel Spatial Modulation Scheme for MIMO System

2012 ◽  
Vol 198-199 ◽  
pp. 1573-1577 ◽  
Author(s):  
Yao Yuan Zhang ◽  
Zi Sheng Zhang ◽  
Ya Fei Lian ◽  
Qian Ding
Keyword(s):  
Rayleigh Fading ◽  
Mimo System ◽  
Spectrum Efficiency ◽  
Spatial Modulation ◽  
Modulation Scheme ◽  
Channel Correlation ◽  
Optimal Detector ◽  
Shift Keying ◽  
Correlated Channel ◽  
Symbol Duration

A novel spatial modulation scheme based on Space-Shift Keying (SSK) modulation is introduced for MIMO system. The proposed scheme doubles the spectrum efficiency of SSK by assigning unique symbols to different combinations of antenna indexes per symbol duration, while retaining the SSK’s inherent advantages. The optimal detector is utilized at the receiver simultaneously. Analytical and simulation results show: 1) in Rayleigh fading channel scenario，the obtained gains in SNR for the same spectral efficiency of the proposed scheme over amplitude/phase modulation (APM), vertical Bell Labs layered structure (V-BLAST) and spatial modulation (SM) systems are obvious; 2) under the correlated channel assumption, the new one still outperforms SM and V-BLAST clearly, which indicates the new one is more robust in the presence of channel correlation.

scholarly journals Statistical Beamforming for Massive MIMO Systems with Distinct Spatial Correlations

Sensors ◽  
2020 ◽  
Vol 20 (21) ◽  
pp. 6255
Author(s):  
Taehyoung Kim ◽  
Sangjoon Park
Keyword(s):  
Massive Mimo ◽  
Degrees Of Freedom ◽  
Mimo Systems ◽  
Mimo System ◽  
Multiple Input Multiple Output ◽  
High Signal ◽  
Spatial Correlations ◽  
Channel Correlation ◽  
Low Correlation ◽  
Noise Ratio

In this paper, we propose a novel statistical beamforming (SBF) method called the partial-nulling-based SBF (PN-SBF) to serve a number of users that are undergoing distinct degrees of spatial channel correlations in massive multiple-input multiple-output (MIMO) systems. We consider a massive MIMO system with two user groups. The first group experiences a low spatial channel correlation, whereas the second group has a high spatial channel correlation, which can happen in massive MIMO systems that are based on fifth-generation networks. By analyzing the statistical signal-to-interference-plus-noise ratio, it can be observed that the statistical beamforming vector for the low-correlation group should be designed as the orthogonal complement for the space spanned by the aggregated channel covariance matrices of the high-correlation group. Meanwhile, the spatial degrees of freedom for the high-correlation group should be preserved without cancelling the interference to the low-correlation group. Accordingly, a group-common pre-beamforming matrix is applied to the low-correlation group to cancel the interference to the high-correlation group. In addition, to deal with the intra-group interference in each group, the post-beamforming vector for each group is designed in the manner of maximizing the signal-to-leakage-and-noise ratio, which yields additional performance improvements for the PN-SBF. The simulation results verify that the proposed PN-SBF outperforms the conventional SBF schemes in terms of the ergodic sum rate for the massive MIMO systems with distinct spatial correlations, without the rate ceiling effect in the high signal-to-noise ratio region unlike conventional SBF schemes.

Sign in / Sign up

Export Citation Format

Share Document