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Adaptive beamforming and direction-finding algorithms for WCDMA.

机译：WCDMA的自适应波束形成和测向算法。

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摘要

Beamforming is one of the popular techniques for suppressing cochannel interference in wireless communication systems, especially for code-division multiple-access (CDMA) based systems where the transmitted signals share the same frequencies. Although the physical channels are designed to be transmitted using orthogonal codes, time dispersion and frequency-selective fading in the transmission channel severely degrade this orthogonality at the receiver. As a result, the physical channels within a target base station appear as interference coming the same direction as the pilot signal, and thus cause poor performance of a pilot-only training-based beamformer. In order to mitigate this effect, we propose a semiblind beamformer algorithm that jointly exploits the pilot signal and other physical channel signals. This approach suppresses the self-interference within the same base station, leads to more accurate cochannel signal separation, and thus improves the performance compared to a conventional pilot-only trained beamformer. Moreover, a constant modulus constraint with a least-squares formulation and a cyclodespreader can be combined with the semiblind approach to refine the antenna weights.;A direction-finding algorithm using a reversed antenna array with training by a pilot signal is also proposed in this dissertation. The direction-of-arrival (DOA) of a signal of interest is computed from an estimate of the phase difference between a conventional beamformer and a second parallel beamformer with the received signals in reversed position. The proposed receiver is not restricted by the number of signals and thus provides accurate DOA estimation when there is high cochannel interference. In addition, a blind version (without pilot signals) of the reversed array algorithm is presented and compared with two other phase-shift-based DOA estimators: the constant modulus array and a subarray approach, both of which also operate blindly.
机译：波束成形是抑制无线通信系统中同频干扰的流行技术之一，尤其是对于基于码分多址（CDMA）的系统，其中发射信号共享相同的频率。尽管物理信道被设计为使用正交码进行传输，但是传输信道中的时间色散和频率选择性衰落严重降低了接收机的正交性。结果，目标基站内的物理信道表现为来自与导频信号相同方向的干扰，从而导致仅基于导频的基于训练的波束形成器的性能较差。为了减轻这种影响，我们提出了一种半盲波束形成器算法，该算法可联合利用导频信号和其他物理信道信号。与传统的仅飞行员训练波束形成器相比，该方法抑制了同一基站内的自干扰，导致更精确的同信道信号分离，从而提高了性能。此外，可以将具有最小二乘公式的恒定模量约束和环扩频器与半盲方法相结合，以精炼天线权重。；还提出了一种使用反向天线阵列并通过导频信号进行训练的测向算法。论文。根据接收信号处于反转位置的常规波束形成器和第二个平行波束形成器之间的相位差估计值，可以计算出感兴趣信号的到达方向（DOA）。所提出的接收器不受信号数量的限制，因此当存在较高的同信道干扰时可以提供准确的DOA估计。此外，提出了反向阵列算法的盲版本（无导频信号），并将其与其他两个基于相移的DOA估计器进行比较：恒模数阵列和子阵列方法，这两种方法也都盲目运行。

著录项

  • 作者

    Wei, Sheng-Luen.;

  • 作者单位

    University of California, Santa Barbara.;

  • 授予单位 University of California, Santa Barbara.;
  • 学科 Engineering Electronics and Electrical.
  • 学位 D.Eng.
  • 年度 2010
  • 页码 156 p.
  • 总页数 156
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类
  • 关键词

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