Freedom R8100 SERIES, Руководство оператора

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Deviation (RF Zone display)
Displays the positive peak frequency deviation of the received modulated carrier (i.e. from the Frequency
Error mean). See negative peak frequency deviation with Display Zone Bar Graphs.
2.2.7.9.1.2 P25 II Zone
Test Pattern (P25 II submenu)
Provides selection for one of 3 TIA-102.CCAA compliant predefined test patterns for BER testing of a
P25 radio in monitor mode as shown in Figure 2.2.7.3.1.2-1. Each measurement uses an ultraframe of
data. Outbound uses 10880 bits (0.009%/bit); inbound uses from 7252 to 7536 bits (~0.013%/bit) if there
is no random-access SAACH to exclude. The following patterns are available:
Figure 2.2.7.9.1.2-1 Test Pattern submenu in P25 II Monitor mode
1031 Hz Tone – The standard tone framed test pattern of the 1031 Hz vocoder tone for either modulation
type and both logical channels.
Calibration (Tone 5%) – The test pattern derived from the standard 1031 Hz Tone test pattern to verify
BER measurements are operating correctly, for either modulation type and both logical channels. The 1st
of every 20 bits is inverted. However, the inbound BER is 4.992% if a random-access SACCH is received
or 4.989% if not (rather than 5% since some of the 20 bits are not to be included in the comparison).
Silence – The framed test pattern for silence at the vocoder for either modulation type and both logical
channels.
Modulation Type (P25 II submenu)
Select the expected type of modulation of the received signal to be analyzed: HCPM (inbound) or
HDQPSK (outbound). The type specified is also used in the Display Zone to enable selection of the Power
Profile for inbound frames.
Modulation Fidelity (P25 II Zone display)
Modulation Fidelity represents how accurate a P25 transmitter reproduces an ideal theoretical modulation
waveform. The measurement is performed by first removing frequency error and symbol deviation gain
error from the received signal then computing the RMS difference between the deviation of the resulting
signal at each symbol decision point and the ideal deviations of those symbols; there should be no bit
errors. On the R8100 this is computed over a symbol interval (180 for HDQPSK; 164 for HCPM) and
reported as an RMS error in % normalized across symbols.
Symbol Deviation (P25 II Zone display)
Displays the symbol deviation estimated by averaging the normalized frequency deviations (of the FM
representation of the phase-based modulation) at symbol times in the received signal and then scaling by
the maximum symbol value. The normalized frequency deviation is computed as the ratio of the actual
frequency measurement at a given symbol or deviation state by the corresponding symbol value. The
HCPM ideal is 2992 Hz; since symbol decisions are based on 60° phase changes they do not correspond
to four frequency deviations. The HDQPSK ideal is 2250 Hz.