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Network and Communications Simulation User Guide & Block Reference DESIGN SOLUT

Network and Communications Simulation User Guide & Block Reference DESIGN SOLUTIONS FOR EVERY DESKTOP CommsimTM and Electronics WorkbenchTM  1989, 1992-2001 Interactive Image Technologies Ltd. All rights reserved. All other brand or product names are trademarks or registered trademarks of their respective companies or organizations. Revision 1  2001 Interactive Image Technologies Ltd. All rights reserved. Published August 2001. Printed in Canada. CS01-E-1721 iii Table of Contents Table of Contents.......................................................................iii Preface.......................................................................................xv Conventions used in this book...............................................................................................................xvi Version Details.....................................................................................................................................xvii Getting help.........................................................................................................................................xviii Technical support service......................................................................................................................xix License Agreement.................................................................................................................................xx Introduction .................................................................................1 A typical communication system..............................................................................................................1 Data source...............................................................................................................................................2 Data encoder.............................................................................................................................................2 Modulator.................................................................................................................................................2 Channel.....................................................................................................................................................2 Demodulator.............................................................................................................................................2 Data decoder.............................................................................................................................................3 Signal sink................................................................................................................................................3 Lowpass equivalent systems.....................................................................................................................3 Block Summary........................................................................................................................................4 Communication blocks.............................................................................................................................4 Core blocks...............................................................................................................................................6 Sample communication simulation...........................................................................................................7 Solving Implicit Equations..........................................................9 Setting up an implicit equation.................................................................................................................9 Solving an implicit equation...................................................................................................................10 Using the Implicit Solver property sheet..................................................................................11 Implicit equation examples.....................................................................................................................12 Simple nonlinear implicit equation ..........................................................................................12 Advanced nonlinear implicit equation......................................................................................12 Table of Contents iv Performing Global Optimization ..............................................15 Global optimization basics .....................................................................................................................15 Cost functions with many local minimum values.....................................................................15 Cost functions with no minimum values ..................................................................................16 Performing global optimization..............................................................................................................16 Using the Optimization Properties dialog box .........................................................................17 Global optimization examples................................................................................................................17 Optimized paper bag problem..................................................................................................17 Two segment approximation of sin(πt) ....................................................................................19 Five segment approximation of sin(πt).....................................................................................20 Troubleshooting .....................................................................................................................................21 Working with Large Diagrams..................................................23 Creating model hierarchy .......................................................................................................................23 Creating a compound block......................................................................................................24 Drilling into a compound block ...............................................................................................25 Automatically configuring a compound block .........................................................................25 Triggering the execution of compound blocks.........................................................................31 Specifying a local time step......................................................................................................32 Keeping track of the number of blocks in a compound block..................................................33 Hiding compound blocks .........................................................................................................33 Configuring pictures on compound blocks...............................................................................33 Labeling connector tabs on compound blocks .........................................................................34 Dissolving a compound block..................................................................................................35 Other things you can do with compound blocks.......................................................................35 Embedding blocks..................................................................................................................................35 Setting up a diagram to be embedded ......................................................................................36 Embedding a block diagram.....................................................................................................36 Editing an embedded block diagram........................................................................................37 Reconnecting an embedded block diagram..............................................................................37 Adding block diagrams...........................................................................................................................37 Using variables to pass signals ...............................................................................................................38 Creating variables ....................................................................................................................38 Scoping variables.....................................................................................................................39 Built-in variables......................................................................................................................41 Using path aliases to reference files .......................................................................................................41 Types of path aliases................................................................................................................42 Displaying conflicts between local and global path aliases......................................................42 Creating path aliases ................................................................................................................42 Specifying path aliases in blocks..............................................................................................44 Creating nested path aliases .....................................................................................................44 Table of Contents v Maintaining an edit history.....................................................................................................................45 Protecting your work..............................................................................................................................46 Protecting block diagrams........................................................................................................46 Protecting compound blocks....................................................................................................48 Protecting embed blocks ..........................................................................................................50 Designing Digital Filters ...........................................................53 Digital filter basics .................................................................................................................................53 Filter operations......................................................................................................................................54 Time domain filters with tapped delay ...................................................................................................54 Time domain filters with transfer functions............................................................................................55 Frequency domain filter implementation................................................................................................55 Comparison of FIR and IIR filters..........................................................................................................56 Interactive filter design with the transferFunction block ........................................................................56 IIR filter design ......................................................................................................................................56 Using the IIR Filter Properties dialog box ...............................................................................57 FIR filter design......................................................................................................................................60 Discrete and continuous FIR filter design................................................................................60 Using the FIR Filter Properties dialog box ..............................................................................61 Working with Other Applications.............................................65 Importing basics .....................................................................................................................................65 Setting up the input file............................................................................................................66 Importing data..........................................................................................................................66 Using the Import Properties dialog box ...................................................................................67 Exporting basics .....................................................................................................................................68 Exporting data..........................................................................................................................68 Using the Export Properties dialog box ...................................................................................69 Commsim-MatLab interface basics........................................................................................................71 Evaluating MatLab expressions ...............................................................................................71 Reading and writing MatLab variables ....................................................................................72 Transmitting data using ActiveX............................................................................................................75 Using the ActiveX read block ..................................................................................................75 Using the ActiveX write block.................................................................................................77 Commsim-specific ActiveX functions......................................................................................79 ActiveX example......................................................................................................................79 DDE basics.............................................................................................................................................80 Creating an app-to-Commsim link with DDEreceive...............................................................81 Creating a Commsim-to-app link with DDEsend.....................................................................83 Creating a two-way link with DDE ..........................................................................................85 Table of Contents vi Creating DDE links with applications that do not support Copy Link and Paste Link.................................................................................................................................88 Creating look-up tables...........................................................................................................................88 Specifying the data source........................................................................................................89 Using the Look-up Table Wizard.............................................................................................91 Using the map block.................................................................................................................93 Examples..................................................................................................................................95 Exchanging information with Mathcad 2000........................................................................................101 Use of the inx and outx keywords...........................................................................................101 Embedding Mathcad documents ............................................................................................101 Editing and updating Mathcad documents .............................................................................102 Scaling and cropping embedded Mathcad documents............................................................103 Examining the properties of an embedded Mathcad document..............................................104 Changing the number of connector tabs on an embedded Mathcad document.......................105 Troubleshooting .....................................................................................................................105 Examples................................................................................................................................106 WMF basics .........................................................................................................................................109 Saving a diagram as a WMF file............................................................................................109 Inserting a WMF file in another application ..........................................................................109 Comm Block Set......................................................................111 Channels category ................................................................................................................................111 AWGN (Complex).................................................................................................................111 AWGN (Real) ........................................................................................................................111 Binary Symmetric Channel ....................................................................................................112 Jakes Mobile ..........................................................................................................................113 Multipath................................................................................................................................113 Propagation Loss....................................................................................................................114 Rice/Rayleigh Fading.............................................................................................................115 Rummler Multipath................................................................................................................116 TWTA....................................................................................................................................117 Complex Math category .......................................................................................................................118 Addition .................................................................................................................................118 Conjugate...............................................................................................................................118 Division..................................................................................................................................119 Inverse....................................................................................................................................119 Multiplication.........................................................................................................................119 Power .....................................................................................................................................119 Square Root............................................................................................................................119 Complex to Mag/Phase ..........................................................................................................120 Complex to Real/Imag ...........................................................................................................120 Mag/Phase to Complex ..........................................................................................................120 Table of Contents vii Real/Imag to Complex ...........................................................................................................120 Demodulators category.........................................................................................................................120 DQPSK, Pi/4-DQPSK Detector.............................................................................................120 FM Demodulator....................................................................................................................121 Integrate & Dump (Complex) ................................................................................................122 Integrate & Dump (Real)........................................................................................................122 PPM Demodulator .................................................................................................................123 PSK Detector .........................................................................................................................123 QAM/PAM Detector..............................................................................................................124 Digital category....................................................................................................................................125 Binary Counter.......................................................................................................................125 Bits to Symbol........................................................................................................................125 D Flip Flop.............................................................................................................................126 Divide by N............................................................................................................................126 JK Flip Flop ...........................................................................................................................127 Mux/Demux ...........................................................................................................................127 Parallel to Serial.....................................................................................................................128 Queue.....................................................................................................................................129 Serial to Parallel.....................................................................................................................130 Symbol to Bits........................................................................................................................130 Encode / Decode category....................................................................................................................131 Block Interleaver....................................................................................................................131 Convolutional Encoder...........................................................................................................131 Convolutional Interleaver.......................................................................................................132 Gray Decoder.........................................................................................................................133 Gray Encoder .........................................................................................................................133 Trellis Decoder ......................................................................................................................134 Trellis Encoder.......................................................................................................................134 Viterbi Decoder (Hard)..........................................................................................................136 Viterbi Decoder (Soft) ...........................................................................................................136 Estimators category ..............................................................................................................................138 Average Power (Complex).....................................................................................................138 Average Power (Real)............................................................................................................138 BER Curve Control................................................................................................................139 Correlation .............................................................................................................................140 Delay Estimator......................................................................................................................141 Bit/Symbol Error Rate............................................................................................................142 Event Time.............................................................................................................................142 Mean ......................................................................................................................................143 Median ...................................................................................................................................143 Variance.................................................................................................................................144 Weighted Mean......................................................................................................................144 Filters category.....................................................................................................................................145 Adaptive Equalizer (Complex)...............................................................................................145 Table of Contents viii Adaptive Equalizer (Real)......................................................................................................145 File FIR..................................................................................................................................147 FIR Filter................................................................................................................................148 IIR..........................................................................................................................................149 Sampling File FIR..................................................................................................................151 Sampling FIR .........................................................................................................................152 MagPhase...............................................................................................................................155 Modulators categories – Complex and Real.........................................................................................157 AM.........................................................................................................................................157 DQPSK,Pi/4-DQPSK.............................................................................................................157 FM..........................................................................................................................................158 FSK........................................................................................................................................159 MSK.......................................................................................................................................160 PM..........................................................................................................................................161 PPM .......................................................................................................................................161 PSK........................................................................................................................................162 QAM/PAM ............................................................................................................................166 SQPSK Modulator .................................................................................................................172 Operators category ...............................................................................................................................173 A/D Converter........................................................................................................................173 Compander.............................................................................................................................174 Complex Exponential.............................................................................................................175 Complex FFT/IFFT................................................................................................................175 Conversions............................................................................................................................177 Decimation.............................................................................................................................179 Delay (Complex)....................................................................................................................179 Delay (Real)...........................................................................................................................180 Gain (dB) ...............................................................................................................................180 IQ Mapper..............................................................................................................................180 Max Index..............................................................................................................................181 Modulo...................................................................................................................................182 Phase Rotate...........................................................................................................................182 Phase Unwrap ........................................................................................................................183 Polynomial .............................................................................................................................183 Spectrum Analyzer ...............................................................................................................................184 PLL category........................................................................................................................................185 Charge Pump..........................................................................................................................185 Loop Filter (2nd Order PLL) .................................................................................................187 Loop Filter (3rd Order PLL)..................................................................................................188 Type-2 Phase Detector...........................................................................................................189 Type-3 Phase Detector...........................................................................................................189 Type-4 Phase Detector...........................................................................................................190 VCO (Complex).....................................................................................................................190 VCO (Real)............................................................................................................................190 Table of Contents ix RF category ..........................................................................................................................................191 Amplifier................................................................................................................................191 Attenuator ..............................................................................................................................192 Coupler...................................................................................................................................193 Double Balanced Mixer .........................................................................................................193 Splitter/Combiner...................................................................................................................195 Switch ....................................................................................................................................196 Variable Attenuator................................................................................................................197 Signal Sources category .......................................................................................................................197 Complex Tone........................................................................................................................197 File Data.................................................................................................................................198 Frequency Sweep ...................................................................................................................199 Impulse...................................................................................................................................200 Impulse Train.........................................................................................................................200 Noise......................................................................................................................................200 PN Sequence..........................................................................................................................201 Random Seed .........................................................................................................................202 Random Symbols ...................................................................................................................202 Rectangular Pulses .................................................................................................................203 Sinusoid..................................................................................................................................204 Walsh Sequence.....................................................................................................................204 Waveform Generator..............................................................................................................205 Core Block Reference.............................................................207 * (multiply)...........................................................................................................................................208 -X (negate)............................................................................................................................................209 / (divide)...............................................................................................................................................211 < (less than)..........................................................................................................................................213 <= (less than or equal to)......................................................................................................................214 == (equal to).........................................................................................................................................215 != (not equal to)....................................................................................................................................218 > (greater than).....................................................................................................................................219 >= (greater than or equal to).................................................................................................................221 1/X (inverse).........................................................................................................................................222 abs ........................................................................................................................................................223 acos.......................................................................................................................................................225 ActiveX read ........................................................................................................................................225 ActiveX write .......................................................................................................................................225 and........................................................................................................................................................226 animate .................................................................................................................................................227 asin .......................................................................................................................................................227 atan2.....................................................................................................................................................228 Table of Contents x bessel....................................................................................................................................................229 bezel .....................................................................................................................................................231 buffer....................................................................................................................................................232 button....................................................................................................................................................234 case.......................................................................................................................................................235 comment...............................................................................................................................................238 const .....................................................................................................................................................238 constraint..............................................................................................................................................240 convert .................................................................................................................................................240 cos ........................................................................................................................................................240 cosh ......................................................................................................................................................241 cost .......................................................................................................................................................241 crossDetect ...........................................................................................................................................241 date.......................................................................................................................................................244 DDE .....................................................................................................................................................244 DDEreceive..........................................................................................................................................245 DDEsend ..............................................................................................................................................245 deadband ..............................................................................................................................................245 derivative..............................................................................................................................................246 dialogConstant......................................................................................................................................246 display ..................................................................................................................................................247 dotProduct ...........................................................................................................................................248 embed ...................................................................................................................................................248 error......................................................................................................................................................248 exp........................................................................................................................................................251 export ...................................................................................................................................................251 expression.............................................................................................................................................251 fft .........................................................................................................................................................254 gain.......................................................................................................................................................255 gaussian................................................................................................................................................257 globalConstraint ...................................................................................................................................258 histogram..............................................................................................................................................258 ifft ........................................................................................................................................................258 import...................................................................................................................................................260 index.....................................................................................................................................................260 int .........................................................................................................................................................261 integrator (1/S) .....................................................................................................................................262 invert ...................................................................................................................................................267 label......................................................................................................................................................267 light ......................................................................................................................................................268 limit ......................................................................................................................................................270 limitedIntegrator (1/S)..........................................................................................................................271 lineDraw...............................................................................................................................................274 log10.....................................................................................................................................................274 Table of Contents xi ln...........................................................................................................................................................275 map.......................................................................................................................................................275 MatLab Expression...............................................................................................................................277 MatLab Read Variable .........................................................................................................................277 MatLab Write Variable ........................................................................................................................277 max.......................................................................................................................................................277 merge....................................................................................................................................................279 meter.....................................................................................................................................................280 min........................................................................................................................................................280 multiply ................................................................................................................................................282 not.........................................................................................................................................................283 OLEobject ............................................................................................................................................284 Editing and updating objects..................................................................................................286 Examining the properties of an embedded object ..................................................................286 Scaling and cropping OLEobject blocks................................................................................287 or ..........................................................................................................................................................288 parabola................................................................................................................................................289 parameterUnknown ..............................................................................................................................290 plot .......................................................................................................................................................290 pow.......................................................................................................................................................291 PRBS....................................................................................................................................................292 psd ........................................................................................................................................................293 pulseTrain.............................................................................................................................................293 quantize ................................................................................................................................................294 ramp......................................................................................................................................................296 realTime ...............................................................................................................................................297 relay......................................................................................................................................................297 resetIntegrator (1/S)..............................................................................................................................298 sampleHold...........................................................................................................................................301 scalarToVec..........................................................................................................................................303 sign.......................................................................................................................................................305 sin.........................................................................................................................................................306 sinh.......................................................................................................................................................306 sinusoid ................................................................................................................................................307 slider.....................................................................................................................................................307 sqrt........................................................................................................................................................308 stateSpace.............................................................................................................................................309 step .......................................................................................................................................................311 stop.......................................................................................................................................................311 stripChart..............................................................................................................................................312 summingJunction..................................................................................................................................312 tan.........................................................................................................................................................314 tanh.......................................................................................................................................................315 timeDelay .............................................................................................................................................316 Table of Contents xii transferFunction....................................................................................................................................319 transpose...............................................................................................................................................323 uniform.................................................................................................................................................323 unitConversion .....................................................................................................................................324 unitDelay..............................................................................................................................................325 unknown...............................................................................................................................................327 userFunction.........................................................................................................................................327 variable.................................................................................................................................................328 vecToScalar..........................................................................................................................................328 vsum ....................................................................................................................................................329 wirePositioner.......................................................................................................................................329 xor ........................................................................................................................................................330 Customizing Commsim ..........................................................333 Customizing Commsim start-up ...........................................................................................................333 Customizing the Commsim window.....................................................................................................334 Customizing the toolbar .........................................................................................................334 Customizing other screen settings..........................................................................................336 Creating custom implicit solvers ..........................................................................................................337 Source files for building a custom implicit solver..................................................................338 Using VissimRequest() in a custom implicit solver ...............................................................338 Building a custom implicit solver...........................................................................................340 Using the constraint block with a custom implicit solver.......................................................340 Creating custom global optimizers .......................................................................................................341 Source files for building a custom global optimizer...............................................................341 Using VissimRequest() in a custom global optimizer ............................................................341 Building a custom global optimizer .......................................................................................343 Extending the Block Set .........................................................345 Before you begin… ..............................................................................................................................345 The big picture .....................................................................................................................................345 Criteria for writing DLLs .......................................................................................................346 Building a DLL......................................................................................................................346 How Commsim talks to a DLL.............................................................................................................347 Calling conventions................................................................................................................348 Simulation level functions......................................................................................................348 Block level functions..............................................................................................................349 Exported functions .................................................................................................................354 Debugging hints....................................................................................................................................357 Using the DLL wizard ..........................................................................................................................358 Editing the VSI.CPP file ........................................................................................................362 Table of Contents xiii Editing Connector Tab Labels ...............................................................................................362 Accessing a custom block from Commsim...........................................................................................363 Adding a custom block to a Commsim menu.........................................................................363 Binding a DLL to a userFunction block.................................................................................363 Commsim Library....................................................................365 Compound blocks.................................................................................................................................365 COSTAS_C.VSM..................................................................................................................365 COSTAS_R.VSM..................................................................................................................366 GMSK.VSM ..........................................................................................................................366 PLL1CPLX.VSM...................................................................................................................366 PLL1REAL.VSM...................................................................................................................366 PLL2CPLX.VSM...................................................................................................................366 PLL2REAL.VSM...................................................................................................................367 TWTA_TBL.VSM.................................................................................................................367 V32DIFDE.VSM ...................................................................................................................367 V32DIFEN.VSM ...................................................................................................................368 VCPG.VSM ...........................................................................................................................368 Data files ..............................................................................................................................................368 AMAM.DAT..........................................................................................................................368 AMPM.DAT ..........................................................................................................................368 DATA_IN.DAT.....................................................................................................................368 PSK_GRAY.DAT..................................................................................................................368 QAM_GRAY.DAT................................................................................................................369 TABLFILT.DAT ...................................................................................................................369 V32QAM.DAT ......................................................................................................................369 V32TRELS.DAT ...................................................................................................................369 VTB3SOFT.DAT ..................................................................................................................369 Sample Block Diagrams .........................................................371 Acronyms and Abbreviations ................................................373 Index.........................................................................................375 Table of Contents xiv xv Preface Welcome to Commsim. Commsim provides the ideal solution for designing and simulating analog and digital end-to-end communication links. The Commsim library supports digital and analog modulation, channel models, demodulation, phase locked loops, error correcting codes, and bit error rate analysis to mention a few. Through its support of complex math, Commsim enables the use of complex envelope simulations. By using lowpass equivalent models, communication engineers can significantly reduce the computing load required to support most communication analysis problems. This topic is discussed in detail in Chapter 1, Introduction. This manual provides a detailed discussion of advanced topics for users of Commsim as well as a complete reference of the Comm and the uploads/Management/ user-guide 15 .pdf