请教高手， matlab 除噪，rls

LSYJY

如下程序是参照matlab官网给的代码改编的，我想用rls滤波器对声音文件进行处理，可是提示
Error using ==> plus
Matrix dimensions must agree.
我正在做毕业设计，希望各位高手指教

       [x,Fs1]=wavread('signal.wav');     % Input to the filter
       b  = fir1(31,0.5);     % FIR system to be identified
       [n,Fs2]=wavread('noise.wav'); % Observation noise signal
       d  = filter(b,1,x)+n;  % Desired signal
       P0 = 10*eye(32); % Initial sqrt correlation matrix inverse
       lam = 0.99;            % RLS forgetting factor
       h = adaptfilt.rls(32,lam,P0);
       [y,e] = filter(h,x,d);
       subplot(2,1,1); plot(1:500,[d;y;e]);
       title('System Identification of an FIR filter');
       legend('Desired','Output','Error');
       xlabel('time index'); ylabel('signal value');
       subplot(2,1,2); stem([b.',h.Coefficients.']);
       legend('Actual','Estimated');
       xlabel('coefficient #'); ylabel('coefficient value'); grid on;