Testing Qpsk Modems, I & Q | Tektronix 071-0590-00 guide

Application Example

Application Example

Testing QPSK Modems, I & Q

		I-Channel BERT
		GB700/1400 Rx
		data	clock
GB700/1400 Tx
I		I	Q-Channel BERT
I		I
DATA	QPSK		GB700/1400 Rx
	QPSK		GB700/1400 Rx
CLOCK	Mod /Demod
CLOCK	up to 1400 Mb/s		data	clock
CLOCK	up to 1400 Mb/s
Q	data rate	Q
GB700/1400 Tx
EXT
CLOCK
INPUT
DATA
CLOCK

2-48	GB1400 User Manual

Image 74

Tektronix 071-0590-00 user manual Testing Qpsk Modems, I & Q

Contents

This document supports firmware version 2.2 and above Page Warranty How to Reach Customer Service TEK-WIDE Table of Contents Tutorial Table of Contents Menus Gpib Theory of Operation Glossary Glossary-1 Index Index-1 List of Figures List of Tables Safety Do Not Remove Instrument Covers SMA ConnectorsBehavior of Outputs Turning Power On or Off Static Sensitive Device Notice How This Manual is Organized Conventions Related Manuals Xvi Getting Started GB1400 Pattern Generator and Error Detector Features Prbs Or User-Defined Test Patterns Symmetrical, Low-Jitter Output WaveformsApplications Sample Applications Powerful Analysis And Reporting Functions Adjustable Inputs For Maximum FlexibilityAuto Search For Easy Setup Burst Mode GB1400T Ordering InformationGigaBERT GB1400 GB1400R GB Comparison GB660/CSA907A GB700 GB1400 Feature Tx and Rx GB1400 Instrument Configurations Standard and Burst Option GB1400 with Burst Option Initial Self-Check Procedure ProcedurePage Operating Basics Functional Overview Bert Basics GB1400 Example, Bert Application Clock Data Controls, Indicators and Connectors Front Panel, GB1400 Generator Tx Front Panel, GB1400 Analyzer RX Generator Tx Display Display Formats1405000 PN23 Frequency kHz Pattern Output 1405000 0E-06 2410538 PN23 Frequency kHz Error Rate TotalizeDelay/ Memory Analyzer RX DisplayPage = clock bar = not clock Generator Output Connectors SectionOutputs and Inputs Generator Clock Section Generator Output Section Generator Rear Panel Changing the Line Fuse Analyzer Input Section Analyzer Monitor Section Analyzer Rear Panel Connectors, Terminations, and Levels DATA/DATA BAR Reset to Factory Default Controls and IndicatorsPower Switches View Angle and Panel Lock Keys Gpib Section Controls Pattern Controls and Function Keys Function Soft Keys F1, F2, F3, and F4 Analyzer Inputs Generator Error Inject Section Affected Input Allowable Control Analyzer Error History Section Sync Loss Analyzer Error Detection Section Analyzer Sync Controls Burst Mode Option Burst Mode Usage Specifications for Burst Mode Transmitter Burst Mode Option Data Value ECL Levels Pecl Levels Display SettingPecl Option for GB1400 Tx Objective of Tutorial Basic Bert testing with the GB1400Key Feature of Tutorial Equipment Required Setup units with default settings Instrument Connections and Controls Setup Generator for PRBS-23 Mode Connect the Generator to the Analyzer Setup Analyzer for AUTO-SEARCH Operation Change the Prbs pattern type Turn off Auto Search and change Generator Outputs Key several times to setup the analyzer for totalize Error Rate display shows no Data or a 50% Error Rate Data signal not detected. SelectedYour data signal You are starting to detect the data signal This Concludes the Tutorial Applications Two Auto Search Synchronization Methods Phase Application Note Auto Search Synchronization Auto Search will find the Data V-THRESHOLD voltage Auto Search will find the Data DelayAuto Search Algorithm Fast Method Auto Search will then attempt to find the Data Pattern II. Auto Search Algorithm BER MethodAuto Search will find the Data Pattern and Polarity Auto Search will determine the Data Delay Page Consideration In Determining The Data Eye Center Delay SpecificationsConsideration In Determining The Eye Data Width GB700/ GB1400 Optical Component Test Fiber Optic Link Test Example Fibre Channel Link Testing Parallel and High-speed Serial Testing Qpsk Modems, I & Q Qpsk Qpsk BER Testing using Prbs Data for 2-Channel I & Q Channel Bert Application Example Reference Functions Common to Generator TX and Analyzer RX Turning Instrument Power ON/OFFMenu Overview Selecting 115 VAC or 230 VAC Operation Locking the Front Panel Recalling the Default SetupSelecting a Pattern Pattern Definitions Selecting the Current Word Pattern Selecting the Active PatternSelecting Prbs Patterns Prbs 2n-1 Test Patterns Selecting RECALLing a Saved Word Pattern Word Basics Creating Word Patterns Using Front Panel ControlsWord Patterns Standard Instruments Instruments Equipped with 1-Mbit Option Order Creating Word Patterns Using MenusLength Fill Creating Word Patterns Under Remote Control Saving Word Patterns 1-Mbit Memory Option Recalling Word Patterns 1-Mbit Memory Option External Clock Input Generator TX FunctionsClock Source and Frequency Clock Source Saving a Frequency Recalling a Frequency Data and Clock Outputs Overview Generator Clock and Data Output Equivalent Circuits Output Setup Rules vs. Termination Impedance Amplitude and Baseline Offset Logically Inverting Output Data D-INV Single-ended or Differential Operation Procedure for Single-ended Operation TX onlyProcedure for Differential Operation TX only Pattern Sync and CLOCK/4 Outputs Error Injection Selecting an Error Inject Mode Data Inhibit Logic Error Inject InputProcedure to Control Error Injection Mode Analyzer RX Functions Automatic Setup Functions SyncDisable Key Auto Search Key Actions Taken by Analyzer when Synchronization is Lost Auto Search With Prbs Patterns Auto Search with Non-PRBS Patterns How to Disable Automatic Pattern ResynchronizationRelationship between Auto Search and Disable Synchronization Threshold Procedure to Set Sync ThresholdSynchronization Lock Threshold Clock, Data, and Reference Data Inputs Input Parameters Procedure to Add Delay Input Data DelayHow F2 and F3 Determine Which Input Can be Set Up Controls Input Terminations for CLOCK, DATA, and REF Data Procedure for Selecting Input TerminationInput Termination Input Threshold Range as a Function of Termination Input Decision ThresholdLogically Inverting Input Data Singled-ended or Differential Operation Selecting the Reference Data ModeProcedure for Selecting the Reference Data Mode Output Setup Monitor Outputs Error Detection Set Up BER How Totalize Results are Measured How Window Results Are Measured How Test Results Are Measured Window Measurement Process Test Measurement Process Procedure to Select a Results Display Mode Display Mode Totalize, Window, or TestTotalize Process Set Up How to Tell Which Display Mode is Active Window Process Set Up Procedure Test Process Set Up Viewing Results BER and Bit ErrorsProcedure to View Desired BER and Bit Error Results All Other Results Test Process only Basic Report Setup Procedure Printing Results Reports Analyzer Setup Report Example Analyzer Setup Report Example End-of-Test Report Procedure to Enable or Disable End-of-Test ReportsEnd-of-Test Reports Example End-of-Window Report Procedure to Enable or Disable End-of-Window ReportsEnd-of-Window Reports Procedure to Enable On-Error Reports On-Error ReportsExample On-Error Report Procedure to Generate an On-Demand Test Summary Report All Other Results Test Intervals Only Result DefinitionsBER = TE / TB ES = TSE US Located in the Error History section of the front Error History IndicatorsAnalyzer performance history indicators are Panel. These indicators will latch on when the indicated Clear Control Analyzer Error MessagesProcedure To Set Up the Audio Alert Function Audio Beeper Function Starting and Stopping Measurements Procedure for Starting the Test Measurement ProcessProcedure for Stopping the Test Process Starting New Totalize and Window Measurement Intervals Menus Functions Performed Using the Menu SystemExample Procedure Illustrating Menus and Functions Menu and Function Pages More Length Mode Report F1ESC F4SET Test Mode = Untimed F1ESC F4SET Reports on = EOT/ERROR General Rules for Using the Menu System Menu Summaries 10. Menu Descriptions 11. Analyzer Menu System Overview 12. Generator Menu System Overview Word Menu Function Definitions Word Edit Edit F1ESC F2- -F3 F4SETWord AT ddddd = bbbbbbbb Format Word Length F1ESC F2- -F3 F4SET LENmmmmm Bytes + n BitsWord Length Length Fill Word Memory WITHhh Word Fill Fill Word Order F1ESC F4SET Word Order = ccc FirstWord Order Order Word Sync Word Sync Thres LEVEL= dWord Synchronization Threshold Sync Buffer Buffer Auto Fast BER Test Length F1ESC F2- -F3 F4SET Test Length = hhmmssTest Length Length Test Mode F1ESC F4SET Test Mode = cccccccTest Mode Mode Test Report F1ESC F4SET Reports on = cccccccccTest Reports Report Test Thres F1ESC F4SET Error Threshold = eeeeeTest Threshold Thres Test Squel On Error Squelch = cccTest Squelch Squel Test Print Print Test Print Test VIEW-PRE F1ESC F4SET result namecount %Test View Previous VIEW-PRE Test View Current VIEW-CUR Test VIEW-CUR Window Mode F1ESC F4SET Window Mode = cccccccWindow Mode Mode Window Interval in Bits Bits FormatF1ESC F4SET Window LEN = 1.0eEE Bits Window Bits Window Second F1ESC F2- -F3 F4SET Window LEN = hhmmssWindow Interval in HrsMinSec Second Window Report END of Window Print = cccWindow Reports Report Baud Baud = ddddRS-232 Baud Rate Baud Parity F1ESC F4SET Parity = ccccRS-232 Parity Parity Size Size = dRS-232 Data Bits Size EOL F1ESC F4SET EOL = cccccRS-232 End-of-Line Char. EOL XON/XOFF F1ESC F4SET XON/XOFF Enable = cccRS-232 Xon/Xoff XON/XOFF Echo F1ESC F4SET RS232 Echo Enable = cccRS-232 Echo Echo F1ESC F4SET Terminator = cccccc Utility Option Option Util Option Utility Version VER Util VER Date F1ESC F2- -F3 F4SET Date = mmm dd yyTime Option Date Time F1ESC F2- -F3 F4SET Time = hhmmssTime Option Time Reference Appendices External Clock Source GB1400 Generator TXInternal Clock Source SMA Data Patterns Data Output True and Complement Clock Output True and Complement Rear Panel Auxiliary Outputs Phase A, Phase B, Clock/2Error Injection NRZ-L Mechanical AC-Power RequirementsRS-232 and Gpib Interfaces Data Input GB1400 AnalyzerClock Input Reference Data Input AUX Synchronization Measurements BER Printer Interface Specifications Bert Primer/ Technical Articles Bert Building Blocks Bert DefinitionBert used to test physical layer Bert Pattern Generation Prbs Patterns Prbs Prbs Generation Circuits a few sample diagrams Doutput Other Tx Patterns Output Amplifiers Bert Receiver or Error Analyzer ComponentsBert Clock Data Coding, NRZ Data Input Amplifiers Error ComparatorReceived Data Pattern Reference BER Computation Confidence Level in BER Measurement Confidence Requires Collecting Many ErrorsStress Testing Additional Reading Auto-Synch Other Bert FeaturesEye Width Measurement Pattern Loading Software Error InsertionPattern Lock Jitter Generation Bit error rate testing How long is long enough? BER Ideal pulse Stressing through pattern generation Bert Technical Articles Bert Technical Articles Bert Technical Articles Ensure Accuracy Of Bit-Error Rate Tests Page Supplying Data Patterns Bert Noise-Margin Stressing Μ F Avergage = Average = Page Data patterns for clock recovery stressing Data Patterns Stored + Peak Examining Jitter 2f BΦ θif B Amplitude UI peak-to-peak Frequency Jitter Tolerance Bert Affects Accuracy Example of Error Rate Measurement Abstract BER Measurement Inaccuracy versus Test Time = n / T Inaccuracy 95% = 2 σ / n ≈ 2/ n Testing for an Upper Limit on Error Rate Reduced Test Time by Stressing SNR = 20 log S / N rms Attenuation dB Example BER Example BER Summary Poisson Error Process Pn = rT n e−rT . n BER Biography Remote Commands Type of Commands Starts on Overview Datathres DATATHRES? Command Line Rules Command Line Terminator Setting Arguments Outside of Legal Ranges Command Examples Command Summary Alphabetical Bytesync n Analyzer only Bytesync? Remote Commands Rescurrate? Tse? Cls Ese n Idn? Ese?Esr? Opc? Lrn?Opc Rst Sre n Sre? Stb? Tse v Analyzer Only Tst?Wai Tse? Analyzer Only Tsr? Analyzer Only Datapattern prbs word rdata Datainvert onoffDatainvert? Prbslength? Datapattern?Prbslength Wordbits l, b1 b2 Recallword mSaveword m Wordmemlen m, l Wordbits?Wordlength l Wordmemord? m Wordmemord m, msb lsbWordmemord? Wordmemory m, l, b1, b2 Wordmemory? m Wordorder msb lsb Example Wordorder lsbPage Wordorder? Memory allocation for Word Memory storage Wordmemory? Gpibbus offbus talklisten GpibaddressGpibaddress? Rsecho? Gpibbus?Rsecho onoff Rspmtlf onoff Rsxonxoff onoff Rspmtlf?Rsprompt s Rspmtlf on Rsxonxoff? Allmem? Wordmemory 0, 16, #HAA, #HBB Wordmemory 1, 8, #HF0 Logo? Header on offHeader? Viewangle? Options?Viewangle Viewangle Clockmemory? ClockfreqClockfreq? Clocksource intext Clockmemory m, fClockmemory? m Clocksource? Clockstpup and clockstpdn ClockstepClockstep? Clockstpup v and clockstpdn Recallfreq m Savefreq m Clockampup and clockampdn AmplitudeAmplitude? Clockampl? Clockampup v and clockampdnClockampl Clockoffup and clockoffdn Clockoffset? Clockoffup v and clockoffdnClockoffset Dataampup and dataampdn Dataampl? Dataampup v and dataampdnDataampl Dataoffup and dataoffdn Dataoffset? Dataoffup v and dataoffdnDataoffset Offset Offset? Errorsingle Errorrate offextrate3rate4rate5rate6rate7Errorrate? Analyzer Commands Resbits? Rescurrate? Resefs? Resdm?Resdmper? Reselapsed? Reserrors?Resefsper? Reslos? Reses?Resesper? Ressesper? Resphaes?Resses? Ressync? Resstart?Resstop? Restotrate? Restes?Restesper? Totalbits? Resus?Resusper? Totaltime? Totalerror?Totalrate? Clockterm neg2v gnd ac Clockterm? Datadelup and datadeldn Datadelup v and datadeldn DatadelayDatadelay? Dataterm neg2v gnd ac Dataterm? Datathres Datathrup and datathrdnDatathrup v and datathrdn Rdatadelup v and rdatadeldn Datathres?Rdatadelup and rdatadeldn Rdataterm neg2v gnd ac RdatadelayRdatadelay? Rdataterm? Rdatathres Rdatathrup and rdatathrdnRdatathrup v and rdatathrdn Rdatathres? Autosearch auto off disab Autosearch? Automode ber, fast Automode? Autosample n Autosample? Autowidth? Autothresh nAutothresh? Dispselect? ErrorresetDispselect total window test Histrybits? Histryclear Histryphase on Histryphase?Histrypower? Histrystat? Histrysync? Sync? Testlength? TestdiscardTestlength t Testprev currentprevious Testmode untimedtimedrepeatTestmode? Testprint Testreport eotonerrorbothnoneTestprev? Testsquelch? Testreport?Testsquelch onoff Teststate runstop Teststate? Testthres Testthres? Winbitlen? Winerror?Winbitlen Winbits? Winprev currentprevious Winmode bitssecWinmode? Winprev? Winreport? Winrate?Winreport onoff Wintime? Winseclen sWinseclen? Printport parallel gpib serial Printenable onoffPrintenable? Printport Parallel Printport?Printstring s Audiorate Audioratup and audioratdnAudioratup v and audioratdn Audiovol? Audiorate?Audiovol Audiovolup and audiovoldn Audiovolup v and audiovoldn Date yyyy-mm-dd Date? Time s Time? MB Option Commands Byteblock a, i, b1, ..., bn Byteblock? a Bytedelete a Byteedit a, b1 Byteedit? a Bytefill i, b1, b2, ..., bn Byteinsert a, i, b1, ..., bn Bytelength m, n Bytelength? Bytemode n Bytemode? Bytesync? Analyzer only Ratio errors/bitsBytesync n Analyzer only Level Editbegin n Editcntrl? Editend n 102 Using the Gpib Interface Gpib Interface Device Settings Interface Functions Gpib Connector Pin-OutsProgramming Gpib Remote Commands Status Byte Gpib Numeric ResponsesGpib Status Reporting Standard Event Status Register Service Request EnableService Request SRQ Test Status Event Register Analyzer only Standard Event Status Enable RegisterTest Status Event Enable Register Analyzer only Power-on settings Gpib Common CommandsAdditional SRQ Gpib Commands Rx only IEEE-488.2 Programming Manual Requirements Functional Elements Specific Command ImplementationsOverlapped vs. Sequential Commands Self Test Query Using the RS-232 Interface Option RS-232 Interface Device Settings RS-232 Interface Testing RS-232 Interface Hardware/ Handshaking Considerations Programming RS-232C Remote Commands RS-232C Error Messages Using GPIB, RS-232 Customer Acceptance Test For GB1400 Generator & Analyzer Performance Verification Functional Test Setup for Functional Test of Standard Instrument Confirmation of Frequency Function Confirmation of Generator Output Data Level Change Confirmation of Error Injection Rates Confirmation of Selectable Analyzer Terminations Performance Verification Confirmation of Buttons and Indicators Panel Lock On OFF Addr Using Front Panel Controls Returning to Factory Default SettingsHow to Recall Factory Default Settings Via Remote Control CLOCK/ Data Outputs Generator TX Factory Default SettingsData Pattern CR/LF Remote InterfacesEOI/LF Misc Auto Search/Pattern Synchronization Analyzer RX Factory Default SettingsError Beeper Current BER Time and DatePrinter Test Parameters Misc Cleaning the Interior Cleaning the ExteriorCleaning the CRT Cleaning Instructions Before You Begin Pattern Editor Requirements and FeaturesWhat is MLPE? List of Features Minimum Requirements If you are using an alternate shell, such as Norton Desktop List of Files on this Disk RS-232 Cabling Page Page Read Before Opening Sealed Wrapper Pattern Editing Software Pattern Editing Software Pattern Editing Software Data Generator PCB Design OverviewPLL Clock Source PCB Data and Clock Output Amplifier PCB GB1400 Analyzer RX Input Amplifier PCB Front Panel PCB Error Counter PCBCommon to both GB1400 TX and GB1400 RX GB1400 Tx Figure I-2. Block Diagram GB1400 RX Glossary/ Index Analog-to-Digital Converter Bit ErrorAddress Attenuation Byte Error DetectionBit Rate Channel Noise Residual error rateMulti-Channel Cable RS-232C Glossary-4 Auto Search Appendices Figures Index-3 Tables