scholarly journals Generalized Complex Quadrature Spatial Modulation

2019 ◽  
Vol 2019 ◽  
pp. 1-12 ◽  
Author(s):  
Manar Mohaisen
Keyword(s):  
Spectral Efficiency ◽  
Mimo System ◽  
Multiple Input Multiple Output ◽  
Spatial Modulation ◽  
System Parameters ◽  
Multiple Input ◽  
Generalized Complex ◽  
High Spectral Efficiency ◽  
Input Multiple Output ◽  
Single Input

Spatial modulation (SM) is a multiple-input multiple-output (MIMO) system that achieves a MIMO high spectral efficiency while maintaining the transmitter computational complexity and requirements as low as those of the single-input systems. The complex quadrature spatial modulation (CQSM) builds on the QSM scheme and improves the spectral efficiency by transmitting two signal symbols at each channel use. In this paper, we propose two generalizations of CQSM, namely, generalized CQSM with unique combinations (GCQSM-UC) and with permuted combinations (GCQSM-PC). These two generalizations perform close to CQSM or outperform it, depending on the system parameters. Also, the proposed schemes require much less transmit antennas to achieve the same spectral efficiency of CQSM, for instance, assuming 16-QAM, GCQSM-PC, and GCQSM-UC require 10 and 15 transmit antennas, respectively, to achieve the same spectral of CQSM which is equipped with 32 antennas.

Adaptive MIMO Systems with High Spectral Efficiency

2009 ◽  
pp. 286-307 ◽  
Author(s):  
Zhendong Zhou ◽  
Branka Vucetic
Keyword(s):  
Spectral Efficiency ◽  
Adaptive System ◽  
Mimo Systems ◽  
Mimo System ◽  
Adaptive Modulation ◽  
Multiple Input Multiple Output ◽  
Adaptive Modulation And Coding ◽  
Multiple Input ◽  
High Spectral Efficiency ◽  
Input Multiple Output

This chapter introduces the adaptive modulation and coding (AMC) as a practical means of approaching the high spectral efficiency theoretically promised by multiple-input multiple-output (MIMO) systems. It investigates the AMC MIMO systems in a generic framework and gives a quantitative analysis of the multiplexing gain of these systems. The effects of imperfect channel state information (CSI) on the AMC MIMO systems are pointed out. In the context of imperfect CSI, a design of robust near-capacity AMC MIMO system is proposed and its good performance is verified by simulation results. The proposed adaptive system is compared with the non-adaptive MIMO system, which shows the adaptive system approaches the channel capacity closer.

scholarly journals SCMA-MIMO system with adaptation to the channel state

2021 ◽  
Vol 2134 (1) ◽  
pp. 012025
Author(s):  
Dmitriy Pokamestov ◽  
Yakov Kryukov ◽  
Eugeniy Rogozhnikov ◽  
Islam Kanatbekuli ◽  
Edgar Dmitriyev
Keyword(s):  
Communication System ◽  
Orthogonal Frequency Division Multiplexing ◽  
Multiple Access ◽  
Mimo System ◽  
Multiple Input Multiple Output ◽  
Network Resources ◽  
Multiple Input ◽  
The Matrix ◽  
High Spectral Efficiency ◽  
Input Multiple Output

Abstract Sparse code multiple access (SCMA) is one of the promising implementations of non-orthogonal multiple access (NOMA) methods. SCMA provides high spectral efficiency and a large number of network resources. We describe a communication system with SCMA, space-time block coding (STBC), multiple input multiple output (MIMO) technology, and orthogonal frequency division multiplexing (OFDM). The architecture of such systems, including algorithms of formation and processing of signals is considered. A method for adapting signals to the state of the spatial channel transmission based on information about the matrix of channel coefficients is proposed. The application of such adaptation allows to compensate the influence of the channel and to reduce the probability of bit errors. We consider the bit error rate (BER) performance of the communication system in different channel models and show the effectiveness of the proposed methods.

scholarly journals Parallel Complex Quadrature Spatial Modulation

2020 ◽  
Vol 11 (1) ◽  
pp. 330
Author(s):  
Sheriff Murtala ◽  
Nishal Muchena ◽  
Tasnim Holoubi ◽  
Manar Mohaisen ◽  
Kang-Sun Choi
Keyword(s):  
Bit Error Rate ◽  
Spectral Efficiency ◽  
Multiple Input Multiple Output ◽  
Spatial Modulation ◽  
Transmission Scheme ◽  
Multiple Input ◽  
Input Multiple Output ◽  
Mimo Transmission ◽  
And Performance ◽  
Ber Performance

In this paper, we propose a new multiple-input multiple-output (MIMO) transmission scheme, called parallel complex quadrature spatial modulation (PCQSM). The proposed technique is based on the complex quadrature spatial modulation (CQSM) to further increase the spectral efficiency of the communication system. CQSM transmits two different complex symbols at each channel use. In contrast with CQSM, the new transmission scheme splits the transmit antennas into groups, and modulates the two signal symbols using the conventional CQSM before transmission. Based on the selected modulation order and the number of possible groups that can be realized, the incoming bits modulate the two signal symbols and the indices of the transmit antennas in each group. We demonstrated that while the complexity and performance of the proposed scheme is the same as that of CQSM, the number of required transmit antennas is significantly reduced. The proposed PCQSM achieves such a benefit without requiring any additional radio frequency (RF) chains. The results obtained from Monte Carlo simulation showed that at a Bit Error Rate (BER) of 10−4, the performance of the PCQSM with two antenna groups closely matches that of CQSM, and outperformed quadrature spatial modulation (QSM) and parallel quadrature spatial modulation (PQSM) by over 0.7 dB. As the number of antenna groups increased to 4, the BER performance of PCQSM with reduced number of transmit antenna and modulation order matches that of QSM. The BER of the proposed scheme using maximum likelihood (ML) receiver is also analyzed theoretically and compared with the BER obtained via simulations.

scholarly journals Pilot Reuse Mode Based on Continuous Pilot Reuse Factors

2020 ◽  
Vol 2020 ◽  
pp. 1-7
Author(s):  
Dongsheng Han ◽  
Kai Fu ◽  
Zhixiong Chen
Keyword(s):  
Theoretical Analysis ◽  
Spectral Efficiency ◽  
Multiple Input Multiple Output ◽  
Multiple Input ◽  
Key Technologies ◽  
High Spectral Efficiency ◽  
Input Multiple Output ◽  
Traditional Mode ◽  
Simulation Results ◽  
Better Than

Massive multiple-input multiple-output techniques have attracted wide attention as one of the key technologies of 5G. Pilot reuse based on the same pilot sequence is necessary among different users due to limited pilot resources. In this study, a pilot reuse mode based on continuous pilot reuse factors is proposed to pursue a flexible pilot reuse mode with high spectral efficiency (SE). In this mode, users in every cell are grouped, and different groups use different pilot reuse factors. Therefore, any overall pilot reuse factor is achieved to increase the flexibility of pilot reuse considerably. A theoretical analysis proves that the proposed pilot reuse based on continuous pilot reuse factors is superior to the traditional pilot reuse based on single pilot reuse factor to some extent in terms of SE. A new method to search the optimal pilot reuse based on continuous pilot reuse factors is also introduced. Simulation results demonstrate that, in most cases, the optimal pilot reuse mode based on continuous pilot reuse factors is better than the traditional mode. Such superiority still exists under a limited number of antennas.

scholarly journals Performance Analysis and Constellation Design for the Parallel Quadrature Spatial Modulation

Entropy ◽  
2020 ◽  
Vol 22 (8) ◽  
pp. 841
Author(s):  
Manar Mohaisen ◽  
Tasnim Holoubi ◽  
Tamer Abuhmed
Keyword(s):  
Multiple Input Multiple Output ◽  
Spatial Dimension ◽  
Spatial Modulation ◽  
Phase Shift Keying ◽  
Constellation Design ◽  
Size Number ◽  
Multiple Input ◽  
Shift Keying ◽  
Input Multiple Output ◽  
Single Input

Spatial modulation (SM) is a multiple-input multiple-output (MIMO) technique that achieves a MIMO capacity by conveying information through antenna indices, while keeping the transmitter as simple as that of a single-input system. Quadrature SM (QSM) expands the spatial dimension of the SM into in-phase and quadrature dimensions, which are used to transmit the real and imaginary parts of a signal symbol, respectively. A parallel QSM (PQSM) was recently proposed to achieve more gain in the spectral efficiency. In PQSM, transmit antennas are split into parallel groups, where QSM is performed independently in each group using the same signal symbol. In this paper, we analytically model the asymptotic pairwise error probability of the PQSM. Accordingly, the constellation design for the PQSM is formulated as an optimization problem of the sum of multivariate functions. We provide the proposed constellations for several values of constellation size, number of transmit antennas, and number of receive antennas. The simulation results show that the proposed constellation outperforms the phase-shift keying (PSK) constellation by more than 10 dB and outperforms the quadrature-amplitude modulation (QAM) schemes by approximately 5 dB for large constellations and number of transmit antennas.

scholarly journals A Tutorial on Nonorthogonal Multiple Access for 5G and Beyond

2018 ◽  
Vol 2018 ◽  
pp. 1-24 ◽  
Author(s):  
Mahmoud Aldababsa ◽  
Mesut Toka ◽  
Selahattin Gökçeli ◽  
Güneş Karabulut Kurt ◽  
Oğuz Kucur
Keyword(s):  
Spectral Efficiency ◽  
Multiple Access ◽  
Multiple Input Multiple Output ◽  
Multiple Access Interference ◽  
Multiple Input ◽  
High Spectral Efficiency ◽  
Input Multiple Output ◽  
Radio Resources ◽  
Very High ◽  
Open Issues

Today’s wireless networks allocate radio resources to users based on the orthogonal multiple access (OMA) principle. However, as the number of users increases, OMA based approaches may not meet the stringent emerging requirements including very high spectral efficiency, very low latency, and massive device connectivity. Nonorthogonal multiple access (NOMA) principle emerges as a solution to improve the spectral efficiency while allowing some degree of multiple access interference at receivers. In this tutorial style paper, we target providing a unified model for NOMA, including uplink and downlink transmissions, along with the extensions to multiple input multiple output and cooperative communication scenarios. Through numerical examples, we compare the performances of OMA and NOMA networks. Implementation aspects and open issues are also detailed.

scholarly journals A Survey on Spatial Modulation and MIMO System for Emerging Wireless Communication

2021 ◽  
Vol 9 (VI) ◽  
pp. 3059-3062
Author(s):  
Prabha Kumari
Keyword(s):  
Wireless Communication ◽  
Mimo Systems ◽  
Mimo System ◽  
Multiple Input Multiple Output ◽  
High Energy ◽  
Spatial Modulation ◽  
Bandwidth Efficiency ◽  
Multiple Input ◽  
Input Multiple Output ◽  
Rf Chain

In this paper we have studied about Spatial Modulation (SM) in MIMO system. Spatial modulation is a unique and newly proposed technique. Spatial modulation is a multiple input multiple output technique which provides higher throughput and gain as compared to Quadrature Amplitude Modulation. Spatial modulation is a technique which enhances the performance of MIMO system. Spatial modulation and MIMO technique are used to attracted research for its high energy and spectral efficiency because it is working on single RF chain. This paper has considered the advantages of spatial modulation and MIMO systems, using different technique to improve the bandwidth efficiency. Some of such MIMO systems applications are discussed wherein become a requirement for an emerging wireless communication system.

A companding approach for PAPR suppression in OFDM based massive MIMO system

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Ajay Kumar Yadav ◽  
Pritam Keshari Sahoo ◽  
Yogendra Kumar Prajapati
Keyword(s):  
Massive Mimo ◽  
Orthogonal Frequency Division Multiplexing ◽  
Mimo System ◽  
Multiple Input Multiple Output ◽  
Average Power ◽  
Base Station ◽  
Convex Optimization Problem ◽  
Multiple Input ◽  
Input Multiple Output ◽  
Mimo Ofdm

Abstract Orthogonal frequency division multiplexing (OFDM) based massive multiuser (MU) multiple input multiple output (MIMO) system is popularly known as high peak-to-average power ratio (PAPR) issue. The OFDM-based massive MIMO system exhibits large number of antennas at Base Station (BS) due to the use of large number of high-power amplifiers (HPA). High PAPR causes HPAs to work in a nonlinear region, and hardware cost of nonlinear HPAs are very high and also power inefficient. Hence, to tackle this problem, this manuscript suggests a novel scheme based on the joint MU precoding and PAPR minimization (PP) expressed as a convex optimization problem solved by steepest gradient descent (GD) with μ-law companding approach. Therefore, we develop a new scheme mentioned to as MU-PP-GDs with μ-law companding to minimize PAPR by compressing and enlarging of massive MIMO OFDM signals simultaneously. At CCDF = 10−3, the proposed scheme (MU-PP-GDs with μ-law companding for Iterations = 100) minimizes the PAPR to 3.70 dB which is better than that of MU-PP-GDs, (iteration = 100) as shown in simulation results.

scholarly journals Energy and Information Beamforming in Airborne Massive MIMO System for Wireless Powered Communications

Sensors ◽  
2018 ◽  
Vol 18 (10) ◽  
pp. 3540 ◽  
Author(s):  
Yurong Wang ◽  
Aijun Liu ◽  
Kui Xu ◽  
Xiaochen Xia
Keyword(s):  
Mimo System ◽  
Multiple Input Multiple Output ◽  
Hardware Complexity ◽  
Mimo Channels ◽  
Channel State ◽  
Active Antennas ◽  
Large Numbers ◽  
Multiple Input ◽  
Input Multiple Output ◽  
Critical Problems

Energy supply and information backhaul are critical problems for wireless sensor networks deployed in remote places with poor infrastructure. To deal with these problems, this paper proposes an airborne massive multiple-input multiple-output (MIMO) system for wireless energy transfer (WET) and information transmission. An air platform (AP) equipped with a two-dimensional rectangular antenna array is employed to broadcast energy and provide wireless access for ground sensors. By exploiting the statistical property of air-terrestrial MIMO channels, the energy and information beamformers are jointly designed to maximize the average received signal-to-interference-plus-noise ratio (SINR), which gives rise to a statistical max-SINR beamforming scheme. The scheme does not rely on the instantaneous channel state information, but still requires large numbers of RF chains at AP. To deal with this problem, a heuristic strongest-path energy and information beamforming scheme is proposed, which can be implemented in the analog-domain with low computational and hardware complexity. The analysis of the relation between the two schemes reveals that, with proper sensor scheduling, the strongest-path beamforming is equivalent to the statistical max-SINR beamforming when the number of AP antennas tends to infinity. Using the asymptotic approximation of average received SINR at AP, the system parameters, including transmit power, number of active antennas of AP and duration of WET phase, are optimized jointly to maximize the system energy efficiency. The simulation results demonstrate that the proposed schemes achieve a good tradeoff between system performance and complexity.

Precoding for Multiuser MIMO

2012 ◽  
pp. 130-156 ◽  
Author(s):  
Elsadig Saeid ◽  
Varun Jeoti ◽  
Brahim Belhaouari Samir
Keyword(s):  
Mimo Systems ◽  
Mimo System ◽  
Multiple Input Multiple Output ◽  
Achievable Rate ◽  
Multiple Access Channels ◽  
Multiple Input ◽  
Input Multiple Output ◽  
Single User ◽  
A New Technique ◽  
Improved Technique

Future Wireless Networks are expected to adopt multi-user multiple input multiple output (MU-MIMO) systems whose performance is maximized by making use of precoding at the transmitter. This chapter describes the recent advances in precoding design for MU-MIMO and introduces a new technique to improve the precoder performance. Without claiming to be comprehensive, the chapter gives deep introduction on basic MIMO techniques covering the basics of single user multiple input multiple output (SU-MIMO) links, its capacity, various transmission strategies, SU-MIMO link precoding, and MIMO receiver structures. After the introduction, MU-MIMO system model is defined and maximum achievable rate regions for both MU-MIMO broadcast and MU-MIMO multiple access channels are explained. It is followed by critical literature review on linear precoding design for MU-MIMO broadcast channel. This paves the way for introducing an improved technique of precoding design that is followed by its performance evaluation.

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