Channel estimation of OFDM system with Expectation Maximization Algorithm

OFDM是一种具有诸多优点的通信技术，它正被逐渐应用于各种高速通信系统中，并且它已经被确认为第四代移动通信系统（4G）中的核心技术。OFDM通信系统具有传输速率快，频谱利用率高，能有效对抗无线信道多径传输和时延扩展的优点，因此在新一代的通信系统中具有非常广泛的应用前景。在移动通信过程中，由于存在多径传输，多普勒效应，以及噪声的影响，信道具有复杂多变的特性，因此，对移动通信信道特性的准确估计也就成了关系到最终通信系统性能的关键因素。通信质量的提高有赖于对无线信道传输特性估计的精确度。作为新一代的通信系统，在OFDM中，信道估计自然也是其整个通信过程的一个重要环节。对于信道估计，通常有盲估计和半盲...As a new communication technology with much advantage OFDM has been used in several new high-speed communication systems, and it has been applied as the core technology in the fourth generation mobile communication system. OFDM system can be fast-rate, high-spectrum-efficiency and can weak the effect of multi-path transmission delay. As that it has wide application prospects. Meanwhile, because of...学位：工学硕士院系专业：物理与机电工程学院物理学系_电磁场与微波技术学号：1982007115231

Object Tracking Based on Adaptive Particle Filter

基于蒙特卡洛模拟的粒子滤波算法被广泛地应用于目标追踪领域。传统的粒子滤波算法在其追踪过程中所使用的粒子数通常是固定不变的,而在实际应用中,这会使算法缺乏高效性。针对这个问题,提出了一种自适应性粒子滤波器,它可以根据实际调整算法运行过程中使用的粒子数目,以使算法在保持对目标进行有效追踪的同时节省计算资源。仿真结果显示了算法的高效性。As an efficient algorithms particle filter has been widely used in the area of object tracking.Normally number of particles being used in the algorithm is given as a constant which would somewhat make the algorithm unstable and inaccurate.As that an adaptive particle filter is proposed,this motion model and particle number can change adaptively according to the object's moving state.And the simulation shows that our algorithm is very effective when used in the tracking program