jens
792f9c50f8
git-svn-id: http://moon:8086/svn/matlab/trunk@33 801c6759-fa7c-4059-a304-17956f83a07c
55 lines
1.2 KiB
Matlab
55 lines
1.2 KiB
Matlab
function [n, Nd, valid, Zf] = timing_coarse(x, N, Ng, L, Zi)
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if (~isfield(Zi, 'valid'))
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Zi = struct('valid', 1, 'n', 0, 'xp', [], 'p', 1.0);
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end
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Zf = Zi;
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Zf.xp = [Zf.xp' x']';
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n = Zf.n;
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Nd = N;
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valid = 0;
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if (length(Zf.xp) < 3*N+Ng)
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return
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end
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RCWIN_ROLLOFF = 0.125;
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[rcwin Nt wng] = txwin_eval(N, Ng, RCWIN_ROLLOFF);
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% RC Windowing at TX
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% Calculate merged CP'
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% -----------------------------------------------
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% | CP | : : | CP | : : | CP |
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% ----------------------------------------------------> nt
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% x0 x1 x2
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%
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% CP' = x0 * (1-w) + x2 * w
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k = 1;
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for nt=N+Ng:N+Ng+N-2,
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for d=1:3,
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Nd = N-2+d;
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x0 = Zf.xp(nt-Nd+1:nt-Nd+L);
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x1 = Zf.xp(nt+1:nt+L);
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x2 = Zf.xp(nt+Nd+1:nt+Nd+L);
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xcps = x0 .* (1-wng') + x2 .* (wng');
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n = 0.5*(abs(x1).^2 + abs(xcps).^2);
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c(k, d) = sum(abs(x1 .* conj(xcps)) - 1.0*n);
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end
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k = k + 1;
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end
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[v1, n1] = max(c);
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[v2, n2] = max(v1);
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Nd = N-2+n2;
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n = mod(n1(n2)-1, N+Ng);
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Zf.xp = Zf.xp(N+Ng+1:length(Zf.xp));
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Zf.n = n;
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valid = 1;
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if (0)
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plot(d); grid;
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pause(0.01);
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end
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