60 lines
1.2 KiB
Text
60 lines
1.2 KiB
Text
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node FIR_proto(x : real; h : real)
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returns (delay: real; val: real);
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let
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delay = 0.0 -> pre x;
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val = x * h;
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tel
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node FIR<<const n : int>>(x : real; h : real^n)
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returns (y : real);
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var tmp : real^n;
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var d : real;
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let
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(d, tmp) = fillred<<FIR_proto; n>>(x, h);
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y = red<<+, n>>(0.0, tmp);
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tel
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node delay_chain(x : real)
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returns (delay : real; val: real);
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let
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delay = 0.0 -> pre x;
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val = x;
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tel
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node delayed_array<< const n : int>>(x : real)
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returns (y : real^n);
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var d : real;
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let
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(d, y) = fill<<delay_chain, n>>(x);
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tel
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function power_acc(p : real; s : real)
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returns (pp : real);
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let
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pp = p + s*s;
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tel
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function scalar_mult(c : real; x : real)
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returns (prop: real; y : real)
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let
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y = x * c;
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prop = c;
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tel
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node NLMS_FIR<< const n : int>>(ref : real; x : real; mu : real)
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returns (y : real; h : real^n);
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var delayed : real^n;
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--var h : real^n;
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var stepsize : real;
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var currstep : real^n;
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var e : real;
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let
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h = (0. ^ n) -> map<<+, n>>(pre h, pre currstep);
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y = FIR<<n>>(ref, h);
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e = x - y;
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delayed = delayed_array<<n>>(ref);
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(stepsize, currstep) = fillred<<scalar_mult, n>>(mu * e / red<<power_acc, n>>(0.0, delayed), delayed);
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tel
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node EchoCancel = NLMS_FIR<<2>>;
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