Tom Tsou | 3522229 | 2016-06-22 16:16:30 -0700 | [diff] [blame^] | 1 | /* |
| 2 | * Polyphase channelizer |
| 3 | * |
| 4 | * Copyright (C) 2012-2014 Tom Tsou <tom@tsou.cc> |
| 5 | * Copyright (C) 2015 Ettus Research LLC |
| 6 | * |
| 7 | * This program is free software: you can redistribute it and/or modify |
| 8 | * it under the terms of the GNU Affero General Public License as published by |
| 9 | * the Free Software Foundation, either version 3 of the License, or |
| 10 | * (at your option) any later version. |
| 11 | * |
| 12 | * This program is distributed in the hope that it will be useful, |
| 13 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 15 | * GNU Affero General Public License for more details. |
| 16 | * |
| 17 | * You should have received a copy of the GNU Affero General Public License |
| 18 | * along with this program. If not, see <http://www.gnu.org/licenses/>. |
| 19 | * See the COPYING file in the main directory for details. |
| 20 | */ |
| 21 | |
| 22 | #include <stdlib.h> |
| 23 | #include <math.h> |
| 24 | #include <assert.h> |
| 25 | #include <string.h> |
| 26 | #include <cstdio> |
| 27 | |
| 28 | #include "Logger.h" |
| 29 | #include "Channelizer.h" |
| 30 | |
| 31 | extern "C" { |
| 32 | #include "common/fft.h" |
| 33 | #include "common/convolve.h" |
| 34 | } |
| 35 | |
| 36 | static void deinterleave(const float *in, size_t ilen, |
| 37 | float **out, size_t olen, size_t m) |
| 38 | { |
| 39 | size_t i, n; |
| 40 | |
| 41 | for (i = 0; i < olen; i++) { |
| 42 | for (n = 0; n < m; n++) { |
| 43 | out[m - 1 - n][2 * i + 0] = in[2 * (i * m + n) + 0]; |
| 44 | out[m - 1 - n][2 * i + 1] = in[2 * (i * m + n) + 1]; |
| 45 | } |
| 46 | } |
| 47 | } |
| 48 | |
| 49 | size_t Channelizer::inputLen() const |
| 50 | { |
| 51 | return blockLen * m; |
| 52 | } |
| 53 | |
| 54 | size_t Channelizer::outputLen() const |
| 55 | { |
| 56 | return blockLen; |
| 57 | } |
| 58 | |
| 59 | float *Channelizer::outputBuffer(size_t chan) const |
| 60 | { |
| 61 | if (chan >= m) |
| 62 | return NULL; |
| 63 | |
| 64 | return hInputs[chan]; |
| 65 | } |
| 66 | |
| 67 | /* |
| 68 | * Implementation based on material found in: |
| 69 | * |
| 70 | * "harris, fred, Multirate Signal Processing, Upper Saddle River, NJ, |
| 71 | * Prentice Hall, 2006." |
| 72 | */ |
| 73 | bool Channelizer::rotate(const float *in, size_t len) |
| 74 | { |
| 75 | size_t hSize = 2 * hLen * sizeof(float); |
| 76 | |
| 77 | if (!checkLen(blockLen, len)) |
| 78 | return false; |
| 79 | |
| 80 | deinterleave(in, len, hInputs, blockLen, m); |
| 81 | |
| 82 | /* |
| 83 | * Convolve through filterbank while applying and saving sample history |
| 84 | */ |
| 85 | for (size_t i = 0; i < m; i++) { |
| 86 | memcpy(&hInputs[i][2 * -hLen], hist[i], hSize); |
| 87 | memcpy(hist[i], &hInputs[i][2 * (blockLen - hLen)], hSize); |
| 88 | |
| 89 | convolve_real(hInputs[i], blockLen, |
| 90 | subFilters[i], hLen, |
| 91 | hOutputs[i], blockLen, |
| 92 | 0, blockLen, 1, 0); |
| 93 | } |
| 94 | |
| 95 | cxvec_fft(fftHandle); |
| 96 | |
| 97 | return true; |
| 98 | } |
| 99 | |
| 100 | /* Setup channelizer paramaters */ |
| 101 | Channelizer::Channelizer(size_t m, size_t blockLen, size_t hLen) |
| 102 | : ChannelizerBase(m, blockLen, hLen) |
| 103 | { |
| 104 | } |
| 105 | |
| 106 | Channelizer::~Channelizer() |
| 107 | { |
| 108 | } |