Agilent Technologies ESG Family/RF Signal Generators Product Note ESG Signal Generator/Option 201 Real-time IS-2000 Mobile Receiver Measurements
Table of contents Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3 IS-2000 measurement background . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4 ESG option 201 real-time CDMA2000 personality . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5 Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Introduction The recent 1999 CDMA Americas Congress marked the milestone of a decade of CDMA. Among the items highlighted were the exciting opportunities for CDMA in the new millennium. With the evolution toward 3G standards, CDMA is providing an even more exciting opportunity. CDMA leads the industry in providing the highest quality voice services and it is also leading the way in delivering wireless data services.
IS-2000 measurement background Prior to the introduction of the ESG signal generator’s Option 201 real-time cdma2000 personality, testing of IS-2000 mobile receivers was performed in a limited fashion using custom solutions or non real-time solutions such as arbitrary waveform generators. Custom solutions had their downsides. They required significant time and effort to develop, they were typically complex and costly, and they provided only limited functionality and flexibility.
ESG Option 201 Real-time cdma2000 personality The ESG’s Option 201 personality provides a complete solution for testing of IS-2000 mobile receiver designs. This section provides an overview of the Option 201 real-time IS-2000 system. It also describes the Option 201 features. Overview The ESG with the Option 201 personality simulates a basestation transmitter to create a forward spread rate 1 (SR1) link for an IS-2000 mobile.
Key Features Key features of the Option 201 personality are highlighted in Table 1 below. The 1-BOX column refers to the IS-95 solution that utilizes one ESG signal generator. The 2-BOX column refers to the IS-2000 solution that utilizes two ESG signal generators; this allows more complex signal structures as described in section in the two-box setup. Table 1 summarizes some differences between the one-box and two-box setups. Table 1.
ESG Option 201 IS-2000 Real-time receiver test setup The Option 201 personality provides significant flexibility in its configuration. It may be configured as a one-box IS-95 setup or as a two-box IS-2000 setup. Since Option 201 is a real-time solution, it requires the Option UN8 Real-time I/Q Baseband Generator for its operation.1 Below are descriptions of a one-box setup and a two-box setup with configuration examples.
After configuring the hardware, follow the steps in Table 2 below to configure the instrument appropriately. In this example, Pilot, Sync, Traffic, and Paging channels are defined. For IS-95, the traffic channel may be defined as RC1 or RC2. This example is intended to illustrate a basic set-up from which the user can customize the instrument to meet his needs. Values in brackets [ ] are for example purposes only and the actual value should be determined by the user.
Figure 4 shows the Link Control menu on the ESG. This menu is used for channel configuration. Notice the effect of the channel power scaling on the individual channel power levels when scaled to 0 dB. Figure 4. ESG Display for CDMA link control After completing the instrument configuration, connect the RF Output of the ESG to a signal analyzer to view the signal, or to a CDMA mobile phone to establish communication.
Two-box setup A two-box ESG Option 201 configuration is for situations where more real-time CDMA channels, power levels, or higher radio configurations are required than are available from a single ESG. In addition to the Pilot, Sync, Paging, and RC1 or RC2 traffic channel, a two-box setup provides two RC3, RC4 or RC5 traffic channels. The RC3, RC4 and RC5 traffic channels allow testing of IS-2000 receiver designs.
The physical hardware configuration for the two-box setup is shown in Figure 7. Two ESG signal generators, each with options UN8 and 201, are required. ESG #1 is used to generate the Pilot, Sync, OCNS, and Paging channels. ESG #2 provides the Traffic channels and the 1.2288 MHz chip clock that drives the data clock for both ESGs with matched delays; the Data Clock input clips the RF to TTL levels (refer to the note regarding cable lengths in Figure 7.
After configuring the hardware appropriately for the two-box setup, follow the steps in Table 3 and Table 4 below to configure the instruments. Table 3 is for the configuration of ESG #1 and Table 4 is for the configuration of ESG #2. Values in brackets [ ] are for example purposes only and the actual value should be determined by the user. Hard key selections are indicated by Bold text. Note: The LC (Long Code) State and the PN Offset of both ESGs must match. Table 3.
Table 4.
Once the instruments have been properly configured, power mapping must be performed to align the power levels of the channels between the two ESGs appropriately. This is required since the two ESGs are not aware of each other’s power level. To perform power mapping, refer to the end of this section. Connect the RF OUTPUT of ESG #1 to a signal analyzer to view the signal, or to a CDMA mobile phone to establish communication.
It is possible to generate a third RC3, RC4 or RC5 traffic channel from ESG #2. In the Link Control menu, channel 2 may be toggled to F-SCH for a second supplemental traffic channel. If three RC3, RC4 or RC5 traffic channels are selected, a "Code Power Err" message will appear with a value of error listed. This means that some of the symbols will have an error associated with them and the code domain will exhibit some artifacts. This is a result of system limitations.
Table 5 shows a sample of the Excel spreadsheet used for power mapping. This example uses OCNS. Table 5. Agilent ESG Option 201 power scaling worksheet, V2.11 Enter desired powers in this column and into the ESG (Blank for Off) Channel # Box #1 OCNS Power is calculated automatically so that total power is 0 dB. Box #2 OCNS Power is calculated automatically so that total power is 0 dB. Pilot 2 3 4 OCNS 1 Total Power (dB) 0.00 2.
Real-time IS-2000 measurements This section provides an overview of various IS-95 and IS-2000 forward link (e.g. mobile receiver) measurements which may be performed with the ESG’s Real-time Receiver Test personality. Measurement overview The ESG Option 201 Real-time cdma2000 personality provides the capability of performing numerous measurements on a mobile receiver including RF performance and protocol-handling capability. This section describes some of these tests.
After setting up the equipment, the ESG Option 201 system is configured as discussed earlier in section 3 of this document. At this point, a signal will be present at the ESG’s RF output. The signal generated by the ESG will appear to the mobile phone as a basestation signal. It is the phone’s duty, at this point, to synchronize to the signal and read the overhead channels.
Intermodulation spurious response attenuation This test measures the ability of the receiver to receive a signal in the presence of two interfering CW tones, which produce intermodulation products in the band of the desired CDMA signal. FER provides the measure of merit. This test is important because intermodulation signals are common in CDMA systems and this test measures the receiver’s tolerance to this interference.
Paging channel protocol development, unidirectional Paging channel protocol development is a subset of messaging and protocol development. The ESG Option 201 personality provides fine control of the paging channel allowing insertion of asynchronous paging messages. This allows the ESG to communicate to the mobile receiver in essentially the same way a basestation would. This simplifies the development and verification of paging commands.
This allows the power and response of the mobile phone’s power control system to be monitored. Figure 12 shows a simulation of the power response of a mobile phone as would be viewed on a signal analyzer. Figure 12. Power control display simulation [Center Frequency = 900 MHz, Mode = cdmaOne, Measure = Waveform(Time Domain), Sweep Time = 30 ms, Res BW = 2 MHz, Scale/Div = 1.00 dB, Ref Value = 0.00 dBm] Demonstration example A demonstration example of a functional test setup is shown in Figure 13.
Once the drive test has been configured to match the mobile phone, the ESG Option 201 personality must also be configured appropriately, as follows: • Frequency set to frequency of mobile phone • Amplitude set to an appropriate level, such as –20 dBm • Pilot channel configured • Sync channel and appropriate Sync type configured • Paging channel configured • Fundamental traffic channel(s) may be configured, optionally • Other parameters, such as PN Offset, may be varied as desired Once the ESG has been appro
Appendix A-Specifications Real-time cdma2000 personality, Option 201 Description Option 201 is a firmware personality built upon the internal real-time I/Q baseband generator (Option UN8). This option will generate fully coded IS-2000 signals (phase 1) for mobile receiver test and provide the stimulus for frame or bit error tests, and functional tests of the mobile unit's protocol handling. It is backward compatible with IS-95 systems using Radio Configurations 1 or 2.
Appendix B – Terms and definitions ASIC – Application Specific Integrated Circuit AWGN – Additive White Gaussian Noise BBG – Base Band Generator BER – Bit Error Rate BLER – Block Error Rate BTS – Base Transceiver Station CDMA – Code Division Multiple Access multiplexing scheme cdmaOneTM – Brand name that describes a complete wireless system incorporating the IS-95 CDMA air interface.
Recommended reading 1. Performing cdma2000 Measurements Today, Agilent Technologies Application Note 1325, literature number 5968-5858E. 2. Understanding CDMA Measurements for Basestations and Their Components, Agilent Technologies Application Note 1311, literature number 5968-0953E. 3. Testing and Troubleshooting Digital RF Communications Receiver Designs, Agilent Technologies Application Note 1314, literature number 5968-3579E. 4.
Ordering information The ESG Option 201 personality can be ordered with a new ESG, or through an upgrade. The upgrade kit is Option 251. The upgrade kit may be downloaded and activated by purchasing a license key. The serial number of the unit as well as the Host ID number must be supplied. This personality requires firmware B.03.40 or higher. It also requires the Real-time I/Q Baseband Generator, option UN8 revision C or higher.
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