Setting up a 1xEV-DV measurement (cdma2000/1xEV-DV)

When setting up an 1xEV DV demodulation measurement, there are several things you need to consider. This topic provides information to setup the 89600 VSA Software to successfully demodulate and measure a 1xEV DV modulated signal.

Begin by following the same measurement procedure used to setup and measure a cdma2000 signal. (See Setting up a cdma2000 Measurement).
After confirming the measurement locks to the measured signal, enable 1xEV-DV measurements by selecting Enable 1xEV-DV analysis from the Format tab [MeasSetup > cdma2000/1xEV-DV

Demod Properties > Format tab > Enable 1xEV-DV analysis].

The measurement will now provide correct 1xEV DV data results (EVM Error vector magnitude (EVM): A quality metric in digital communication systems. See the EVM metric in the Error Summary Table topic in each demodulator for more information on how EVM is calculated for that modulation format., etc.) and active channel identification for QPSK Quadrature phase shift keying, 8PSK, or 16QAM encoded F-PDCH channels. A standard cdma2000 measurement would not produce correct data results.
Making Predefined F-PDCH Active Channels measurements This procedure describes how to to make Predefined F-PDCH Active Channelsmeasurements for the F-PDCH channels (Walsh code 32).

Use Predefined F-PDCH Active Channels measurements when the VSA's auto detection algorithm is not properly identifying the F PDCH active channels or modulation formats. Predefined F-PDCH Active Channels forces the VSA to override the auto detection algorithm and to recognize all F-PDCH channels specified by the Predefined F-PDCH Active Channels parameters as active. To completely define the measurement channels, you must specify the Walsh code assignments and modulation formats for both the F-PDCH0 and F-PDCH1 channels. The defined F-PDCH channels are always presumed active regardless of actual input signal. The total number of identified active channels includes those specified by the F-PDCH0, F-PDCH1and any additional active channels detected by the active channel algorithm. This feature will be disabled if 1xEV-DV capabilities are not enabled.
1. To enable Predefined F-PDCH Active Channels measurements select Predefined F-PDCH Active Channels from the Predefined Channels tab [MeasSetup > cdma2000/1xEV-DV Demod Properties > Predefined Channels tab]
2. Next define (or specify) the desired F-PDCH active channels using the Predefined F-PDCH Active Channels parameters. Enter a value for each of the following parameters:
  - Walsh Code Column Index
  - Walsh Mask
  - F-PDCH0 and F-PDCH1 Number of Channels
  - F-PDCH0 and F-PDCH1 Modulation
  These parameters are used by all measurement trace data results.
Making Adaptive Modulation and Coding (AMC Adaptive Modulation and Coding) measurements
This procedure describes how to make Adaptively Modulated Coding (AMC) signal measurements for the F-PDCH channel.

1xEV DV supports Adaptive Modulation and Coding (AMC) in the F-PDCH channel. In the AMC system, the modulation scheme of each packet data channel and the code channel allocation on the code domain may be dynamically changed between QPSK, 8PSK or 16 QAM Quadrature Amplitude Modulation every sub-packet length. The F-PDCH sub-packet length can be transmitted using 1, 2 or 4 slot durations. The VSA does not directly support AMC signal measurements, however, AMC measurements can be accomplished on a slot-by-slot basis. This is because the measurement algorithm can only detect one modulation scheme at a time for the selected slots (measurement interval). For example, if a measurement interval includes slots wherein the modulation scheme changes, the VSA's modulation auto-detection algorithm will incorrectly assume that the entire measurement interval uses the same modulation type. This will result in improperly demodulated bits, inaccurate synthesized reference signals, and ultimately, incorrect code domain and composite measurement results.

If a code channel changes modulation format or active status within the measured result length, you can obtain correct measurement results by limiting the measurement to intervals that have a constant modulation scheme. You will use the Measurement Offset and Measurement Interval parameters to specify the input data region and the Use Gated Active Channel Detection and Use Gated Modulation Detection properties to limit the detection region to the specified Measurement Interval. It is important that you select measurement intervals that adhere to the following criteria: it should contain only one modulation type and the total number of slots is equivalent to an integral number of F-PDCH sub-packet lengths.

Recall that an F-PDCH channel sub-packet may be transmitted using 1, 2 or 4 slots in length and that the modulation scheme can only change at sub packet boundaries.

To properly measure a 1XEV-DV signal with Adaptively Modulated Coding on the F-PDCH channel (Walsh Code Length 32), follow these setup instructions.
1. Select the Use gated modulation detection and Use gated active channel detection modes from the Time tab [MeasSetup > cdma2000/1xEV-DV Demod Properties > Time tab]. This makes sure that only those slots within the specified Measurement Interval are included in the measurement data.
2. Then carefully specify the appropriate measurement interval using the Measurement Interval and Measurement Offset parameters [MeasSetup > cdma2000/1xEV-DV Demod Properties > Time tab]. This defines the specific input signal region used for Code Domain Power and Despread Channel measurements.
3. If a Despread Channel measurement of an F-PDCH channel does not automatically detect the correct modulation scheme, you can override it by selecting the manual Modulation mode and specifying the desired modulation format [MeasSetup > cdma2000/1xEV-DV Demodulation Properties > Channel/Layer tab].
4. Also, if the VSA is not correctly auto-detecting the active channels, possible due to extreme power changes (burst on/off), you can override the threshold level by using the Active Channel Threshold parameter on the Advanced tab [MeasSetup > cdma2000/1xEV-DV Demod Properties > Advanced tab].