volp2.zip_android开发

% File: c4_qamdemo.m % Software given here is to accompany the textbook: W.H. Tranter, % K.S. Shanmugan, T.S. Rappaport, and K.S. Kosbar, Principles of % Communication Systems Simulation with Wireless Applications, % Prentice Hall PTR, 2004. % levelx = input('Number of D levels > '); levely = input('Number of Q levels > '); m = input('Number of symbols > '); n = input('Number of samples per symbol > '); bw = input('Filter bandwidth, 0<bw<1 > '); % [xd,xq] = qam(levelx,levely,m,n); % [b,a] = butter(6,bw); % determine filter coefficients yd = filter(b,a,xd); % filter direct coefficient yq = filter(b,a,xq); % filter quadrature coefficient % subplot(2,2,1) % first pane plot(xd,xq,'o') % unfiltered scatterplot a = 1.4; maxd = max(xd); maxq = max(xq); mind = min(xd); minq = min(xq); axis([a*mind a*maxd a*minq a*maxq]) axis equal xlabel('xd'); ylabel('xq') % subplot(2,2,2) % second pane plot(yd,yq) % filtered scatterplot axis equal; xlabel('xd'); ylabel('xq'); % sym = 30; % number of symbols in time plot nsym = (0:sym*n)/n; % x axis vector for time plots subplot(2,2,3) % third pane plot(nsym(1:sym*n),yd(1:sym*n)) % filtered direct component xlabel('symbol index'); ylabel('xd'); % subplot(2,2,4) % fourth pane plot(nsym(1:sym*n),yq(1:sym*n)) % filtered quadrature component xlabel('symbol index'); ylabel('xq'); % End of script file.