Result Length, Start Boundary and Analysis Parameters (TD-SCDMA)

Default: (See TD-SCDMA Standard Setups/Presets Table.)

The Result Length, Start Boundary, Analysis Sub frame, and Analysis Timeslot parametersneed to be specified to completely define the region of the TD-SCDMA frame that is demodulated and analyzed.

Result Length determines the signal capture length in terms of sub frames. This is the data used by the VSA for demodulation and signal analysis. Make sure that the result length is long enough to capture all the desired data.

Start Boundary specifies when to start the Result Length data capture. The Start Boundary can be specified as Sub-frame or 2 frames (see Selecting a Start Boundary below):

Sub-frames Starts the result length data capture at the first demodulated sub-frame.

2 Frames: Starts the results length data capture at even numbered frames.

The VSA acquires enough data to ensure that the Start Boundary and the specified Result Length data will be captured.

Analysis Sub-frame specifies which sub-frame, within the acquired Result Length, is used for analysis and trace data measurement results. The available selections include the acquired sub-frames.

Analysis Timeslot specifies which sub-frames timeslot, within the selected Analysis Sub-frame, is used for analysis and trace data measurement results. The available selections include timeslots 0 through 6, the DwPTS and UpPTS timeslots.

Selecting a Start Boundary

$image\TDsCDMA_StartBoundry_wmf.jpg$

To automatically specify the Timeslot and Sub-frame information, use the Copy Mkr To Analysis TS/SF marker feature: from the Overall Time trace data display, simply right click on the trace display and select Copy Mkr To Analysis TS/SF.

Data Analysis Example

The following example shows how to set the Result Length, Start Boundary, Analysis Sub-frame and Analysis TimeSlot parameters to specify timeslot 3 in Sub-frame number 1 as the Analysis Timeslot:

$image\TDsCDMA_ResultLen_wmf.jpg$

Start Boundary = Sub-frame

Result Length = 2 Sub-frames

Analysis Sub-frame = 1

Analysis Timeslot = TS3.

Using Triggered Measurements

When making triggered measurements, the demodulation algorithm requires some amount of data prior to the beginning of the desired sub-frame, in order for demodulation to begin on that sub-frame. This is handled internally but if there are delay differences between the sub-frame boundary in the incoming signal and the trigger then the Trigger Delay may need to be adjusted in order to supply enough data before the beginning of the sub-frame. For instance, if an external trigger occurs 20 us after the beginning of the desired sub-frame then Trigger Delay would need to be set to -20 us.