APCO-25 Standard (Digital Demod)

APCO-25 is a collection of standards developed and promoted to provide interoperability and efficient spectrum usage for digital public safety radio applications (police, fire, etc.).

The Digital Demodulator provides presets for the following APCO-25 modulation types:

Phase 1 C4FM (APCO 25) modulation format analysis using the FSK modulation format
Phase 2 HCPM (APCO 25 P2 (HCPM)) modulation format analysis using the CPM (FM) modulation format
Phase 2 HDQPSK (APCO 25 P2 (HDQPSK)) modulation format analysis using the FSK modulation format

The demodulator settings for each of these presets is listed in Using Standard Setups.

Several filters have been included specifically for use with HCPM and HDQPSK signals. They are 1REC, 3RC, 4RC, and APCO-25 Phase 2 RC Filter.