#N canvas 0 68 891 823 10; #N canvas 10 567 633 314 unknown_system~ 0; #X obj 26 26 inlet~; #X obj 26 268 outlet~; #X obj 115 227 s~ unknown_signal; #X text 116 249 (for visualization); #X obj 26 113 fexpr~ $f2*$x1 + $f3*$x1[-1] + $f4*$x1[-2]; #X obj 122 81 f 0.33; #X obj 218 81 f 0.33; #X obj 315 82 f 0.33; #X obj 122 53 r a0; #X obj 218 55 r a1; #X obj 315 56 r a2; #X connect 0 0 4 0; #X connect 4 0 1 0; #X connect 4 0 2 0; #X connect 5 0 4 1; #X connect 6 0 4 2; #X connect 7 0 4 3; #X connect 8 0 5 0; #X connect 9 0 6 0; #X connect 10 0 7 0; #X restore 245 268 pd unknown_system~; #X obj 305 434 tgl 20 0 audio_io empty empty 0 -6 0 8 -262144 -1 -1 0 1; #X text 330 436 <- Audio IO; #N canvas 523 194 390 347 adaptive_filter~ 0; #X obj 37 35 inlet~; #X text 22 15 input signal; #X obj 143 35 inlet~; #X text 122 15 desired signal; #X obj 36 291 outlet~; #X msg 249 63 adaptation 1; #X obj 249 42 loadbang; #X obj 224 214 s~ adaptive_signal; #X text 224 234 (for visualization); #X obj 249 141 r clear; #X msg 248 162 clear; #X obj 37 156 lms2~ 3 0.01; #X obj 116 265 unpack f f f; #X obj 116 293 outlet; #X obj 162 293 outlet; #X obj 208 293 outlet; #X obj 249 94 r mu; #X msg 249 116 mu \$1; #X connect 0 0 11 0; #X connect 2 0 11 1; #X connect 5 0 11 0; #X connect 6 0 5 0; #X connect 9 0 10 0; #X connect 10 0 11 0; #X connect 11 0 4 0; #X connect 11 0 7 0; #X connect 11 2 12 0; #X connect 12 0 13 0; #X connect 12 1 14 0; #X connect 12 2 15 0; #X connect 16 0 17 0; #X connect 17 0 11 0; #X restore 117 337 pd adaptive_filter~; #X obj 524 255 spectrum~; #N canvas 0 0 450 300 graph6 0; #X array adapt 512 float 0; #X coords 0 1 511 -1 200 140 1; #X restore 656 625 graph; #X text 700 769 -- 512 samples ---; #X obj 46 438 tgl 20 0 scopes_on empty empty 0 -6 0 8 -262144 -1 -1 0 1; #X obj 524 238 r~ adaptive_signal; #X text 125 241 x[n]; #X text 256 300 d[n]; #X text 107 356 y[n]; #X obj 775 238 r scopes_on; #X obj 775 26 r scopes_on; #X obj 524 26 r~ unknown_signal; #N canvas 0 0 450 300 graph6 0; #X array unkn 512 float 0; #X coords 0 1 511 -1 200 140 1; #X restore 654 453 graph; #X text 698 597 -- 512 samples ---; #X text 76 438 <- Visualization IO; #X text 481 137 (1); #X text 481 338 (2); #N canvas 452 215 456 231 scope_stuff 0; #X obj 45 38 r~ adaptive_signal; #X obj 83 63 r scopes_on; #X obj 279 69 r scopes_on; #X obj 241 44 r~ unknown_signal; #X obj 83 96 metro 1000; #X obj 44 139 tabwrite~ adapt; #X obj 279 95 metro 1000; #X obj 240 138 tabwrite~ unkn; #X connect 0 0 5 0; #X connect 1 0 4 0; #X connect 2 0 6 0; #X connect 3 0 7 0; #X connect 4 0 5 0; #X connect 6 0 7 0; #X restore 755 795 pd scope_stuff; #X text 582 510 (3); #X text 581 686 (4); #X text 86 760 (3) d[n] in time domain; #X text 86 777 (4) y[n] in time domain; #X text 86 742 (2) amplitude of the output signal y[n]; #X text 86 711 (1) amplitude of the desired signal d[n] (= output of the unknown system); #X obj 84 599 bng 20 250 50 0 clear empty empty 0 -6 0 8 -262144 -1 -1; #X text 113 601 <- clear coefficients \, so adaptation will start again ; #X floatatom 46 471 5 0 100 0 - init_tlp tlp; #X obj 685 26 r tlp; #X obj 685 238 r tlp; #X text 90 469 <- temporal lowpass for spectrum view (0...100); #X text 54 689 VISUALIZATIONS:; #X text 42 522 unknown system:; #X text 72 546 d[n] =; #X floatatom 159 378 5 0 0 1 c0 - -; #X floatatom 223 378 5 0 0 1 c1 - -; #X floatatom 285 378 5 0 0 1 c2 - -; #X text 40 578 adaptive filter:; #X floatatom 84 627 8 0 0 0 - mur mu; #X text 146 627 <- step size parameter mu (learning rate); #N canvas 215 124 617 210 init 0; #X msg 43 99 2; #X obj 269 45 loadbang; #X obj 43 122 s init_tlp; #X msg 138 98 0.33; #X msg 179 99 0.33; #X msg 223 100 0.33; #X obj 138 121 s a0r; #X obj 178 122 s a1r; #X obj 223 123 s a2r; #X obj 295 123 s mur; #X msg 294 99 0.01; #X msg 515 103 \; pd dsp \$1; #X obj 515 78 r audio_io; #X obj 381 123 s signalr; #X msg 380 98 0; #X connect 0 0 2 0; #X connect 1 0 0 0; #X connect 1 0 3 0; #X connect 1 0 4 0; #X connect 1 0 5 0; #X connect 1 0 10 0; #X connect 1 0 14 0; #X connect 3 0 6 0; #X connect 4 0 7 0; #X connect 5 0 8 0; #X connect 10 0 9 0; #X connect 12 0 11 0; #X connect 14 0 13 0; #X restore 699 795 pd init; #X floatatom 125 547 4 0 1 0 - a0r a0; #X text 158 547 x[n] +; #X text 244 547 x[n-1] +; #X floatatom 211 547 4 0 1 0 - a1r a1; #X floatatom 312 548 4 0 1 0 - a2r a2; #X text 345 549 x[n-2]; #N canvas 425 56 479 415 PROBLEM_DESCRIPTION 0; #X text 33 89 In this example the adaptive filter tries to identify an unknown system.; #X text 34 124 The unknown system is a FIR filter of order 3 and the adaptive system is an adaptive transversal filter using the LMS algorithm (see lms~ help-patch) with 3 coefficients.; #X text 75 224 d[n] = h0*x[n] + h1*x[n-1] + h2*x[n-2]; #X text 35 188 unknown system:; #X text 74 209 FIR Filter \, order = 3; #X text 35 259 adaptive system:; #X text 77 278 LMS \, 3 coefficients (c0 \, c1 \, c2); #X text 35 342 The System Identification problem is sucessfull \, if c0=h0 \, c1=h1 and c2=h2. Then the unknown and the adaptive system have the same behavior.; #X text 60 40 SYSTEM IDENTIFICATION IN A NOISE FREE ENVIRONMENT; #X text 77 292 step-size parameter mu; #X restore 34 94 pd PROBLEM_DESCRIPTION; #N canvas 298 58 425 643 OBSERVATIONS 0; #X text 24 20 OBSERVATIONS; #X obj 27 119 bng 20 250 50 0 empty empty empty 0 -6 0 8 -262144 -1 -1; #N canvas 863 469 389 255 mu1 0; #X obj 20 14 inlet; #X obj 20 68 s signalr; #X msg 20 47 0; #X obj 20 111 s clear; #X obj 20 179 s mur; #X msg 20 158 0.5; #X connect 0 0 2 0; #X connect 0 0 3 0; #X connect 0 0 5 0; #X connect 2 0 1 0; #X connect 5 0 4 0; #X restore 27 143 pd mu1; #X text 26 95 e.g. mu = 0.5:; #X obj 29 201 bng 20 250 50 0 empty empty empty 0 -6 0 8 -262144 -1 -1; #X text 26 179 e.g. mu = 1e-05:; #X text 25 59 1) influenc of mu:; #X text 84 119 -> very fast adaptation \, but c0 \, c1 \, c2; #X text 104 134 are not so precise; #X text 83 201 -> slower adaptation \, but very precise; #X text 27 430 2) influenc of white vs. non-white input signal:; #X obj 30 490 bng 20 250 50 0 empty empty empty 0 -6 0 8 -262144 -1 -1; #N canvas 863 469 389 255 mu2 0; #X obj 20 14 inlet; #X obj 20 68 s signalr; #X msg 20 47 0; #X obj 20 111 s clear; #X obj 20 179 s mur; #X msg 20 158 1e-05; #X connect 0 0 2 0; #X connect 0 0 3 0; #X connect 0 0 5 0; #X connect 2 0 1 0; #X connect 5 0 4 0; #X restore 29 225 pd mu2; #N canvas 863 469 389 255 in1 0; #X obj 20 14 inlet; #X obj 20 68 s signalr; #X msg 20 47 0; #X obj 20 111 s clear; #X obj 20 179 s mur; #X msg 20 158 0.001; #X connect 0 0 2 0; #X connect 0 0 3 0; #X connect 0 0 5 0; #X connect 2 0 1 0; #X connect 5 0 4 0; #X restore 30 514 pd in1; #X obj 32 570 bng 20 250 50 0 empty empty empty 0 -6 0 8 -262144 -1 -1; #N canvas 863 469 389 255 in2 0; #X obj 20 14 inlet; #X obj 20 68 s signalr; #X obj 20 111 s clear; #X obj 20 179 s mur; #X msg 20 47 1; #X msg 20 158 0.001; #X connect 0 0 4 0; #X connect 0 0 2 0; #X connect 0 0 5 0; #X connect 4 0 1 0; #X connect 5 0 3 0; #X restore 32 594 pd in2; #X text 28 469 white signal:; #X text 30 550 non-white signal:; #X text 87 569 -> c0 \, c1 \, c2 not precise; #X text 90 489 -> c0 \, c1 \, c2 precise; #X text 29 274 how to choose mu ?; #X text 72 300 0 < mu < 2/(abs(x[n])^2); #X text 72 321 -> abs(x[n])^2 is the tap-input energy; #X text 94 336 at time n (lenght of x[n] is PDs; #X text 46 373 Note: this only ensures "stability on average"; #X text 94 351 blocksize - so use block~ to change it!); #X connect 1 0 2 0; #X connect 4 0 12 0; #X connect 11 0 13 0; #X connect 14 0 15 0; #X restore 34 120 pd OBSERVATIONS; #X text 33 73 ReadMe:; #N canvas 0 0 642 300 input_signal~ 0; #X obj 77 90 noise~; #X obj 201 84 inlet; #X obj 77 217 *~; #X obj 210 273 outlet~; #X obj 201 115 sel 0 1; #X msg 91 190 1; #X msg 121 190 0; #X obj 325 88 noise~; #X text 53 64 white signal:; #X text 292 63 non white signal:; #X obj 322 224 *~; #X msg 336 197 1; #X msg 366 197 0; #X obj 324 112 hip~ 300; #X obj 492 148 bp~ 2543 2; #X obj 406 149 bp~ 1000 3; #X obj 323 148 bp~ 100 2; #X connect 0 0 2 0; #X connect 1 0 4 0; #X connect 2 0 3 0; #X connect 4 0 5 0; #X connect 4 0 12 0; #X connect 4 1 6 0; #X connect 4 1 11 0; #X connect 5 0 2 1; #X connect 6 0 2 1; #X connect 7 0 13 0; #X connect 10 0 3 0; #X connect 11 0 10 1; #X connect 12 0 10 1; #X connect 13 0 14 0; #X connect 13 0 15 0; #X connect 13 0 16 0; #X connect 14 0 10 0; #X connect 15 0 10 0; #X connect 16 0 10 0; #X restore 117 210 pd input_signal~; #X obj 117 162 vradio 20 1 1 2 empty signalr empty 0 -6 0 8 -262144 -1 -1 0; #X text 144 163 white signal (noise); #X text 145 183 non white signal (filtered noise); #X obj 524 43 spectrum~; #X text 33 32 SYSTEM IDENTIFICATION IN A NOISE FREE ENVIRONMENT; #X connect 0 0 3 1; #X connect 3 1 36 0; #X connect 3 2 37 0; #X connect 3 3 38 0; #X connect 8 0 4 0; #X connect 12 0 4 2; #X connect 13 0 56 2; #X connect 14 0 56 0; #X connect 30 0 56 1; #X connect 31 0 4 1; #X connect 52 0 0 0; #X connect 52 0 3 0; #X connect 53 0 52 0;