电信科1002班田苗苗1007080204.doc

题目: 数字图像处理 摘要翻译与分析: Abstract x1----A new non iterative algorithm is proposed to estimate the sampled impulse response of unknown channels. With the proper choice of the training sequence（训练序列）, implementation of the proposed channel estimator （估计器）requires only additions and subtractions, i.e., no multiplications or divisions are needed. Moreover, the structure of the estimator is so simple that it can be easily implemented using an ordinary microprocessor with minimal storage. The channel estimate can serve in reducing the effects of inter symbol interference either by the maximum likelihood sequence estimator (MLSE最大似然序列估计器) using the Viterbi algorithm（维特比算法）, or by channel equalization with a direct solution to obtain the optimum equalizer taps（抽头）. A new procedure for the latter case is proposed here using the Levin son-Trench algorithm for fast start-up （启动）of adaptive equalizers in noisy environments. The performance of the proposed algorithm is evaluated through simulation and it is compared to some of the existing techniques. Computational efficiency is also taken into account. Results of simulation show the superiority （优越性）of the proposed scheme. 摘要翻译：一种新的非迭代算法提出了计算采脉冲响应的未知的信道。信道估计的实现只需要加法和乘法此外，估计的结构非常简单可以使用普通的微处理器的最小存储容易实现。信道估计维特比算法最大似然序列用以获得最佳的均衡器抽头直接求解均衡信道对于后者的情况下提出了一个新的程序使用莱文森算法快速启动在嘈杂的环境中的自适应均衡器。所提出的算法的性能评价通过仿真和比较了一些现有的技术计算效率也考虑。仿真结果表明所提出的方案Abstract x2—The development of an adaptive infinite impulse response (IIR无限脉冲响应) linear equalizer is described. Using discrete time Wiener filtering theory, a closed form（封闭式） for the optimum mean-square error IIR filter is derived. A performance comparison using both minimum and non-minimum phase channels indicates the complexity/performance advantages inherent in the IIR system compared to an optimum finite impulse response (FIR有限脉冲响应) solution. The minimum phase spectral factorization（谱分解）, which is an integral part of the derivation