Page 1CSNC 2012 Integration of COMPASS in a multi-GNSS receiver: frontend design, signal processing...
21
Page 1 CSNC 2012 CSNC 2012 Integration of COMPASS in a multi-GNSS receiver: frontend design, signal processing issues and results from early operations N. Falk, T. Hartmann, G. Heinrichs, T.Pany, B. Riedl, J. Winkel IFEN GmbH Günter Stangl Austrian Academy of Science Place: Guangzhou, China Session S2 Date&Time: May 17 th , 2012 2:20 p.m. – 2:45 p.m.
-
Upload
madeleine-parrish -
Category
Documents
-
view
214 -
download
0
Transcript of Page 1CSNC 2012 Integration of COMPASS in a multi-GNSS receiver: frontend design, signal processing...
Page 1 CSNC 2012
CSNC 2012
Integration of COMPASS in a multi-GNSS receiver: frontend design, signal processing issues and results from early operations
N. Falk, T. Hartmann, G. Heinrichs, T.Pany, B. Riedl, J. WinkelIFEN GmbH
Günter StanglAustrian Academy of Science
Place: Guangzhou, ChinaSession S2
Date&Time: May 17th, 2012 2:20 p.m. – 2:45 p.m.
Page 2 CSNC 2012
Motivation
COMPASS
Upcoming GNSS
Three frequencies
High signal power
ICD successively released
11 satellites in orbit
Received also outside China
IFEN SX-NSR
Multi-GNSS PC-based SwRx
Used for
GNSS/INS integration
Scientific experiments
Prototype space receivers
GNSS reference stations
Reflectometry
Spectrum monitoring
Need to be integratedNeed to be integrated
Introduction
RF Front-End
Signal Processing
Results
Introduction
RF Front-End
Signal Processing
Results
Page 3 CSNC 2012
Update IGS Reference Site GRAB for COMPASS
PC-based software installed at GRAZ47°4'2"N, 15°29'37"Efor IGS Multi-GNSS Experiment
PC-based software installed at GRAZ47°4'2"N, 15°29'37"Efor IGS Multi-GNSS Experiment
35 40 45 50 55 60 65 70-2
-1
0
1
2
Day of Year 2012
Res
idu
als
[mm
]
GRAB: x=4194424.7572 y=1162700.9373 z=4647247.4854
GPS L1/L2 daily coordinate repeatabilityGPS L1/L2 daily coordinate repeatability
Page 4 CSNC 2012
SX-NSR – Key Components
RF Front-End4 RF bands up to 15 MHz simultaneously
GPS L1, L2P, L2C, L5
Galileo E1, E5a, E5b, E6
SBAS L1, L5
GLONASS G1, G2
User specific ≤ 2.5 GHz
Frontend coupling for 8 bands
Dual antenna operation
1 x high-speed USB2.0
Interfaces to IMU, PPS, clock, baro., …
20.48 or 40.96 MHz sample rate
External power supply
Signal Processing SoftwareWindows personal computer 2GB RAM, SSSE3 capable processor
Ultra high sensitivity, ~20-30 channels per CPU core
Signal conditioning and pre-processing
GNSS baseband processing (acquisition and tracking) for all civil GNSS signals plus GPS L2P
Sensor data synchronization and processing
Application programming interface for external C/C++ code
Introduction
RF Front-End
Signal Processing
Results
Introduction
RF Front-End
Signal Processing
Results
Page 5 CSNC 2012
GRAB Galileo Performance
2 3 4 5 6 7 8
-5
0
5
10
15
20
Time [hour]
Co
de
min
us
Car
rier
[m
] E1B+C
E5aI +Q
E5bI +Q
E6I +Q
E5Qa+b (AltBOC)
Introduction
RF Front-End
Signal Processing
Results
Introduction
RF Front-End
Signal Processing
Results
Page 6 CSNC 2012
Issue 1:RF Frontend
Introduction
RF Front-End
Signal Processing
Results
Introduction
RF Front-End
Signal Processing
Results
Page 7 CSNC 2012
Envisaged Frequency Bands
Centre frequencies (front-end no.)
Sample rate/No. of bits Bandwidth
GPS L1(1), L2(1), L5(1) 20.48 MHz@2 bit 15 MHz
GLONASS G1(2), G2(2) 20.48 MHz@2 bit 15 MHz
Galileo E1(1), E5a(1), E5b(1), E6(2)
20.48 MHz@2 bit 15 MHz
COMPASS B1(2), B2(1), B3(1) 20.48 MHz@2 bit 15 MHz
Need 8 frequency bands to track all GNSS: Need 8 frequency bands to track all GNSS:
Reuse: L1/E1, L5/E5a, E5b/B2, E6/B3Reuse: L1/E1, L5/E5a, E5b/B2, E6/B3
Introduction
RF Front-End
Signal Processing
Results
Introduction
RF Front-End
Signal Processing
Results
Page 8 CSNC 2012
Synchronize 2 x NavPort4
Each NavPort-4 frontend supports
4 x ADC [email protected] MHz (single chip)
Decimation for USB transfer
Inter – frontend link
Synchronizes two NavPort-4
devices by
Hardware Connections:
Reference clock (10 MHz)
interconnection
Inter - frontend link
Introduction
RF Front-End
Signal Processing
Results
Introduction
RF Front-End
Signal Processing
Results
Page 9 CSNC 2012
Synchronization Performance
Synchronization performance of 2 x NavPort-4
Synchronization guarantee of 475 ps = +/- 14 cm
With calibration < 70 ps = +/- 2 cm
Cable/RF filter dependent biases
0 500 1000 1500 2000 2500 3000 3500-500
-400
-300
-200
-100
0
100
200
300
400
500
GPS time - t0 = 341686.994 s [s]
HW
del
ay ji
tter
[p
s]
code = 1677.33 +/- 131.37 ps, CA carrier = 273.99 +/- 16.14 ps
CodeCarrier
Introduction
RF Front-End
Signal Processing
Results
Introduction
RF Front-End
Signal Processing
Results
Page 10 CSNC 2012
RF Pecularities
COMPASS B1 also received quite well through L1 path
2nd order Bessel 15 MHz bandpass at RF (ceramic filter)
Useful for applications with limited computational resources
Currently E6/B3 share same filter centred on E6
Better to center between E6 and B3
Better to have more than 15 MHz bandwidth
Introduction
RF Front-End
Signal Processing
Results
Introduction
RF Front-End
Signal Processing
Results
Page 11 CSNC 2012
COMPASS Bands at GRAB
B2/E5bB2/E5b
B1B1
E6/B3E6/B3
0 1 2 3 4 5 6 7 8 9 1005
1015
Frequency [MHz]
PS
D [
dB]
0 1 2 3 4 5 6 7 8 9 1005
1015
Frequency [MHz]
PS
D [
dB]
0 1 2 3 4 5 6 7 8 9 1005
1015
Frequency [MHz]
PS
D [
dB]
okok
okok
nono
Introduction
RF Front-End
Signal Processing
Results
Introduction
RF Front-End
Signal Processing
Results
Page 12 CSNC 2012
Issue 2:Signal Processing
Introduction
RF Front-End
Signal Processing
Results
Introduction
RF Front-End
Signal Processing
Results
Page 13 CSNC 2012
COMPASS Signal Information
COMPASS ICD
Definies primary codes for B1/B2
Modulation scheme
Stanford
COMPASS M1 code on B3
Post-correlation Analysis
Gives secondary codes
Other receiver manufacturers (Trimble, Septentrio)
Hints how to retrieve time-of-week
RINEX3.txt (Ver. 3.01)
How to label COMPASS data
Introduction
RF Front-End
Signal Processing
Results
Introduction
RF Front-End
Signal Processing
Results
Page 14 CSNC 2012
COMPASS Acquisition
Cold start mode for all 37 PRNs on B2 (no almanac available)
Primary code FFT order 13 = 0.25 chip resolution
Tcoh = 4 ms (averaging data bit, sec. code transistions)
Doppler bin = 250 Hz
25 noncoherent integrations
Handover to B1, B3
Equivalent correlators:
Intel Atom N2600: 84000
nVidia GTX 480: 1460000
COMPASS C3 at GRABCOMPASS C3 at GRAB
No source code change necessaryNo source code change necessary
Introduction
RF Front-End
Signal Processing
Results
Introduction
RF Front-End
Signal Processing
Results
Page 15 CSNC 2012
COMPASS Carrier Tracking
Sync. to secondary code
GEO: 11, IGSO/MEO: 11111011001010110001
Tcoh = 2 ms
Costas phase disc, 2 x 1 ms Freq. disc
No source code change necessaryNo source code change necessary
0 5 10 15 20 25 30-5
0
5x 10
4
PI
COMPASS_B1_dump_PRN5.dumplog
GPS time - t0 = 0.102 s [s]
Data
0 5 10 15 20 25 30-5
0
5x 10
4
PQ
GPS time - t0 = 0.102 s [s]
Data
COMPASS C5 at GRABCOMPASS C5 at GRAB
Introduction
RF Front-End
Signal Processing
Results
Introduction
RF Front-End
Signal Processing
Results
Page 16 CSNC 2012
0 20 40 60 80 100 120 140-3
-2
-1
0
1
2
3
4COMPASS_B1_dump_PRN5.dumplog
GPS time - t0 = 0.102 s [s]
Cod
e m
inus
car
rier
[m]
COMPASS Code Tracking
Double delta (0.2/0.4 chip for multipath mitigation)
MEDLL possible
No source code change necessaryNo source code change necessary
COMPASS C5 at GRABCOMPASS C5 at GRABIntroduction
RF Front-End
Signal Processing
Results
Introduction
RF Front-End
Signal Processing
Results
Page 17 CSNC 2012
Time-of-Week
Time-of-Week needed to output pseudoranges
Detected preambel for all COMPASS satellites on B1/B2
111000100100000
Verification method necessary to avoid false detections
Repetition period
300 bits = 6 s for IGSO/MEO
300 bits = 0.6 s for GEO
Possible to resolve code ambiguity
Satellite range and satellite clock uncertainity << 0.6 s
Open question where is t = 0.0 s?
Beginng or end of preamble? Somewhere else?
Choice needs to be consistent with other receiver manufacturers
Introduction
RF Front-End
Signal Processing
Results
Introduction
RF Front-End
Signal Processing
Results
Page 18 CSNC 2012
Typical Satellite Passes at GRAB
0 5 10 15 2030
35
40
45
50
55
60
Time [hour]
C/N
0 [d
BH
z]
L5I+QE1B+C
L2P
L2CME6I+Q
E5Qa+b
L1C/A
G2C/A
GPS G01Galileo E11
GLONASS R02
B2
COMPASS C9
G1C/A
EGNOS
PRN126
E5bI+Q
E5aI+QB1
Introduction
RF Front-End
Signal Processing
Results
Introduction
RF Front-End
Signal Processing
Results
Page 19 CSNC 2012
Number of Tracked Satellites at GRAB
0 5 10 15 200
5
10
15
Time [hour]
No
. of
Sat
ellit
es
SBAS
COMPASS
GPSGLONASS
Galileo
Introduction
RF Front-End
Signal Processing
Results
Introduction
RF Front-End
Signal Processing
Results
Page 20 CSNC 2012
RINEX 3.01 RECORD
> 2012 05 08 19 29 59.9928750 0 30 -.007124506646
G02 21092229.752 8 -12551435.480 8 -2285.185 8 48.858 .000 .000 .000 .000 21092231.120 6 -9780309.753 6 -1780.671 6 41.239 .000 .000 .000 .000
G05 22549464.755 7 -5861392.994 7 2297.161 7 42.364 22549458.135 5 -635000.313 5 1788.874 5 33.652 22549468.505 5 -4567319.412 5 1790.027 5 35.172 .000 .000 .000 .000
G08 23761353.067 5 54539314.60815 -2998.850 5 31.895 .000 .000 .000 .000 .000 .000 .000 .000 .000 .000 .000 .000
G10 22688648.245 6 -3410892.906 6 -81.241 6 39.084 .000 .000 .000 .000 .000 .000 .000 .000 .000 .000 .000 .000
G12 20993639.976 7 -10987397.717 7 -2814.953 7 46.188 20993634.792 6 -7999070.800 6 -2192.678 6 37.645 20993642.430 6 -8561575.883 6 -2193.480 6 40.298 .000 .000 .000 .000
G14 22925142.626 6 -2459435.689 6 -2975.740 6 38.193 .000 .000 .000 .000 22925147.672 5 -1916453.603 5 -2318.835 5 31.926 .000 .000 .000 .000
G21 21924257.271 7 -4453191.383 7 3383.472 7 42.337 .000 .000 .000 .000 21924260.144 5 -3470029.683 5 2636.606 5 35.542 .000 .000 .000 .000
G24 18599842.418 8 -24823587.484 8 1214.278 8 50.225 .000 .000 .000 .000 18599845.342 7 -19343019.703 7 946.207 7 44.384 .000 .000 .000 .000
G25 18293798.747 8 -24012299.647 8 -889.044 8 52.132 18293792.655 7 -16826080.339 7 -692.501 7 44.582 18293802.676 7 -18710861.922 7 -692.763 7 45.807 18293793.102 8 -21153403.273 8 -663.769 8 53.706
G29 18041801.200 8 -24586957.156 8 358.796 8 51.297 18041791.556 7 -17755852.893 7 279.946 7 45.642 18041802.496 7 -19158645.472 7 279.593 7 47.080 .000 .000 .000 .000
G30 22065376.043 6 -4270971.868 6 3645.716 6 41.824 .000 .000 .000 .000 22065380.165 5 -3328032.260 5 2840.846 5 35.082 .000 .000 .000 .000
G31 19343788.275 8 -20948295.856 8 1030.209 8 48.911 19343780.144 7 -15631495.518 7 802.312 7 42.041 19343789.529 7 -16323331.607 7 802.786 7 43.573 .000 .000 .000 .000
E12 34986424.281 6 -6134034.806 6 2717.969 6 41.744 34986430.598 6 -3721862.468 6 2028.637 6 39.551 34986430.673 6 -3818958.462 6 2083.061 6 39.904 34986431.537 6 199854524.133 6 2056.451 6 39.843 34986430.133 5 -487615.336 5 2208.319 5 34.733
E51 22244373.167 7 -23314534.408 7 -1677.232 7 46.362 22244372.703 7 -16474985.039 7 -1252.944 7 44.497 22244372.021 7 -17730863.168 7 -1284.950 7 44.976 22244400.808 7 -13698399.487 7 -1268.725 7 44.871 .000 .000 -1431.050 1 -100.000
R06 22089581.739 6 -2450329.242 6 -1663.537 6 39.135 22089475.020 5 -1738267.283 5 -1293.631 5 30.946
R07 21367530.890 7 -6527192.440 7 1287.174 7 43.497 21367422.511 6 -4780065.151 6 1001.010 6 39.130
R13 18485882.995 8 -19988456.525 8 -3176.579 8 49.927 18485774.594 7 -15423855.919 7 -2470.684 7 45.481
R14 17187286.439 8 -26632938.040 8 874.009 8 48.435 17187179.301 6 -20262544.282 6 679.903 6 41.761
R15 21070602.620 7 -6503363.114 7 4258.800 7 44.193 21070495.904 6 -4679771.372 6 3312.292 6 38.859
R17 21136832.218 7 -6644149.185 7 3769.240 7 45.478 21136722.846 6 -4586440.551 6 2931.538 6 37.940
R22 22449982.016 7 -365176.433 7 -3847.451 7 42.860 22449863.094 5 -34672.80615 -2992.105 5 31.003
R23 18162483.976 8 -21278160.292 8 -2386.122 8 49.830 18162375.127 7 -16084685.430 7 -1855.545 7 47.326
R24 17426973.614 8 -24760575.061 8 1320.419 8 51.317 17426863.073 7 -19020417.633 7 1026.936 7 47.986
S24 36245930.928 7 -25188074.783 7 83.251 7 42.535
C03 107960885.213 5 -7401700.365 5 76.959 5 33.055 107960887.631 5 -5723856.403 5 59.717 5 35.431 .000 .000 .000 .000
C05 106352500.781 6 -7250695.210 6 96.716 6 39.253 106352501.903 7 -5606603.698 7 75.781 7 42.427 .000 .000 .000 .000
C06 6937511.160 6 -10890516.594 6 418.214 6 40.826 6937494.133 6 -8406430.829 6 323.291 6 41.561 .000 .000 .000 .000
C09 6328734.962 7 -12518967.097 7 1329.123 7 42.376 6328735.427 7 -9673679.887 7 1026.108 7 43.608 .000 .000 .000 .000
C11 174505598.792 6 23004089.358 6 -2903.541 6 36.361 174505587.303 6 17790952.786 6 -2243.826 6 37.164 .000 .000 .000 .000
C30 21803155.594 8 .000 -1432.620 8 48.137 21803188.932 8 -19611359.363 8 -1107.628 8 52.581 .000 .000 .000 .000
Data can be downloaded at: ftp://olggps.oeaw.ac.at/pub/igsmgex/ or CDDIS, BKGData can be downloaded at: ftp://olggps.oeaw.ac.at/pub/igsmgex/ or CDDIS, BKG
Page 21 CSNC 2012
CONCLUSIONS
COMPASS fits well into a generic tracking scheme
Acquisition and tracking without source code changes
Fits also well to SX-NSR application programming interface
No results yet for B3, the most precise signal
Unexpected many satellites tracked in Europe
Need to look for applications
Interference probably an issue as B1/B3 band have no
heritage on GNSS use in Europe
