N5161A/62A/81A/82A/83A MXG Signal Generators User's Guide

Custom Digital Modulation (Option 431)Using Finite Impulse Response (FIR) Filters in ARB Custom ModulationUsing Finite Impulse Response (FIR) Filters in ARB Custom ModulationFinite Impulse Response filters can be used to refine the transitions between symbol decision pointsof the generated waveforms.Figure 11-12 Filter MenuMode > ARB Custom Modulation > Single Carrier Setup > FilterAvailable only when the filter selected =Root Nyquist or NyquistThis softkey changes, dependingon the selected filter–type.Only applies to DualARB Modulation. Referto page 139.Available only when thefilter selected = GaussianOpens the IS–95filter selectionmenu.page 284Thisreplaces thecurrent FIRfilter with thefactoryinstalleddefault filtersettings forthe currentmodulationtype.For details on each key, use key help as described on page 42.Creating a User–Defined FIR Filter Using the FIR Table EditorIn this procedure, you use the FIR Values table editor to create and store an 8–symbol, windowedsync function filter with an oversample ratio of 4.Accessing the Table Editor1. Press Preset.2. Press Mode > ARB Custom Modulation > Single Carrier Setup > Select > Nyquist.3. Press Filter > Define User FIR.4. Press More 1 of 2 > Delete All Rows > Confirm Delete of All Rows.This will initialize the table editor as shown in Figure 11- 13.Agilent N5161A/62A/81A/82A/83A MXG Signal Generators User’s Guide 279