MIMO Mode Research Articles

ISAR Imaging for Drone Detection Based on Backprojection Algorithm Using Millimeter-Wave Fast Chirp Modulation MIMO Radar

ISAR Imaging for Drone Detection Based on Backprojection Algorithm Using Millimeter-Wave Fast Chirp Modulation MIMO Radar

Low-Complex AI-Empowered Receiver for Spatial Media-Based Modulation MIMO Systems

Low-Complex AI-Empowered Receiver for Spatial Media-Based Modulation MIMO Systems

Transmit Waveform Design Based on Ambiguity Function Shaping for Distributed Coherent Aperture Radar in MIMO Mode

Transmit Waveform Design Based on Ambiguity Function Shaping for Distributed Coherent Aperture Radar in MIMO Mode

Design of Dynamic Offset Spatial Modulation MIMO for Low-Cost Consumer Electronics Devices

Design of Dynamic Offset Spatial Modulation MIMO for Low-Cost Consumer Electronics Devices

Information-Guided Antenna Selection and Activation for Spatial Modulation MIMO Systems

Information-Guided Antenna Selection and Activation for Spatial Modulation MIMO Systems

Data Transmission and Reception in Spatial Modulation MIMO Wireless Systems and Analysis in Nakagami-m Fading Channels

Data Transmission and Reception in Spatial Modulation MIMO Wireless Systems and Analysis in Nakagami-m Fading Channels

Modulation and coding methods in 5th generation networks

The fifth generation (5G) of wireless communication networks represents a groundbreaking shift in the realm of connectivity, enabling a wide array of transformative applications and services. This article delves into the pivotal role played by modulation and coding methods in the context of 5G networks. It explores their significance, delves into recent research and publications within the field, and outlines the direction for future research endeavors. Modulation and coding (M&C) are fundamental for 5G networks, enhancing data rates, reliability, and reducing interference. This article delves into their role in 5G networks, addressing challenges, including fading channels, interference, and diverse user needs. Recent research explores advanced modulation schemes like 256-QAM and 1024-QAM, requiring error correction coding techniques like Turbo codes and LDPC codes. Massive MIMO, using multiple antennas at both ends, is supported by adaptive coding and modulation. Adaptive Modulation and Coding (AMC) dynamically adjusts schemes based on real-time channel conditions, balancing data rate and reliability. Non-Orthogonal Multiple Access (NOMA) accommodates massive device connectivity, allowing multiple users to share resources with different power levels and modulation schemes. The study aims to comprehensively analyze 5G's M&C methods, assess modulation schemes for higher data rates, evaluate error correction coding, investigate Massive MIMO and adaptive modulation for spectral efficiency, and scrutinize NOMA's potential for massive device connectivity. Results highlight the importance of advanced modulation schemes, efficient error correction coding, and adaptive techniques in realizing 5G objectives, enabling higher data rates, lower latency, and improved reliability. NOMA is promising for accommodating many connected devices in 5G. M&C are essential for efficient and reliable data transmission in 5G, with ongoing research refining techniques for 6G and beyond. Integrating machine learning and AI into M&C algorithms holds promise for enhancing network efficiency and reliability.

Tunable four-port MIMO/self-multiplexing THz graphene patch antenna with high isolation

A tunable terahertz four-port multiple-input-multiple-output (MIMO) graphene-based microstrip patch antenna with self-multiplexing ability is designed and numerically studied. Insertion of cross-slot in the graphene patch improved the isolation level to the order of 50\(-\)70 dB in the four-port MIMO mode operation. Four separate biasing pads are used to obtain independent frequency tunability, which gives rise to MIMO and/or self-diplexing, self-triplexing, and self-quadruplexing operation, by using different combinations of dc bias voltages. The MIMO and self-multiplexing actions are attained while using common ground plane and continuous graphene patch. The MIMO performance parameters like envelope correlation coefficient (ECC), diversity gain, mean effective gain, port-to-port isolation, etc. are found to be within the acceptable limits. A four-port equivalent circuit model of the MIMO antenna is presented to provide insight into the radiation mechanism and to validate the simulation results. The designed four port antenna is found to provide ECC in the order of 0.0073 and isolation in the range of 35–43 dB while it is operated in the self-diplexing with two-port MIMO mode operation.

Ergodic Rate Analysis of Massive Spatial Modulation MIMO System With NOMA in Cooperative Relay Networks

In this article, by introducing nonorthogonal multiple access (NOMA) scheme into the massive spatial modulation (SM) MIMO in cooperative relay networks, a massive cooperative NOMA-aided SM (NOMA-SM) system is presented. The ergodic rate performance of uplink massive cooperative NOMA-SM with finite alphabet inputs is investigated over Rayleigh fading channels. According to the performance analysis, the mutual information between the SM signals transmitted by users and the signal received at the base station (BS) is derived. Based on this, the theoretical lower bound and tight approximation of the ergodic rates are deduced for performance evaluation. With the aforementioned results, simple expressions of the ergodic rates are derived for the system with single-antenna relay, which can simplify the calculation of theoretical ergodic rate. Besides, when the number of receive antennas at the BS is very large, the asymptotic ergodic rate analysis is presented for massive cooperative NOMA-SM system, and the corresponding asymptotic lower bounds of the ergodic rate are derived. Simulation results indicate that the presented theoretical analysis is valid and can match the corresponding simulation well. Thus, the ergodic rate performance can be well assessed in theory.

Detection of Spatially Modulated Signals via RLS: Theoretical Bounds and Applications

This paper characterizes the performance of massive multiuser spatial modulation MIMO systems, when a regularized form of the least-squares method is used for detection. For a generic distortion function and right unitarily invariant channel matrices, the per-antenna transmit rate and the asymptotic distortion achieved by this class of detectors are derived. Invoking an asymptotic characterization, we address two particular applications. Namely, we derive the error rate achieved by the computationally-intractable optimal Bayesian detector, and we propose an efficient approach to tune LASSO-type detectors. We further validate our derivations through various numerical experiments.

Expectation Propagation Aided Signal Detection for Uplink Massive Generalized Spatial Modulation MIMO Systems

In this paper, we propose a joint signal detection algorithm under the framework of the expectation propagation (EP) algorithm for uplink massive multiuser multiple-input multiple-output (MIMO) systems with generalized spatial modulation (GSM). By projecting the discrete probability distribution into a multivariate complex Gaussian function, the symbol beliefs of the tridimensional GSM constellation are calculated via the iterative propagation of the mean vectors and covariance matrices. To reduce the computational complexity, an efficient separate signal detection called two-stage EP (TS-EP) algorithm is designed. In the first stage, the active transmit antenna indices are determined via the EP. Each vector-valued variable node (VN) in the factor graph is decomposed into multiple sub-VNs, and the invalid sub-VNs of the determined silent transmit antennas are pruned from the factor graph. In the second stage, since the modulation symbols are independent conditioned on the active transmit antennas, the symbols are independently detected by adopting the EP with univariate complex Gaussian approximations, and the number of probability calculations for each symbol belief is significantly reduced in the subsequent EP update. Simulation results illustrate that the proposed EP and TS-EP signal detection schemes outperform the recently proposed counterparts. Moreover, the proposed TS-EP algorithm strikes a desirable and flexible performance-complexity tradeoff.

Parallel signal detection for generalized spatial modulation MIMO systems

Generalized Spatial Modulation is a recently developed technique that is designed to enhance the efficiency of transmissions in MIMO Systems. However, the procedure for correctly retrieving the sent signal at the receiving end is quite demanding. Specifically, the computation of the maximum likelihood solution is computationally very expensive. In this paper, we propose a parallel method for the computation of the maximum likelihood solution using the parallel computing library OpenMP. The proposed parallel algorithm computes the maximum likelihood solution faster than the sequential version, and substantially reduces the worst-case computing times.

Capacity analysis of cooperative amplify and forward–quadrature spatial modulation MIMO system

Capacity analysis of cooperative amplify and forward–quadrature spatial modulation MIMO system

Low spatial complexity adaptive artificial neural network post-equalization algorithms in MIMO visible light communication systems.

In this paper, we experimentally propose a feasible and low spatial complexity adaptive artificial neural network (AANN) post-equalization algorithm in MIMO visible light communication (VLC) systems. By introducing the power ratio and the MIMO least mean square (MIMO-LMS) post-equalization algorithm into the structure design process of the artificial neural network (ANN) post-equalization algorithm, we reduced the spatial complexity of the post-ANN equalization algorithm to less than 10%. At the same time, the bit error rate (BER) performance of AANNs did not decrease. Finally, we achieved a data rate of 2.1Gbps in the AANN equalized 16QAM superposition coding modulation (SCM) and carrier-less amplitude-phase (CAP) single-receiver MIMO (SR-MIMO) VLC system.

Performance analysis of AGSM adaptive unipolar MIMO-OFDM for visible light communication

Visible light communication is a leading technology in wireless communication which provides free spectrum with high data rate. In this paper, improvement of the data rate is achieved in the adaptive transmission for U-OFDM system which works on switching of various MIMO modes. In VLC system different MIMO modes give different performance on the basis of their modulation size. The adaptive system switches between spatial modulation (SM), spatial multiplexing (SMUX), repetition code (RC) and adaptive generalized spatial modulation (AGSM) MIMO modes on the basis of received SNR and target Bit Error rate to attain high spectral efficiency (χ). The performance of adaptive generalized spatial modulation mode is analysed and compared with the three modes (RC, SM, SMUX) over 2×2, 4×4, 8×8 MIMO systems in realistic channel models. The simulation results show that significant improvement in data rate and spectral efficiency is achieved using AGSM MIMO mode in comparison to SM, RC and SMUX MIMO modes.

Performance Analysis of Uplink Massive Multiuser SM-MIMO System With Imperfect Channel State Information

In this paper, the error performance and spectrum efficiency (SE) of uplink massive multiuser spatial modulation (SM) MIMO systems with zero-forcing detection for perfect and imperfect channel state information (CSI) are investigated over composite Rayleigh fading channels. We firstly derive the error probabilities of transmit antenna index detection and transmitted symbol detection of each user. Using these results, the bit error rate (BER) performance of the system under perfect CSI is analyzed. Furthermore, a closed-form average BER of the system is derived. We generalize the analytical results of perfect CSI to those of imperfect CSI for practicality, and derive a closed-form BER for the system with imperfect CSI. Based on this, two asymptotic BER expressions are developed to characterize the error performance of the system for large-scale receive antennas and high SNR. By means of the asymptotic expressions, the diversity order of the system is attained. Besides, we derive a lower bound on the achievable SE of the system with imperfect CSI. With this lower bound, an approximate expression of the achievable SE is obtained in closed form. Simulation results indicate that our theoretical analysis is valid, and agrees with simulation results well.

Constellation Design for Media-Based Modulation Using Block Codes and Squaring Construction

Efficient constellation design is important for improving performance in communication systems. The problem of multidimensional constellation design has been studied extensively in the literature in the context of multidimensional coded modulation and space-time coded MIMO systems. Such constellations are formally called as lattice codes, where a finite set of points from a certain high dimensional lattice is chosen based on some criteria. In this paper, we consider the problem of constellation/signal set design for media-based modulation (MBM), a recent MIMO channel modulation scheme with promising theoretical and practical benefits. Constellation design for MBM is fundamentally different from those for multidimensional coded modulation and conventional MIMO systems mainly because of the inherent sparse structure of the MBM signal vectors. Specifically, we need a structured sparse lattice code with good distance properties. In this work, we show that using an (N,K) non-binary block code in conjunction with the lattice based multilevel squaring construction, it is possible to systematically construct a signal set for MBM with certain guaranteed minimum distance. The MBM signal set obtained using the proposed construction is shown to achieve significantly improved bit error performance compared to conventional MBM signal set. In particular, the proposed signal set is found to achieve higher diversity slopes in the low-to-moderate SNR regime.

PERFORMANCE IMPROVEMENT OF THE BASE STATION ANTENNA BY USING MIMO IN MOBILE COMMUNICATION SYSTEM

This paper presents a design of base station antenna with high performance dual-polarized network sites and 4X4 MIMO Sector Antenna subscriber sites with sturdy constructions for micro-base-station applications. In this research the proposed one is design dual-polarized network sites are 5.25-5.85 GHZ, 2-FT (0.6M) height for point to point (PTP) link and point to multi point (PMP) link ePMP 4x4 MU-MIMO Sector Antenna for subscriber module at ePMP 3000, 5.8 GHz (5825 to 5875 MHz) Access Point RF frequency band for SU-MIMO 4X4 MIMO mode of transmission. Those frequencies used is the fifth generation (5G) mobile network planning and it improves the performance of the network in terms of coverage and capacity by using 4X4 MIMO antennas for indoor propagation model. Measured that the results shows the antenna has a 45MHz RF channel bandwidth with Antenna Gain is 28.58 dBi, port Free Space Path Loss is more than 117.53 dB and Performance 99.9995 % for 10.0 Mbps. This can be utilized for broadband base station in the cutting edge wireless correspondence framework. The Link Planner has been used to simulate network coverage and throughput performance of 4X4 MIMO antenna configurations of the deployed networks. The average simulated throughput per sector of 4X4 MIMO configuration was seen to be better than the 2X2 MIMO configuration.

Receivers for the uplink of multiuser generalized spatial modulation MIMO systems

Receivers for the uplink of multiuser generalized spatial modulation MIMO systems

Sparse detection with orthogonal matching pursuit in multiuser uplink quadrature spatial modulation MIMO system

Quadrature spatial modulation (QSM) is one of the most prevalent transmission techniques for future wireless mobile network due to its high spectral efficiency (SE) and low complexity. However, it is restrictive to downlink of the cellular network deployments. Therefore, this paper proposes QSM for the multiuser uplink data transmission that increases the SE of the network by deploying multiple antennas at the mobile user with only two radio frequency (RF) chains. Maximum likelihood (ML) decoder is used to detect the received signal and attains the optimal detection performance but it is impractical because of its high computational complexity. Consequently, this paper proposes compressed sensing (CS) based orthogonal matching pursuit (OMP) detection as it has a suboptimal performance with a low computational complexity which can be a practical solution in the high-density uplink multiuser network. However, conventional OMP algorithm has a low estimation performance due to multiuser interference which corrupt channel matrix. Thus, this work design an equalizer that mitigates the multiuser interference and improve the detection performance by orthonormalizing the columns of channel matrix. Simulation analysis confirm that the proposed QSM technique based on CS detector outperforms the conventional schemes in terms of SE and bit error rate (BER).