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IEEE International Conference on systems, Man, and Cybernetics (SMC)

作者： Tong, Bufan Chen, Juan Wang, Hang Yu, Yakun Beijing Univ Chem Technol Coll Informat Sci & Technol Beijing Peoples R China Shanghai Jiao Tong Univ Sch Biomed Engn Shanghai Peoples R China

ISBN: (纸本)9781538616451

Aiming at multiple-input multiple-output (MIMO) systems with multiple time delays in the process industry, all-pole approximation is proposed for different time delays in this paper. What is more, in order to reinforce the tracking performance and controller robustness in the case of uncertainty and disturbance, loop transfer recovery method at output side is proposed to realize the multiple-loops control for MIMO systems with different time delays. And the characteristics of closed-loop transfer function has been recovered to the expected ideal system. For the performance evaluation of disturbance rejection ability and tolerance for uncertainty, the indices in frequency domain are utilized to assess the robust stability of the system. The simulation result shows that the proposed method has advantages of good decoupling performance, strong disturbance rejection ability and strong robust stability, which can meet the control requirements of MIMO systems with multiple time delays.

关键词： multiple-input multiple-output system multiple time delays loop transfer recovery at output side robustness

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Rate-Adaptive Modulation for Square OSTBCs in Arbitrarily Correlated Rayleigh Fading With Imperfect Channel Estimation

Rate-Adaptive Modulation for Square OSTBCs in Arbitrarily Co...

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12th IEEE International Workshop on Signal Processing Advances in Wireless Communications

作者： Jacobs, Lennert Moeneclaey, Marc Conti, Andrea Univ Ghent TELIN Dept DIGCOM Grp St Pietersnieuwstr 41 B-9000 Ghent Belgium Univ Ferrara ENDIF I-44100 Ferrara Italy

ISBN: (纸本)9781424493326

multiple-input multiple-output (MIMO) systems employing adaptive modulation have been widely used for their potential to optimize the spectral efficiency while keeping the bit error probability (BEP) under a certain target level. In this paper, we examine a MIMO system using square orthogonal space-time block codes (OSTBCs) with rate-adaptive M-QAM and operating over arbitrarily correlated Rayleigh fading channel with imperfect channel estimation. Assuming finite-rate feedback without delay, we derive accurate closed-form expressions for the average BEP, spectral efficiency and bit error outage of our system. The presented expressions allow to easily study the impact of channel estimation errors and fading correlation on the performance of rate-adaptive MIMO OSTBC systems.

关键词： Approximation methods BEP Channel estimation Closed-form solution MIMO MIMO communication MIMO system Rayleigh channels Rayleigh channels Receivers adaptive modulation arbitrarily correlated Rayleigh fading bit error probability channel estimation error statistics imperfect channel estimation multiple-input multiple-output system orthogonal codes orthogonal space-time block codes quadrature amplitude modulation rate-adaptive M-QAM rate-adaptive modulation space-time block codes square OSTBC

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Downlink Multiuser MIMO-OFDM systems

Downlink Multiuser MIMO-OFDM Systems

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8th International Joint Conference on e-Business and Telecommunications (ICETE)

作者： Aust, Sebastian Ahrens, Andreas Cano-Broncano, Francisco Benavente-Peces, Cesar Univ Technol Business & Design Hsch Wismar Dept Elect Engn & Comp Sci Commun Signal Proc Grp Philipp Muller Str 14 D-23966 Wismar Germany Univ Politecn Madrid EUIT Telecomunicac Ctra Valencia Km 7 Madrid 28031 Spain

ISBN: (纸本)9783642357541

multiple input multiple output (MIMO) techniques for wireless communication systems have attracted in the last years huge research activity due to the possibility of improving the link performance by increasing the channel capacity and decreasing the bit-error rate (BER). Due to the strongly increasing demand in high-data rate transmission systems, frequency non-selective MIMO links have reached a state of maturity and frequency selective MIMO links are in the focus of interest. In this field, the combination of MIMO transmission and OFDM (orthogonal frequency division multiplexing) can be considered as an essential part of fulfilling the requirements of future generations of wireless systems. However, single-user scenarios have reached a state of maturity. By contrast multiple users' scenarios require substantial further research, where in comparison to ZF (zero-forcing) multiuser transmission techniques, the individual user's channel characteristics are taken into consideration in this contribution. Furthermore, the use of multiple antennas both at the transmit and the receive front-ends introduces a correlation effect between the antennas due to their proximity producing interference. In consequence, the BER increases and the channel capacity decreases. The goal of the present contribution is to analyze the system performance under different spatial antennas distributions for Multiuser MIMO-OFDM systems in correlated and non-correlated fading channels. The performed joint optimization of the number of activated MIMO layers and the number of transmitted bits per subcarrier along with the appropriate allocation of the transmit power shows that not necessarily all user-specific MIMIO layers per subcarrier have to be activated in order to minimize the overall BER under the constraint of a given fixed data throughput.

关键词： multiple-input multiple-output system Orthogonal Frequency Division multiplexing Singular-value Decomposition Bit Allocation Power Allocation Wireless Transmission

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Optimally Efficient Max-log APP Demodulation in MIMO systems

Optimally Efficient Max-log APP Demodulation in MIMO Systems

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IEEE Global Telecommunications Conference (GLOBECOM 2010)

作者： Prasad, Narayan Kalbat, Khalid Wang, Xiaodong Columbia Univ Dept Elect Engn New York NY 10027 USA Columbia Univ Dept Elect Engn New York NY 10027 USA

ISBN: (纸本)9781424456383

In this paper we consider the design of multi-stream demodulators for multiple-input multiple-output (MIMO) systems. Our proposed MIMO demodulator is based on the stack tree-search strategy and provides soft-outputs in the form of exact max-log log-likelihood ratios (max-log LLRs). We prove that our proposed demodulator is optimally efficient in that it visits the least number of nodes among all optimal tree-search based demodulators. We conduct a comprehensive complexity analysis of the optimally efficient demodulators. We also identify key parameters associated with our proposed demodulator that can be tuned to realize near max-log performance with substantially reduced complexity, as demonstrated via simulations.

关键词： MIMO communication MIMO system a-posteriori probability demodulation max-log APP demodulation max-log LLR max-log log-likelihood ratio maximum likelihood estimation multiple-input multiple-output system multistream demodulator probability stack tree-searc

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Computationally Efficient Lattice Reduction for MIMO-OFDM systems

Computationally Efficient Lattice Reduction for MIMO-OFDM Sy...

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6th Annual IEEE International Conference on Wireless and Mobile Computing, Networking and Communications (WiMob)/STMWC/NASSUE/CMPA/VECON/AWSAN/AWSAN

作者： Liu, Wei Choi, Kwonhue Liu, Huaping Oregon State Univ Sch EECS Corvallis OR 97331 USA Yeungnam Univ Dept Informat & Commun Engn Kyongsan 712749 South Korea

ISBN: (纸本)9781424477425

We propose a computationally efficient lattice reduction (LR) algorithm for multiple-input multiple-output (MIMO) orthogonal frequency division multiplexing (OFDM) systems in frequency-selective fading channels. In our proposed algorithm, we exploit the inherent feature of unimodular transformation matrix P that remains the same for frequency components which have relatively high amplitude correlation. We eliminate the redundant calculations by reducing brute-force LR iterations among adjacent subcarriers. We simulate the error performance and complexity of the proposed algorithm under various MIMO-OFDM system configurations. The results demonstrate that the proposed algorithm could significantly reduce the LR complexity by up to 90% multiplications and 99% divisions of brute-force LR while maintaining the system performance.

关键词： multiple-input multiple-output system orthogonal frequency division multiplexing frequency-selective channel lattice reduction

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Performance Improvement Analysis of Wireless MIMO Channel in the Presence of Keyhole

Performance Improvement Analysis of Wireless MIMO Channel in...

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15th International Conference on Advanced Communications Technology (ICACT)

作者： Mostafa, Md. Golam Karim, Md. Masud Azam, M. Z. Rahman, Ziaur Bari, Sarwar Majumder, S. P. BUET Dept EEE Dhaka Bangladesh

ISBN: (纸本)9788996865018;9781467331487

Wireless communication systems always demand higher data rates and better quality of service (QoS). Transmission reliability in a wireless channel with high path loss, time-varying multipath fading and power and bandwidth limitations, is a testing issue. multiple-input multiple-output (MIMO) systems can reduce the effect of these channel interferences and achieve reliable signal transmission at high data rate. Space-time block code (STBC) is a coding scheme for the use of multiple transmits antennas providing a simple transmit diversity scheme. In certain MIMO fading environments, the offered channel capacity can be very low, where despite rich local scattering and uncorrelated transmit and receive signals, the system has a single degree of freedom. This effect has been termed as keyhole or pinhole effect. This contribution analyzes the average symbol error rate (SER) performance of MIMO systems employing orthogonal STBC with M-PSK constellations over fading channels in the presence of the keyhole. The Nakagami-m distribution has been considered for MIMO channel modeling. We derive the probability density function (PDF) of instantaneous signal-to-noise ratio (SNR) and an integral equation to calculate the average SER after space-time block decoding in such channels. Numerical results show that the keyhole significantly degrades the SER performance of the STBC in MIMO channels. The performance of such channels is a function of fading figure, m and diversity.

关键词： Keyhole multiple-input multiple-output system Nakagami-m fading space-time block codes symbol error rate

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Coherent SVD-assisted and Iteratively Detected MIMO Multimode Transmission

Coherent SVD-assisted and Iteratively Detected MIMO Multimod...

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19th International Conference on Microwaves, Radar and Wireless Communications (MIKON)

作者： Aust, Sebastian Ahrens, Andreas Lochmann, Steffen Univ Technol Hsch Wismar Business & Design Fac Engn Dept Elect Engn & Comp Sci Philipp Mtiller Str 14 D-23952 Wismar Germany

ISBN: (纸本)9781457714351

In this contribution a coherent (2x2) (multiple input multiple output) MIMO transmission with iterative detection over a measured multimode fiber channel is studied. Extrinsic information transfer (EXIT) charts are used for analyzing and optimizing the convergence behaviour of the iterative demapping and decoding. The results show BER and energy-per-hit improvements when using optimized MIMO transmission as compared to conventional (single input single output) SISO transmission techniques.

关键词： multiple-input multiple-output system Singular-Value Decomposition Bit Allocation Optical Fibre Transmission Multimode fiber (MMF)

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Complexity-Reduced Channel Matrix Inversion for MIMO systems in Time-Varying Channels

Complexity-Reduced Channel Matrix Inversion for MIMO Systems...

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2010 IEEE 71st Vehicular Technology Conference

作者： Liu, Wei Choi, Kwonhue Liu, Huaping Oregon State Univ Sch EECS Corvallis OR 97331 USA Yeungnam Univ Dept Informat & Commun Engn Kyongsan 712749 South Korea

ISBN: (纸本)9781424425198

Inversion of channel matrix is required for commonly used detection schemes in multiple-input multiple-output (MIMO) systems. In time-varying fading channels, frequent matrix inversion is computationally intensive for mobile terminals operating at high data rates. Several existing papers have addressed this problem for MIMO orthogonal frequency division multiplexing systems by employing interpolation since the channel coefficients are correlated in the frequency domain. The correlation of the channel in the time domain, i.e., the channel matrices at consecutive symbol intervals vary only slightly, could also be exploited. We propose an algorithm that exploits second-order extrapolation in the time domain to lower the computational complexity of matrix inversion. While existing schemes are mainly designed for linear MIMO detection, the proposed algorithm can be applied for both non-linear detection such as ordered successive interference cancelation (OSIC) and linear detection. The proposed scheme can be efficiently implemented with only addition and integer multiplication. Simulation results of the proposed scheme applied in MIMO OSIC detection demonstrate that it can significantly reduce the matrix inversion complexity while maintaining the system performance.

关键词： multiple-input multiple-output system time-varying fading channel matrix inversion extrapolation

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Reliable Control for a Class of MIMO Nonlinear systems with Time-Delay by Adaptive Iterative Learning Control

Reliable Control for a Class of MIMO Nonlinear Systems with ...

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39th Chinese Control Conference (CCC)

作者： Liu Heng Wang Yanjie Zhang Ruikun Qingdao Univ Sci & Technol Sch Math & Phys Qingdao 266061 Peoples R China Qingdao Univ Sci & Technol Res Inst Math & Interdisciplinary Sci Qingdao Peoples R China

ISBN: (数字)9789881563903

ISBN: (纸本)9789881563903

This paper presents an iterative learning control strategy for a class of multiple-input multiple-output (MIMO) nonlinearly parameterized systems with unknown time-varying state delays and actuator faults. To deal with the non-linearity caused by the unknown time-varying state delays and actuator faults in the MIMO nonlinear system, the P-type iterative learning controller with a fully-saturated parameter updating law is proposed. By constructing a composite energy function(CEF), the convergence analysis of the tracking error is given. Finally, a numerical simulation is used to verify the effectiveness and correctness of the control scheme proposed in this paper.

关键词： Iterative Learning Control Time-varying state delays Actuator faults multiple-input multiple-output system

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Advanced lifting wavelet transform and V-degree polynomial-based channel estimation in MIMO-GFDM

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INTERNATIONAL JOURNAL OF COMMUNICATION systemS 2024年第4期37卷 e5672-e5672页

作者： Ray, Deepak Kumar Oza, Shruti Bharati Vidyapeeth Univ Coll Engn Dept Elect & Telecommun Pune 411043 India

The future generation of wireless communications systems uses the generalized frequency division multiplexing (GFDM) due to its viable candidate waveform to perform multiple user scheduling. It is a non-orthogonal waveform susceptible to intercarrier and intersymbol interference (ISI);still, it offers flexible pulse shaping that enhances the efficiency of user scheduling. Here, to accomplish spatial diversity, the multiple-input multiple-output (MIMO) is incorporated with GFDM to enhance the performance;there is also an extra inter-antenna interference problem that limits the model's performance. The issue concerning inter-antenna interference can be resolved by adopting pilot-based information transfer. The detection of a signal at the receiver based on the minimum mean square error has the issue of computational complexity while enhancing the estimation quality of a detector. Hence, a low-complexity channel estimation technique is proposed in this research using the V-degree polynomial-based channel estimation technique, wherein the cubic order computation is reduced to square order. Also, the proposed adaptive pulse shaping technique, wherein the filter coefficient is optimized using the gazelle optimization algorithm (GOA) to provide optimal pulse shaping filter parameters by employing bit error rate (BER) as the objective function. The performance of a proposed V-degree polynomial-based channel estimation is analyzed based on various assessment measures like BER and MSE and acquired the minimal values of 5.75E-05 and 2.07E-05, respectively. To design a novel technique to improve the performance of multiple-input multiple-output generalized frequency division multiplexing (MIMO-GFDM) system for 5G *** introduce a low-complexity channel estimation process based on an enhanced V-degree polynomial-based low-complexity channel estimator (EVd-LCE) in the MIMO-GFDM *** recommend a lifting-based wavelet transform (L-WT) with GFDM waveform to maximize

关键词： a pilot symbol gazelle optimization generalized frequency division multiplexing multiple-input multiple-output system polynomial-based channel estimation pulse shaping wireless communications

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