HP 83236B PCS Interface CDMA/PCS Base Station Test Software, User’s Guide Software Version A.02.01 HP Part No. 83236-90121 Printed in U. S. A.
Copyright © Hewlett-Packard Company 1996 RESTRICTED RIGHTS LEGEND Use, duplication or disclosure by the U. S. Government is subject to restrictions as set forth in subparagraph (c) (1) (ii) of the Rights in Technical Data and Computer Software Clause in DFARS 252.227-7013. Hewlett-Packard Company 3000 Hanover Street Palo Alto, CA 94304 U.S.A. Rights for non-DOD U. S. Government Departments and Agencies are as set forth in FAR 52.227-19 (c) (1, 2).
In this Book This book documents the use of the CDMA/PCS Base Station Test Software supplied with the PCS Interface. It focuses specifically on the use of the PCS Interface in testing CDMA/PCS base station equipment. Chapter 1, Getting Started This chapter provides the steps for loading and running the CDMA/PCS base station test software. Start here.
Conventions Used in this Book The following terms are used throughout this book: • • • • • Test Set - the HP 8921A Cell Site Test Set. Cellular Adapter - the HP 83203B or 83205A CDMA Cellular Adapter. PCS Interface - the HP 83236A,B; used to translate PCS signals into the range of the Test Set. Software - the CDMA/PCS Base Station Test Software, described in this book. Test System - the combination of a Test Set, a Cellular Adapter, and a PCS Interface.
Table of Contents Contents 1 Getting Started Introduction 12 Who should use the CDMA/PCS BS Test Software? Product Description 12 Software Operation in Brief 12 Required Equipment 13 12 Step 1: Make Connections 14 Step 2: Load and Run the CDMA/PCS BS Test Software 15 Navigation of the CDMA/PCS BS Test Software 17 Step 3: Configure the Software 18 Step 4: Perform CDMA Tests 21 If You Had Problems 21 5
Contents 2 Making Measurements Overview 25 Transmitter Measurements 25 Receiver Measurements 25 Other 25 Average Power 26 Overview 26 Requirements 26 Steps 27 Notes 27 Modulation Quality (Rho) 28 Overview 28 Requirements 28 Steps 29 Notes 29 Code Domain Power 30 Overview 30 Requirements 30 Steps 31 Notes 31 Code Domain Timing 32 Overview 32 Requirements 32 Steps 33 Notes 33 Code Domain Phase 34 Overview 34 Requirements 34 Steps 35 Notes 35 Transmit Spectrum 36 6
Contents Overview 36 Requirements 36 Steps: Go to Spectrum Analyzer @ Present Chan 37 Steps: Go to Spectrum Analyzer & Enter Freq 38 Notes 39 Receiver Sensitivity 40 Overview 40 Requirements 40 Steps 41 Notes 41 Receiver Performance in Additive Noise 42 Overview 42 Requirements 42 Steps 43 Notes 43 Search for PN Offset 44 Overview 44 Requirements 44 Steps 45 Notes 45 Check Even-Second Clock 46 Overview 46 Requirements 46 Steps 47 Notes 47 7
Contents 3 Operating Overview Overview 50 Configuration Information 50 Reference Information 50 Selecting a PCS Band 51 Steps 51 Notes 51 Compensating for TX and RX Measurement Path Loss 53 Requirements Steps 53 Notes 53 53 Saving Configuration Information to Memory 54 Requirements Steps 54 Notes 54 54 Loading Configuration Information from Memory 55 Requirements Steps 55 Notes 55 55 Purging Configuration Information from Memory 56 Requirements Steps 56 Notes 56 56 Using Autostart 57 Turning On t
Contents Setting the Test System “Beep” 59 Steps 59 Notes 59 An Alternative Test-System-to-Base-Station Timebase Configuration 60 Steps 60 Notes 60 9
Contents 4 Troubleshooting Overview 64 Errors When Loading and Running the Software 65 Memory Overflow Errors 65 Test System Configuration Errors at Runtime 66 Other Test System Configuration Errors 67 Configuration Information is Not Updated as Saved 67 Menu Screens in this Book do not Match the Screens that You See Errors While Attempting Measurements 69 CDMA Measurement not Correlating 69 Frame Error Rate (Receiver Measurements) 71 Questionable Measurement Results 73 Overview 73 Average Power 73 Rho
1 Getting Started Getting Started Follow the steps in this chapter to load and run the CDMA/PCS BS Test Software, to connect the test equipment, and to make initial settings to configure your Test System.
Chapter 1, Getting Started Introduction Introduction Who should use the If you are installing, commissioning, or maintaining Personal Communication Services (PCS) sites using the Code Division Multiple Access (CDMA) standard, CDMA/PCS BS this Software will assist you in performing tests of transmitter and receiver Test Software? performance.
Chapter 1, Getting Started Introduction Required Equipment You must supply: Supplied with the Test System: Means to control base station and read FER. HP 8921A Opt. 600, 601, 603 or an HP 8921A with an HP 83203B or 83205A Cellular Adapter. CDMA PCS Base Station. HP 83236A, B PCS Interface Cable Kit HP 83236A, B Cable Kit (Supplied with the HP 83236A,B) CDMA PCS Base Station Test Software (Supplied with the HP 83236A, B) Cables to connect the base station to the Test System. (See table below.
Chapter 1, Getting Started Step 1: Make Connections Step 1: Make Connections Make the connections between the elements of the Test System and the base station as shown in figure 2. NOTE: This figure does not illustrate all rear-panel connections between the Cellular Adapter and Test Set. Refer to the Cellular Adapter User’s Guide to verify these connections. EVEN SECOND/ SYNC IN CDMA Base Station Even-Second Clock 19.
Chapter 1, Getting Started Step 2: Load and Run the CDMA/PCS BS Test Software Step 2: Load and Run the CDMA/PCS BS Test Software The next step is to get the CDMA/PCS BS Test Software loaded into the Test Set and running on the IBASIC controller. Locate the memory card supplied with the PCS Interface and follow the steps of figure 3 and figure 4. 1 Press POWER. 2 Wait for display to appear (approximately 20 seconds). 3 Press PRESET. 4 Insert the System Utility Software card.
Chapter 1, Getting Started Step 2: Load and Run the CDMA/PCS BS Test Software 5 Press TESTS to display the TESTS (Main Menu) screen. 6 Position the cursor at Select Procedure Location: and select it. 7 Position the cursor at Card and select it. 8 Position the cursor at Select Procedure Filename: and select it. 9 Position the cursor at Choices: and select PCSCDMA. 10 PCSCDMA XXXXXXXX YYYYYYYY Position the cursor at Run Test and select it. The Software is now loading.
Chapter 1, Getting Started Step 2: Load and Run the CDMA/PCS BS Test Software Navigation of the CDMA/PCS BS Test Software After the Software has loaded, you should see the CDMA/PCS BS Test Software’s main menu screen on the display of the Test Set (see figure 5). Important features of this screen are indicated in the figure with notes on their use. Main Selection and Cursor Control Some menu selections open lower-level menus, others allow entry of numeric data.
Chapter 1, Getting Started Step 3: Configure the Software Step 3: Configure the Software The first time you run the Software you must enter information about your setup and the base station being tested. Use these steps: 1 From the CDMA PCS Main Menu, scroll to and select Configuration Information Menu. 2 Configuration Information Menu CDMA PCS Main Menu Return to Main Menu Base Station Channel . . . . . . . . . 220 Base Station PN Offset . . . . . . . . 16 Base Station Reference Freq. . . 19.
Chapter 1, Getting Started Step 3: Configure the Software 5 Scroll to and select TX Measurement Path Loss. Enter the loss (through cables, couplers, and attenuators) between your base station’s transmitter test port and the RF IN/OUT port of the PCS Interface. Configuration Information Menu Return to Main Menu Base Station Channel . . . . . . . . . 220 Base Station PN Offset . . . . . . . . 16 Base Station Reference Freq. . . 19.6608 MHz Base Station Reference To . . . .
Chapter 1, Getting Started Step 3: Configure the Software 9 This completes the required entries. You may now save your entries or press the Main Menu (k5) key to return to the main menu. To save entries see, “Saving Configuration Information to Memory” in Chapter 3. USER k1 k2 k3 k4 k5 20 User keys 1-5 correspond to the fields on the top right corner of the test set screen.
Chapter 1, Getting Started Step 4: Perform CDMA Tests Step 4: Perform CDMA Tests Now that you have successfully run the Software and entered your configuration values, you can go on to making CDMA measurements. Refer to chapter 2, "Making Measurements" to see detailed steps for performing CDMA measurements. If You Had Problems If you were unable to load and run the Software or make the required entries, refer to chapter 4, "Troubleshooting" for help.
Chapter 1, Getting Started Step 4: Perform CDMA Tests 22
2 Making Measurements Making Measurements This chapter contains descriptions of the most common receiver and transmitter tests performed on CDMA base station equipment. For each test, requirements are listed and the steps to perform the measurement are provided.
Chapter 2, Making Measurements 24
Chapter 2, Making Measurements Overview Overview This chapter presents measurement tasks most commonly performed when testing CDMA/PCS base station equipment. The measurements are separated by type: transmitter tests, followed by the receiver tests. For descriptions of general Software use, refer to chapter 3, "Operating Overview". NOTE: The test procedures outlined in this chapter require that you have already configured the Test System as outlined in chapter 1, "Getting Started".
Chapter 2, Making Measurements Average Power Average Power Overview Average power is a time-averaged broadband measurement of the transmitted signal strength at the RF IN/OUT port on the front panel of the PCS Interface. The average power measurement is “uncorrelated”; it does not require the reference signals (Even-Second clock and 19.6608 MHz timebase) needed for other tests.
Chapter 2, Making Measurements Average Power Steps 1 2 3 4 5 6 7 8 9 Connect the equipment as shown in figure 6. In the main menu, enter the Base Station Channel number for the transmitter being tested. Set up the base station to transmit on the channel number entered in step 2. From the main menu, choose Perform Average Power Measurements. The resulting screen (see figure 7) will display average power (in Watts).
Chapter 2, Making Measurements Modulation Quality (Rho) Modulation Quality (Rho) Overview In this measurement, the modulated signal is compared to an ideal, reference waveform to determine the performance of the transmitter’s modulation circuitry. Rho values are in the range of 0 to 1. A value of 1 indicates perfect correlation to the reference (high modulation quality). CDMA base station standards require that transmitters have rho performance of 0.912 or higher.
Chapter 2, Making Measurements Modulation Quality (Rho) Steps 1 2 3 4 5 6 7 8 9 Connect the equipment as shown in figure 8. In the main menu, enter the Base Station Channel number for the transmitter being tested. Also in the main menu, enter the Base Station PN Offset. Set up the base station to transmit (pilot only) on the channel number entered in step 2. Verify that the REF UNLOCK light on the front of the Cellular Adapter is not lit. Scroll to and select Measure Rho Parameters screen (see figure 9).
Chapter 2, Making Measurements Code Domain Power Code Domain Power Overview The Code Domain Power measurement shows the relative power in each of the Walsh channels of a transmitted signal. Signal strength of the Pilot, Paging, Sync, and Traffic channels are displayed (in dB).
Chapter 2, Making Measurements Code Domain Power Steps 1 2 3 4 5 6 7 8 Connect the equipment as shown in figure 10. In the main menu, enter the Base Station Channel number for the transmitter being tested. Also in the main menu, enter the Base Station PN Offset. Scroll to and select Go to Code Domain Analyzer Screen. Verify that the Measurement field at the bottom of the display is set to Power. If it is not, scroll down and set it to Power. Turn on your base station transmitter.
Chapter 2, Making Measurements Code Domain Timing Code Domain Timing Overview Similar to the Code Domain Power test, this measurement shows the timing relationship between the various Walsh channels and the Pilot channel.
Chapter 2, Making Measurements Code Domain Timing Steps 1 2 3 4 5 6 7 8 9 Connect the equipment as shown in figure 12. In the main menu, enter the Base Station Channel number for the transmitter being tested. Also in the main menu, enter the Base Station PN Offset. Scroll to and select Go to Code Domain Analyzer Screen. Scroll to the Measurement field at the bottom of the display and set to Timing (if not already selected).
Chapter 2, Making Measurements Code Domain Phase Code Domain Phase Overview Similar to the Code Domain Power measurement, this measurement shows the relative phase relationship of the various Walsh channels referenced to the pilot channel (Walsh 0).
Chapter 2, Making Measurements Code Domain Phase Steps 1 2 3 4 5 6 7 8 9 Connect the equipment as shown in figure 14. In the main menu, enter the Base Station Channel number for the transmitter being tested. Also in the main menu, enter the Base Station PN Offset. Scroll to and select Go to Code Domain Analyzer Screen. Scroll to the Measurement field at the bottom of the display and set to Phase (if not already selected).
Chapter 2, Making Measurements Transmit Spectrum Transmit Spectrum Overview It is often useful to look at the transmitter signal with the spectrum analyzer to see its overall symmetry and occupied bandwidth, and to identify potential sources of interference.
Chapter 2, Making Measurements Transmit Spectrum Steps: Go to 1 Connect the equipment as shown in figure 16. Spectrum Analyzer 2 In the main menu, enter the Base Station Channel number for the transmitter being tested. @ Present Chan 3 4 5 6 Turn on your base station transmitter. Scroll to and select Go to Spectrum Analyzer @ Present Chan. The spectrum analyzer display will appear and the center frequency will be set to match the channel number entered in step 2 (see figure 17).
Chapter 2, Making Measurements Transmit Spectrum Steps: Go to 1 Connect the equipment as shown in figure 16. Spectrum Analyzer 2 Turn on your base station transmitter. 3 In the main menu, scroll to and select Go to Spectrum Analyzer & Enter & Enter Freq 4 NOTE: Freq. The PCS Interface analyzer attenuation setting will appear in the field labelled HP83236 Input Attenuator. This value is optimized based on your entries for base station power and cable losses.
Chapter 2, Making Measurements Transmit Spectrum Notes For either spectrum analyzer mode (Go To Spectrum Analyzer @ Present Chan or Go To Spectrum Analyzer & Enter Freq), do not make changes to RF port selections, tune frequency, or other “setup” fields. You may change spectrum-analyzer-specific settings such as Ref level, Span, and Marker.
Chapter 2, Making Measurements Receiver Sensitivity Receiver Sensitivity Overview In this test, the CDMA generator sends a calibrated signal to the base station’s receiver. For a given RF level, the resulting Frame Error Rate (FER) is measured. Standards specify an FER of 1.0% or less at an RF level of −119 dBm.
Chapter 2, Making Measurements Receiver Sensitivity Steps 1 2 3 4 Connect the equipment as shown in figure 19. In the main menu, enter the Base Station Channel number. Scroll to and select Setup CDMA Generator. Scroll to RF Level and enter the signal generator level for your sensitivity measurement (in dBm). 5 Scroll to and set the Generator Mode to Data. 6 Scroll to and set the RX PN Offset, typically to 0. 7 Scroll to and set the Data Source to Random.
Chapter 2, Making Measurements Receiver Performance in Additive Noise Receiver Performance in Additive Noise Overview In this test, the CDMA signal generator is used with the Additive White Gaussian Noise (AWGN) source to simulate an uplink signal to the base stations’s receiver. Various levels of signal-to-noise (Eb/No) can be used and the resulting Frame Error Rate (FER) is measured at each Eb/No level.
Chapter 2, Making Measurements Receiver Performance in Additive Noise Steps 1 2 3 4 Make the equipment connections as shown in figure 21. On the main menu screen, enter the Base Station Channel number. Scroll to and select Setup CDMA Generator. Set the Generator Mode to Eb/No. Note that a new field appears called Eb/No Level. 5 Set the Eb/No Level as called for in the test standard or in your base station test procedures (for example, 5.5 dB). 6 Scroll to and set the RX PN Offset, typically to 0.
Chapter 2, Making Measurements Search for PN Offset Search for PN Offset Overview If you are unsure of the PN offset for the transmitter and channel you plan to test, the Software provides this utility to search for and display the PN offset.
Chapter 2, Making Measurements Search for PN Offset Steps 1 2 3 4 5 Connect the equipment as shown in figure 23. In the main menu, enter the Base Station Channel number for the transmitter being tested. Turn on your base station transmitter (pilot channel must be on). Scroll to and select Search for PN Offset and the Software will begin the search. The Software will search for the PN offset in segments, displaying a message on the screen to show which segment is being searched.
Chapter 2, Making Measurements Check Even-Second Clock Check Even-Second Clock Overview Most CDMA transmitter tests require an Even-Second clock signal from the base station in order to correlate the measurement. If you are receiving an error stating Cannot correlate to input signal. Check setup. , you may have a problem with your Even-Second clock signal. This Software utility allows you to check for a valid clock signal from the base station.
Chapter 2, Making Measurements Check Even-Second Clock Steps 1 2 3 4 5 6 Notes You can start with the connections shown in figure 24. You will get prompts from the Software to change the Even-Second clock connection when needed. In the main menu, scroll to and select Check Even Second Clock. You will have to make a change to the connections, as shown on the display. Switch the Even-Second clock signal from the EVEN SECOND/SYNC IN port to the TRIGGER/QUALIFIER IN port on the Cellular Adapter.
Chapter 2, Making Measurements Check Even-Second Clock 48
3 Operating Overview Operating Overview This chapter describes general operation of the Software.
Chapter 3, Operating Overview Overview Overview This chapter provides detail on Software operations not covered in chapter 1, "Getting Started" or chapter 2, "Making Measurements".
Chapter 3, Operating Overview Selecting a PCS Band Selecting a PCS Band With the HP 83236B PCS Interface, the Software supports several “channel plans” used in PCS systems internationally. By selecting the appropriate plan, you can use channel numbers (rather than frequencies) to tune the signal generator and analyzer for testing. NOTE: If you use the HP 83236A PCS Interface, only the North American Band is supported, and the procedure described on this page does not apply.
Chapter 3, Operating Overview Selecting a PCS Band Table 1 Channel plans for PCS Band selections. PCS Band Channel Plan To calculate the transmitter frequency: North American Band Channel range: 0 to 1199 Transmitter frequencies: 1930 to 1989.95 MHz Offset: −80 MHz Channel spacing: 50 kHz TX freq = (channel × 0.05) + 1930 MHz RX freq = (channel × 0.
Chapter 3, Operating Overview Compensating for TX and RX Measurement Path Loss Compensating for TX and RX Measurement Path Loss The Software can compensate for losses (through cables, attenuators, couplers, and so forth) between the Test System and the base station for the best accuracy in average power and receiver measurements. The loss values are entered into the Configuration Information Menu and are saved to memory if the Save Info To Memory feature is used.
Chapter 3, Operating Overview Saving Configuration Information to Memory Saving Configuration Information to Memory The information about your setup and base station entered into the Configuration Information Menu can be saved to memory. This saves time when running the Software at a later date and helps to prevent entry errors. The stored data is loaded automatically any time you re-run the Software.
Chapter 3, Operating Overview Loading Configuration Information from Memory Loading Configuration Information from Memory The information about your setup and base station entered into the Configuration Information Menu can be saved in memory. This data is loaded automatically when you re-run the Software. You can also load the data manually. This procedure describes steps for manually loading the data. Requirements • Data previously saved to a RAM disk.
Chapter 3, Operating Overview Purging Configuration Information from Memory Purging Configuration Information from Memory The information about your setup and base station entered into the Configuration Information Menu can be saved in memory. This data is loaded automatically when you re-run the Software. In some instances however, you might wish to use default data. If so, you must clear your saved values from memory. This procedure describes steps for manually purging the memory.
Chapter 3, Operating Overview Using Autostart Using Autostart “Autostart” is a feature of the Test Set’s IBASIC controller and is used to customize the instrument for a specific task. The autostart feature allows you to “flip a switch” to configure the Test Set to automatically run whatever program is currently stored in its non-volatile memory when the instrument is first turned on.
Chapter 3, Operating Overview Viewing Instrument Connections Viewing Instrument Connections In setting up your Test System, you may have questions about connections between the Test Set, Cellular Adapter, and PCS Interface as well as the connections to the CDMA/PCS base station. In the Configuration Information Menu is a selection that displays connection diagrams for the front and rear panels. Steps 1 2 3 4 5 6 7 8 Notes From the main menu, select Configuration Information Menu.
Chapter 3, Operating Overview Setting the Test System “Beep” Setting the Test System “Beep” The Software can provide an audio tone (beep) to let you know when selections are made in the menu screens. This beep sounds when you change menu screens, choose an entry field, and when you complete an entry. In its default mode, the beep function is set to a medium volume (Quiet). You can customize the beep function as follows: • • If you don’t want to hear the beep at all, you can turn it off.
Chapter 3, Operating Overview An Alternative Test-System-to-Base-Station Timebase Configuration An Alternative Test-System-to-Base-Station Timebase Configuration Chapter 1 describes the most common method of connecting timebases between the Test System and the base-station-under-test. This section shows an alternative way of connecting the timebases using the CDMA TIMEBASE IN port of the CDMA Cellular Adapter (rather than the rear-panel SYNTH REF IN port).
Chapter 3, Operating Overview An Alternative Test-System-to-Base-Station Timebase Configuration CDMA TIMEBASE IN EVEN SECOND/ SYNC IN 8320 5A H C D MA CE L LU LA R A D A P T E R RF IN /OUT TO RF IN/OUT TRIGGER/ MAX.PWR QUALIFIER IN DATA IN PWR REF UNLOCK EVEN SECOND/ SYNC IN DIAGNOSTIC MONIT OR CDMA TIMEBASE 1.2288 MHz OUT 19.6608 MHz OUT 16 X CHIP CDMA Base Station 83 236B H P C S I N TE RF A C E TEST SET 1.8-2.
Chapter 3, Operating Overview An Alternative Test-System-to-Base-Station Timebase Configuration 62
4 Troubleshooting Use this chapter if you have encountered Software errors or if you are questioning measurement results.
Chapter 4, Troubleshooting Overview Overview Use table 2 to locate your problem or a received error message, then refer to the page number shown. Memory overflow errors "Memory Overflow Errors" on page 65 Message: HP-IB Command not accepted. Option not installed.
Chapter 4, Troubleshooting Errors When Loading and Running the Software Errors When Loading and Running the Software Memory Overflow Errors Problem: The random access memory (RAM) space of the Test Set is shared by IBASIC programs and the Save/Recall storage registers. If you have saved a large number of registers in your Test Set, you may encounter a “memory overflow” error when you first attempt to load the Software.
Chapter 4, Troubleshooting Errors When Loading and Running the Software Test System Configuration Errors at Runtime Problem: When it is first run, the Software checks to see that all required elements of a CDMA/PCS Test System are present. If it does not find a CDMA Cellular Adapter or a PCS Interface, it will report the following errors: HP-IB Command not accepted. Option not installed.
Chapter 4, Troubleshooting Errors When Loading and Running the Software Other Test System Configuration Errors Problem: Additional errors can be reported when using the Software, depending on which measurement modes are being used: Compensation not performed. Check DUPLEX OUT cable. Retry? This error can be reported if the cabling between the Test Set and PCS Interface is not correct.
Chapter 4, Troubleshooting Errors When Loading and Running the Software Menu Screens in this Book do not Match the Screens that You See Problem: You may have loaded another software procedure from the utility software memory card that is shipped with each PCS Interface. Procedures for Test System Connectivity (SYS_CONN) and Manual Control (MANUAL) also reside on the memory card and are loaded in the same manner as the CDMA/PCS BS test software. Solution: 1 Return to the main menu.
Chapter 4, Troubleshooting Errors While Attempting Measurements Errors While Attempting Measurements CDMA Measurement not Correlating Problem: If your Test System is not set up correctly for some of the tests, you may see the following message posted at the top of the display: Cannot correlate to input signal. Check setup.
Chapter 4, Troubleshooting Errors While Attempting Measurements 4 Test System timebase reference not connected. Verify that you have access to the base station’s reference timebase signal (typically 19.6608 MHz). The reference should be connected to the SYNTH REF IN port on the rear of the Cellular Adapter. If configured correctly, the REF UNLOCK indicator on the Cellular Adapter should not be on. 5 Transmitter not turned on.
Chapter 4, Troubleshooting Errors While Attempting Measurements Frame Error Rate (Receiver Measurements) Problem: If your Test System is not set up correctly for receiver tests, you may see erroneous results (extremely high FER or the inability to return a measurement) on the tool you use for displaying the Frame Error Rate calculated by the base station.
Chapter 4, Troubleshooting Errors While Attempting Measurements 5 RX PN Offset not set to zero. For receiver testing, the CDMA Generator is simulating the reverse channel (uplink) signal as it would be sent by a mobile phone. Mobiles transmit on system time, so the PN Offset should be set to zero. Make sure that the field RX PN Offset has an entry of 0. 6 CDMA Generator level delivered to the receiver test port of the base station is low.
Chapter 4, Troubleshooting Questionable Measurement Results Questionable Measurement Results Overview Refer to the topics in this section if you are seeing measurement results with no indicated errors, but you are failing a test or you believe you’re getting erroneous results. The following pages list some common sources of measurement errors for each type of test.
Chapter 4, Troubleshooting Questionable Measurement Results Rho Measurements Sources of errors in rho measurement include the following: Input signal is outside the measurement range of the PCS Interface The specified range for rho measurements with the PCS Interface is −13 to +30 dBm (50 µW to 1 W) when testing base station transmitters. Verify that the signal applied to the RF IN/OUT port of the PCS Interface falls within this range before continuing with your tests.
Chapter 4, Troubleshooting Questionable Measurement Results Sensitivity tests: random data not selected for signal source For receiver sensitivity measurements, check to see that the CDMA Generator is set to send random data. In the CDMA Generator Menu Selection screen, the Generator Mode should be set to Data and the Data Source should be set to Random. Performance in additive noise: signal source not set for Eb/No For this test, noise is added to the channel using the AWGN generator.
Chapter 4, Troubleshooting Questionable Measurement Results 76
Glossary Glossary Access Channel A reverse CDMA channel used by mobile stations for communicating to the base station. The access channel is used for short signaling message exchanges such as call originations, responses to pages, and registrations. The access channel is a slotted random access channel. Added White Gaussian Noise (AWGN) A broadband noise source used in conjunction with a CDMA signal source to test receiver performance.
Glossary Code Domain Analyzer An instrument that measures individual Walsh Channel characteristics in a CDMA channel. The Cellular Adapter can display all 64 Walsh Channels in a received signal and display their power, phase, and timing relationship. Eb/N0 The ratio between the energy of each information bit (Eb) and the noise spectral density (N o). This ratio is usually expressed in dB.
Glossary Frame A basic timing interval in the system. For the Access channel, paging channel, and traffic channel, a frame is 20 ms long. For the sync channel, a frame is 26.666...ms long.
Glossary Personal Communication Services (PCS) Emerging wireless networks using digital modulation formats and operating in the frequency band between 1.8 and 2.4 GHz. Pilot Channel An unmodulated, directsequence, spread-spectrum signal transmitted continuously by each CDMA base station.
Glossary Rho The measure of the waveform quality of a modulated signal in a CDMA system. A received signal is compared to an ideal, reference, signal. A high correlation between the received signal and the reference represents a high waveform quality factor. Sync Channel A code channel in the forward CDMA channel that synchronizes the mobile station with the base station. Sync Pulse A pulse that starts both the frame delay timer and the PN sequence delay timers.
Glossary Walsh Function One of 2N timeorthogonal binary functions (note that the functions are orthogonal after mapping 0 to 1, and 1 to −1). Walsh Symbol The time necessary to transmit one Walsh function on the reverse CDMA channel. Zero Offset Pilot PN Sequence A pilot PN sequence aligned with System Time such that the first chip on every evensecond mark is the "1" following the fifteen consecutive "0"s.
Index B bad measurements, 73 base station definition, 77 beep setting volume level, 59 beginning use of the software, 11 C cable losses receiver path, 53 transmitter path, 53 CDMA definition, 77 CDMA channel definition, 77 CDMA frequency assignment definition, 77 CDMA generator definition, 77 CDMA measurement not correlating, 69 CDMA TIMEBASE IN port, 60 Cellular Adapter definition, 77 channel definition, 77 channel plans, 51 check even second clock measurements other, 46 clearing Save/Recall registers, 6
Index front panel, 58 instruments, 14 rear panel, 58 timebases, 60 correlation, 69 correlation errors, 69 84 D data block definition, 78 description product, 12 E Eb definition, 78 Eb/No, 42 definition, 78 equipment required, 13 errors, 63 Configuration Information, 67 frame error rate (FER), 71 HP-IB, 66 measurement, 69, 73 measurement not correlating, 69 memory overflow, 65 menu screens don’t match, 68 PCS Interface, 66 runtime, 66 software, 65 system configuration, 66 Even-Second clock definition, 78
Index F FER definition, 78 finite inpulse response filter definition, 78 FIR filter definition, 78 forward CDMA channel definition, 78 forward link definition, 78 forward traffic channel definition, 78 frame definition, 79 frame clocks definition, 79 frame delay pulse definition, 79 frame delay timer definition, 79 frame error rate, 42 definition, 79 frame error rate (FER), 40, 42 frame error rate measurement problems, 71 G getting started, 11 H hardware required, 13 HP-IB command not accepted, 66 HP-IB
Index I instrument connections, 14, 58 intermediate frequency definition, 79 86 L Loading Configuration Information, 55 loading the software, 15 M main menu screen, 17 making connections, 14 making measurements, 23 Mcps definition, 79 measurement errors, 69 measurement results average power, 73 code domain measurements, 74 receiver tests, 74 rho, 74 measurements, 23 average power, 26 code domain phase, 34 code domain power, 30 code domain timing, 32 modulation quality (rho), 28 other, 44 questionable re
Index N navigation of software menus, 17 noise source, 42 Noise, Added White Gaussian definition, 77 O offset quadrature phase shift keying definition, 79 OQPSK definition, 79 P paging channel definition, 79 PCS definition, 79 PCS Band selection, 51 PCS frequencies, 51 PCS Interface definition, 79 error messages, 66 Personal Communications Services definition, 80 phase, code domain, 34 pilot channel definition, 80 pilot PN sequence definition, 80 pilot sequence offset index definition, 80 PN chip definit
Index Q QPSK definition, 80 quadrature phase shift keying definition, 80 quadrature spreading definition, 80 questionable measurement results, 73 88 R receiver performance in additive noise, 42 receiver sensitivity, 40 receiver tests suspect measurement results, 74 reference signal definition, 80 references connections, 60 registers clearing, 65 required equipment, 13 reverse CDMA channel definition, 80 reverse link definition, 80 reverse traffic channel definition, 80 rho, 28 definition, 81 suspect meas
Index T Test Set definition, 81 timebase connections, 60 timing, code domain, 32 tone, audio, 59 traffic channel definition, 81 transmit spectrum, 36 trigger event definition, 81 troubleshooting, 63 TX Measurement Path Loss, 53 U UCT definition, 81 Universal Coordinated Time definition, 81 uplink definition, 81 V viewing connect diagrams, 58 89
Index W Walsh chip definition, 81 Walsh cover definition, 81 Walsh function definition, 82 Walsh symbol definition, 82 90 Z zero offset pilot definition, 82
