P25 Technical Diagrams

Technical Specifications

Specification

Class A

Class B

Portable Mobile B.Station Portable Mobile B.Station
Reference Sensitivity (dBm) -116 -116 -116 -116 -116 -116
Adjacent Channel Reject. (dBc) -60 -60 -70 -50 -60 -70
Spurious Response Reject. (dBc) -70 -80 -90 -60 -70 -70
RX Audio Distortion 5% (-26dB)
Carrier Freq Error (ppm)  
< 100 MHz 5 5 2.5 5 5 5
100 < = > 225 MHz 2.5 2.5 1.5 2.5 2.5 1.5
225 < = > 250 MHz 2.0 2.0 0.5 2.0 2.0 0.5
520 < = > 896 MHz 1.5 1.5 0.15 1.5 1.5 0.15
896 < = > 1000 MHz 1.5 1.5 0.1 1.5 1.5 0.1
Conducted Spur. Emis. (dBm) -13 -13 -13 -13 -13 -13
Adjacent Channel Power (dBc) -70 -70 -70 -70 -70 -70
Mod. Fidelity for C4FM (AM %) 5.0 5.0 5.0 5.0 5.0 5.0
Mod. Fidelity for CPQSK (EVM %) 6 6 6 12.5 12.5 12.5
IQ Origin Offset (dB) -25 -25 -30 -20 -20 -25
Low Speed Data 88.89 Bits Per Second (4 Octets every 360 ms)
Rate of Modulation 4800 Symbols Per Second (2 bits per Symbol)

Talk Around Configuration

Downlink Frame Structure

Dibit Symbol Mapping to Modulation Phase or Deviation
Information
Bit Symbol
Symbol CPQSK
Phase Change
C4FM
Deviation
01 +3 +135 +1.80 kHz
00 +1 +45 +0.60 kHz
10 -1 -45 -0.60 kHz
11 -3 -135 -1.80 kHz