The following parameters are measured in the Modulation Measurement mode.

This measurement displays the Power vs RB grid, an RB Color Map, the measurements table, and measurement progress bar. See Figure: Power versus Resource Block Measurement View.

Shows the PDSCH power of each RB using color. The y‑axis is frequency (sub‑carriers) and the x‑axis is time (sub‑frame). There are ten columns for the ten sub‑frames. The number of subcarriers varies depending on the bandwidth chosen and hence the number of RBs on the y‑axis. Each cell in the grid corresponds to a particular RB in a particular sub‑frame. As the measurement progresses, each sub‑frame is measured and the cells in the grid are colored according to the PDSCH power in the RB.

The color mapping of the RB power level is determined by the RB Color Map Max Value and RB Color Map Range submenus. Setting these values can be done by entering them manually or by pressing Autoscale Color Map.

This progress bar indicates the sub‑frame that is currently being measured.

Markers are available for use in the Power vs Resource Block measurement. The markers will outline the selected RB. Above the two-dimensional grid, the specific RB subcarrier/sub‑frame coordinates will be displayed along with its power level.

This measurement displays the constellation of the demodulated symbols over the first sub‑frame and a results table of the measurements described below. See Figure: Constellation Measurement View.

Reference Signal power displayed in dBm or Watts. The reference signal is used for downlink channel estimation.

The RMS (%) of all the error vectors, between the reconstructed ideal signals and the received signals, divided by the RMS value of the ideal signals. When EVM Max Hold is On (Setup menu), two values are displayed. The first number is the maximum EVM (rms) value since Reset and the second number is the current measured value. Reset occurs when setup parameters are changed or by toggling the EVM Max Hold button.

The difference between the measured carrier frequency and the specified carrier frequency is the frequency error. This number is only as accurate as the frequency reference that is used, and is typically only useful with a good external frequency reference or GPS.

Carrier Frequency is the measured transmitter operating center frequency.

Sync signal power displayed in dBm or Watts.

The peak (%) of all the error vectors, between the reconstructed ideal signals and the received signals, divided by the RMS value of the ideal signals. When EVM Max Hold is On (Setup menu), two values are displayed. The first number is the maximum EVM value since Reset and the second number is the current measured value.

Freq Error displayed in parts per million (ppm).

Cell identifying information sent by the transmitter in the sync signal.

This measurement shows the power levels of key physical layer Control Channels and also includes the numerical results table described in the Constellation section above. EVM per control channel is also available (see Figure: Control Channel Power), as well as a table view showing the power in both per-resource-element and total power formats. Refer to Control Channel Power Menu.

Reference Signal power displayed in dBm. The reference signal is used for downlink channel estimation.

Primary Sync Signal power displayed in dBm or Watts. The primary sync signal is used to obtain slot synchronization. It contains information needed for cell search.

Secondary Sync Signal power displayed in dBm or Watts. The secondary sync signal is used to obtain frame synchronization and cell identity. It contains information needed for cell search.

Physical Broadcast Channel Power. This physical channel carries system information for user equipment (UE) requiring access to the network.

Physical Control Format Indicator Channel Power. This channel provides information to enable the UE to decode the PDCCH and PDSCH channels.

Physical Hybrid Automatic Repeat Request Indicator Channel. Transmits the channel coded HARQ indicator codeword used for error correction.

Physical Downlink Control Channel.

Ng is a parameter that determines the number of PHICH (Physical Hybrid ARQ Indicator Channel) groups in a LTE sub-frame (this number is constant for all sub-frames).

Measures the delay between the signals from two antennas at the antenna ports.

Modulation Summary displays the Ref Signal (RS) Power, Sync Signal (SS) Power, EVM (rms), Freq Error (Hz and ppm), Cell ID and PBCH Power in a table format. Refer to individual modulation measurement descriptions for additional detail on each measurement.