diff options
| author | Thomas Habets <thomas@habets.se> | 2020-08-12 16:20:26 +0100 |
|---|---|---|
| committer | mormj <34754695+mormj@users.noreply.github.com> | 2020-10-19 13:28:31 -0400 |
| commit | cc4cd94e326d6348228bd7d6763d99b8777124e6 (patch) | |
| tree | 343972b821f7deddf4d0b8cb98d6ec04cbe41e32 /gr-digital/lib | |
| parent | cf5264adf550ced75dc8262b71ae365707a63cc1 (diff) | |
digital/correlate_access_code: Prevent false triggers
Leftover data from last time CAC triggered, or just leading zeroes
being ignored.
This commit prevents these by assuring that we've processed at least
as many bits as the code is, before allowing a trigger.
Diffstat (limited to 'gr-digital/lib')
8 files changed, 30 insertions, 8 deletions
diff --git a/gr-digital/lib/correlate_access_code_bb_ts_impl.cc b/gr-digital/lib/correlate_access_code_bb_ts_impl.cc index 0312defe11..c9a8f6e390 100644 --- a/gr-digital/lib/correlate_access_code_bb_ts_impl.cc +++ b/gr-digital/lib/correlate_access_code_bb_ts_impl.cc @@ -90,6 +90,7 @@ unsigned long long correlate_access_code_bb_ts_impl::access_code() const inline void correlate_access_code_bb_ts_impl::enter_search() { d_state = STATE_SYNC_SEARCH; + d_data_reg_bits = 0; } inline void correlate_access_code_bb_ts_impl::enter_have_sync() @@ -137,8 +138,12 @@ int correlate_access_code_bb_ts_impl::general_work(int noutput_items, while (count < noutput_items) { // shift in new data d_data_reg = (d_data_reg << 1) | ((in[count++]) & 0x1); - - // compute hamming distance between desired access code and current data + if (d_data_reg_bits + 1 < d_len) { + d_data_reg_bits++; + continue; + } + // compute hamming distance between desired access code and current + // data uint64_t wrong_bits = 0; uint64_t nwrong = d_threshold + 1; diff --git a/gr-digital/lib/correlate_access_code_bb_ts_impl.h b/gr-digital/lib/correlate_access_code_bb_ts_impl.h index d4024703cd..bae61249f5 100644 --- a/gr-digital/lib/correlate_access_code_bb_ts_impl.h +++ b/gr-digital/lib/correlate_access_code_bb_ts_impl.h @@ -26,6 +26,7 @@ private: unsigned long long d_access_code; // access code to locate start of packet // access code is left justified in the word unsigned long long d_data_reg; // used to look for access_code + unsigned int d_data_reg_bits = 0; // used to makes sure we've seen the whole code unsigned long long d_mask; // masks access_code bits (top N bits are set where // N is the number of bits in the access code) unsigned int d_threshold; // how many bits may be wrong in sync vector diff --git a/gr-digital/lib/correlate_access_code_ff_ts_impl.cc b/gr-digital/lib/correlate_access_code_ff_ts_impl.cc index a78b924caa..1a0548cc9b 100644 --- a/gr-digital/lib/correlate_access_code_ff_ts_impl.cc +++ b/gr-digital/lib/correlate_access_code_ff_ts_impl.cc @@ -90,6 +90,7 @@ unsigned long long correlate_access_code_ff_ts_impl::access_code() const inline void correlate_access_code_ff_ts_impl::enter_search() { d_state = STATE_SYNC_SEARCH; + d_data_reg_bits = 0; } inline void correlate_access_code_ff_ts_impl::enter_have_sync() @@ -138,8 +139,12 @@ int correlate_access_code_ff_ts_impl::general_work(int noutput_items, // shift in new data d_data_reg = (d_data_reg << 1) | (gr::branchless_binary_slicer(in[count++]) & 0x1); - - // compute hamming distance between desired access code and current data + if (d_data_reg_bits + 1 < d_len) { + d_data_reg_bits++; + continue; + } + // compute hamming distance between desired access code and current + // data uint64_t wrong_bits = 0; uint64_t nwrong = d_threshold + 1; diff --git a/gr-digital/lib/correlate_access_code_ff_ts_impl.h b/gr-digital/lib/correlate_access_code_ff_ts_impl.h index ab2af2067a..b0b24de639 100644 --- a/gr-digital/lib/correlate_access_code_ff_ts_impl.h +++ b/gr-digital/lib/correlate_access_code_ff_ts_impl.h @@ -26,6 +26,7 @@ private: unsigned long long d_access_code; // access code to locate start of packet // access code is left justified in the word unsigned long long d_data_reg; // used to look for access_code + unsigned int d_data_reg_bits = 0; // used to makes sure we've seen the whole code unsigned long long d_mask; // masks access_code bits (top N bits are set where // N is the number of bits in the access code) unsigned int d_threshold; // how many bits may be wrong in sync vector diff --git a/gr-digital/lib/correlate_access_code_tag_bb_impl.cc b/gr-digital/lib/correlate_access_code_tag_bb_impl.cc index 8794edbae1..82c93854a0 100644 --- a/gr-digital/lib/correlate_access_code_tag_bb_impl.cc +++ b/gr-digital/lib/correlate_access_code_tag_bb_impl.cc @@ -94,8 +94,12 @@ int correlate_access_code_tag_bb_impl::work(int noutput_items, uint64_t wrong_bits = 0; uint64_t nwrong = d_threshold + 1; - wrong_bits = (d_data_reg ^ d_access_code) & d_mask; - volk_64u_popcnt(&nwrong, wrong_bits); + if (d_data_reg_bits < d_len) { + d_data_reg_bits++; + } else { + wrong_bits = (d_data_reg ^ d_access_code) & d_mask; + volk_64u_popcnt(&nwrong, wrong_bits); + } // shift in new data d_data_reg = (d_data_reg << 1) | (in[i] & 0x1); diff --git a/gr-digital/lib/correlate_access_code_tag_bb_impl.h b/gr-digital/lib/correlate_access_code_tag_bb_impl.h index ae92a84645..904b383419 100644 --- a/gr-digital/lib/correlate_access_code_tag_bb_impl.h +++ b/gr-digital/lib/correlate_access_code_tag_bb_impl.h @@ -22,6 +22,7 @@ private: unsigned long long d_access_code; // access code to locate start of packet // access code is left justified in the word unsigned long long d_data_reg; // used to look for access_code + unsigned int d_data_reg_bits = 0; // used to makes sure we've seen the whole code unsigned long long d_mask; // masks access_code bits (top N bits are set where // N is the number of bits in the access code) unsigned int d_threshold; // how many bits may be wrong in sync vector diff --git a/gr-digital/lib/correlate_access_code_tag_ff_impl.cc b/gr-digital/lib/correlate_access_code_tag_ff_impl.cc index ee41af6724..67d051978a 100644 --- a/gr-digital/lib/correlate_access_code_tag_ff_impl.cc +++ b/gr-digital/lib/correlate_access_code_tag_ff_impl.cc @@ -95,8 +95,12 @@ int correlate_access_code_tag_ff_impl::work(int noutput_items, uint64_t wrong_bits = 0; uint64_t nwrong = d_threshold + 1; - wrong_bits = (d_data_reg ^ d_access_code) & d_mask; - volk_64u_popcnt(&nwrong, wrong_bits); + if (d_data_reg_bits < d_len) { + d_data_reg_bits++; + } else { + wrong_bits = (d_data_reg ^ d_access_code) & d_mask; + volk_64u_popcnt(&nwrong, wrong_bits); + } // shift in new data d_data_reg = (d_data_reg << 1) | (gr::branchless_binary_slicer(in[i]) & 0x1); diff --git a/gr-digital/lib/correlate_access_code_tag_ff_impl.h b/gr-digital/lib/correlate_access_code_tag_ff_impl.h index 793e6a123f..536cef6340 100644 --- a/gr-digital/lib/correlate_access_code_tag_ff_impl.h +++ b/gr-digital/lib/correlate_access_code_tag_ff_impl.h @@ -22,6 +22,7 @@ private: unsigned long long d_access_code; // access code to locate start of packet // access code is left justified in the word unsigned long long d_data_reg; // used to look for access_code + unsigned int d_data_reg_bits = 0; // used to makes sure we've seen the whole code unsigned long long d_mask; // masks access_code bits (top N bits are set where // N is the number of bits in the access code) unsigned int d_threshold; // how many bits may be wrong in sync vector |