Transcript Alcatel Company Presentation

MORE EGSE
Page 1
MORE EGSE
IF & BB EGSE
Allan Variance &
RF EGSE
back next
September 2005
All rights reserved © 2005, Alcatel Alenia Space
Phase A/B1- EGSE Activities-1
Page 2
Beginning in January 2007:
 EGSE system definition including:
 Analysis of EGSE functional and performance requirements
 Analysis of the Radio-Science Experiment applicable documentation.
 Definition of EGSE overall architecture and of the interfaces between main
EGSE components (RF equipment, digital and power equipment, MMI
workstations, etc.)
 Establishment of an overall EGSE development plan and schedule
 Produce the design specification
 WBRS preliminary study including:
 Analysis of the requirements related to the deep space ranging system with
focus on the wideband ranging signaling system (WBRS).
 Integrate the EGSE level simulation with system level simulations
(developed by University of Rome).
back next
September 2005
All rights reserved © 2005, Alcatel Alenia Space
Phase A/B1- EGSE Activities-2
Page 3
 EGSE RF system definition including:
 Analysis of EGSE RF functional and performance requirements
 Definition of RF EGSE architecture
 Contribute to overall EGSE development plan and schedule
 Analyze the Radio-Science Experiment applicable documentation.
 Analyze the requirements related to Allan Variance.
 Produce the Allan Variance Test Set design specification
 Implement the Allan Variance Test set to be used for B/B testing
back next
September 2005
All rights reserved © 2005, Alcatel Alenia Space
BB Heritage
Page 4
Hardware Platform
Software Platform
Industrial PC equiped with:
• IF receiver (up to 3)
• IF Modulator (up to 2)
• BPSK Dem. (up to 3)
• Frame Synch +Vit. Dec. + RS Dec.
(up to 3)
• RNG Processor
• TC Generator
• IRIG-B receiver
• Frequency Distributor
• CPU
• Hard Disk
Operating System
Red Hat Linux v.9.0
IF Inp.
IF
Reveiver
TLM
SC
Demodulator
+ Bit Synch
Frame Synch
+ Vit. + RS .
TLM
TFT
RNG
IF Out.
Ranging
&
phase Meas.
IF
Modulator &
Test
TM/TC & RNG
Processor
RNGmeas.
LOCAL
H.D.
PCI-BUS
Test loop
FFT
RNG
CPU
TLC
TLC Gen.
TLM
Freq. Synth.
&
Distributor
IRIG-B
Reader
5/10 MHz
IRIG-B
TLC/TLM
Time
TCP/IP link
back next
September 2005
All rights reserved © 2005, Alcatel Alenia Space
Main Features: RANGING (1/2 cont.)
Page 5
Ranging function



Code ranging ESA standard
interface the RF system by means the IF Receiver in down-link (the same as for the TLM link) and
the IF Modulator for the Up-link link (the same as for the TLC link)
generate the ranging tone and the code for ranging measurements being the tone signal BPSK
modulated by the ranging code; the tone frequency and code length are programmable whilst the
CodeLength
Code Repetition Period may be computed by CRP  2
ToneFreq.







the maximum usable code length is 2 Exp. 24
supply the ranging signal to the IF Modem (the same of the TLC system) for PM modulation with
the correct modulation index
receive from the IF receiver the down linked ranging signal for ranging measurements
solve code ambiguity due to the propagation delay
perform accurate range measurement by measuring the time elapsed between emitted and
received code
store in mass memory the ranging measurements data
transmit to the SCC all the stored data by means of TCP/IP link according to the communication
protocol
back next
September 2005
All rights reserved © 2005, Alcatel Alenia Space
Main Features: RANGING (2/2)
Page 6
Summary of characteristics
 Ranging tone
 Ranging modulation index
 Tone mod.
90°)
 Modulation scheme
 Maximum code length
 Ranging accuracy
 STC protocol
 M&C protocol
100 KHz to 1,5 MHz
0,1 to 2 rad. (down-link)
two selectable phase (programmable from 10° to
PCM/PSK/PM
2 Exp 24
1ns
MKII (modified) on TCPIP (IEEE 802.3)
EDEN protocol on TCPIP (IEEE 802.3)
back next
September 2005
All rights reserved © 2005, Alcatel Alenia Space
WBRS migration
Page 7
Main Improvements needed
 WBRS standard
 20 MHz tone
 Improved accuracy
 Integration of post processing SW
Ref. freq.
(10 | 20 MHz from H maser)
Tone (to modulator)
x2
1 PPS
AGC
LPF
x4
Modification in architecture
clk
90°
 Possible trough reconfiguration in
FPGA
 Possibility to change IF front end
BPF
Rec'd
tone
(demodulated)
in
A/D
Digital
Signal
Processor
(4 points FFT,
small scale lin. fit,
time tagging)
Replica tone
VCO
LPF
VGA
A/D
digital
filter
D/A
tone PLL
computer I/F
filter
progr.
Doppler Comp.
(tone PLL presteering).
back next
September 2005
All rights reserved © 2005, Alcatel Alenia Space
Allan Variance test set-up 1/2
Page 8
 The test bench is designed in order to measure the Allan variance of
frequency standards and it is known as Dual-Mixer Time Difference
(DMTD) scheme
 The L.O. frequency is set in order to have a residual frequency of 1 Hz,
the time interval counter measures the time difference between the two
signals, from the fluctuation of the time difference it is possible to
calculate the Allan variance.
DUT
FILTER + ZCD
L.O.
REFERENCE
OSCILLATOR
TIME
INTERVAL
COUNTER
FILTER + ZCD
DUAL MIXER METHOD
back next
September 2005
All rights reserved © 2005, Alcatel Alenia Space
Allan Variance test set-up 2/2
Page 9
 The uncertainty sources are :
 Reference oscillator residual phase noise.
 Noise introduced from the ZCD ( Zero Crossing Detector )
 Measurement from “noise floor evaluation” test setup will allow to
understand the real accurarcy of the test set up.
FILTER + ZCD
L.O.
REFERENCE
OSCILLATOR
TIME
INTERVAL
COUNTER
FILTER + ZCD
REFERENCE
DUAL MIXER METHOD (NOISE FLOOR EVALUATION)
back next
September 2005
All rights reserved © 2005, Alcatel Alenia Space