Table Of ContentAutonomous Software-Defined
Radio Receivers for Deep
Space Applications
Jon Hamkins and Marvin K. Simon, Editors
Jet Propulsion Laboratory
California Institute of Technology
DEEP SPACE COMMUNICATIONS AND NAVIGATION SERIES
DEEP SPACE COMMUNICATIONS AND NAVIGATION SERIES
Issued by the Deep Space Communications and Navigation Systems
Center of Excellence
Jet Propulsion Laboratory
California Institute of Technology
Joseph H. Yuen, Editor-in-Chief
Published Titles in this Series
Radiometric Tracking Techniques for Deep-Space Navigation
Catherine L. Thornton and James S. Border
Formulation for Observed and Computed Values of
Deep Space Network Data Types for Navigation
Theodore D. Moyer
Bandwidth-Efficient Digital Modulation with Application
to Deep-Space Communications
Marvin K. Simon
Large Antennas of the Deep Space Network
William A. Imbriale
Antenna Arraying Techniques in the Deep Space Network
David H. Rogstad, Alexander Mileant, and Timothy T. Pham
Radio Occultations Using Earth Satellites:
A Wave Theory Treatment
William G. Melbourne
Deep Space Optical Communications
Hamid Hemmati, Editor
DEEP SPACE COMMUNICATIONS AND NAVIGATION SERIES
Spaceborne Antennas for Planetary Exploration
William A. Imbriale, Editor
Autonomous Software-Defined Radio Receivers for
Deep Space Applications
Jon Hamkins and Marvin K. Simon, Editors
Autonomous Software-Defined
Radio Receivers for Deep
Space Applications
Jon Hamkins and Marvin K. Simon, Editors
Jet Propulsion Laboratory
California Institute of Technology
DEEP SPACE COMMUNICATIONS AND NAVIGATION SERIES
Autonomous Software-Defined Radio Receivers for
Deep Space Applications
2006
The research described in this publication was carried out at the
Jet Propulsion Laboratory, California Institute of Technology, under
a contract with the National Aeronautics and Space Administration.
Reference herein to any specific commercial product, process, or service
by trade name, trademark, manufacturer, or otherwise, does not constitute
or imply its endorsement by the United States Government or the
Jet Propulsion Laboratory, California Institute of Technology.
Table of Contents
Foreword..............................................................................................................xiii
Preface....................................................................................................................xv
Acknowledgments................................................................................................xvii
Contributors..........................................................................................................xix
Chapter 1: Introduction and Overview.....................................................1
by Jon Hamkins and Marvin K. Simon
1.1 Preliminaries.............................................................................................3
1.1.1 Signal Model...................................................................................3
1.1.2 Anatomy of the Received Signal...................................................5
1.2 Radio Receiver Architectures.............................................................8
1.2.1 A Conventional Radio Receiver....................................................8
1.2.2 Electra............................................................................................10
1.2.3 An Autonomous Radio.................................................................10
1.3 Estimators and Classifiers of the Autonomous Radio.............12
1.3.1 Carrier Phase Tracking.................................................................12
1.3.2 Modulation Classification............................................................13
1.3.3 Signal-to-Noise Ratio Estimation................................................13
1.3.4 Frequency Tracking......................................................................14
1.4 An Iterative Message-Passing Architecture.................................14
1.4.1 Messages from the Symbol-Timing Estimator...........................15
1.4.2 Messages from the Phase Tracker...............................................15
1.4.3 Messages from the Modulation Classification............................15
1.4.4 Messages from the Decoder.........................................................15
1.5 A Demonstration Testbed..................................................................16
References.........................................................................................................16
Chapter 2: The Electra Radio....................................................................19
by Edgar Satorius, Tom Jedrey, David Bell, Ann Devereaux,
Todd Ely, Edwin Grigorian, Igor Kuperman, and Alan Lee
2.1 Electra Receiver Front-End Processing........................................20
2.1.1 AGC...............................................................................................22
2.1.2 ADC...............................................................................................24
v
vi
2.1.3 Digital Downconversion and Decimation...................................25
2.2 Electra Demodulation..........................................................................25
2.2.1 Frequency-Acquisition and Carrier-Tracking Loop...................27
2.2.2 Navigation: Doppler Phase Measurement...................................30
2.2.3 Symbol-Timing Recovery............................................................30
2.2.4 Viterbi Node Sync and Symbol SNR Estimation.......................33
2.3 Electra Digital Modulator....................................................................39
References.........................................................................................................42
Chapter 3: Modulation Index Estimation...............................................45
by Marvin K. Simon and Jon Hamkins
3.1 Coherent Estimation............................................................................46
3.1.1 BPSK.............................................................................................46
3.1.2 M-PSK...........................................................................................50
3.2 Noncoherent Estimation.....................................................................54
3.3 Estimation in the Absence of Knowledge of the
Modulation, Data Rate, Symbol Timing, and SNR......................56
3.4 Noncoherent Estimation in the Absence of
Carrier Frequency Knowledge..........................................................61
Chapter 4: Frequency Correction............................................................63
by Dariush Divsalar
4.1 Frequency Correction for Residual Carrier..................................63
4.1.1 Channel Model..............................................................................64
4.1.2 Optimum Frequency Estimation over an AWGN Channel........64
4.1.3 Optimum Frequency Estimation over a Raleigh
Fading Channel.............................................................................65
4.1.4 Open-Loop Frequency Estimation...............................................66
4.1.5 Closed-Loop Frequency Estimation............................................67
4.2 Frequency Correction for Known Data-Modulated Signals....72
4.2.1 Channel Model..............................................................................72
4.2.2 Open-Loop Frequency Estimation...............................................74
4.2.3 Closed-Loop Frequency Estimation............................................74
4.3 Frequency Correction for Modulated Signals with
Unknown Data........................................................................................78
4.3.1 Open-Loop Frequency Estimation...............................................79
4.3.2 Closed-Loop Frequency Estimation............................................80
References.........................................................................................................83
Table of Contents vii
Chapter 5: Data Format and Pulse Shape Classification................85
by Marvin K. Simon and Dariush Divsalar
5.1 Coherent Classifiers of Data Format for BPSK...........................86
5.1.1 Maximum-Likelihood Coherent Classifier of Data
Format for BPSK..........................................................................86
5.1.2 Reduced-Complexity Data Format BPSK Classifiers................88
5.1.3 Probability of Misclassification for Coherent BPSK.................89
5.2 Coherent Classifiers of Data Format for QPSK..........................94
5.2.1 Maximum-Likelihood Coherent Classifier of Data
Format for QPSK..........................................................................94
5.2.2 Reduced-Complexity Data Format QPSK Classifiers................96
5.2.3 Probability of Misclassification for Coherent QPSK.................97
5.3 Noncoherent Classification of Data Format for BPSK.............98
5.3.1 Maximum-Likelihood Noncoherent Classifier of Data
Format for BPSK..........................................................................98
5.3.2 Probability of Misclassification for Noncoherent BPSK.........105
5.4 Maximum-Likelihood Noncoherent Classifier of Data
Format for QPSK.................................................................................108
5.5 Maximum-Likelihood Coherent Classifier of Data Format
for BPSK with Residual and Suppressed Carriers..................109
5.6 Maximum-Likelihood Noncoherent Classifier of Data
Format for BPSK with Residual and Suppressed
Carriers...................................................................................................113
5.7 Maximum-Likelihood Pulse Shape Classification....................117
References.......................................................................................................119
Chapter 6: Signal-to-Noise Ratio Estimation.....................................121
by Marvin K. Simon and Samuel Dolinar
6.1 Signal Model and Formation of the Estimator...........................123
6.1.1 Sampled Version.........................................................................123
6.1.2 I&D Version................................................................................126
6.2 Methods of Phase Compensation.................................................129
6.3 Evaluation of h±....................................................................................131
6.4 Mean and Variance of the SNR Estimator...................................132
6.4.1 Exact Moment Evaluations........................................................132
6.4.2 Asymptotic Moment Evaluations..............................................136
viii
6.5 SNR Estimation in the Presence of Symbol Timing Error.....145
6.5.1 Signal Model and Formation of the Estimator..........................146
6.5.2 Mean and Variance of the SNR Estimator................................149
6.6 A Generalization of the SSME Offering Improved
Performance..........................................................................................150
6.7 A Method for Improving the Robustness of the
Generalized SSME...............................................................................156
6.8 Special Case of the SSME for BPSK-Modulated Data............158
6.9 Comparison with the Cramer–Rao Lower Bound on the
Variance of SNR Estimators............................................................161
6.10 Improvement in the Presence of Frequency Uncertainty......165
6.11 The Impact of the Oversampling Factor on the
Performance of the Modified SSME in the Presence of
Symbol Timing Error..........................................................................171
6.12 Other Modulations..............................................................................175
6.12.1 Offset QPSK................................................................................175
6.12.2 QAM............................................................................................179
6.13 The Time-Multiplexed SSME............................................................180
6.13.1 An Adaptive SSME....................................................................184
References.......................................................................................................188
Appendix 6-A Derivation of Asymptotic Mean and Variance
of SSME..............................................................................190
Chapter 7: Data Rate Estimation............................................................193
by Andre Tkacenko and Marvin K. Simon
7.1 Data Rate Estimation Based on the Mean of the SSME
SNR Estimator......................................................................................194
7.1.1 Signal Model and Assumptions.................................................194
7.1.2 Relation of the SSME SNR Estimator to Data Rate
Estimation....................................................................................196
7.1.3 SSME Data Rate Estimation Algorithm....................................200
7.1.4 GLRT-Type SSME Data Rate Estimation Algorithm..............201
7.2 Effects of Symbol-Timing Error on Estimating the
Data Rate................................................................................................201
7.2.1 Accounting for the Symbol-Timing Error.................................202
7.3 Quantization of the Symbol-Timing Error...................................204
Table of Contents ix
7.3.1 All-Digital Implementation of the SSME-Based Data
Rate Estimator.............................................................................205
7.3.2 SSME Data Rate/SNR/Symbol-Timing Error Estimation
Algorithm....................................................................................208
7.3.3 GLRT-Type SSME Data Rate/SNR/Symbol-Timing
Error Estimation Algorithm.......................................................209
7.4 Simulation Results for the SSME-Based Estimation
Algorithms.............................................................................................209
7.4.1 Performance Metrics Used for Evaluating the Estimation
Algorithms...................................................................................210
7.4.2 Behavior of the SSME-Based Data Rate Estimation
Algorithms as a Function of SNR..............................................213
7.4.3 Behavior of the SSME-Based Data Rate Estimation
Algorithms as a Function of Symbol-Timing Error.................220
References.......................................................................................................226
Chapter 8: Carrier Synchronization......................................................227
by Marvin K. Simon and Jon Hamkins
8.1 Suppressed versus Residual Carrier Synchronization..........229
8.2 Hybrid Carrier Synchronization......................................................230
8.3 Active versus Passive Arm Filters................................................233
8.4 Carrier Synchronization of Arbitrary Modulations..................247
8.4.1 MPSK..........................................................................................247
8.4.2 QAM and Unbalanced QPSK....................................................259
8.4.3 π/4 Differentially Encoded QPSK.............................................264
References.......................................................................................................264
Appendix 8-A Cramer–Rao Bound on the Variance of the
Error in Estimating the Carrier Phase of a
BPSK Signal......................................................................266
Chapter 9: Modulation Classification...................................................271
by Jon Hamkins and Marvin K. Simon
9.1 Preliminaries.........................................................................................272
9.1.1 Signal Model...............................................................................272
9.1.2 Conditional-Likelihood Function..............................................273
9.2 Modulation Classifiers.......................................................................274
9.2.1 ML Classifiers.............................................................................274
9.2.2 Suboptimum Classifiers.............................................................276