The ESA MUSIC Project MultiUser

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The ESA MUSIC Project Multi-User Interference
Cancellation - ESA/ESTEC Contract 13095/98/NL/SB

• Advanced Mobile Satellite Systems Technologies
  presentation days
• ESA./ESTEC 14-15 November 2000

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The MUSIC Project Mission

• The MUSIC experiment
• (Multi-USer Interference Cancellation receiver)
• is a research project supported by the European
  Space Agency
• which is aimed at the validation of an
• Adaptive Interference Mitigating Detector
• suited for use in a CDMA-based mobile satellite
  network

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The MUSIC Project Mission

• The MUSIC experiment
• (Multi-USer Interference Cancellation receiver)
• is a research project supported by the European
  Space Agency
• which is aimed at the validation of an
• Adaptive Interference Mitigating Detector
• suited for use in a CDMA-based mobile satellite
  network

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MUSIC Breadboard Setup
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Presentation Outline

• Overall System Description and Architectural
  Issues(M. Luise, CPR)
• Design of DSP HW and Analog TX/RX ends(G.
  Colleoni, STM)
• Breadboard HW partitioning and ASIC Design(L.
  Fanucci, CPR)

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Technical Specs Tables MUSIC TX 1/2
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Technical Specs Tables MUSIC TX 2/2
As output from WP200
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Technical Specs Tables MUSIC RX 1/2
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Technical Specs Tables MUSIC RX 2/2
lt
lt
As output from WP200
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Breadboard Control and Monitoring via LabVIEW
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Breadboard Control and Monitoring via LabVIEW
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A Corner of the MUSIC Lab in Pisa
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The MUSIC TX SW Setup
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The MUSIC TX SW Setup
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SW CDMA Signal Generation ...
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AWG Loading and Run
PC Slot
AWG
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Sat Channel Emulation Noise Generation
MUSIC Testing Overall Set-up
LabView Virtual Instrument
NOISECOM UFX 7107
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The MUSIC TX/RX Analog IF front-end
More in the presentation to follow by G.
Colleoni, STMicroelectronics
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MUSIC RXDirect IF sampling
Spectrum after A/D conversion
Digital downconversion to baseband
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The PROTEO Signal Processing Board
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The PROTEO Signal Processing Board
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MUSIC RX Architecture
More on HW partitioning to follow by L. Fanucci,
CPR-Team
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The Digital Multi-Rate Front-End 1/2
Downconverting to Baseband via a DCO
fIFD
BB
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The Digital Multi-Rate Front-End 2/2
Cascaded Integrator-Comb (CIC) Filter
A low-complexity solution to perform low-pass
filtering and decimation with no noise spectrum
aliasing
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Ancillary Receiver Functions
SYNCHRONIZATION Timing Spreading code
acquisition Chip clock tracking Carrier
Carrier frequency tracking Carrier phase
recovery
DETECTION Signal Interpolation Signal sense
MONITORING AND MEASUREMENT Signal-to-noise plus
interference ratio Bit error rate Chip Timing
Carrier Loop Lock
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Code Timing Acquisition Unit (CTAU)
Correlation Time L symbol intervals
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Performance of CTAU with Different Kind of Pilots
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Linear Interpolation Unit (LIU)
Td Tc/4
lminteger delay, mmfractional delay
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Chip Clock Tracking Unit (CCTU)
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Chip-timing Error Detector (CED)
Non-coherent, non decision-aided processing
Lock detector not shown
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Automatic Frequency Control Unit (AFCU)
Frequency Error Detector (FED)
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Carrier Phase Recovery Unit (CPRU)(embedded with
EC-BAID)
Decision-Aided at EC-BAID output !
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The MUSIC core The EC-BAID 1/2
E
EC-BAID Extended Complex-valued Blind Adaptive
Interference-mitigating Detector is a baseband
single-channel digital detector to counteract
multiple-access interference
F. Giannetti. R. De Gaudenzi, M. Luise "Design
of a Low-Complexity Adaptive Interference-Rejectio
n Detector for DS/SS Receivers in CDMA Radio
Networks", IEEE Trans. Commun, vol. COM-46 n. 1,
Jan 1998.
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The MUSIC core The EC-BAID 2/2
The C-BAID is a linear adaptive detector with
complex-valued coefficients h1(m) , m0,1,...,L-1
CMF outputs array
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Features of the EC-BAID

• Blind no need for training sequences to aid
  algorithm convergence, nor knowledge of
  interferers' parameters
• Robust to asynchronous MAI even for large
  interferer-to-useful channel power ratios
• Insensitive to the unknown phase of the useful
  signal and compatible with conventional QPSK
  phase estimators
• Robust to residual carrier frequency errors with
  respect toconventional DA-MMSE
• Insensitive to carrier frequency offsets on the
  interfering signals
• Suited to low-power ASIC implementation on a
  low-cost user terminal.

J. Romero-Garcia, F. Giannetti. R. De Gaudenzi,
M. Luise A Frequency Error Resistant Blind CDMA
Detector",IEEE Trans. Commun., July 2000
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Interference-Mitigation Capability of EC-BAID
Spreading FactorL64 WHE-PN Codes 1 User 18
Interferers6 dB STRONGER than the useful channel
each. (C/I)sc-6 dB
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The EC-BAID ASIC with Embedded CPRU 1/2
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The EC-BAID ASIC with Embedded CPRU 2/2
0.25 mm Technology
More on ASIC Design to follow by L. Fanucci,
CPR-Team
R. De Gaudenzi, E. Letta, L. Fanucci, F.
Giannetti, M. Luise "VLSI Implementation of a
CDMA Blind Interference-Mitigating Detector", to
appear on the IEEE Jou. Sel. Areas Commun
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Some Results Bit-True Simulations 1/2
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Some Results Bit-True Simulations 2/2
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70MHz IF CDMA Signal Noise
Chip Rate 2.048 Mchip/s L64, Bit-rate64
kb/s DataPilot Channel
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BB Filtered/Interpolated Digital CDMA Signal
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The Double-PROTEO Config with EC-BAID on FPGA
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Current Status and Further Development Steps

• EC-BAID FPGA Implementation finalized
• ASIC layout finalized
• Final Receiver BER Testing Started
• ASIC foundry run scheduled
• ASIC Integration and Testing planned

Soon to be ended...
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CIC Equalization
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Signal Decimation with the CIC Filter 1/2
rdecimation factor
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Signal Decimation with the CIC Filter 2/2
Thats How the CIC Works
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AWG Aperture Equalizer
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TX/RX Filtering
IF Filter
Mixer
fIF
fIFD
AWG
SignalMAI
fLO
To Noise Generation
Combining
more in the detailed presentation
Local Oscillator
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HW Partitioning of RX Functions
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Bit-True Design Sample (Hierarchical Diagram)
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CCTU Lock Detector
Low-pass Filtering
Threshold with Hysteresis
Nonlinearity
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The EC-BAID Long-term BER Dirft
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Adaptive EC-BAID with Leakage
Standard EC-BAID
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Leak Factor Optimization
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Optimization of the EC-BAID Window Length
Optimum Length 2 symbol intervals (0.510.5)
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EC-BAID Functional Block Diagram 1/2
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EC-BAID Functional Block Diagram 2/2