VisSim/Comm TM User Guide Version 8.0 Eritek, Inc. i Eritek, Inc. Visual Solutions, Inc. VisSim/Comm User’s Guide - Version 8.0 Copyright © 2011 Eritek, Inc. All rights reserved. Eritek, Inc. Visual Solutions, Inc. Printed and bound in the USA. 18450 Sydnor Hill Ct. 487 Groton Road vcug-080-01 Leesburg, VA 20175 Westford, MA O1886 Trademarks VisSim is a trademark of Visual Solutions. VisSim/Comm is a joint trademark of Eritek and Visual Solutions. Other products mentioned in this manual are trademarks of their respective manufacturers. Copy and use The information in this document is subject to change without notice and restrictions does not represent a commitment by either Eritek or Visual Solutions. Eritek and Visual Solutions do not assume responsibility for errors that may appear in this document. No part of this manual may be reprinted or reproduced or utilized in any form or by any electronic, mechanical, or other means without permission in writing from Eritek. The Software may not be copied or reproduced in any form, except as stated in the terms of the Software license agreement. Use, duplication, or disclosure by the US Government is subject to restrictions as set forth in FAR 52.227-19, subparagraph (c)(i)(ii) of DOD FAR SUPP 252.227-7013, or equivalent government clause for other agencies. ii Contents Preface ...................................................................................................... x Online VisSim/Comm documentation ................................................................................ x Conventions used in this manual ........................................................................................ x For VisSim/Comm Personal Edition (PE) users ................................................................ xi Technical support service ................................................................................................. xii Introduction .............................................................................................. 1 A typical communication system ........................................................................................ 1 Lowpass equivalent systems ............................................................................................... 3 Communication blocks ....................................................................................................... 3 VisSim/Comm Overview .......................................................................... 7 Starting VisSim/Comm ....................................................................................................... 7 The VisSim/Comm environment ........................................................................................ 7 Inserting blocks .................................................................................................... 8 Connecting blocks ................................................................................................ 8 Block connectors .................................................................................................. 8 Diagram timing .................................................................................................... 9 Random numbers .................................................................................................. 9 Setting up block parameters ............................................................................... 10 Global variables .................................................................................................. 10 Choosing an integration method ......................................................................... 11 Multirate diagrams ............................................................................................................ 11 Configuring compound blocks for local rate mode ............................................ 12 Output plots ...................................................................................................................... 12 BER curves ......................................................................................................... 12 Eye plots ............................................................................................................. 13 Frequency domain plots ..................................................................................... 13 Phase scatter plots .............................................................................................. 14 Filter Viewer ..................................................................................................................... 16 Generating BER curves .................................................................................................... 17 Enabling multiple consecutive runs .................................................................... 18 Varying the SNR for each run ............................................................................ 18 Calculating BER measurements ......................................................................... 18 Sample communication simulation ................................................................................... 20 Comm Block Set ..................................................................................... 23 Channels category ............................................................................................................. 23 AWGN (Complex or Real) ................................................................................. 23 Binary Symmetric Channel ................................................................................ 24 Jakes Mobile ....................................................................................................... 25 iii Contents Mobile Fading .................................................................................................... 25 Multipath ............................................................................................................ 26 Propagation Loss ................................................................................................ 27 Rice/Rayleigh Fading ......................................................................................... 28 Rummler Multipath ............................................................................................ 28 Saleh-Valenzuela ................................................................................................ 29 TWTA (Analytical) ............................................................................................ 31 TWTA (Table Lookup) ...................................................................................... 33 Vector AWGN .................................................................................................... 33 Complex Math category ................................................................................................... 34 Complex Addition .............................................................................................. 34 Complex Conjugate ............................................................................................ 34 Complex Division .............................................................................................. 34 Complex Inverse ................................................................................................ 34 Complex Multiplication ..................................................................................... 35 Complex Power .................................................................................................. 35 Complex Square Root ........................................................................................ 35 Complex to Mag/Phase ...................................................................................... 35 Complex to Real/Imag........................................................................................ 35 Mag/Phase to Complex ...................................................................................... 36 Real/Imag to Complex........................................................................................ 36 Demodulators category ..................................................................................................... 36 Differential PSK Detector .................................................................................. 36 FM Demodulator ................................................................................................ 37 IQ Detector ......................................................................................................... 37 PPM Demodulator .............................................................................................. 38 PSK Detector ...................................................................................................... 39 QAM/PAM Detector .......................................................................................... 39 Digital category ................................................................................................................ 40 Accumulate & Dump ......................................................................................... 40 Binary Counter ................................................................................................... 41 Bits to Symbol .................................................................................................... 41 Buffer 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