LTE FDD/TDD Signal Analyzer Measurement Guide : LTE Analyzer (Option 883) : LTE Control Channel
 
LTE Control Channel
To select control channel measurement go to main menu and press MEASURE > MEASUREMENT >Control Channel. The control channel measurements are set up using the SETUP Menu (LTE Control Channel). LTE control channel measurement shows the power levels of key physical layer control channels and can evaluate active antenna systems for dynamic physical layer attributes and received power levels. An example LTE control channel measurement is shown in Figure: LTE Control Channel Measurement.
 
LTE Control Channel Measurement
1. LTE Analyzer Status Panel: Each measurement features a unique status panel that displays settings and information relevant to the current measurement and view settings. This panel provides quick access to the MIMO antenna selection and status, NG parameter, sweep setting, and channel bandwidth configuration. See Status Panel (LTE Control Channel).
2. PCI SUMMARY: This area shows the physical cell ID, including the sector ID, cell group number, frequency error, time offset, cyclic prefix, and sync status. Sync status can indicate if there is a PSS or SSS failure, a Full Sync, or an Unknown condition. Also noted is the instrument’s reference clock accuracy of Internal, External, or GNSS (GPS) high accuracy (requires GPS).
3. POWER: Shows power levels in dBm and watts of each physical layer control:
• Reference Signal (RS) Power: The reference signal is used for downlink channel estimation.
• Primary Synchronization Signal (P-SS) Power. The primary sync signal is used to obtain slot synchronization. It contains information needed for cell search.
• Secondary Synchronization Signal (S-SS) Power: The secondary sync signal is used to obtain frame synchronization and cell identity. It contains information needed for cell search.
• Physical Broadcast Channel (PBCH) Power: This physical channel carries system information for user equipment (UE) requiring access to the network.
• Physical Control Format Indicator Channel (PCFICH) Power: This channel provides information to enable the UE to decode the PDCCH and PDSCH channels.
• Physical Hybrid Automatic Repeat Request Indicator Channel (PHICH): Transmits the channel coded HARQ indicator codeword used for error correction.
• Physical Downlink Control Channel (PDCCH): Physical channel that carries downlink control information (DCI) such as scheduling assignments and other control information.
• TOTAL: Displays total POWER/RE (power per resource element) and POWER in dBm and watts. The total power for a signal is calculated as the product of the EPRE (Energy per Resource Element) for the signal and the number of REs in one unit (sub-frame, half-frame, or frame) depending on periodicity of the signal in the frame (signal present in every sub-frame, half-frame, or frame), averaged over the number of symbols in the same unit over which REs are counted. Total EVM is not calculated.
4. SETUP Menu: The control channel measurement settings are configured in the SETUP menu. See SETUP Menu (LTE Control Channel).
SETUP Menu (LTE Control Channel)
The control channel SETUP menu is available in MEASURE > MEASUREMENT > Control Channel > SETUP.
SETUP Menu (LTE Control Channel)
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ANTENNA
Sets the MIMO antenna number (0 to 3, or AUTO) to use during a measurement. AUTO will use the antenna with the highest received signal power.
CYCLIC PREFIX
Sets the cyclic prefix (or guard time interval) to Normal, Extended, or Auto. The cyclic prefix is a duplication of a fraction of the symbol end. This setting affects the OFDM symbol sensitivity to time dispersion.
DUPLEX TYPE
Selects either frequency division duplex (FDD) or time division duplex (TDD).
UL/DL CONFIG
Available only in TDD duplex type. Sets the uplink/downlink (UL/DL) configuration, or Frame Format. This selection determines which sub-frames are uplink sub-frames and which are downlink sub-frames, and where the transitions between uplink and downlink sub-frames occur.
CFI
Selects the control format indicator (CFI) which indicates how many OFDM symbols are used for carrying the control channel at each sub-frame. CFI1 uses the first symbol at the sub-frame for PDCCH allocation. CFI2 uses the first and the second symbol for PDCCH. CFI3 uses the first three symbols for PDCCH.
NG: Selects the NG parameter of 1/6, 1/2, 1, or 2. NG is a parameter that determines the number of PHICH (Physical Hybrid ARQ Indicator Channel) groups in an LTE sub-frame (this number is constant for all sub-frames).
PRESET SETUP
Presets the SETUP menu to default settings.
Status Panel (LTE Control Channel)
The status panel illustrated in this section is unique to the current analyzer and to the particular measurement and view that is selected. Figure: Status Panel with Minimized Status Panel Icons (LTE Control Channel Measurement) shows the LTE status panel with minimized status panel icons that covers the LTE control channel measurement.
Status Panel with Minimized Status Panel Icons (LTE Control Channel Measurement) 
 
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.
NG: Selects the NG parameter of 1/6, 1/2, 1, or 2. NG is a parameter that determines the number of PHICH (Physical Hybrid ARQ Indicator Channel) groups in an LTE sub-frame (this number is constant for all sub-frames).
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.
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.