LTE FDD/TDD Signal Analyzer Measurement Guide : LTE Analyzer (Option 883) : LTE Adjacent Channel Power
 
LTE Adjacent Channel Power
To select Adjacent Channel Power (ACP) measurement go to main menu and press MEASURE > MEASUREMENT. The ACP measurements are set up using the SETUP Menu (LTE ACP). Adjacent channel power is a measure of the power that leaks into adjacent transmit channels. The ACP measurement measures the power present in the transmit channel (refer to LTE Channel Power) along with the adjacent transmit channels that have been configured in the SETUP menu.
Adjacent Channel Power Ratio Measurement
1. The status panel provides quick access to common spectrum analyzer settings. See STATUS PANEL (LTE ACP).
2. Green integration bandwidth edge of lower alternate channels.
3. Red integration bandwidth edge of lower adjacent and alternate channels.
4. Blue integration bandwidth edge of lower main and adjacent channels.
5. The ACP measurements parameters are setup suing setup menu. See SETUP Menu (LTE ACP).
Frequency and span settings for many signal standards can be set as follows:
1. Select MEASURE on the main menu.
2. Select ACP from the MEASUREMENT button.
3. Select SETUP and then do the following:
• Channel spacing
• Main integration bandwidth
• adjacent integration bandwidth
• alternate integration bandwidth
• Limit testing
• Main channel limit
• adjacent channel limit
• alternate channel limit
Adjacent channel power is a constant measurement; after it is turned on, it remains on until a different measurement is selected or the sweep is paused. ACP is calculated at the end of each sweep.
SETUP Menu (LTE ACP)
The Adjacent Channel Power SETUP menu is available in MEASURE > MEASUREMENT > ACP > SETUP. Once the ACP measurement is selected, the SETUP menu can be quickly accessed by tapping on the summary display area below the spectrum window.
SETUP Menu (ACP)
 
CHANNEL SPACING
Sets the channel frequency spacing (center channel to center channel).
MAIN INTEG BW
Sets the range of integration used in calculating the power within the channel. The integration bandwidth (IBW) is displayed as two vertical dashed lines for each channel.
ADJ INTEG BW
Sets the range of integration bandwidth used in calculating the power in the adjacent channel.
ALT INTEG BW
Sets the range of integration used in calculating the power in the alternate channel.
LIMIT TYPE
Selects Absolute or Relative for the limit evaluation.
LIMITS
Turns on or off the use of ACP limits.
MAIN CH LIMIT
Sets the main channel limit.
ADJ CH LIMIT
Sets the adjacent channel limit.
ALT CH LIMIT
Sets the alternate channel limit.
PRESET SETUP
Sets all ACP setup parameters to default. Turns off limits.
 
STATUS PANEL (LTE ACP)
Below is the status panel with the corresponding minimized status panel icons for adjacent channel power measurement.
Status Panel with Minimized Status Panel Icons (Adjacent Channel Power)
 
MIMO ANTENNAS: Toggles the current MIMO antenna setting between AUTO or to select one of the available antennas. When a single antenna is selected, a blue underscore will appear below the antenna icon. The antenna icon is highlighted green when receiving a signal.
SWEEP: Toggles the current sweep setting between continuously or sweep once.
SWEEP ONCE
When sweep is set to single sweep, SWEEP ONCE updates the measurement display. Data continues to be captured in the background.
REF LEVEL
Sets the reference level of the top graticule line in the selected units. If the reference level offset is not zero, OFFSET REF LEVEL is displayed at this location. Refer to Setting Amplitude.
SCALE/DIV
Sets the graticule scale/division for log-based units. This setting does not apply to linear units.
CHANNEL BW
Sets the measurement channel bandwidth. The available bandwidth settings depend on the selected band and bandwidth option installed in the instrument.
CENTER FREQUENCY
Sets the center frequency of the measurement channel.
ATTEN LEVEL
When auto attenuation is off, sets input attenuation.
PRE AMP
Toggles the low-noise front-end preamplifier on or off. Refer to Setting Amplitude.
TRACES
Displays the current status of up to six traces in a quick-view summary. The summary information includes the trace number, type, mode, and detector type. The active trace will show a highlighted background with the mode and detector type restated under the table. Pressing a trace in the summary panel activates the pressed trace and opens the TRACE menu, which allows you to select and set up an individual trace as desired. Refer to Setting Trace Parameters.
FREQ REFERENCE
Indicates the current frequency reference source of Internal, External, or GNSS (GPS) Hi Accuracy (requires GPS). The instrument automatically selects the frequency reference in the following order of priority: external, GNSS (GPS), then the internal time base.