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Working version of p-code plus tests

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Note that there is an error in IS GPS 200 H, which is where we get the
testvectors from. This commit passes against test vectors from the
proposed modification: IS GPS 200 H PIRN 001
This commit is contained in:
Cillian O'Driscoll
2015-11-04 09:30:33 +00:00
parent 2b57a7501e
commit 3edad8812e
2 changed files with 214 additions and 25 deletions
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36
src/algorithms/libs/gps_pcode.cc
View File

@@ -172,14 +172,14 @@ const unsigned int GPS_P_Code_Generator::X2B_EXTRA_LENGTH = 965;
const unsigned int GPS_P_Code_Generator::X2A_EPOCHS_LAST_X2_EPOCH = 104;
const unsigned int GPS_P_Code_Generator::X2B_EPOCHS_LAST_X2_EPOCH = 104;
void GPS_P_Code_Generator::get_chips( int sv, uint64_t first_chip_index, unsigned num_chips,
void GPS_P_Code_Generator::get_chips( int prn, uint64_t first_chip_index, unsigned num_chips,
std::vector< short > &_dest ) const
{
// A couple of quick checks:
if( sv < 1 or sv > 37 )
if( prn < 1 or prn > 210 )
{
LOG(ERROR) << "Invalid SV number: " << sv
<< " should be in the range 1 to 37 (inclusive)";
LOG(ERROR) << "Invalid SV number: " << prn
<< " should be in the range 1 to 210 (inclusive)";
}
if( first_chip_index > GPS_P_CODE_LENGTH_CHIPS )
@@ -197,6 +197,14 @@ void GPS_P_Code_Generator::get_chips( int sv, uint64_t first_chip_index, unsigne
}
// OK now we can proceed:
// IS GPS 200H - The first 37 PRN codes are unique, identified by sv
// below. For PRN values greater than 37 we create the code for
// (prn-1) % 37 + 1 and delay it by floor( (prn-1)/37 ) days
int sv = ( prn - 1 ) % 37 + 1;
int num_days = (prn-1) / 37;
uint64_t day_shift = num_days*10230000LL*24LL*3600LL;
first_chip_index = first_chip_index + day_shift;
first_chip_index %= GPS_P_CODE_LENGTH_CHIPS;
//Ensure we have space:
_dest.resize( num_chips );
@@ -204,7 +212,7 @@ void GPS_P_Code_Generator::get_chips( int sv, uint64_t first_chip_index, unsigne
// Establish the starting phase:
// 1) account for the delay of the x2 register
int64_t first_chip_index_x2 = first_chip_index - sv + 1;
int64_t first_chip_index_x2 = first_chip_index - sv;
while( first_chip_index_x2 < 0 )
{
first_chip_index_x2 += GPS_P_CODE_LENGTH_CHIPS;
@@ -293,11 +301,14 @@ void GPS_P_Code_Generator::get_chips( int sv, uint64_t first_chip_index, unsigne
extra_code_period = X2A_EXTRA_LENGTH;
}
if( x2a_epoch >= max_num_epochs )
if( x2a_epoch >= max_num_epochs-1 )
{
this_code_period = this_code_period + extra_code_period;
x2a_ind += GPS_X2A_CODE_LENGTH;
x2a_epoch--;
if( x2a_epoch == max_num_epochs )
{
x2a_ind += GPS_X2A_CODE_LENGTH;
}
x2a_epoch = max_num_epochs-1;
}
unsigned int chips_to_gen = std::min( num_chips - dest_ind,
@@ -345,11 +356,14 @@ void GPS_P_Code_Generator::get_chips( int sv, uint64_t first_chip_index, unsigne
extra_code_period = X2B_EXTRA_LENGTH;
}
if( x2b_epoch >= max_num_epochs )
if( x2b_epoch >= max_num_epochs - 1 )
{
this_code_period = this_code_period + extra_code_period;
x2b_ind += GPS_X2B_CODE_LENGTH;
x2b_epoch--;
if( x2b_epoch == max_num_epochs )
{
x2b_ind += GPS_X2B_CODE_LENGTH;
}
x2b_epoch = max_num_epochs - 1;
}
unsigned int chips_to_gen = std::min( num_chips - dest_ind,

203
src/tests/arithmetic/pcode_generation_test.cc
View File

@@ -34,12 +34,75 @@
#include "GPS_P_CODE.h"
#include "gps_pcode.h"
// Test vectors from IS GPS 200 H
// Note there are some errors in that document as per:
//http://www.gps.gov/technical/icwg/meetings/2015/PIRN-IS-200H-001.pdf
// in particular:
// PRN : OLD : NEW
// 66 : 2111 : 6111
// 69 : 4166 : 0166
// 70 : 2251 : 6251
const std::vector< short > first_12_chips_octal = {
04444, 04000, 04222, 04333, 04377, 04355, 04344, 04340, 04342, 04343,
04343, 04343, 04343, 04343, 04343, 04343, 04343, 04343, 04343, 04343,
04343, 04343, 04343, 04343, 04343, 04343, 04343, 04343, 04343, 04343,
04343, 04343, 04343, 04343, 04343, 04343, 04343, // <-- 37
03373, 03757, 07545, 05440, 04402, 04023, 00233, 02337, 03375, 03754,
03544, 07440, 01402, 06423, 01033, 02637, 07135, 05674, 00514, 06064,
01210, 06726, 01171, 06656, 01105, 06660, // <-- 63
/* IS GPS 200 H:
05112, 00667, 02111, 05266, 04711, 04166, 02251, 05306, 04761, 02152,
05247, 05736, 02575, 03054, 03604, 03520, 05472, 04417, 02025, 03230,
05736, 04575, 02054, 03204, 03720, 05572, 04457, 04005, 02220, 03332,
03777, 03555, // <- 95
03444, 07400, 01422, 02433, 07037, 01635, 06534, 05074, 00614, 06124,
01270, 02716, 05165, 00650, 06106, 05261, 06752, 05147, 00641, 06102,
01263, 02713, 03167, 03651, 07506, 05461, 00412, 06027, 01231, 02736, // <-125
07175, 01654, 06504, 01060, 02612, 07127, 05671, 04516, 04065, 04210,
04326, 00371, 06356, 05345, 00740, 06142, 01243, 06703, 05163, 04653,
04107, 04261, 00312, 02525, 07070, 01616, 02525, 07070, 03616, 07525, // <- 155
05470, 04416, 04025, 04230, 00336, 06375, 01354, 06744, 05140, 04642,
00103, 06263, 01313, 06767, 01151, 02646, 07101, 05662, 00513, 02067,
03211, 03726, 03571, 03456, 03405, 03420, 05432, 00437, 06035, 01234, // <- 185
01067, 06611, 05126, 04671, 00116, 06265, 01310, 06766, 01151, 02646,
03101, 07662, 05513, 04467, 04011, 04226, 04331, 00376, 06355, 05344,
00740, 06142, 01243, 06703, 01163 //<- 210 */
/* PRN IS GPS 200 H 001:*/
05112, 00667, 06111, 05266, 04711, 00166, 06251, 05306, 00761, 06152,
01247, 01736, 02575, 03054, 03604, 07520, 05472, 00417, 02025, 07230,
05736, 00575, 02054, 03204, 07720, 05572, 04457, 00005, 02220, 03332,
03777, 03555, 03444, 07400, 01422, 02433, 07037, 01635, 06534, 05074,
00614, 06124, 01270, 06716, 05165, 00650, 06106, 05261, 06752, 05147,
00641, 06102, 01263, 02713, 03167, 03651, 07506, 05461, 00412, 06027,
01231, 02736, 07175, 01654, 06504, 01060, 02612, 07127, 05671, 04516,
04065, 04210, 04326, 00371, 06356, 05345, 00740, 06142, 01243, 06703,
05163, 04653, 04107, 04261, 00312, 02525, 07070, 01616, 02525, 03070,
03616, 07525, 05470, 04416, 04025, 04230, 00336, 06375, 01354, 06744,
05140, 04642, 00103, 06263, 01313, 06767, 01151, 02646, 07101, 05662,
00513, 02067, 03211, 03726, 03571, 03456, 03405, 07420, 05432, 00437,
06035, 01234, // <- 185
01067, 06611, 05126, 04671, 00116, 06265, 01310, 06766, 01151, 02646,
03101, 07662, 05513, 04467, 04011, 04226, 04331, 00376, 06355, 05344,
00740, 06142, 01243, 06703, 01163 //<- 210 */
};
TEST(PCodeGenTest, X1ATest)
{
std::vector< short > dest;
gps_x1a_code_gen( dest );
// IS GPS 200 H
std::vector< short > first_12_chips = { 0, 0, 1, 0, 0, 1, 0, 0, 1, 0, 0, 0 };
for( unsigned int ii = 0; ii < 12; ++ii )
{
EXPECT_EQ( dest[ii], first_12_chips[ii] ) << "ii: " << ii;
}
// From Octave:
std::vector< short > last12Bits = { 1, 1, 0, 0, 0, 0, 0, 1, 1, 1, 1, 0 };
@@ -56,6 +119,13 @@ TEST(PCodeGenTest, X1BTest)
gps_x1b_code_gen( dest );
// IS GPS 200 H
std::vector< short > first_12_chips = { 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 0 };
for( unsigned int ii = 0; ii < 12; ++ii )
{
EXPECT_EQ( dest[ii], first_12_chips[ii] ) << "ii: " << ii;
}
// From Octave:
std::vector< short > last12Bits = { 0, 1, 0, 1, 1, 1, 0, 0, 1, 0, 1, 0 };
@@ -73,6 +143,14 @@ TEST(PCodeGenTest, X2ATest)
gps_x2a_code_gen( dest );
// IS GPS 200 H
std::vector< short > first_12_chips = { 1, 0, 0, 1, 0, 0, 1, 0, 0, 1, 0, 1};
for( unsigned int ii = 0; ii < 12; ++ii )
{
EXPECT_EQ( dest[ii], first_12_chips[ii] ) << "ii: " << ii;
}
// From Octave:
std::vector< short > last12Bits = {0, 0, 0, 0, 1, 0, 1, 1, 1, 1, 1, 1};
@@ -90,7 +168,16 @@ TEST(PCodeGenTest, X2BTest)
gps_x2b_code_gen( dest );
// From Octave:
// IS GPS 200 H
std::vector< short > first_12_chips = { 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 0 };
for( unsigned int ii = 0; ii < 12; ++ii )
{
EXPECT_EQ( dest[ii], first_12_chips[ii] ) << "ii: " << ii;
}
// From Octave :
std::vector< short > last12Bits = {0, 0, 1, 0, 1, 0, 1, 1, 1, 0, 0, 0};
for( unsigned int ii = 0; ii < 12; ++ii )
@@ -101,7 +188,7 @@ TEST(PCodeGenTest, X2BTest)
}
TEST(PCodeGenTest, FirstChipsTest)
TEST(PCodeGenTest, FirstChipsTest1)
{
std::vector< short > dest;
@@ -120,20 +207,50 @@ TEST(PCodeGenTest, FirstChipsTest)
unsigned int num_chips = 24;
int sv = 1;
int first_chip_index = sv;
pcode_gen.get_chips( sv, 0, num_chips, dest );
pcode_gen.get_chips( sv, first_chip_index, num_chips, dest );
EXPECT_EQ( dest.size(), num_chips );
for( unsigned ii = 0; ii < num_chips; ++ii )
for( unsigned ii = 0, jj = first_chip_index; ii < num_chips; ++ii, ++jj)
{
short res = x1a[ii] ^ x1b[ii] ^ x2a[ii] ^ x2b[ii];
short res = x1a[jj] ^ x1b[jj] ^ x2a[jj-sv] ^ x2b[jj-sv];
EXPECT_EQ( dest[ii], res );
}
}
TEST(PCodeGenTest, First12ChipsAll )
{
std::vector< short > dest;
GPS_P_Code_Generator pcode_gen;
unsigned int num_chips = 12;
int num_err = 0;
for( int sv = 1; sv <= 210; ++sv )
{
pcode_gen.get_chips( sv, 0, num_chips, dest );
short res = 0;
for( int ii=0; ii < num_chips; ++ii )
{
//short theBit = ( first_12_chips_octal[ sv - 1 ] >> (11-ii) ) & 0x01;
res = (res<<1) | dest[ii];
//EXPECT_EQ( dest[ii], theBit ) << " sv " << sv << " bit " << ii;
}
short icd = first_12_chips_octal[ sv - 1];
EXPECT_EQ( res, icd ) << " sv " << sv << ". icd: " << std::oct << icd
<< ". actual: " << std::oct << res << std::dec << ". num_err: " << ++num_err;
}
EXPECT_EQ( num_err, 0 );
}
TEST(PCodeGenTest, EndX1EpochTest)
{
std::vector< short > dest;
@@ -163,7 +280,7 @@ TEST(PCodeGenTest, EndX1EpochTest)
for( unsigned ii = 0; ii < num_chips; ++ii )
{
short res = x1a[4092-num_chips+ii]
^ x1b[4092] ^ x2a[4092-num_chips+ii]
^ x1b[4092] ^ x2a[4092-num_chips+ii-sv]
^ x2b[4092];
EXPECT_EQ( dest[ii], res );
@@ -188,19 +305,36 @@ TEST(PCodeGenTest, StartSecondX1EpochTest)
unsigned int num_chips = 24;
uint64_t end_x1_epoch = 4092LL*3750LL;
uint64_t start_ind = end_x1_epoch;
int sv = 1;
uint64_t start_ind = end_x1_epoch;
pcode_gen.get_chips( sv, start_ind, num_chips, dest );
EXPECT_EQ( dest.size(), num_chips );
for( unsigned ii = 0; ii < num_chips; ++ii )
unsigned ii = 0;
for( ii = 0; ii < sv && ii < num_chips; ++ii )
{
short res = x1a[ii] ^ x1b[ii]
^ x2a[4092-sv + ii] ^ x2b[ 4092 ];
EXPECT_EQ( dest[ii], res );
}
for( ; (ii - sv ) < 37 && ii < num_chips; ++ii )
{
short res = x1a[ii] ^ x1b[ii]
^ x2a[ 4091 ] ^ x2b[ 4092 ];
EXPECT_EQ( dest[ii], res );
}
for( ; ii < num_chips; ++ii )
{
short res = x1a[ii]
^ x1b[ii] ^ x2a[4091]
^ x2b[4092];
^ x1b[ii] ^ x2a[ii-37-sv]
^ x2b[ii-37-sv];
EXPECT_EQ( dest[ii], res );
}
@@ -259,7 +393,7 @@ TEST(PCodeGenTest, Prn37Test)
GPS_P_Code_Generator pcode_gen;
int sv = 37;
unsigned int num_chips = 24+sv-1;
unsigned int num_chips = 24+sv;
uint64_t start_ind = 0;
@@ -267,13 +401,54 @@ TEST(PCodeGenTest, Prn37Test)
EXPECT_EQ( dest.size(), num_chips );
for( unsigned ii = sv-1; ii < num_chips; ++ii )
for( unsigned ii = sv; ii < num_chips; ++ii )
{
short res = x1a[ii]
^ x1b[ii] ^ x2a[ii-sv+1]
^ x2b[ii-sv+1];
^ x1b[ii] ^ x2a[ii-sv]
^ x2b[ii-sv];
EXPECT_EQ( dest[ii], res );
}
}
TEST(PCodeGenTest, NewPrnTest)
{
std::vector< short > dest;
std::vector< short > dest0;
GPS_P_Code_Generator pcode_gen;
int sv = 137;
unsigned int num_chips = 24;
uint64_t start_ind = 0;
int prn0 = (sv-1)%37 + 1;
int day_shift = (sv-1)/37;
uint64_t start_ind0 = start_ind + day_shift*10230000LL*24LL*3600LL;
pcode_gen.get_chips( sv, start_ind, num_chips, dest );
pcode_gen.get_chips( prn0, start_ind0, num_chips, dest0 );
EXPECT_EQ( dest.size(), num_chips );
EXPECT_EQ( dest0.size(), num_chips );
for( unsigned ii = 0; ii < num_chips; ++ii )
{
EXPECT_EQ( dest[ii], dest0[ii] );
}
// From the IS GPS 200H:
// PRN = 137: first 12 chips = o0371 (octal)
// 0 0 0 0 1 1 1 1 1 0 0 1
std::vector< short > first_12_chips_icd = {
0, 0, 0, 0, 1, 1, 1, 1, 1, 0, 0, 1
};
for( unsigned int ii = 0; ii < 12; ++ii )
{
EXPECT_EQ( dest[ii], first_12_chips_icd[ii] );
}
}