LMS算法matlab实现

-LMS算法function yn,W,en=LMS(xn,dn,M,mu,itr)% LMS(Least Mean Squre)算法% 输入参数:% xn 输入的信号序列 (列向量)% dn 所期望的响应序列 (列向量)% M 滤波器的阶数 (标量)% mu 收敛因子(步长) (标量) 要求大于0,小于xn的相关矩阵最大特征值的倒数 % itr 迭代次数 (标量) 默认为xn的长度,Mitrlength(xn)% 输出参数:% W 滤波器的权值矩阵 (矩阵)% 大小为M x itr,% en 误差序列(itr x 1) (列向量) % yn 实际输出序列 (列向量)% 参数个数必须为4个或5个if nargin = 4 % 4个时递归迭代的次数为xn的长度 itr = length(xn);elseif nargin = 5 % 5个时满足Mitrlength(xn) | itrM error(迭代次数过大或过小!); endelse error(请检查输入参数的个数!);end% 初始化参数en = zeros(itr,1); % 误差序列,en(k)表示第k次迭代时预期输出与实际输入的误差W = zeros(M,itr); % 每一行代表一个加权参量,每一列代表-次迭代,初始为0% 迭代计算for k = M:itr % 第k次迭代 x = xn(k:-1:k-M+1); % 滤波器M个抽头的输入 y = W(:,k-1). * x; % 滤波器的输出 en(k) = dn(k) - y ; % 第k次迭代的误差 % 滤波器权值计算的迭代式 W(:,k) = W(:,k-1) + 2*mu*en(k)*x;end% 求最优时滤波器的输出序列yn = inf * ones(size(xn);for k = M:length(xn) x = xn(k:-1:k-M+1); yn(k) = W(:,end).* x;end调用LMS算法%function main()close all% 周期信号的产生 t=0:99;xs=10*sin(0.5*t);figure;subplot(2,1,1);plot(t,xs);grid;ylabel(幅值);title(it输入周期性信号);% 噪声信号的产生randn(state,sum(100*clock);xn=randn(1,100);subplot(2,1,2);plot(t,xn);grid;ylabel(幅值);xlabel(时间);title(it随机噪声信号);% 信号滤波xn = xs+xn;xn = xn. ; % 输入信号序列dn = xs. ; % 预期结果序列M = 20 ; % 滤波器的阶数rho_max = max(eig(xn*xn.); % 输入信号相关矩阵的最大特征值mu = rand()*(1/rho_max) ; % 收敛因子 0 mu 1/rhoyn,W,en = LMS(xn,dn,M,mu);% 绘制滤波器输入信号figure;subplot(2,1,1);plot(t,xn);grid;ylabel(幅值);xlabel(时间);title(it滤波器输入信号);% 绘制自适应滤波器输出信号subplot(2,1,2);plot(t,yn);grid;ylabel(幅值);xlabel(时间);title(it自适应滤波器输出信号);% 绘制自适应滤波器输出信号,预期输出信号和两者的误差figure plot(t,yn,b,t,dn,g,t,dn-yn,r);grid;legend(自适应滤波器输出,预期输出,误差);ylabel(幅值);xlabel(时间);title(it自适应滤波器);运行结果LMS算法DSP程序#includemath.h#define PI 3.1415926#define Coeff 16 /定义阶数16阶#define num 1024 /点数int FIRLMS(int *nx,float *nh,int nError,int nCoeffNum); /LMS函数声明float hCoeff,fU; /h 单位脉冲响应 fu-2U的值int xnum,ynum,znum;/x 输入信号，y输出，z 误差信号main()int i,out; out=0;fU=0.0005;for ( i=0;iCoeff;i+ )hi=0;/初始化 噪声信号for ( i=0;inum;i+ )xi=256*sin(i*2*PI/34);/初始化输入信号yi=zi=0;/初始化 输出信号 误差信号for ( i=Coeff+1;inum;i+ )out=FIRLMS(x+i,h,out-xi-1,Coeff);/ 设置断点，调用LMS函数yi=out;zi=yi-xi;exit(0); /推出int FIRLMS(int *nx,float *nh,int nError,int nCoeffNum)int i,r;float fWork;r=0;for ( i=0;inCoeffNum;i+ )fWork=nxi*nError*fU; /h(n+1)=h(n)+2u*e(n)*x(n)nhi+=fWork;r+=(nxi-i*nhi);r/=128;return r;运行结果音频采集程序#include #include #include #include #include #include #include #include #include 5502_FLASH.h#include E2PROM_Function.h#include CODEC.h#undef CODEC_ADDR#define CODEC_ADDR 0x1AUint16 SourData165536=0;Uint16 SourData265536=0;Uint16 SourData365536=0;Uint16 OutData165536=0;Uint16 OutData265536=0;Uint16 OutData365536=0;#pragma DATA_SECTION (SourData1,.Audio_in_data1);#pragma DATA_SECTION (SourData2,.Audio_in_data2);#pragma DATA_SECTION (SourData3,.Audio_in_data3);#pragma DATA_SECTION (OutData1,.Audio_out_data1);#pragma DATA_SECTION (OutData2,.Audio_out_data2);#pragma DATA_SECTION (OutData3,.Audio_out_data3);/ 定义McBSP的句柄MCBSP_Handle hMcbsp;/*-*/ FUNCTION: MAIN/*-*/ void main(void) Uint16 DataTempLeft = 0;/ 暂存采样数据 Uint16 DataTempRight = 0;/ Initialize CSL library - This is REQUIRED ! CSL_init();#if TESTCOMMAND=1TestCommand =AUDIOTRY;/试听#endif#if TESTCOMMAND=2TestCommand =AUDIOCOPY;/录音并回放#endif/ The main frequency of system is 240MHz/ 该频率是为了设置IIC模块的需要设置的,为了使用I2C_setup函数 PLL_setFreq(1, 0xC, 0, 1, 3, 3, 0); /EMIF初始化 Emif_Config(); / Open McBSP port 1 and get a McBSP type handlehMcbsp = MCBSP_open(MCBSP_PORT1,MCBSP_OPEN_RESET);/ Config McBSPport 1 by use previously defined structureMcbsp_Config(hMcbsp);/I2C初始化I2C_cofig(); /CODEC寄存器初始化inti_AIC(); /*-*/ / Receive the ADC output data of CODEC / Then output the received data to DAC of CODEC /*-*/while(1) /* 左通路数据 */while(!MCBSP_rrdy(hMcbsp);DataTempLeft = MCBSP_read16(hMcbsp); /* 右通路数据 */ while(!MCBSP_rrdy(hMcbsp);