Technical data

608 Chapter 20
W-CDMA or W-CDMA (with HSDPA) Over Air
Metrics Provided by the W-CDMA or W-CDMA (with HSDPA) Over Air
Measurement
W-CDMA or W-CDMA (with HSDPA)
Over Air
Metrics Provided by the W-CDMA or W-CDMA (with
HSDPA) Over Air Measurement
This section contains descriptions of the individual W-CDMA or W-CDMA (with
HSDPA) transmitter metrics in the Metrics view of the screen. For expected result
values and possible causes of error if the expected results are not met, see
“Interpretation of Over the Air Measurement Results” on page 612.
Freq (Frequency)
Frequency is the selected transmitter operating frequency you have entered (or
calculated from the channel number you have entered).
Freq Error (Frequency Error)
Frequency error is the frequency difference between your transmitter's actual center
frequency and the frequency (or channel) you entered.
Scramble Code
The Scrambling Code being measured (manual or auto). In W-CDMA or W-CDMA
(with HSDPA), each Access Network (or BTS) output signal is scrambled by
multiplying each of its data channels by a unique pseudo-noise (PN) code. In the
W-CDMA specifications, this is referred to as a Scrambling Code.
Noise Floor
Noise Floor is the average power level of all the inactive channels.
Carr Feedthru or Carr FT (Carrier Feedthrough)
Carrier Feedthrough is a result of the RF carrier signal feeding through the I/Q
modulator and riding on the output circuitry without being modulated.
EVM Pilot and EVM Comp (Pilot (CPICH) and Composite Error Vector
Magnitude
EVM is the measure of signal quality specified as a percent of noise to pure signal.
It is the difference between the measured waveform and the theoretical modulated
waveform (the error vector). EVM metrics are used to measure the modulation
quality of a transmitter. The 3GPP standard requires the Composite EVM not to
exceed 17.5% for normal W-CDMA (defined as Test Models 1 and 4), and not to
exceed 12.5% in the case of 16QAM HSDPA (defined as Test Model 5).