周睿, 李英善. 基于变换域的迭代MPD算法[J]. 微电子学与计算机, 2022, 39(8): 71-77. DOI: 10.19304/J.ISSN1000-7180.2021.1042
引用本文: 周睿, 李英善. 基于变换域的迭代MPD算法[J]. 微电子学与计算机, 2022, 39(8): 71-77. DOI: 10.19304/J.ISSN1000-7180.2021.1042
ZHOU Rui, LI Yingshan. Iterative MPD algorithm based on transform domain[J]. Microelectronics & Computer, 2022, 39(8): 71-77. DOI: 10.19304/J.ISSN1000-7180.2021.1042
Citation: ZHOU Rui, LI Yingshan. Iterative MPD algorithm based on transform domain[J]. Microelectronics & Computer, 2022, 39(8): 71-77. DOI: 10.19304/J.ISSN1000-7180.2021.1042

基于变换域的迭代MPD算法

Iterative MPD algorithm based on transform domain

  • 摘要: 相较于传统正交频分复用(Orthogonal Frequency Division Multiplexing, OFDM)技术,滤波OFDM(Filtered OFDM, F-OFDM)技术具有子载波带宽灵活可变和抑制频谱带外泄露等优点,是面向未来无线通信系统的候选波形之一.但是在高动态通信场景下,时变信道中存在的多普勒频偏现象却依然会严重损害F-OFDM系统的性能.针对该问题,提出一种基于变换域的迭代消息传递检测(Message Passing Detection, MPD)算法.MPD算法基于稀疏因子图,通过在收发节点间进行迭代式的消息传递和状态更新,最终实现对多普勒频偏的抑制.此外,通过对检测过程中的干扰进行高斯等效,能够一定程度上降低迭代MPD检测算法的复杂度.进一步的,所提算法基于变换域的设计思路,能够充分利用时变多径信道在变换域的增强型稀疏性,以此有效减少MPD算法中收发节点间的连接支路数,进而降低检测算法的计算复杂度.基于F-OFDM系统的仿真结果表明,相较于传统的时频域MPD算法,所提基于变换域的迭代MPD算法在系统误码率和计算复杂度上均有更为优异的性能表现.

     

    Abstract: Compared with the traditional orthogonal frequency division multiplexing (OFDM) modulation scheme, filter OFDM (F-OFDM) enjoys the superiorities of flexible subcarrier bandwidth and reduced out-of-band emission, which makes it one of the key candidate waveforms for future wireless communication systems. However, under the scenarios with high mobility, the Doppler frequency shifts (DFOs) can seriously degrade the performance of F-OFDM systems. To cope with this problem, an iterative message passing detection (MPD) algorithm based on transform domain is proposed in this paper. The MPD algorithm is based on a sparse factor graph and utilizes iterative massage transmission and update to achieve the suppression of the DFOs. Besides, the interference in the detection can be modeled as a Gaussian variable, which has the benefit to reduce the complexity of the MPD. Furthermore, based on the transform domain, the proposed iterative MPD algorithm can make full use of the enhanced channel sparsity in the transform domain, which effectively decreases the branches between the transceiver nodes in the MPD, and further reduces the complexity of the algorithm. Finally, based on the F-OFDM system, the simulation results show than the proposed scheme enjoys an improvement over the computational complexity and also the system performance compared with the traditional counterpart.

     

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