设x(n) = x1(n) + x2(n)，x1(n)是窄带信号，定义为x1(n) = sin(0.05πn +φ)，φ是在[0, 2π)区间上均匀分布的随机相位。x2(n)是宽带信号，它由一个零均值、方差为1的白噪声信号e(n)激励一个线性滤波器而产生，其差分方程为x2(n) = e(n) + 2e(n-1) + e(n-2)。

　　(1)计算x1(n)和x2(n)各自的自相关函数，并画出其函数图形。据此选择合适的延时，以实现谱线增强。

　　(2)产生一个x(n)序列。选择合适的μ值。让x(n)通过谱线增强器。画出输出信号y(n)和误差信号e(n)的波形，并分别与x1(n)和x2(n)进行比较。-Let x (n) = x1 (n)+ x2 (n), x1 (n) is a narrowband signal, is defined as x1 (n) = sin (0.05πn+φ), φ is in [0, 2π) uniformly distributed interval random phase. x2 (n) is a wideband signal, which consists of a zero mean and variance of a white noise signal e (n) incentive to produce a linear filter, and its differential equation is x2 (n) = e (n)+ 2e (n-1)+ e (n-2). (1) Calculation x1 (n) and x2 (n) each of the autocorrelation function and draw the graph of a function. Accordingly appropriate delay, in order to achieve line enhancement. (2) generating a x (n) sequences. Select the appropriate μ values. Let x (n) through line enhancer. Draw the output signal y (n) and the error signal e (n) of the waveform, respectively, and x1 (n) and x2 (n) for comparison.