Keysight Technologies N9072 W9072A cdma2000®/cdmaOne

X-Series Measurement Application

Demo Guide Introduction

This demonstration guide provides step-by-step instructions for making key CDMA base station transmitter and component measurements. Each demonstration is given a brief description of its function and the corresponding measurement steps on the and/or signal analyzer. Demonstration Preparation

The N/W9072A cdma2000/cdmaOne Product type Model number Required options measurement application provides key transmitter measurements for –– 503 or 506 – frequency range to 3 GHz or analyzing cdma2000 and cdmaOne MXG vector 6 GHz systems based on the 3GPP2 signal generator N5182A (or –– 651, 652 or 654 – Internal baseband generator Technical Specifications Group Note: ESG-C can E4438C) (30/60/125 MSa/s, 8 Msa memory) cdma2000 (TSG-C) specifications also be used –– UNV- Enhanced dynamic range (required for better ACP performance) (C.S0010-D) for base station. Signal Studio N7601B –– 3FP – N5182A connectivity for 3GPP2 All demonstrations use an X-Series V1.5.0.0 or later –– EFP – Basic IS95A/cdma2000 license option signal analyzer with the N/W9072A CDMA cdma2000/cdmaOne measurement –– Required: application, and an N5182A MXG –– 503, 508 (507 for EXA and CXA), 513, 526, 543, N9030A PXA, vector signal generator with N7601B 544 or 550 – frequency range up to 50 GHz N9020A MXA, 3GPP2 CDMA Signal Studio software. (7.5 GHz for CXA, 26.5 GHz for EXA and MXA) N9010A EXA, or –– Recommended: X-Series N9000A CXA –– EA3 – Electronic attenuator, 3.6 GHz This demonstration guide describes signal analyzer Note: For PXA and –– P0x – Preamplifier (P03, P08) or (P07 for CXA) how to evaluate key product features CXA, the firmware –– BBA – Analog baseband IQ inputs through demonstrations and is not revision must be (required for analog baseband analysis, intended to be a detailed user’s guide. A.08.03 or later. not available on EXA and CXA) Prior knowledge of the Keysight –– PFR – Precision frequency reference Technologies, Inc. products is not required for these demonstrations and X-Series N9072A – 2FP or –– cdma2000/cdmaOne measurement step-by-step instructions are provided. cdma2000/ 2TP application, fixed perpetual or transportable cdmaOne license option (for PXA, MXA or EXA) measurement The demonstrations found within this W9072A – 2FP –– cdma2000/cdmaOne measurement application, document assume basic knowledge application fixed perpetual license (for CXA only) of cdma2000 physical layer signal characteristics. For more in-depth Install N7601B to generate and download the Controller PC for signal waveform into the MXG via GPIB or cdmaOne and cdma2000 technical Signal Studio LAN (TCP/IP) – please refer to the online information, please visit documentation for installation and setup www.keysight.com/find/cdma2000

Keystrokes surrounded by [ ] indicate hard keys on X-Series analyzers, while key names surrounded by { } indicate soft keys located on the right edge of the X-Series display.

Helpful tip: Update your instrument firmware and software to the latest version, available at www.keysight.com/find/xseries_software www.keysight.com/find/signalstudio

3 Demonstration Setup

Connect the PC, X-Series, and MXG

Connect a PC (loaded with N7601B Signal Studio for 3GPP2 CDMA software and Keysight I/O libraries) to the N5182A MXG via GPIB or LAN. Follow the Signal Studio instructions to complete the connection, then perform the following steps to inter- connect the X-Series and MXG (see Figure 1 for a graphical overview):

A. Connect the MXG RF Output port to the X-Series RF Input port B. Recommend to connect the MXG 10 MHz Out to the X-Series Ext Ref In port (rear panel) for frequency accuracy

Figure 1. Demonstration setup

4 Generate CDMA Instructions Keystrokes waveform with Signal On the MXG Studio on N5182A MXG Preset the MXG [Preset] Check the IP address. [Utility] {I/O Config} {LAN Setup} The N7601B Signal Studio software On the Signal Studio software for 3GPP2 CDMA is a Windows-based utility that simplifies the creation Double-click on the CDMA shortcut on the Run the Keysight Signal Studio desktop or access the program via the Windows of standards-based waveforms for for 3GPP2 CDMA. CDMA including 1xEV-DO. start menu To establish a new connection, click on the Verify the software is communi- {System} pull-down menu at the top of the Signal cating with the instrument via the Studio program window. Next, select {Run System GPIB or LAN (TCP/IP) link. Configuration Wizard} In the tree view, left pane of the main window, select Instrument under Hardware. Set the basic parameters of the Click the green Preset button and set: MXG vector signal generator. Frequency = 915.2375 MHz Amplitude = -10 dBm RF Output = On Delete the default IS95A Forward setup in the signal studio use the button In the tree view, left pane of the main window, Reselect the cdma2000 select WFM1. In the right pane, click button, forward signal. from the pull-down list, click on CDMA2000 Forward, See Figure 2.

Click Generate and Download button on the Download the signal to top tool bar. Keysight MXG. If you encounter any errors, please refer to the online help of Signal Studio software. File > Save As > cdma2000_demo setup.scp Save the signal file for future use. (name it as you like.)

Figure 2. Signal Studio’s setup of the cdma2000 forward signal

5 Demonstrations

Demonstration 1: X-Series instructions Keystrokes

Channel power Preset the signal analyzer [Mode Preset] [Mode]>{cdma2000} Select CDMA mode Power is the fundamental parametric Note: The exact page may vary. of any communication system. In CDMA, one of the fundamental Change frequency to 915.2375 MHz {Center Freq} [9][1][5][.][2][3][7][5] {MHz} enabling technologies is power Choose transmitter device. [Mode Setup]>{}>{Device BTS} control. The accuracy of the power control system depends greatly on the Active channel power measurement. [Meas]>{Channel Power} base station’s ability to monitor and Tune on a bar graph. [View/Display]>{Bar Graph On} transmit the proper values of power. Observe the blue bar indicating the spectrum channel width and the quan- See Figure 3. Note: The X-series signal analyzer titative values given beneath. can make measurements on both the Examine setting. forward and reverse links, but only Use this step to make setup changes in [Meas Setup] the forward link will be demonstrated any measurement in this guide.

In the N/W9072A, the channel power measurement determines the total rms power in a user-specified band- width. The power (PSD) is also displayed in dBm/Hz. The following power measurement parameters can be controlled: –– Integration (defaults to 1.23 MHz) –– Channel power span (defaults to 1.845 MHz) –– Number of trace averages (defaults to 20) –– Data points displayed (101 to 20001, defaults to 1001)

Figure 3. Channel power

6 Demonstration 2: An additional requirement for the The specification for measuring ACPR CDMA signal generator is that its requires a comparison of the power in Adjacent channel power ACP performance be very good. The the RF channel to the power at sev- Keysight MXG N5182A vector signal eral offsets. This can be done either The adjacent channel power measure- generator provides industry-leading as a power ratio or a power density. ment is not part of the CDMA stan- adjacent channel leakage ratio From Figure 4, the +885 kHz ACPR dards, however, individual network (ACLR) performance for result would be C dBc (relative to A) equipment manufacturers typically communication1. This ensures the in power-ration method. In the power specify ACP as a figure-of-merit for power measured in the adjacent density method, the +885 kHz ACPR component testing. ACPR is the ratio channels is caused by the device results would be C/B dB. of adjacent-channel power to the under test, and not the signal average power level of the channel. generator or the signal analyzer.

When testing ACPR, it is important to take into account the power statistics of the signal. A signal with a higher peak-to-average ratio may cause more interference in the adjacent channel. Thus, ACPR measurements can provide different results depending on the signal configuration. The safest approach is to use at least one of the realistic high-stress stimulus signals, and test with various combinations of Walsh-code channels. Therefore, a signal generator with this flexibility is highly recommended.

Figure 4. Adjacent channel power ratio specification

1. MXG provides a superior ACLR for 3GPP W-CDMA of less than –73 dBc at +5 dBm output.

7 The N/W9072A provides the ability Set up the X-Series analyzer to analyze the CDMA signal. to perform the ACP test automatically X-Series instructions Keystrokes with method according to the specifications and displaying the Activate (ACP) measurement. [Meas]>{ACP} results. [Meas setup]>{More}> Optimize for dynamic range. –– Adjust integration bandwidth {Meas Method}>{Integration BW} (defaults to 1.23 MHz) Adjust the power level by changing [AMPTD]>{Ref Value} [-10] {dBm} –– Evaluate up to 6 adjacent Ref Value. channel pairs [Meas Setup]>{More 1 of 2}> {Noise Correction On Off} –– Optimize dynamic range with Turn on Noise Correction. more narrower RBW selection See Figure 5. of integration bandwidth (IBW) (defaults measurement method to 30 KHz RBW) –– Choose adjacent channel offset frequency, reference bandwidth, and limit values –– Adjust and display both absolute and relative limits –– Measure the total power in dBm or the PSD in dBm/Hz –– View bar graph and/or spectrum

Figure 5. ACP measurement for a cdma2000 SR1 signal

8 Demonstration 3: Set up the X-Series analyzer to analyze the CDMA signal. X-Series instructions Keystrokes Spectrum emission mask Active the spectrum emission mask The spectrum emission mask is measurement. [Meas]>{Spectrum Emission Mask} one of the in-band-of-channel Observe the mask and trace in the measurements that measures upper window and the table of See Figure 6. measured values in the lower window. distortion and interference within the system band, but outside of the Choose the type of values to display. [View/Display]>change {Abs Peak Pwr Observe the measurement values transmitting channel. & Freq} to {Rel Peak Pwr & Freq} or change in the lower window to reflect {Integrated Power} The performance standards recom- the selected value type. mended by the 3GPP2 (refer to View customizable offset and limits. C.S0010-D_v2.0, section 4.4.1.3) for Measurement parameters as well as [Meas Setup]>{Offset/Limits}>{More}> cdma2000 have specific limits for limit values may be customized for {Limits} transmitted spurious emissions. This any of the six offset pairs or for any measurement has different limits for individual offset different frequency offsets measured in different resolution bandwidths.

With one-button SEM measurements in N/W9072A, the X-Series signal analyzer makes this measurement very simple versus a traditional spectrum analyzer, which can be tedious and time consuming.

–– View table and spectrum formats. –– Measure the total power in dBm or the PSD in dBm/Hz. –– Select the average or peak detector (defaults to average). –– Choose offset frequency, reference bandwidth, and limit values. –– Customize reference channel span, step frequency, and resolution bandwidth.

Figure 6. Spectrum emission mask

9 Demonstration 4: Generate a cdma2000 forward 12 channel signal in Signal Studio. Signal Studio instructions Keystrokes Code domain analysis In the tree view, left pane of the main window, select Carrier 1 under WFM1. Walsh codes are the fundamental Change the carrier of CDMA2000. In the right pane, click the Channel channelization mechanism for CDMA. Forward for new channel configuration. Configuration, change to 12 Channel Measuring code-domain power is Forward from the drop-down menu essential for verifying that each code channel is operating at its proper level Download the signal to the MXG. Press Generate and Download button on and to identify problems throughout the top tool bar. the transmitter design, from coding to the RF section. System imperfections, such as amplifier non-linearity, will present themselves as an undesired X-Series instructions Keystrokes distribution of power in the code domain. Activate the code domain measurement. [Meas]>{Code Domain} [View/Display]>{Power Graph & Metrics}> The code domain power provides Change the Walsh code algorithm to {Code Order}>{ Bit Reverse} a quick view of all of the channel bit-reverse and examine the new result. elements’ contributions for a given See Figure 7. frequency assignment and PN offset. Use the marker to examine Walsh code. [Marker]>[Select Marker 1], rotate KNOB Unlike cdmaOne, in cdma2000 the A bar for each channel with height to highlight widest Walsh channel measurement is complicated by the proportionately representative of the fact that the Walsh code lengths vary channel power and the bar width See Figure 81. to accommodate the different data proportional to the data rate. rates and SRs of the different RCs. 1 The data rate programmed into the MXG will seem different than that measured with the In the N/W9072A, there are two X-Series. In actuality, they are the same. The MXG gives the data rate in bits per second, while algorithms that display the code the X-Series measures the data rate in symbols per second. The data rates are related through channel power. The Hadamard algo- the radio configuration and the spreading rate. rithm displays each Walsh code in sequence and uses the Consolidated Marker feature to display the compost representation of the traffic channel. The other is a bit-reverse algorithm that displays the channels as consolidated code spaces.

10 Additionally, the N/W9072A will X-Series instructions Keystrokes de-spread any single code channel to provide magnitude and phase error Change the Walsh code algorithm back [View/Display]>{Power Graph & data, EVM data, symbol power versus to Hadamard. Metrics}>{Code Order}>{Hadamard} time plots, symbol polar vector plots, Run single measurement. [Single] and demodulated (but not decoded) [View/Display]> I and Q bits. Display the code domain in quad view. {Code Domain (Quad View)} –– Take advantage of the multi-result view: [Marker] Put the marker on. Rotate KNOB or [↑]/[↓] to move the 2 –– Code power and symbol rates bar marker to the third bar with display of W4 graph and table [Marker→]>{Mkr→Despread} –– I/Q symbol magnitude and phase View magnitude error, phase error and EVM plots for Walsh code 2. errors and EVM plots See Figure 9. –– Symbol power plot Show I and Q symbol bits. [View/Display]>{Demod Bits} –– I and Q bits The display bits are those of Walsh code 2. See Figure 10. [Meas Setup]>{More}>{Capture Intvl}> Inspect more data. [10]>{PCG}. Up to 32 PCGs can be captured, and the Back to {More 1 of 3}, {Meas Interval} [3]> bits of any serial combination of those {PCG}, can be reviewed. {Meas Offset}>[5]>{PCG}

Figure 7. Code domain power in bit-reverse code order

11 Figure 8. Code domain power measurement marker identifies correct code 2 assignment and power level for active Walsh code W4

Figure 9. Code domain power in quad view

Figure 10. Symbol power and demodulated I/Q bits

12 Demonstration 5: Generate a cdma2000 forward 9 channel signal in the Signal Studio. Signal Studio instructions Keystrokes accuracy In the tree view, left pane of the main (Composite rho) window, select Carrier 1. In the right pane, Change the filter type to improve EVM. click on Filter, pull-down menu of the packet In the CDMA standard, the specified type to choose IS95 EVM EQ measurement for modulation accu- racy is rho. Rho is the ratio of the Download the signal to the MXG. Press Generate and Download button correlated power to the total power. on the top tool bar. The correlated power is computed by removing frequency, phase and time offsets and performing a cross Setup the X-Series analyzer to analyze the cdma2000 forward Pilot signal. correlation between the corrected X-Series instructions Keystrokes signal and an ideal reference. Go to modulation accuracy With N/W9072A, the X-series measurement in a single [Meas]>{More 1 of 2}>{Modulation signal analyzer can help to evaluate measurement control. Accuracy (Composite Rho)} the quality of the transmitter for a Press [Single] multichannel signal, detect spreading Observe the I/Q measured polar vector display on the right and the quantitative See Figure 11. or scramble errors, identify certain data provided on the left. problems between baseband and RF sections, and analyze errors that Examine limit values menu. [Meas Setup]>{Limits} cause high interference in the signal. [View/Display]>{Power Timing & Phase}

–– Measure EVM, rho, and peak code View Power, Timing, Phase and CDE See Figure 12. domain error (Pk CDE) by each Walsh code. –– Customize limits for rms EVM, peak Note: Follow the message if “Multi channel Estimator” is not at On. EVM, rho, peak CDE, timing error and phase error –– Specify rate and PN offsets –– View I/Q polar constellation and magnitude error, phase error, and EVM plots –– Read power, timing, phase and EVM data for each active channel –– Choose to include or exclude the I/Q origin offset in the EVM calculation

Figure 11. Modulation accuracy with cdma2000 forward 12 channel signal

13 In the 3GPP2 C.S0010, there are 4.2.1.2 Pilot channel to Measures the time Less than two paragraphs (refer to 4.2.1.2, and code channel time offset or timing error 50 nanoseconds 4.2.1.3) that specify the timing and tolerance between the pilot phase tests for transmitters. The (Walsh 0) and each table in the right shows the detailed of the other Walsh descriptions and limitations for these codes. two items. 4.2.1.3 Pilot channel to Measures the phase Less than code channel phase difference between 50 milliradians or Figure 12 shows the power, timing, tolerance the pilot channel and 2.86 degrees phase and CDE for each active each Walsh channel. Walsh code.

Figure 12. Power, Timing, Phase and CDE by each Walsh code

14 Demonstration 6: Set up the X-Series analyzer to analyze the CDMA signal. X-Series instructions Keystrokes Power statistics (CCDF) Active the CCDF. [Meas]>{More 1 of 2}>{Power Stat CCDF} The complementary cumulative [Trace/Detector]>{Store Ref Trace}, then distribution function (CCDF) is a plot Set the 9 channel signal trace as a select {Ref Trace On} of peak-to-average power ratio (PAR) reference. versus probability and it characterizes [Single] the power statistics of a signal. [Restart] CCDF is a key tool for power amplifier design for cdma2000 base station, Send another 4 channel signal into the See Figure 13. which is particularly challenging MXA. Measure its CCDF again. In general, the peak-to-average power because the amplifier must be ratio increases as more channels are capable of handling the high PAR activated. the signal exhibits while maintaining good adjacent channel leakage performance. Designing multicarrier power amplifiers pushes complexity yet another step farther.

In cdma2000, as in cdmaOne, the 9-channel signal power statistics of the signal depend AWGN Reference on channel configuration, modulation, filtering, clipping level, and other 4-channel signal factors. In general, the peak-to- average power ratio increases as more channels are activated.

–– Customize information bandwidth (defaults to 1.5 MHz) –– Specify measurement interval 0.1% PTA ratio values –– Set a reference trace or compare for 4-channel to Gaussian noise trace –– Take advantage of the 0.01 dB Figure 13. The CCDF curves for two cdma2000 SR1 signals with different histogram resolution channel configurations

15 Demonstration 7: Generate a cdma2000 forward Pilot-only signal in Signal Studio. Signal Studio instructions Keystrokes QPSK EVM Click on Carrier 1 under Waveform Setup Modify the waveform setup. The quadrature phase shift keying on the explorer menu on the left. (QPSK) error vector magnitude (EVM) Click on Channel Configuration in the Change the pre-defined channel measurement is a measure of phase manual of 3GPP2 on the right, pull-down configuration to Pilot. and amplitude modulation quality that menu of the packet type to find Pilot relates the performance of the actual signal compared to an ideal signal Download the signal to the MXG. Press Generate and Download button as a percentage, as calculated over on the top tool bar. the course of the ideal constellation. These phase and frequency errors Set up the X-Series analyzer to analyze the cdma2000 forward Pilot signal. are measures of modulation quality for the cdma2000 (3GPP2) system, X-Series instructions Keystrokes and can be quantified through QPSK [Meas]>{More 1 of 2}>{QPSK EVM} EVM measurements. This is just Switch on the QPSK EVM measurement. for a single channel signal in QPSK See Figure 14. modulation. It is useful in trouble- [View/Display]>{I/Q Error} shooting when the cdma2000 signal View magnitude and phase error and EVM plots. fails the synchronization. EVM can be See Figure 15. measured on any single code channel in QPSK without de-scrambling. It can be used for Pilot EVM. For multiple code channel signals, the modulation accuracy (composite rho) measurement is available in cdma2000 mode.

–– Determine rms and peak EVM (maximum and average) –– View I/Q polar vector diagram or magnitude error, phase error, and EVM plots –– Specify measurement interval (128 to 1536, defaults to 512 chips)

Figure 14. QPSK EVM in I/Q measured polar graph

16 Figure 15. QPSK EVM in I/Q error quad view

Related Literature Product Web Sites

Keysight AN1311 Understanding N/W9072A cdma2000/cdmaOne: CDMA Measurements for Base www.keysight.com/find/n9072a and Stations and Their Components, www.keysight.com/find/w9072a Literature Number 5968-0953E X-Series signal analyzers: www.keysight.com/find/X-Series Designing and Testing cdma2000 Base Stations (Application Note 1357), X-Series advanced measurement applications: Literature Number 5980-1303E www.keysight.com/find/X-Series_Apps Signal Studio software: PSA Series Spectrum analyzers www.keysight.com/find/SignalStudio E4406A Vector Signal Analyzer cdma2000 and 1xEV-DV Measurement Signal generators: Personalities, Literature Number www.keysight.com/find/sg 5988-3694EN

17 18 | Keysight | Keysight N9072 & W9072A cdma2000/cdmaOne X-Series Measurement Application - Demo Guide

myKeysight For more information on Keysight Technologies’ products, applications or www.keysight.com/find/mykeysight services, please contact your local Keysight A personalized view into the information most relevant to you. office. The complete list is available at: www.lxistandard.org www.keysight.com/find/contactus LAN eXtensions for Instruments puts the power of and the Web inside your test systems. Keysight is a founding member of the LXI Americas consortium. Canada (877) 894 4414 www.keysight.com/find/ThreeYearWarranty Brazil 55 11 3351 7010 Keysight’s commitment to superior product quality and lower total cost Mexico 001 800 254 2440 of ownership. The only test and measurement company with three-year United States (800) 829 4444 warranty standard on all instruments, worldwide. Asia Pacific Keysight Assurance Plans Australia 1 800 629 485 www.keysight.com/find/AssurancePlans China 800 810 0189 Hong Kong 800 938 693 Up to five years of protection and no budgetary surprises to ensure your India 1 800 112 929 instruments are operating to specification so you can rely on accurate Japan 0120 (421) 345 measurements. Korea 080 769 0800 www.keysight.com/quality Malaysia 1 800 888 848 Singapore 1 800 375 8100 Keysight Electronic Measurement Group Taiwan 0800 047 866 DEKRA Certified ISO 9001:2008 Other AP Countries (65) 6375 8100 Quality Management System Europe & Middle East Keysight Channel Partners Austria 0800 001122 www.keysight.com/find/channelpartners Belgium 0800 58580 Get the best of both worlds: Keysight’s measurement expertise and product Finland 0800 523252 breadth, combined with channel partner convenience. France 0805 980333 Germany 0800 6270999 Ireland 1800 832700 cdma2000 is a US registered certification mark of the Industry Israel 1 809 343051 Association Italy 800 599100 Luxembourg +32 800 58580 Netherlands 0800 0233200 Russia 8800 5009286 Spain 0800 000154 Sweden 0200 882255 Switzerland 0800 805353 Opt. 1 (DE) Opt. 2 (FR) Opt. 3 (IT) United Kingdom 0800 0260637

For other unlisted countries: www.keysight.com/find/contactus (BP-05-19-14)

This information is subject to change without notice. © Keysight Technologies, 2011-2014 Published in USA, August 1, 2014 5990-8011EN www.keysight.com