Channel power measures the average time domain power within the selected bandwidth and is expressed in dBm. Received Signal Strength Indicator (RSSI) is vendor‑defined and is often the same as Channel Power.
The Error Vector Magnitude is the ratio in percent of the difference between the reference waveform and the measured waveform. EVM metrics are used to measure the modulation quality of a transmitter. Both rms and peak values over the downlink portion are displayed (the preamble portion is excluded for this measurement).
Relative Constellation Error is similar to EVM but is expressed in dB (RCE = 20 log (EVM in % ⁄ 100)). Both rms and peak values over an entire downlink subframe are displayed. (The preamble portion is excluded for this measurement).
Carrier frequency is the measured frequency of the input signal after demodulation, and is the same as the tuned center frequency of the instrument plus the measured frequency error from demodulation.
Three cell sectors may produce signals with different preambles. The Sector ID may be 0, 1, or 2. The Sector ID is displayed in several of the Demodulator measurement screen.
Carrier to Interference-plus-Noise Ratio (CINR), expressed in decibels (dBs), is a measurement of signal effectiveness. The carrier is the desired signal, and the interference can either be noise or co-channel interference or both. In order for the signal receiver to be able to decode the signal, the signal must fall into an acceptable CINR range.
Physical CINR is an estimate of C / (N+I) ratio on non-boosted data sub-carriers. It is calculated by measuring the power of the sub-carriers in the preamble (where the sub-carrier allocations are known for the primary BS and interfering BS). The power of the primary preamble detected is used as the carrier power (C). The power of all the other interfering preambles is used as the interference power (I) and the noise (N) is measured using the power in the guard interval.
This measurement displays the six strongest preamble signals in bar graph form. The Preamble Index, Relative Pwr, Cell ID, and Sector ID are listed for each preamble signal. The PCINR, calculated from all six preambles, and the Base Station ID, of the strongest preamble signal, are listed below the table.
