| 29 | | // Design root raised-cosine filter |
| 30 | | // |
| 31 | | //----------------------------------------------------------------------------- |
| 32 | | /** \brief Calculate square-root raised-cosine filter coefficients |
| 33 | | |
| 34 | | DesignRRCFilter calculates the coefficients for a square-root raised-cosine |
| 35 | | (RRC) finite impulse response (FIR) filter commonly used in digital |
| 36 | | communications. The input parameters are as follows |
| 37 | | |
| 38 | | - \f$k\f$ : samples per symbol |
| 39 | | - \f$m\f$ : sample delay |
| 40 | | - \f$\beta\f$ : excess bandwidth (rolloff) factor |
| 41 | | |
| 42 | | The function returns a pointer to the filter coefficients as well as an |
| 43 | | integer value describing the length of the filter. The length of the |
| 44 | | filter is always |
| 45 | | |
| 46 | | \f[ |
| 47 | | h_{len} = 2 k m + 1 |
| 48 | | \f] |
| 49 | | |
| 50 | | The filter coefficients themselves are derived from the following equation |
| 51 | | |
| 52 | | \f[ |
| 53 | | h\left[z\right] = |
| 54 | | 4\beta \frac{ \cos\left[(1+\beta)\pi z\right] + |
| 55 | | \sin\left[(1+\beta)\pi z\right] / (4\beta z) } |
| 56 | | { \pi \sqrt{T}\left[ 1-16\beta^2z^2\right] } |
| 57 | | \f] |
| 58 | | |
| 59 | | where \f$z=n/k-m\f$, and \f$T=1\f$ for most cases. |
| 60 | | |
| 61 | | The function compensates for the two cases where \f$h[n]\f$ might be |
| 62 | | undefined in the above equation, viz. |
| 63 | | |
| 64 | | \f[ |
| 65 | | \mathop {\lim }\limits_{z \to 0 } h(z) = |
| 66 | | \frac{ 4\beta \left[ 1 + \frac{1-\beta\pi }{ 4\beta } \right] } |
| 67 | | { \pi\sqrt{T}\left( 1-16\beta^2 z^2 \right) } |
| 68 | | \f] |
| 69 | | |
| 70 | | and |
| 71 | | |
| 72 | | \f[ |
| 73 | | \mathop {\lim }\limits_{z \to \pm \frac{1}{4\beta} } h(z) = |
| 74 | | \frac{(1+\beta)}{2\pi}\sin\left[\frac{(1+\beta)\pi}{4\beta}\right] |
| 75 | | - \frac{(1-\beta)}{2}\cos\left[\frac{(1-\beta)\pi}{4\beta}\right] |
| 76 | | + \frac{2\beta}{\pi}\sin\left[\frac{(1-\beta)\pi}{4\beta}\right] |
| 77 | | |
| 78 | | \f] |
| 79 | | |
| 80 | | \param[in] k samples per symbol |
| 81 | | \param[in] m symbol delay |
| 82 | | \param[in] beta excess bandwidth/rolloff factor ( 0 < beta < 1 ) |
| 83 | | \param[out] h pointer to filter coefficients |
| 84 | | \param[out] h_len length of filter, h_len = 2*m*k+1 |
| 85 | | |
| 86 | | */ |
| 87 | | |
| 88 | | void DesignRRCFilter( |
| 89 | | unsigned int k, // samples per symbol |
| 90 | | unsigned int m, // delay |
| 91 | | float beta, // rolloff factor ( 0 < beta <= 1 ) |
| 92 | | float *& h, // pointer to filter coefficients |
| 93 | | unsigned int & h_len // length of filter (len = 2*m*k+1) |
| 94 | | ) |
| 95 | | { |
| 96 | | h_len = 0; |
| 97 | | |
| 98 | | if ( k < 1 ) { |
| 99 | | std::cerr << "ERROR: SigProc::DesignRRCFilter: k must be greater than 0" |
| 100 | | << std::endl; |
| 101 | | throw 0; |
| 102 | | } else if ( m < 1 ) { |
| 103 | | std::cerr << "ERROR: SigProc::DesignRRCFilter: m must be greater than 0" |
| 104 | | << std::endl; |
| 105 | | throw 0; |
| 106 | | } else if ( (beta < 0.0f) || (beta > 1.0f) ) { |
| 107 | | std::cerr << "ERROR: SigProc::DesignRRCFilter: beta must be in [0,1]" |
| 108 | | << std::endl; |
| 109 | | throw 0; |
| 110 | | } else; |
| 111 | | |
| 112 | | unsigned int n; |
| 113 | | float z, t1, t2, t3, t4, T(1.0f); |
| 114 | | float pi(3.14159265358979f); |
| 115 | | |
| 116 | | h_len = 2*k*m+1; |
| 117 | | h = new float[h_len]; |
| 118 | | |
| 119 | | // Calculate filter coefficients |
| 120 | | for (n=0; n<h_len; n++) { |
| 121 | | |
| 122 | | z = float(n)/float(k)-float(m); |
| 123 | | t1 = cosf((1+beta)*pi*z); |
| 124 | | t2 = sinf((1-beta)*pi*z); |
| 125 | | |
| 126 | | // Check for special condition where z equals zero |
| 127 | | if ( n == k*m ) { |
| 128 | | t4 = 4*beta/(pi*sqrtf(T)*(1-(16*beta*beta*z*z))); |
| 129 | | h[n] = t4*( 1 + (1-beta)*pi/(4*beta) ); |
| 130 | | } else { |
| 131 | | t3 = 1/((4*beta*z)); |
| 132 | | |
| 133 | | float g = 1-16*beta*beta*z*z; |
| 134 | | g *= g; |
| 135 | | |
| 136 | | // Check for special condition where 16*beta^2*z^2 equals 1 |
| 137 | | if ( g < 1e-3 ) { |
| 138 | | float g1, g2, g3, g4; |
| 139 | | g1 = -(1+beta)*pi*sin((1+beta)*pi/(4*beta)); |
| 140 | | g2 = cos((1-beta)*pi/(4*beta))*(1-beta)*pi; |
| 141 | | g3 = -sin((1-beta)*pi/(4*beta))*4*beta; |
| 142 | | g4 = -2*pi; |
| 143 | | |
| 144 | | h[n] = (g1+g2+g3)/g4; |
| 145 | | } else { |
| 146 | | t4 = 4*beta/(pi*sqrtf(T)*(1-(16*beta*beta*z*z))); |
| 147 | | h[n] = t4*( t1 + (t2*t3) ); |
| 148 | | } |
| 149 | | } |
| 150 | | } |
| 151 | | } |
| 152 | | |
| 153 | | //----------------------------------------------------------------------------- |
| 154 | | // |
| 155 | | // Design Gaussian filter |
| 156 | | // |
| 157 | | //----------------------------------------------------------------------------- |
| 158 | | /** \brief Calculate Gaussian filter coefficients |
| 159 | | |
| 160 | | DesignRRCFilter calculates the coefficients for a square-root raised-cosine |
| 161 | | (RRC) finite impulse response (FIR) filter commonly used in digital |
| 162 | | communications. The input parameters are as follows |
| 163 | | |
| 164 | | - \f$k\f$ : samples per symbol |
| 165 | | - \f$m\f$ : sample delay |
| 166 | | - \f$\beta\f$ : excess bandwidth factor |
| 167 | | |
| 168 | | The function returns a pointer to the filter coefficients as well as an |
| 169 | | integer value describing the length of the filter. The length of the |
| 170 | | filter is always |
| 171 | | |
| 172 | | \f[ |
| 173 | | h_{len} = 2 k m + 1 |
| 174 | | \f] |
| 175 | | |
| 176 | | The filter coefficients themselves are derived from the following equation |
| 177 | | |
| 178 | | \f[ |
| 179 | | h\left[z\right] = \frac{1}{\sqrt[4]{2\pi\sigma}} |
| 180 | | e^{\left(-z^2/{4\sigma^2}\right)} |
| 181 | | \f] |
| 182 | | |
| 183 | | where \f$z=n/k-m\f$ and \f$\sigma=\beta\f$. |
| 184 | | |
| 185 | | \param[in] k samples per symbol |
| 186 | | \param[in] m symbol delay |
| 187 | | \param[in] beta excess bandwidth/rolloff factor ( 0 < beta < 1 ) |
| 188 | | \param[out] h pointer to filter coefficients |
| 189 | | \param[out] h_len length of filter, h_len = 2*m*k+1 |
| 190 | | |
| 191 | | */ |
| 192 | | |
| 193 | | void DesignGaussianFilter( |
| 194 | | unsigned int k, // samples per symbol |
| 195 | | unsigned int m, // delay |
| 196 | | float beta, // rolloff factor ( 0 < beta ) |
| 197 | | float *& h, // pointer to filter coefficients |
| 198 | | unsigned int & h_len // length of filter (len = 2*m*k+1) |
| 199 | | ) { |
| 200 | | h_len = 0; |
| 201 | | |
| 202 | | if ( k < 1 ) { |
| 203 | | std::cerr << "ERROR: SigProc::DesignGaussianFilter: k must be greater than 0" |
| 204 | | << std::endl; |
| 205 | | throw 0; |
| 206 | | } else if ( m < 1 ) { |
| 207 | | std::cerr << "ERROR: SigProc::DesignGaussianFilter: m must be greater than 0" |
| 208 | | << std::endl; |
| 209 | | throw 0; |
| 210 | | } else if ( beta < 0.0f) { |
| 211 | | std::cerr << "ERROR: SigProc::DesignGaussianFilter: beta must be greater than 0" |
| 212 | | << std::endl; |
| 213 | | throw 0; |
| 214 | | } else; |
| 215 | | |
| 216 | | h_len = 2*k*m + 1; |
| 217 | | h = new float[h_len]; |
| 218 | | float sigma(beta); ///\todo determine how to calculate sigma from beta |
| 219 | | float pi(3.14159265358979f); |
| 220 | | float g1( 2*sigma*sigma ); |
| 221 | | float g2( 1/sqrtf(g1*pi) ); |
| 222 | | float z; |
| 223 | | |
| 224 | | for (unsigned int n=0; n<h_len; n++) { |
| 225 | | // Check for special condition where z equals zero |
| 226 | | if ( n == k*m ) { |
| 227 | | h[n] = g2; |
| 228 | | } else { |
| 229 | | z = float(n)/float(k)-float(m); |
| 230 | | h[n] = expf(-z*z/g1)*g2; |
| 231 | | } |
| 232 | | } |
| 233 | | } |
| 234 | | |
| 235 | | //----------------------------------------------------------------------------- |
| 236 | | // |
| 237 | | // FIR polyphase filter bank |
| | 33 | // P/N Sequence |
| 241 | | // Initializing constructor |
| 242 | | FIRPolyphaseFilterBank::FIRPolyphaseFilterBank( |
| 243 | | char * _type, // type of filter |
| 244 | | unsigned int _k, // samples per symbol |
| 245 | | unsigned int _m, // delay |
| 246 | | float _beta, // excess bandwidth factor |
| 247 | | unsigned int _Npfb // number of filters |
| 248 | | ) |
| 249 | | { |
| 250 | | k = _k; |
| 251 | | m = _m; |
| 252 | | beta = _beta; |
| 253 | | Npfb = _Npfb; |
| 254 | | |
| 255 | | H = NULL; |
| 256 | | |
| 257 | | if ( strcmp(_type,"rrcos")==0 ) { |
| 258 | | // Square-root raised-cosine filter |
| 259 | | CalculateRRCFilterCoefficients(); |
| 260 | | TransposeCoefficientMatrix(); |
| 261 | | } else if ( strcmp(_type,"drrcos")==0 ) { |
| 262 | | // Derivative square-root raised-cosine filter |
| 263 | | CalculateRRCFilterCoefficients(); |
| 264 | | CalculateDerivativeFilterCoefficients(); |
| 265 | | TransposeCoefficientMatrix(); |
| 266 | | } else if ( strcmp(_type,"gaussian")==0 ) { |
| 267 | | // Gaussian filter |
| 268 | | CalculateGaussianFilterCoefficients(); |
| 269 | | TransposeCoefficientMatrix(); |
| 270 | | } else if ( strcmp(_type,"dgaussian")==0 ) { |
| 271 | | // Derivative gaussian filter |
| 272 | | CalculateGaussianFilterCoefficients(); |
| 273 | | CalculateDerivativeFilterCoefficients(); |
| 274 | | TransposeCoefficientMatrix(); |
| 275 | | } else { |
| 276 | | std::cerr << "ERROR: FIRPolyphaseFilterBank: unknown filter type : " << _type << std::endl; |
| 277 | | throw 0; |
| | 37 | PNSequence::PNSequence(unsigned int _g, unsigned int _a) { |
| | 38 | unsigned int i; |
| | 39 | |
| | 40 | // extract shift register length from generator polynomial |
| | 41 | unsigned long g_tmp(_g); |
| | 42 | m = 0; |
| | 43 | // this loop effectively counts the placement of the MSB in _g |
| | 44 | for (i=0; i<sizeof(unsigned long)*8; i++) { |
| | 45 | if ( g_tmp & 0x0001 ) |
| | 46 | m = i; |
| | 47 | g_tmp >>= 1; |
| 320 | | // push input value into buffer |
| 321 | | void FIRPolyphaseFilterBank::PushInput(short _x) |
| 322 | | { |
| 323 | | // Add _x to input buffer |
| 324 | | v.Push( _x ); |
| 325 | | } |
| 326 | | |
| 327 | | // compute filter output from current buffer state using specific filter |
| 328 | | void FIRPolyphaseFilterBank::ComputeOutput( |
| 329 | | short &y, // output sample |
| 330 | | unsigned int _b // filter bank index |
| 331 | | ) |
| 332 | | { |
| 333 | | // Ensure the requested filter bank index does not exceed the number |
| 334 | | // of filters actually in the bank |
| 335 | | if ( _b >= Npfb ) |
| 336 | | { |
| 337 | | std::cerr << "ERROR: SigProc::FIRPolyphaseFitlerBank::ComputeOutput, " |
| 338 | | << " index exceeds filter bank size (" |
| 339 | | << _b << " > " << Npfb << ")" << std::endl; |
| 340 | | throw 0; |
| 341 | | } |
| 342 | | |
| 343 | | // Set B to memory block in filter bank array |
| 344 | | unsigned int B; |
| 345 | | B = _b*h_len; |
| 346 | | |
| 347 | | // Compute dot product |
| 348 | | dot_product( H+B, v.GetHeadPtr(), h_len, y); |
| 349 | | |
| 350 | | } |
| 351 | | |
| 352 | | // compute filter output from current buffer state using specific filter |
| 353 | | void FIRPolyphaseFilterBank::ComputeOutput( |
| 354 | | short &y, // output sample |
| 355 | | unsigned int _b, // filter bank index |
| 356 | | short *_v // external memory buffer array |
| 357 | | ) |
| 358 | | { |
| 359 | | // Ensure the requested filter bank index does not exceed the number |
| 360 | | // of filters actually in the bank |
| 361 | | if ( _b >= Npfb ) |
| 362 | | { |
| 363 | | std::cerr << "ERROR: SigProc::FIRPolyphaseFitlerBank::ComputeOutput, " |
| 364 | | << " index exceeds filter bank size (" |
| 365 | | << _b << " > " << Npfb << ")" << std::endl; |
| 366 | | throw 0; |
| 367 | | } |
| 368 | | |
| 369 | | // Set B to memory block in filter bank array |
| 370 | | unsigned int B; |
| 371 | | B = _b*h_len; |
| 372 | | |
| 373 | | // Compute dot product |
| 374 | | dot_product( H+B, _v, h_len, y); |
| 375 | | |
| 376 | | } |
| 377 | | |
| 378 | | // Reset filter buffer |
| 379 | | void FIRPolyphaseFilterBank::ResetBuffer() |
| 380 | | { |
| 381 | | v.Release(); |
| 382 | | |
| 383 | | // Load buffer with zeros |
| 384 | | for (unsigned int i=0; i<h_len; i++) |
| 385 | | v.Push( 0 ); |
| 386 | | } |
| 387 | | |
| 388 | | // Print filter buffer |
| 389 | | void FIRPolyphaseFilterBank::PrintBuffer() |
| 390 | | { |
| 391 | | v.Print(); |
| 392 | | } |
| 393 | | |
| 394 | | // Print filter bank coefficients to the screen |
| 395 | | void FIRPolyphaseFilterBank::PrintFilterBankCoefficients() |
| 396 | | { |
| 397 | | if ( H == NULL ) |
| 398 | | { |
| 399 | | std::cout << "ERROR: SigProc::FIRPolyphaseFilterBank: " |
| 400 | | << "cannot print filter coefficients (matrix empty)" |
| 401 | | << std::endl; |
| 402 | | return; |
| 403 | | } |
| 404 | | |
| 405 | | unsigned int r, c, B; |
| 406 | | std::cout << "H = [" << std::endl; |
| 407 | | for (r=0; r<Npfb; r++ ) { |
| 408 | | B = r*h_len; |
| 409 | | printf(" "); |
| 410 | | |
| 411 | | for (c=0; c<h_len; c++) { |
| 412 | | printf("%0.3f ", H[B + c]); |
| 413 | | } |
| 414 | | printf(";\n"); |
| 415 | | } |
| 416 | | std::cout << " ]" << std::endl; |
| 417 | | |
| 418 | | } |
| 419 | | |
| 420 | | // |
| 421 | | void FIRPolyphaseFilterBank::TransposeCoefficientMatrix() |
| 422 | | { |
| 423 | | // create temporary pointer |
| 424 | | float * H_tmp; |
| 425 | | H_tmp = H; |
| 426 | | |
| 427 | | // allocate new memory for filter bank coefficients |
| 428 | | H = new float[h_len*Npfb]; |
| 429 | | |
| 430 | | // reshape matrix |
| 431 | | unsigned int i(0), r, c; |
| 432 | | for (r=0; r<Npfb; r++) { |
| 433 | | for (c=0; c<h_len; c++) |
| 434 | | H[i++] = H_tmp[c*Npfb + r]; |
| 435 | | } |
| 436 | | |
| 437 | | delete [] H_tmp; |
| 438 | | } |
| 439 | | |
| 440 | | |
| 441 | | // Calculate root raised-cosine coefficients |
| 442 | | void FIRPolyphaseFilterBank::CalculateRRCFilterCoefficients() |
| 443 | | { |
| 444 | | if ( H != NULL ) |
| 445 | | delete [] H; |
| 446 | | |
| 447 | | // create over-sampled pulse |
| 448 | | DesignRRCFilter(Npfb*k, m, beta, H, h_len); |
| 449 | | |
| 450 | | // Apply scaling factor to filter coefficients |
| 451 | | float h_scale = float(k); |
| 452 | | for (unsigned int i=0; i<h_len; i++) |
| 453 | | H[i] /= h_scale; |
| 454 | | |
| 455 | | // |
| 456 | | h_len = ( h_len - 1 ) / Npfb; |
| 457 | | |
| 458 | | } |
| 459 | | |
| 460 | | // |
| 461 | | void FIRPolyphaseFilterBank::CalculateGaussianFilterCoefficients() |
| 462 | | { |
| 463 | | if ( H != NULL ) |
| 464 | | delete [] H; |
| 465 | | |
| 466 | | } |
| 467 | | |
| 468 | | // Calculate derivative filter coefficients |
| 469 | | void FIRPolyphaseFilterBank::CalculateDerivativeFilterCoefficients() |
| 470 | | { |
| 471 | | unsigned int N = h_len*Npfb; |
| 472 | | |
| 473 | | float * dH = new float[N]; |
| 474 | | |
| 475 | | for (unsigned int i=0; i<N; i++) { |
| 476 | | if ( i==0 ) { |
| 477 | | dH[0] = H[1] - H[N-1]; |
| 478 | | } else if ( i==N-1 ) { |
| 479 | | dH[N-1] = H[0] - H[N-2]; |
| 480 | | } else { |
| 481 | | dH[i] = H[i+1] - H[i-1]; |
| 482 | | } |
| 483 | | dH[i] /= 2.0f; |
| 484 | | } |
| 485 | | |
| 486 | | delete [] H; |
| 487 | | H = dH; |
| 488 | | } |
| 489 | | |
| 490 | | |
| 491 | | iir_filter::iir_filter(float a_coeff[], unsigned int len_a, float b_coeff[], unsigned int len_b) : len_A(len_a), len_B(len_b), next_v(0) |
| 492 | | { |
| 493 | | |
| 494 | | A = new float[len_a]; |
| 495 | | B = new float[len_b]; |
| 496 | | |
| 497 | | for (unsigned int i = 0; i < len_a; ++i) |
| 498 | | A[i] = a_coeff[i]; |
| 499 | | |
| 500 | | for (unsigned int i = 0; i < len_b; ++i) |
| 501 | | B[i] = b_coeff[i]; |
| 502 | | |
| 503 | | if (len_A > len_B) |
| 504 | | len_v = len_A; |
| 505 | | else |
| 506 | | len_v = len_B; |
| 507 | | |
| 508 | | v = new float[len_v]; |
| 509 | | |
| 510 | | for (unsigned int i = 0; i < len_v; ++i) |
| 511 | | v[i] = 0; |
| 512 | | |
| 513 | | } |
| 514 | | |
| 515 | | void iir_filter::ResetBuffer() |
| 516 | | { |
| 517 | | for (unsigned int i = 0; i < len_v; ++i) |
| 518 | | v[i] = 0; |
| 519 | | } |
| 520 | | |
| 521 | | void iir_filter::do_work(short x, short &y) |
| 522 | | { |
| 523 | | // calculate new v[n] |
| 524 | | int v_idx = next_v; |
| 525 | | |
| 526 | | v[next_v] = x; |
| 527 | | |
| 528 | | for (unsigned int i = 1; i < len_A; ++i) { |
| 529 | | |
| 530 | | --v_idx; |
| 531 | | if (v_idx < 0) |
| 532 | | v_idx += len_v; |
| 533 | | |
| 534 | | v[next_v] -= (short) (A[i] * v[v_idx]); |
| 535 | | |
| 536 | | } |
| 537 | | |
| 538 | | // Now calculate the output value |
| 539 | | v_idx = next_v; |
| 540 | | float out = 0; |
| 541 | | |
| 542 | | for (unsigned int i = 0; i < len_B; ++i) { |
| 543 | | out += (B[i] * v[v_idx]); |
| 544 | | |
| 545 | | --v_idx; |
| 546 | | if (v_idx < 0) |
| 547 | | v_idx += len_v; |
| 548 | | } |
| 549 | | |
| 550 | | next_v = (++next_v) % len_v; |
| 551 | | |
| 552 | | if (out < SHRT_MIN) |
| 553 | | y = SHRT_MIN; |
| 554 | | else if (out > SHRT_MAX) |
| 555 | | y = SHRT_MAX; |
| 556 | | else |
| 557 | | y = (short) out; |
| 558 | | } |
| 559 | | |
| 560 | | |
| 561 | | fir_filter::fir_filter(float a_coeff[], unsigned int len_a) : len_A(len_a), len_v(len_a),next_v(0) |
| 562 | | { |
| 563 | | #ifdef FPM |
| 564 | | A = new mad_fixed_t[len_a]; |
| 565 | | v = new mad_fixed_t[len_v]; |
| 566 | | #else |
| 567 | | A = new float[len_a]; |
| 568 | | v = new short[len_v]; |
| 569 | | #endif |
| 570 | | |
| 571 | | for (unsigned int i = 0; i < len_a; ++i) |
| 572 | | #ifdef FPM |
| 573 | | A[i] = mad_f_tofixed(a_coeff[i]); |
| 574 | | #else |
| 575 | | A[i] = a_coeff[i]; |
| 576 | | #endif |
| 577 | | |
| 578 | | |
| 579 | | for (unsigned int i = 0; i < len_v; ++i) |
| 580 | | v[i] = 0; |
| 581 | | |
| 582 | | |
| 583 | | } |
| 584 | | |
| 585 | | void fir_filter::do_work(bool run_filter, short x, short &y) |
| 586 | | { |
| 587 | | // calculate new v[n] |
| 588 | | int v_idx = next_v; |
| 589 | | |
| 590 | | v[next_v] = x; |
| 591 | | next_v = (++next_v) % len_v; |
| 592 | | |
| 593 | | if (!run_filter) { // Do not create an output value |
| 594 | | y = 0; |
| 595 | | return; |
| 596 | | } |
| 597 | | |
| 598 | | // Now calculate the output value |
| 599 | | #ifdef FPM |
| 600 | | mad_fixed_t out(0); |
| 601 | | #else |
| 602 | | float out(0.0); |
| 603 | | #endif |
| 604 | | |
| 605 | | for (unsigned int i = 0; i < len_A; ++i) { |
| 606 | | if (v[v_idx]) { |
| 607 | | #ifdef FPM |
| 608 | | out = mad_f_add(out, mad_f_mul(A[i], v[v_idx])); |
| 609 | | #else |
| 610 | | out += (A[i] * v[v_idx]); |
| 611 | | #endif |
| 612 | | } |
| 613 | | |
| 614 | | --v_idx; |
| 615 | | if (v_idx < 0) |
| 616 | | v_idx += len_v; |
| 617 | | } |
| 618 | | |
| 619 | | #ifdef FPM |
| 620 | | y = (short) out; |
| 621 | | #else |
| 622 | | if (out < SHRT_MIN) |
| 623 | | y = SHRT_MIN; |
| 624 | | else if (out > SHRT_MAX) |
| 625 | | y = SHRT_MAX; |
| 626 | | else |
| 627 | | y = (short) out; |
| 628 | | #endif |
| 629 | | } |
| 630 | | |
| 631 | | void fir_filter::reset() |
| 632 | | { |
| 633 | | |
| 634 | | for (unsigned int i = 0; i < len_v; ++i) |
| 635 | | v[i] = 0; |
| 636 | | |
| 637 | | next_v = 0; |
| | 75 | PNSequence::~PNSequence() { |
| | 76 | delete [] g; |
| | 77 | delete [] a; |
| | 78 | delete [] s; |