• Title/Summary/Keyword: Multiple input multiple output

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A Comparative Study of List Sphere Decoders for MIMO Systems

  • Pham, Van-Su;Yoon, Giwan
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2009.05a
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    • pp.143-146
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    • 2009
  • In this paper, we investigated the list sphere decoders (LSD) for multiple-input multiple-output (MIMO) systems. We showed that the ordering procedures play an important role in LSD in order to achieve the low complexity without degrading the bit-error-rate (BER) performance. Then, we proposed a novel ordering algorithm for the LSD which uses a look-up table and simply comparative operations. Comparative results in terms of BER performance and computational complexity are provided through computer simulations.

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Zero forcing based sphere decoder for generalized spatial modulation systems

  • Jafarpoor, Sara;Fouladian, Majid;Neinavaie, Mohammad
    • ETRI Journal
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    • v.41 no.2
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    • pp.145-159
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    • 2019
  • To reduce the number of radio frequency (RF) chains in multiple input multiple output (MIMO) systems, generalized spatial modulation (GSM) techniques have been proposed in the literature. In this paper, we propose a zero-forcing (ZF)-based detector, which performs an initial pruning of the search tree that will be considered as the initial condition in a sphere decoding (SD) algorithm. The proposed method significantly reduces the computational complexity of GSM systems while achieving a near maximum likelihood (ML) performance. We analyze the performance of the proposed method and provide an analytic performance difference between the proposed method and the ML detector. Simulation results show that the performance of the proposed method is very close to that of the ML detector, while achieving a significant computational complexity reduction in comparison with the conventional SD method, in terms of the number of visited nodes. We also present some simulations to assess the accuracy of our theoretical results.

Low-Overhead Feedback Topology Design for the K-User MIMO Interference Alignment

  • Jin, Jin;Gao, Xiang-Chuan;Li, Xingwang;Cavalcante, Charles Casimiro;Li, Lihua
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.12 no.11
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    • pp.5304-5322
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    • 2018
  • Since designing a feedback topology is a practical way to implement interference alignment at reduced cost of channel state information (CSI) feedback, six feedback topologies have been presented in prior works for a K-user multiple-input multiple-output interference channel. To fully reveal the potential benefits of the feedback topology in terms of the saving of CSI overhead, we propose a new feedback topology in this paper. By efficiently performing dimensionality-decreasing at the transmitter side and aligning interference signals at a subset of receivers, we show that the proposed feedback topology obtains substantial reduction of feedback cost over the existing six feedback designs under the same antenna configuration.

PSO-optimized Pareto and Nash equilibrium gaming-based power allocation technique for multistatic radar network

  • Harikala, Thoka;Narayana, Ravinutala Satya
    • ETRI Journal
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    • v.43 no.1
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    • pp.17-30
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    • 2021
  • At present, multiple input multiple output radars offer accurate target detection and better target parameter estimation with higher resolution in high-speed wireless communication systems. This study focuses primarily on power allocation to improve the performance of radars owing to the sparsity of targets in the spatial velocity domain. First, the radars are clustered using the kernel fuzzy C-means algorithm. Next, cooperative and noncooperative clusters are extracted based on the distance measured using the kernel fuzzy C-means algorithm. The power is allocated to cooperative clusters using the Pareto optimality particle swarm optimization algorithm. In addition, the Nash equilibrium particle swarm optimization algorithm is used for allocating power in the noncooperative clusters. The process of allocating power to cooperative and noncooperative clusters reduces the overall transmission power of the radars. In the experimental section, the proposed method obtained the power consumption of 0.014 to 0.0119 at K = 2, M = 3 and K = 2, M = 3, which is better compared to the existing methodologies-generalized Nash game and cooperative and noncooperative game theory.

Incremental Antenna Selection Based on Lattice-Reduction for Spatial Multiplexing MIMO Systems

  • Kim, Sangchoon
    • Journal of Advanced Information Technology and Convergence
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    • v.10 no.1
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    • pp.1-14
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    • 2020
  • Antenna selection is a method to enhance the performance of spatial multiplexing multiple-input multiple-output (MIMO) systems, which can achieve the diversity order of the full MIMO systems. Although various selection criteria have been studied in the literature, they should be adjusted to the detection operation implemented at the receiver. In this paper, antenna selection methods that optimize the post-processing signal-to-noise ratio (SNR) and eigenvalue are considered for the lattice reduction (LR)-based receiver. To develop a complexity-efficient antenna selection algorithm, the incremental selection strategy is adopted. Moreover, for improvement of performance, an additional iterative selection method is presented in combination with an incremental strategy.

Limited Feedback Interference Alignment in MIMO Power Line Communication with Common-mode Reception

  • Ahiadormey, Roger Kwao;Anokye, Prince;Park, Seok-Hwan;Lee, Kyoung-Jae
    • Journal of Advanced Information Technology and Convergence
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    • v.9 no.2
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    • pp.1-14
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    • 2019
  • This paper considers a multiple-input multiple-output (MIMO) power line communication (PLC) network where interference alignment (IA) technique is used to mitigate the interference that arises in multi-user networks. IA as a precoding technique requires perfect channel state information (CSI) to achieve maximum multiplexing gain. Due to the common-mode reception at the receiver ports, we assume imperfect CSI for the IA precoding design. Here, the CSI is quantized and sent via feedback to the transmit ports. For different levels of CSI quantization, we evaluate the performance of various IA algorithms via Monte Carlo simulations. Simulation results reveal the superior performance of the proposed scheme due to common-mode reception in IA MIMO PLC networks. It is shown that for a quantization level of 5 bits, the CM reception improves the sum-rate by up to 70%.

Suppression of High Frequency Distortion in the Multiple-Input Current-Mode MAX Circuits by Adjustment of Transconductance (전류 모드 다 입력 MAX회로에서 트랜스컨덕턴스 조정에 의한 고주파 왜곡 억제)

  • 이준수;손홍락;김형석
    • Proceedings of the IEEK Conference
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    • 2003.07b
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    • pp.1053-1056
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    • 2003
  • A distortion suppression technology for employing multiple inputs in 3n+1 type current mode Max circuit is proposed using the adjustment of transconductance. If the number of inputs in current mode Max circuit increases, the high frequency distortion in the output signal grows. In this paper, it has been disclosed that the distortion in the multiple input Max circuit is proportional to sum of parasitic capacitance in input terminals, to the derivative of the output signal and also to the inverse of transconductance of the common diode-connected transistor. The proposed idea is by employing as larger transconductance of the common diode-connected transistor as possible. The effectiveness of the proposed idea has been proved through the HSPICE simulation.

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Suppression of the High Frequency Distortion by Adjustment of Transconductance of the Diode-Connected Transistor in the Current Mode Max Circuit for Multiple Inputs (다수 입력용 전류모드 Max 회로에서 다이오드결선 트랜지스터의 트랜스컨덕턴스 조정에 의한 고주파 왜곡 억제)

  • 이준수;손홍락;김형석
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.40 no.11
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    • pp.37-44
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    • 2003
  • A distortion suppression technology for employing multiple inputs in 3n+1 type current mode Max circuit is proposed using the adjustment of transconductance. If the number of input blocks of the current mode Max circuit increases, the high frequency distortion in the output signal grows. In this paper, it has been disclosed that the distortion in the multiple input Max circuit is proportional to such accumulated parasitic capacitance, to the derivative of the output signal and also to tile inverse of transconductance of the common diode-connected transistor. The proposed idea is by employing as larger transconductance of the common diode-connected transistor as possible. The effectiveness of the proposed idea has been proved through the HSPICE simulation for the current mode Max circuits with various numbers of input signals.

Transient Performance of a Hybrid Electric Vehicle with Multiple Input DC-DC Converter

  • Nashed, Maged N.F.
    • Journal of Power Electronics
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    • v.3 no.4
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    • pp.230-238
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    • 2003
  • Electric vehicles (EV) demands for greater acceleration, performance and vehicle range in pure electric vehicles plus mandated requirements to further reduce emissions in hybrid electric vehicles (HEV) increase the appeal for combined on-board energy storage systems and generators. And the power electronics plays an important role in providing an interface between fuel cells (FC) and loads. This paper deals with a multiple input DC-DC power converter devoted to combine the power flowing of multi-source on energy systems. The multi-source is composed of (i) FC system as a prime power demands, (ii) super capacitor banks as energy storage devices for high and intense power demands, (iii) superconducting magnetic energy storage system (SMES), (iv) multiple input DC-DC power converter and (v) a three phase inverter-fed permanent magnet synchronous motor as a drive. In this system, It is used super capacitor banks and superconducting magnetic energy replaces from the battery system. The modeling and transient performance simulation is effective for reducing transient influence caused by sudden charge of effective load. The main purpose of power electronic converters is to convert the DC power output from the fuel cell and other to a suitable AC voltage, which can be connected to electric loads directly (PMSM). The fuel cell and other output is connected to the DC-DC converter, which regulates the DC link voltage.

A study of QoS for High Speed MIOQ Packet Switch (다중 입출력 큐 방식 고속 패킷 스위치를 위한 QoS에 대한 연구)

  • Ryu, Kyoung-Sook;Choe, Byeong-Seog
    • Journal of Internet Computing and Services
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    • v.9 no.2
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    • pp.15-23
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    • 2008
  • This paper proposes the new structural MOQ(Multiple Input/Output-Queued) switch which guarantees QoS while maintaining high efficiency and deals with the Anti-Empty algorithm which is new arbitration algorithm to be used for the proposed switch. The new structure of the proposed switch based on MIQ, MOQ is designed to have the same buffer speed as the external line speed. Also, the proposed switch makes it possible to remove the weak point of existing methods and introduces the new method of the MOQ operation to support QoS. Therefore, this switch is equal to the Output Queued switch in efficiency and delay, and guarantees the high-speed switching supporting QoS without cell loss.

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