Radar Signals

Team DDU......Page 1
CONTENTS......Page 9
Preface......Page 15
1 Introduction......Page 17
1.1 Basic Relationships: Range–Delay and Velocity–Doppler......Page 18
Box 1A: Doppler Effect......Page 19
1.2 Accuracy, Resolution, and Ambiguity......Page 23
1.3 Environmental Diagram......Page 29
1.4 Other Trade-Offs and Penalties in Waveform Design......Page 31
1.5 Concluding Comments......Page 33
Problems......Page 34
References......Page 35
2.1 Complex Representation of Bandpass Signals......Page 36
Box 2A: I and Q Components of Narrow Bandpass Signal......Page 38
2.2 Matched Filter......Page 40
Box 2B: Filter Matched to a Baseband Rectangular Pulse......Page 43
2.3 Matched Filter for a Narrow Bandpass Signal......Page 45
2.4 Matched-Filter Response to Its Doppler-Shifted Signal......Page 47
Problems......Page 48
References......Page 49
3.1 Main Properties of the Ambiguity Function......Page 50
3.2 Proofs of the AF Properties......Page 52
3.3 Interpretation of Property 4......Page 54
3.4 Cuts Through the Ambiguity Function......Page 56
3.6 Periodic Ambiguity Function......Page 58
Box 3A: Variants of the Periodic Ambiguity Function......Page 60
3.7 Discussion......Page 62
Appendix 3A: MATLAB Code for Plotting Ambiguity Functions......Page 63
Problems......Page 67
References......Page 68
4.1 Constant-Frequency Pulse......Page 69
4.2 Linear Frequency-Modulated Pulse......Page 73
4.2.1 Range Sidelobe Reduction......Page 77
4.2.2 Mismatch Loss......Page 82
4.3 Coherent Train of Identical Unmodulated Pulses......Page 83
Problems......Page 88
References......Page 89
5.1 Costas Frequency Coding......Page 90
5.1.1 Costas Signal Definition and Ambiguity Function......Page 91
5.1.2 On the Number of Costas Arrays and Their Construction......Page 96
5.1.3 Longer Costas Signals......Page 99
5.2 Nonlinear Frequency Modulation......Page 102
Appendix 5A: MATLAB Code for Welch Construction of Costas Arrays......Page 112
Problems......Page 113
References......Page 115
6 Phase-Coded Pulse......Page 116
Box 6A: Aperiodic Correlation Function of a Phase-Coded Pulse......Page 117
Box 6B: Properties of the Cross-Correlation Function of a Phase Code......Page 120
6.1 Barker Codes......Page 121
6.1.1 Minimum Peak Sidelobe Codes......Page 122
6.1.2 Nested Codes......Page 123
6.1.3 Polyphase Barker Codes......Page 125
6.2 Chirplike Phase Codes......Page 129
6.2.1 Frank Code......Page 131
Box 6C: Perfectness of the Frank Code......Page 133
6.2.2 P1, P2, and Px Codes......Page 134
6.2.3 Zadoff–Chu Code......Page 138
Box 6D: Perfectness of the Zadoff–Chu Code......Page 140
Box 6E: Rotational Invariance of the Zadoff–Chu Code Aperiodic ACF Magnitude......Page 141
6.2.4 P3, P4, and Golomb Polyphase Codes......Page 142
6.2.5 Phase Codes Based on a Nonlinear FM Pulse......Page 144
6.3 Asymptotically Perfect Codes......Page 148
6.4 Golomb's Codes with Ideal Periodic Correlation......Page 150
Box 6F: Deriving the Perfect Golomb Biphase Code......Page 151
Box 6G: Deriving the Golomb Two-Valued Code with Ideal Periodic Cross-Correlation......Page 152
6.5 Ipatov Code......Page 153
6.6 Optimal Filters for Sidelobe Suppression......Page 156
6.7 Huffman Code......Page 158
6.8 Bandwidth Considerations in Phase-Coded Signals......Page 161
6.9 Concluding Comments......Page 171
Appendix 6A: Galois Fields......Page 172
Appendix 6B: Quadriphase Barker 13......Page 174
Appendix 6C: Gaussian-Windowed Sinc......Page 175
Problems......Page 176
References......Page 180
7 Coherent Train of LFM Pulses......Page 184
7.1 Coherent Train of Identical LFM Pulses......Page 185
7.2 Filters Matched to Higher Doppler Shifts......Page 189
7.3 Interpulse Weighting......Page 192
7.4 Intra- and Interpulse Weighting......Page 195
7.5 Analytic Expressions of the Delay–Doppler Response of an LFM Pulse Train with Intra- and Interpulse Weighting......Page 196
7.5.1 Ambiguity Function of N LFM Pulses......Page 197
7.5.2 Delay–Doppler Response of a Mismatched Receiver......Page 198
7.5.3 Adding Intrapulse Weighting......Page 199
7.5.4 Examples......Page 201
Problems......Page 205
References......Page 206
8.1 Introduction to MTI Radar......Page 207
8.1.1 Single Canceler......Page 208
8.1.2 Double Canceler......Page 209
8.2.1 Staggered-PRF Concept......Page 211
8.2.2 Actual Frequency Response of Staggered-PRF MTI Radar......Page 215
8.2.3 MTI Radar Performance Analysis......Page 218
Box 8A: Improvement Factor Introduced through the Autocorrelation Function......Page 220
Box 8B: Optimal MTI Weights......Page 222
8.3.1 Single-PRF Pulse Train Blind Zones and Ambiguities......Page 226
8.3.2 Solving Range–Doppler Ambiguities......Page 228
8.3.3 Selection of Medium-PRF Sets......Page 230
Box 8C: Binary Integration......Page 236
Problems......Page 238
References......Page 241
9.1 Diversity for Recurrent Lobes Reduction......Page 242
9.2 Diversity for Bandwidth Increase: Stepped Frequency......Page 244
9.2.1 Ambiguity Function of a Stepped-Frequency Train of LFM Pulses......Page 245
9.2.2 Stepped-Frequency Train of Unmodulated Pulses......Page 247
9.2.3 Stretch-Processing a Stepped-Frequency Train of Unmodulated Pulses......Page 252
9.2.4 Stepped-Frequency Train of LFM Pulses......Page 261
9.3 Train of Complementary Pulses......Page 278
Box 9A: Operations That Yield Equivalent Complementary Sets......Page 281
9.3.1 Generating Complementary Sets Using Recursion......Page 282
9.3.2 Complementary Sets Generated Using the PON Construction......Page 283
9.3.3 Complementary Sets Based on an Orthogonal Matrix......Page 285
9.4 Train of Subcomplementary Pulses......Page 286
9.5 Train of Orthogonal Pulses......Page 289
Box 9B: Autocorrelation Function of Orthogonal-Coded Pulse Trains......Page 290
9.5.1 Orthogonal-Coded LFM Pulse Train......Page 293
9.5.2 Orthogonal-Coded LFM–LFM Pulse Train......Page 295
9.5.3 Orthogonal-Coded LFM–NLFM Pulse Train......Page 297
Appendix 9A: Generating a Numerical Stepped-Frequency Train of LFM Pulses......Page 300
Problems......Page 302
References......Page 307
10 Continuous-Wave Signals......Page 310
10.1 Revisiting the Periodic Ambiguity Function......Page 311
10.2 PAF of Ideal Phase-Coded Signals......Page 313
10.3 Doppler Sidelobe Reduction Using Weight Windows......Page 317
10.4 Creating a Shifted Response in Doppler and Delay......Page 321
10.5 Frequency-Modulated CW Signals......Page 322
10.5.1 Sawtooth Modulation......Page 325
10.5.2 Sinusoidal Modulation......Page 327
10.5.3 Triangular Modulation......Page 331
10.6 Mixer Implementation of an FM CW Radar Receiver......Page 334
Appendix 10A: Test for Ideal PACF......Page 339
Problems......Page 340
References......Page 342
11 Multicarrier Phase-Coded Signals......Page 343
Box 11A: Orthogonal Frequency-Division Multiplexing......Page 346
11.1 Multicarrier Phase-Coded Signals with Low PMEPR......Page 348
11.1.1 PMEPR of an IS MCPC Signal......Page 349
Box 11B: Closed-Form Multicarrier Bit Phasing with Low PMEPR......Page 351
11.1.2 PMEPR of an MCPC Signal Based on COCS of a CLS......Page 355
11.2 Single MCPC Pulse......Page 357
11.2.1 Identical Sequence......Page 358
11.2.2 MCPC Pulse Based on COCS of a CLS......Page 361
11.3 CW (Periodic) Multicarrier Signal......Page 366
11.4.1 ICS MCPC Diverse Pulse Train......Page 374
11.4.2 COCS of a CLS MCPC Diverse Pulse Train......Page 376
11.4.3 MOCS MCPC Pulse Train......Page 377
11.4.4 Frequency Spectra of MCPC Diverse Pulse Trains......Page 380
11.5 Summary......Page 381
Problems......Page 383
References......Page 388
A.1 Ambiguity Function Plot with a GUI......Page 389
A.2 Creating Complex Signals for Use with ambfn1.m or ambfn7.m......Page 406
A.3 Cross-Ambiguity Function Plot......Page 410
A.4 Generating a CW Periodic Signal with Weighting on Receive......Page 416
Index......Page 419