点目标检测的自适应波束形成算法与TMS320C6201植入优化研究

【作者】 王华斌；

【导师】 姚萌；

【作者基本信息】 华东师范大学 ， 通信与信息系统， 2004， 硕士

【摘要】 用于辅助诊断乳腺癌的超短脉冲(微波)近场成像方法(MicrowaveNear-Field Imaging)的主要原理是：采用超短脉冲对介质层的穿透性能甄别人体的乳腺癌组织和正常组织之间的电气特性不同(相当宽的频率范围内乳腺癌组织与正常组织的介电常数和导电系数差异值可达10倍)，对早期乳腺癌组织进行成像。由于检测微波场形成波束较宽，要检测早期乳腺癌组织(1cm)，必须对辐射场波束进行有效地控制和处理。在波束形成场处理中，自适应波束形成技术是关键技术之一，运用波束形成技术产生空间定向波束使天线主波束配准检测目标，以提高检测的灵敏度和精确度。 本文以科技攻关基础重点项目“乳腺癌超短脉冲(微波)近场成像方法和早期乳腺癌诊断方法研究(03JC14026)”为背景，结合乳腺癌微波近场成像实际检测环境，提出以相位补偿算法和RLS(递归最小二乘)算法相结合(相位补偿算法用于信号空域处理，RLS算法用于信号时域处理)的时—空自适应波束形成算法，对接收天线阵来的脉冲信号进行实时处理。 对算法的理论可行性分析和MATLAB模拟，表明时—空自适应波束形成算法在抑制随机噪声信号和皮肤表面反射干扰信号上有很大的效能。 为实现信号处理的实时性，运用TI公司的DSPs芯片TMS320C6201和DSPs的并行处理和流水线特点对算法模型以及算法最终实现代码进行优化、评估，提出基于时—空自适应波束形成算法模型的硬件系统实现构架。 本文研究结果可推广到医学成像领域，也可以作为移动通信中智能天线信号处理方式的一种参考。更多还原

【Abstract】 Microwave Near-Field Imaging is a new method of assisting in diagnosing breast cancer [1][2][3][4][5]. It detects breast cancer with electromagnetic wave pulse by it’s penetrating capability. The physical basis[6][7] for microwave detection of breast cancer is the significant contrast in the dielectric properties of normal and malignant breast tissue. While in the Early Detection of Breast Cancer, for the width of beam is larger than the diameter (1 cm) of the malignant breast tissue. And it is important to control the beam width. Adaptive beamforming is a key technology to process the beam width. We use the method of Adaptive beamforming to make a directional beam which matching the malignant breast tissue, and to improve the precision of detection.Considering the practicality during early detection of breast Cancer this thesis gives the time-space adaptive beamforming arithmetic to process the received signal of antenna array. The theory analysis and the MATLAB simulation prove that the time-space adaptive beamforming arithmetic can restrain random noise and the interferential signal reflecting from the breast skin effectively.Considering the real-time performance during detection, in this thesis the algorithm is simplified and optimized in platform of DSP chip of TMS320C6201 successfully.This method can be applied in the other medicinal imaging fields. It also provides a reference to the signal process of smart antenna.更多还原