LPC线预测分析.docx

线性预测分析matlab程序注意：程序只支持单声道wav文件，可以自行录制一句话。Levinson-Durbin算法：S为信号向量，P为预测阶数% Levinson-Durbinfunction a = LD(s, P)N = length(s); % r(j),j = 0:P;for j = 0 : P r(j+1) = sum(s(1:N-j).*s(j+1:N);enda = zeros(1, P);E = r(1);for i = 1 : P temp = 0; for j = 1 : i-1 temp = temp + a(j) * r(i-j+1); end ki = (r(i+1) - temp) / E; a(i) = ki; a_temp = a; % for j = i-1 : -1: 1 a(j) = a_temp(j) - ki * a_temp(i-j); end E = (1 - ki * ki) * E;EndMatlab主程序：clear all, close all,% speech, fs, nBits = wavread(speech.wav);%speech, fs, nBits = wavread(a4.wav);P = 10;% figure(1);subplot(2,2,1);plot(speech);title();subplot(2,2,2);plot(abs(fft(speech);title();% 1. winSize = floor(0.025 * fs); % 25ms,8000*0.025200nFrame = floor(length(speech) / winSize); % speech = filter(1,-0.94, 1, speech);subplot(2,2,3);plot(speech);title();subplot(2,2,4);plot(abs(fft(speech);title();% a = zeros(1, nFrame*P);err = zeros(1,length(speech);frameData = zeros(1,P+winSize); % hamwin = hamming(2*P+winSize);for m = 1:nFrame % startPos = (m-1) * winSize + 1; endPos = startPos + winSize - 1; ai_start = (m-1) * P +1; ai_end = ai_start + P - 1; if m = 1 frameData(P+1:P+winSize) = speech(startPos:endPos); else frameData = speech(startPos - P:endPos); end % frameData = frameData .* hamwin(1:P+winSize); a(ai_start:ai_end) = LD(frameData(P+1:P+winSize), P); % for i = 1 : winSize err(startPos+i) = frameData(P+i) - sum(a(ai_start:ai_end).*frameData(P+i-1:-1:P+i-P); end buildspeech(startPos:endPos) = filter(1,1,-1*a(m-1)*P+1:m*P),err(startPos:endPos); buildspeech(startPos:endPos) = buildspeech(startPos:endPos) ./ hamwin(P+1:P+winSize); %end% buildspeech = filter(1, 1,-0.94, buildspeech); %wavwrite(err,fs,nBits,error.wav);wavwrite(buildspeech,fs,nBits,buildspeech.wav);figure(2);subplot(2,1,1);plot(err);subplot(2,1,2);plot(abs(fft(err);figure(3);subplot(2