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An Improved Semi-Orthogonal User Selection Algorithm Based on Condition Number for Multiuser MIMO Systems

China Communications 2014年第A01期11卷 23-30页

作者： LU Xinlu WU Jun HUANG Xinlin LI Wenfeng LU Jianmin GONG Zhengwei ComputerScienceandTechnologyDepartment TongjiUniversityShanghai201804China HuaweiTechnologiesCo. LtdShanghai201206China

In multiple-input multiple-Out （MIMO） systems, the user selection algorithm plays an important role in the realization of multiplexing gain. In this paper, an improved Semi-orthogonal User Selection algorithm based on condition number is proposed. Besides, a new MIMO pre- coding scheme is designed. The proposed SUS- CN （SUS with condition number） algorithm outperforms the SUS algorithm for the selection of users with better matrix inversion property, thus a higher information rate for selected user pair is achieved. The designed MIMO precoding matrix brings benefits of the power equality at transmitted terminals, the limited dynamic range of the power over time, and a better power efficiency. The simulation results give the key insights into the im- pact of the different condition number value and users on the sum-rate capacity.

关键词： multiple-input multiple-output sumrate capacity condition number semi-orthogonaluser selection

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Performance analysis of MIMO-SESS with Alamouti scheme over Rayleigh fading channels

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EURASIP JOURNAL ON WIRELESS COMMUNICATIONS AND NETWORKING 2011年第1期2011卷 1-13页

作者： Ma, Shichuan Lim Nguyen Yang, Yaoqing (Lamar) Jang, Won Mee Univ Nebraska Dept Comp & Elect Engn Omaha NE 68182 USA

Self-encoded spread spectrum (SESS) is a novel modulation technique that acquires its spreading sequence from the random input data stream rather than through the use of the traditional pseudo-noise code generator. It has been incorporated with multiple-input multiple-output (MIMO) systems as a means to combat fading in wireless channels. In this paper, we present the analytical study of the bit-error rate (BER) performance of MIMO-SESS systems under Rayleigh fading. The BER expressions are derived in closed form, and the veracity of the analysis is confirmed by numerical calculations that demonstrate excellent agreement with simulation results. The performance analysis shows that the effects of fading can be effectively mitigated by taking advantage of spatial and temporal diversities. For example, a 2 x 2 MIMO-SESS system can achieve about 7 dB performance improvement at 10-4 BER over a MIMO PN-coded spread spectrum system.

关键词： self-encoded spread spectrum iterative detection multiple-input multiple-output Alamouti scheme

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Reconfigurable MIMO antenna: previous advancements and the potential for future wireless communication

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INTERNATIONAL JOURNAL OF MICROWAVE AND WIRELESS TECHNOLOGIES 2024年第3期16卷 524-534页

作者： Kumari, Puja Dwari, Santanu Indian Inst Technol Indian Sch Mines Dept Elect Engn Dhanbad India

Future smart reconfigurable antennas (RAs) (Haupt R-L and Lanagan M (2013) Reconfigurable antennas. IEEE Antennas and Propagation Magazine 55, 49-61) will likely be fully multipurpose and controlled by software and equipped with machine learning skills that can discern and respond to alterations in the radio frequency environment. Cognitive radio utilizations will be accomplished using a new generation of antenna technology and communication protocols. The effective use of frequencies and the use of polarization diversity and radiation pattern reconfigurability to send data over existing congested frequencies will be major advantages for such applications. The usage of antennas that can be reconfigured in multiple-input multiple-output (MIMO) channels will enhance channel capacity while simultaneously improving channel efficiency and lowering costs (Christodoulou C-G, Tawk Y, Lane S-A and Erwin S-R (2012) Reconfigurable antennas for wireless and space applications. Proceedings of the IEEE 100, 2250-2261). There are a lot of antennas used both at the transmitter and at the receiver front end in a MIMO system. The benefit of employing such arrangements is that different types of information can be conveyed at a similar time, boosting the spectral efficiency of communication in a multipath situation. The coding rate, modulation level, and transmission signaling method of a MIMO system can all be changed in response to changing channel circumstances and user needs. In a MIMO context, polarization reconfigurable/frequency-reconfigurable/radiation pattern RA increase the degree of freedom and enhancing the system's performance. The usage of such antennas greatly enhances capacity by enabling a choice of various polarization configurations and pattern diversity. Antenna arrays that can be reconfigured are also an appealing MIMO system solution that needs to retain robust communication channels, particularly in portable gadgets where the area is limited.

关键词： multiple-input multiple-output PIN diode reconfigurable antenna varactor diode

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New RoF-PON architecture using polarization multiplexed wireless MIMO signals for NG-PON

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OPTICS COMMUNICATIONS 2015年 344卷 55-64页

作者： Elmagzoub, M. A. Mohammad, Abu Bakar Shaddad, Redhwan Q. Al-Gailani, Samir A. Univ Teknol Malaysia InfoComm Res Alliance Lightwave Commun Res Grp Johor Baharu 81310 Malaysia

Next-generation access networks require provision of wireless services and high data rate to meet the huge demands for mobility and multiple services. Moreover, reusing the currently deployed optical distribution networks (ODNs) is highly beneficial and cost effective for providing the new high data rate wireless demands. In this paper, bidirectional radio over fiber passive optical network (RoF-PON) capable of handling multiple-input-multiple-output (MIMO) streams at low cost, high spectral efficiency and backward compatibility with currently deployed PUN, is proposed. To the best of our knowledge, all the existing RoF MIMO solutions have not considered compatibility with currently deployed ODNs. Eight laser diodes (LDs) at the central office (CO) are enough for the whole system, instead of having LD or optical transmitter at each remote antenna unit (RAU), which makes a colorless and cost-effective RAU. Twenty four wavelengths are generated using optical comb technique. Each two 16-QAM MIMO signals that have the same carrier frequency in the downstream (DS) transmission are optically combined using polarization-division-multiplexing (PDM), where each two upstream (US) MIMO signals are time division multiplexed. The PDM configuration doubles spectral efficiency with a power penalty of only 1.5 dB. The proposed architecture is a bidirectional asymmetric RoF-PON with total 40/10 Gb/s for DS/US transmission. Even after transmission over 20 km SMF and splitting ratio of 32, acceptable transmission performance and widely separated constellation diagrams for the 16-QAM signals are achieved, with bit error rate (BER) of 10(-6) for DS signals and 10(-3) for the US signals which can be reduced down to 10(-6) by using forward error correction (FEC). (C) 2015 Elsevier B.V. All rights reserved.

关键词： Stacked TDM-PON Next generation PON Polarization multiplexing Radio over fiber multiple-input multiple-output

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Opportunistic Decode-and-Forward Relaying With Beamforming in Two-Wave With Diffuse Power Fading

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IEEE TRANSACTIONS ON VEHICULAR TECHNOLOGY 2012年第7期61卷 3050-3060页

作者： Lu, Yao Yang, Nan Dai, Huaiyu Wang, Xiaoxiang Beijing Univ Posts & Telecommun Key Lab Universal Wireless Commun Beijing 100876 Peoples R China Commonwealth Sci & Ind Res Org ICT Ctr Wireless & Networking Technol Lab Marsfield NSW 2122 Australia N Carolina State Univ Dept Elect & Comp Engn Raleigh NC 27695 USA

In this paper, we propose new opportunistic decode-and-forward (DF) relaying with beamforming for multirelay networks, where an N-s-antenna source communicates with an N-d-antenna destination with the aid of N parallel single-antenna relays. Among these relays, only one relay that correctly decodes the signal from the source and has the highest instantaneous signal-to-noise ratio (SNR) to the destination is selected for transmission. The source employs maximum ratio transmission (MRT) to transmit, whereas the destination performs maximum ratio combining (MRC) to the received signals. To examine the benefits of the proposed scheme, we first derive the exact outage probability for independently but nonidentically distributed (i.n.i.d.) two-wave with diffuse power (TWDP) fading channels. We then derive an easy-to-compute expression for the exact outage probability to reduce computational cost. Our results encompass Rayleigh and Rician fading as special cases. We further derive a compact expression for the asymptotic outage probability, which characterizes two factors governing the network performance at high SNRs, i.e., the diversity order and the array gain. We demonstrate that our scheme preserves the maximum diversity order of N x min {N-s, N-d}. Additionally, we derive the optimal power allocation factor, which provides a practical design rule to optimally distribute the total transmission power between the source and the selected relay to minimize the outage probability.

关键词： Decode and forward (DF) multiple-input multiple-output opportunistic relaying optimal power allocation two-wave with diffuse power (TWDP) fading

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Dual-Band Dual-LP/CP Antennas Using Combined Metasurface and Patch For UHF/2.45-GHz RFID Readers

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IEEE ACCESS 2024年 12卷 78833-78842页

作者： Doan, Thi Ngoc Hien Nguyen, Khac Kiem Ta, Son Xuat Hanoi Univ Sci & Technol Sch Elect & Elect Engn Hanoi 100000 Vietnam

This paper proposes dual-band dual linearly-polarized (LP)/circularly-polarized (CP) antennas using combined metasurface and patch for ultra high frequency (UHF) and 2.45-GHz RF identification (RFID) readers. A metasurface and two stacked patches are employed for the lower and upper bands, respectively. The metasurface and patches are incorporated with a common feeding structure which is composed of two orthogonal microstrip lines and a crossed slot to produce the dual-wideband dual-LP radiation. To reduce the back radiation and improve the gain, the antenna is backed by a metallic cavity. Taking advantage of its low-profile structure, the dual-LP antenna is further integrated with a dual-band branch-line coupler to realize dual-CP radiation. Both proposed antennas yield stable radiation performances across dual operating bands which completely cover the assigned RFID spectrum at the UHF (860 - 960 MHz) and 2.45-GHz (2400 - 2500 MHz) bands.

关键词： Dual-band dual polarization metasurface patch antenna RF identification (RFID) backed-cavity hybrid coupler multiple-input multiple-output

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Feasibility of Space-Division-multiplexed Transmission of IEEE 802.11 n/ac-Compliant Wireless MIMO Signals Over OM3 Multimode Fiber

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JOURNAL OF LIGHTWAVE TECHNOLOGY 2018年第11期36卷 2076-2082页

作者： Lei, Yi Li, Jianqiang Meng, Ziyi Wu, Rui Wan, Zhiquan Fan, Yuting Zhang, Wenjia Yin, Feifei Dai, Yitang Xu, Kun Beijing Univ Posts & Telecommun State Key Lab Informat Photon & Opt Commun Inst Informat Photon & Opt Commun Beijing 100876 Peoples R China Shanghai Jiao Tong Univ State Key Lab Adv Opt Commun Syst & Networks Shanghai 200240 Peoples R China

In this paper, we have experimentally demonstrated the feasibility of space-division-multiplexed 3 x 3 multiple-input multiple-output (MIMO) transmission over a single OM3 multimode fiber (MMF) using commercial IEEE 802.11 n/ac access points. Throughput performance for different fiber length links under a range of fiber bending conditions was evaluated. To study the throughput improvement by MIMO technology, throughput performance of single-input single-output (SISO), 2 x 2 MIMO and 3x3MIMO over separate SMF links was also measured for comparison. It is shown that, spatially-multiplexed MMF channel with 3x3MIMO configuration could provide a significant throughput increase in comparison with SISO and 2x2MIMO SMFs configurations, and present a comparable performance with 3x3MIMO SMFs configuration. Meanwhile, the analyses of the impact of fiber bending indicate that, even under a tight fiber bending radius as low as 2 mm, the system performance could still keep at an acceptable level. With all fiber bending radii tested, within each 5-min measurement time, the fiber channel is found to be good enough to provide throughput greater than twice the average SISO value for more than 87.66% and 72.72% of the time, at the 2.4 and 5 GHz bands, respectively. These results together point out a very simple and cost-saving solution for future in-building DASs to distribute wireless MIMO signals using commercially-availableMMFinfrastructure by space division multiplexing technique, even though it may encounter tight bending conditions.

关键词： Multimode fiber multiple-input multiple-output radio-over-fiber space-division-multiplexing

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System identification and model-based control for distributed parameter systems

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COMPUTERS & CHEMICAL ENGINEERING 2004年第8期28卷 1361-1375页

作者： Zheng, D Hoo, KA Texas Tech Univ Dept Chem Engn Lubbock TX 79409 USA

A linear, low-order input/output model is identified for a nonlinear distributed parameter system using a combination of singular value decomposition and the Karhunen Loeve expansion. The model captures the dominant behavior of the system around a nominal operating point. A quadratic dynamic model-based controller (QDMC) is designed based on this low-order model. Sufficient conditions for closed-loop stability are presented and proven. The system identification method and the resulting QDMC controller are demonstrated on a nonlinear multiple-input multiple-output (MIMO) chemical reactor that produces benzene from the hydro-dealkylation of toluene. (C) 2003 Elsevier Ltd. All rights reserved.

关键词： empirical eigenfunctions Karhunen Loeve expansion singular value decomposition QDMC multiple-input multiple-output

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Analysis of MIMO MRT/SC Systems

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WIRELESS PERSONAL COMMUNICATIONS 2012年第1期62卷 117-126页

作者： Rui, Xianyi Soochow Univ Sch Elect & Informat Engn Suzhou Peoples R China

multiple-input multiple-output (MIMO) diversity systems with maximum ratio transmission at the transmitter and selection combining at the receiver (MRT/SC) are presented to obtain the tradeoff between the system performance and receiver complexity. Closed-form expressions for average symbol error rate (SER) in single-user scenario and average capacity in multi-user scenario are derived to get the performance of MIMO MRT/SC systems under independent and identically distributed (i.i.d.) Rayleigh fading. Our study shows that performance of MIMO MRT/SC systems outperforms that of MIMO space-time block coding systems. The analytical results are compared with the simulation results and a good agreement is obtained.

关键词： multiple-input multiple-output Maximum ratio transmission Selection combining Symbol error rate Average capacity

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Robust Weighted Sum-Rate Maximization for the Multi-Stream MIMO Interference Channel With Sparse Equalization

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IEEE TRANSACTIONS ON COMMUNICATIONS 2015年第10期63卷 3645-3659页

作者： Helmy, Ahmed G. Hedayat, Ahmad Reza Al-Dhahir, Naofal Univ Texas Dallas Dept Elect Engn Richardson TX 75080 USA Cisco Syst Inc San Jose CA 95134 USA

In this paper, we study the problem of per-stream maximum sum-rate joint precoder and minimum mean-squared error equalizer design for the multi-input multi-output interference channel. We consider the general case of more than three users with more than one stream per user. We propose a generalized iterative algorithm which directly maximizes the sum-rate without assuming the signal-to-noise ratio to be infinite. To reduce complexity, which can become prohibitive for large network size, we examine the performance-complexity tradeoffs involved in a sparse equalizer design. Joint precoder and equalizer optimization requires alternation between the forward and reverse links and assumes perfect synchronization between the transmitters and receivers at each network node, resulting in extensive overhead and spectral efficiency loss. To overcome this serious drawback, we propose a new design approach based on weighted-sum-rate maximization assuming a virtual equalizer type at the transmitter to limit the optimization process to the transmitter side. In addition, we quantify the sum-rate loss due to mismatched equalizer types and demonstrate the robustness of our proposed sum-rate weighting strategy to such mismatches with perfect or imperfect channel knowledge. Finally, we derive asymptotic performance expressions and verify their accuracy numerically even for a moderate number of users.

关键词： Interference channel weighted sum-rate maximization sparse equalization alternating optimization multiple-input multiple-output

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