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 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