diff options
Diffstat (limited to 'gr-digital/lib/digital_ofdm_frame_sink.cc')
-rw-r--r-- | gr-digital/lib/digital_ofdm_frame_sink.cc | 405 |
1 files changed, 0 insertions, 405 deletions
diff --git a/gr-digital/lib/digital_ofdm_frame_sink.cc b/gr-digital/lib/digital_ofdm_frame_sink.cc deleted file mode 100644 index f8fb1bbb1d..0000000000 --- a/gr-digital/lib/digital_ofdm_frame_sink.cc +++ /dev/null @@ -1,405 +0,0 @@ -/* -*- c++ -*- */ -/* - * Copyright 2007,2008,2010,2011 Free Software Foundation, Inc. - * - * This file is part of GNU Radio - * - * GNU Radio is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License as published by - * the Free Software Foundation; either version 3, or (at your option) - * any later version. - * - * GNU Radio is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with GNU Radio; see the file COPYING. If not, write to - * the Free Software Foundation, Inc., 51 Franklin Street, - * Boston, MA 02110-1301, USA. - */ - -#ifdef HAVE_CONFIG_H -#include "config.h" -#endif - -#include <digital_ofdm_frame_sink.h> -#include <gr_io_signature.h> -#include <gr_expj.h> -#include <gr_math.h> -#include <math.h> -#include <cstdio> -#include <stdexcept> -#include <iostream> -#include <string.h> - -#define VERBOSE 0 - -inline void -digital_ofdm_frame_sink::enter_search() -{ - if (VERBOSE) - fprintf(stderr, "@ enter_search\n"); - - d_state = STATE_SYNC_SEARCH; - -} - -inline void -digital_ofdm_frame_sink::enter_have_sync() -{ - if (VERBOSE) - fprintf(stderr, "@ enter_have_sync\n"); - - d_state = STATE_HAVE_SYNC; - - // clear state of demapper - d_byte_offset = 0; - d_partial_byte = 0; - - d_header = 0; - d_headerbytelen_cnt = 0; - - // Resetting PLL - d_freq = 0.0; - d_phase = 0.0; - fill(d_dfe.begin(), d_dfe.end(), gr_complex(1.0,0.0)); -} - -inline void -digital_ofdm_frame_sink::enter_have_header() -{ - d_state = STATE_HAVE_HEADER; - - // header consists of two 16-bit shorts in network byte order - // payload length is lower 12 bits - // whitener offset is upper 4 bits - d_packetlen = (d_header >> 16) & 0x0fff; - d_packet_whitener_offset = (d_header >> 28) & 0x000f; - d_packetlen_cnt = 0; - - if (VERBOSE) - fprintf(stderr, "@ enter_have_header (payload_len = %d) (offset = %d)\n", - d_packetlen, d_packet_whitener_offset); -} - - -unsigned char digital_ofdm_frame_sink::slicer(const gr_complex x) -{ - unsigned int table_size = d_sym_value_out.size(); - unsigned int min_index = 0; - float min_euclid_dist = norm(x - d_sym_position[0]); - float euclid_dist = 0; - - for (unsigned int j = 1; j < table_size; j++){ - euclid_dist = norm(x - d_sym_position[j]); - if (euclid_dist < min_euclid_dist){ - min_euclid_dist = euclid_dist; - min_index = j; - } - } - return d_sym_value_out[min_index]; -} - -unsigned int digital_ofdm_frame_sink::demapper(const gr_complex *in, - unsigned char *out) -{ - unsigned int i=0, bytes_produced=0; - gr_complex carrier; - - carrier=gr_expj(d_phase); - - gr_complex accum_error = 0.0; - //while(i < d_occupied_carriers) { - while(i < d_subcarrier_map.size()) { - if(d_nresid > 0) { - d_partial_byte |= d_resid; - d_byte_offset += d_nresid; - d_nresid = 0; - d_resid = 0; - } - - //while((d_byte_offset < 8) && (i < d_occupied_carriers)) { - while((d_byte_offset < 8) && (i < d_subcarrier_map.size())) { - //gr_complex sigrot = in[i]*carrier*d_dfe[i]; - gr_complex sigrot = in[d_subcarrier_map[i]]*carrier*d_dfe[i]; - - if(d_derotated_output != NULL){ - d_derotated_output[i] = sigrot; - } - - unsigned char bits = slicer(sigrot); - - gr_complex closest_sym = d_sym_position[bits]; - - accum_error += sigrot * conj(closest_sym); - - // FIX THE FOLLOWING STATEMENT - if (norm(sigrot)> 0.001) d_dfe[i] += d_eq_gain*(closest_sym/sigrot-d_dfe[i]); - - i++; - - if((8 - d_byte_offset) >= d_nbits) { - d_partial_byte |= bits << (d_byte_offset); - d_byte_offset += d_nbits; - } - else { - d_nresid = d_nbits-(8-d_byte_offset); - int mask = ((1<<(8-d_byte_offset))-1); - d_partial_byte |= (bits & mask) << d_byte_offset; - d_resid = bits >> (8-d_byte_offset); - d_byte_offset += (d_nbits - d_nresid); - } - //printf("demod symbol: %.4f + j%.4f bits: %x partial_byte: %x byte_offset: %d resid: %x nresid: %d\n", - // in[i-1].real(), in[i-1].imag(), bits, d_partial_byte, d_byte_offset, d_resid, d_nresid); - } - - if(d_byte_offset == 8) { - //printf("demod byte: %x \n\n", d_partial_byte); - out[bytes_produced++] = d_partial_byte; - d_byte_offset = 0; - d_partial_byte = 0; - } - } - //std::cerr << "accum_error " << accum_error << std::endl; - - float angle = arg(accum_error); - - d_freq = d_freq - d_freq_gain*angle; - d_phase = d_phase + d_freq - d_phase_gain*angle; - if (d_phase >= 2*M_PI) d_phase -= 2*M_PI; - if (d_phase <0) d_phase += 2*M_PI; - - //if(VERBOSE) - // std::cerr << angle << "\t" << d_freq << "\t" << d_phase << "\t" << std::endl; - - return bytes_produced; -} - - -digital_ofdm_frame_sink_sptr -digital_make_ofdm_frame_sink(const std::vector<gr_complex> &sym_position, - const std::vector<unsigned char> &sym_value_out, - gr_msg_queue_sptr target_queue, unsigned int occupied_carriers, - float phase_gain, float freq_gain) -{ - return gnuradio::get_initial_sptr(new digital_ofdm_frame_sink(sym_position, sym_value_out, - target_queue, occupied_carriers, - phase_gain, freq_gain)); -} - - -digital_ofdm_frame_sink::digital_ofdm_frame_sink(const std::vector<gr_complex> &sym_position, - const std::vector<unsigned char> &sym_value_out, - gr_msg_queue_sptr target_queue, unsigned int occupied_carriers, - float phase_gain, float freq_gain) - : gr_sync_block ("ofdm_frame_sink", - gr_make_io_signature2 (2, 2, sizeof(gr_complex)*occupied_carriers, sizeof(char)), - gr_make_io_signature (1, 1, sizeof(gr_complex)*occupied_carriers)), - d_target_queue(target_queue), d_occupied_carriers(occupied_carriers), - d_byte_offset(0), d_partial_byte(0), - d_resid(0), d_nresid(0),d_phase(0),d_freq(0),d_phase_gain(phase_gain),d_freq_gain(freq_gain), - d_eq_gain(0.05) -{ - std::string carriers = "FE7F"; - - // A bit hacky to fill out carriers to occupied_carriers length - int diff = (d_occupied_carriers - 4*carriers.length()); - while(diff > 7) { - carriers.insert(0, "f"); - carriers.insert(carriers.length(), "f"); - diff -= 8; - } - - // if there's extras left to be processed - // divide remaining to put on either side of current map - // all of this is done to stick with the concept of a carrier map string that - // can be later passed by the user, even though it'd be cleaner to just do this - // on the carrier map itself - int diff_left=0; - int diff_right=0; - - // dictionary to convert from integers to ascii hex representation - char abc[16] = {'0', '1', '2', '3', '4', '5', '6', '7', - '8', '9', 'a', 'b', 'c', 'd', 'e', 'f'}; - if(diff > 0) { - char c[2] = {0,0}; - - diff_left = (int)ceil((float)diff/2.0f); // number of carriers to put on the left side - c[0] = abc[(1 << diff_left) - 1]; // convert to bits and move to ASCI integer - carriers.insert(0, c); - - diff_right = diff - diff_left; // number of carriers to put on the right side - c[0] = abc[0xF^((1 << diff_right) - 1)]; // convert to bits and move to ASCI integer - carriers.insert(carriers.length(), c); - } - - // It seemed like such a good idea at the time... - // because we are only dealing with the occupied_carriers - // at this point, the diff_left in the following compensates - // for any offset from the 0th carrier introduced - unsigned int i,j,k; - for(i = 0; i < (d_occupied_carriers/4)+diff_left; i++) { - char c = carriers[i]; - for(j = 0; j < 4; j++) { - k = (strtol(&c, NULL, 16) >> (3-j)) & 0x1; - if(k) { - d_subcarrier_map.push_back(4*i + j - diff_left); - } - } - } - - // make sure we stay in the limit currently imposed by the occupied_carriers - if(d_subcarrier_map.size() > d_occupied_carriers) { - throw std::invalid_argument("digital_ofdm_mapper_bcv: subcarriers allocated exceeds size of occupied carriers"); - } - - d_bytes_out = new unsigned char[d_occupied_carriers]; - d_dfe.resize(occupied_carriers); - fill(d_dfe.begin(), d_dfe.end(), gr_complex(1.0,0.0)); - - set_sym_value_out(sym_position, sym_value_out); - - enter_search(); -} - -digital_ofdm_frame_sink::~digital_ofdm_frame_sink () -{ - delete [] d_bytes_out; -} - -bool -digital_ofdm_frame_sink::set_sym_value_out(const std::vector<gr_complex> &sym_position, - const std::vector<unsigned char> &sym_value_out) -{ - if (sym_position.size() != sym_value_out.size()) - return false; - - if (sym_position.size()<1) - return false; - - d_sym_position = sym_position; - d_sym_value_out = sym_value_out; - d_nbits = (unsigned long)ceil(log10(float(d_sym_value_out.size())) / log10(2.0)); - - return true; -} - - -int -digital_ofdm_frame_sink::work (int noutput_items, - gr_vector_const_void_star &input_items, - gr_vector_void_star &output_items) -{ - const gr_complex *in = (const gr_complex *) input_items[0]; - const char *sig = (const char *) input_items[1]; - unsigned int j = 0; - unsigned int bytes=0; - - // If the output is connected, send it the derotated symbols - if(output_items.size() >= 1) - d_derotated_output = (gr_complex *)output_items[0]; - else - d_derotated_output = NULL; - - if (VERBOSE) - fprintf(stderr,">>> Entering state machine\n"); - - switch(d_state) { - - case STATE_SYNC_SEARCH: // Look for flag indicating beginning of pkt - if (VERBOSE) - fprintf(stderr,"SYNC Search, noutput=%d\n", noutput_items); - - if (sig[0]) { // Found it, set up for header decode - enter_have_sync(); - } - break; - - case STATE_HAVE_SYNC: - // only demod after getting the preamble signal; otherwise, the - // equalizer taps will screw with the PLL performance - bytes = demapper(&in[0], d_bytes_out); - - if (VERBOSE) { - if(sig[0]) - printf("ERROR -- Found SYNC in HAVE_SYNC\n"); - fprintf(stderr,"Header Search bitcnt=%d, header=0x%08x\n", - d_headerbytelen_cnt, d_header); - } - - j = 0; - while(j < bytes) { - d_header = (d_header << 8) | (d_bytes_out[j] & 0xFF); - j++; - - if (++d_headerbytelen_cnt == HEADERBYTELEN) { - - if (VERBOSE) - fprintf(stderr, "got header: 0x%08x\n", d_header); - - // we have a full header, check to see if it has been received properly - if (header_ok()){ - enter_have_header(); - - if (VERBOSE) - printf("\nPacket Length: %d\n", d_packetlen); - - while((j < bytes) && (d_packetlen_cnt < d_packetlen)) { - d_packet[d_packetlen_cnt++] = d_bytes_out[j++]; - } - - if(d_packetlen_cnt == d_packetlen) { - gr_message_sptr msg = - gr_make_message(0, d_packet_whitener_offset, 0, d_packetlen); - memcpy(msg->msg(), d_packet, d_packetlen_cnt); - d_target_queue->insert_tail(msg); // send it - msg.reset(); // free it up - - enter_search(); - } - } - else { - enter_search(); // bad header - } - } - } - break; - - case STATE_HAVE_HEADER: - bytes = demapper(&in[0], d_bytes_out); - - if (VERBOSE) { - if(sig[0]) - printf("ERROR -- Found SYNC in HAVE_HEADER at %d, length of %d\n", d_packetlen_cnt, d_packetlen); - fprintf(stderr,"Packet Build\n"); - } - - j = 0; - while(j < bytes) { - d_packet[d_packetlen_cnt++] = d_bytes_out[j++]; - - if (d_packetlen_cnt == d_packetlen){ // packet is filled - // build a message - // NOTE: passing header field as arg1 is not scalable - gr_message_sptr msg = - gr_make_message(0, d_packet_whitener_offset, 0, d_packetlen_cnt); - memcpy(msg->msg(), d_packet, d_packetlen_cnt); - - d_target_queue->insert_tail(msg); // send it - msg.reset(); // free it up - - enter_search(); - break; - } - } - break; - - default: - assert(0); - - } // switch - - return 1; -} |