PRC-16 is a Chinese sourced PSKPhase-Shift Keying data link, traced to Shanghai. Suspected user Chinese Military. A woman speaking Chinese has been heard on this frequency before.
An idle tone that repeats every 720ms is possibly a marker to keep the channel free from interfering operators. The data portion of the signal always occurs in a burst, and follows a very similar format to MIL-STD-188-110 App.A 16-tone OFDM, only lacking the pilot tone. PRC-16 has been seen using BPSKBinary Phase-Shift Keying (1 bit per symbol) modulation in its subcarriers at 75bd each. Each burst lasts about 1150 msmilliseconds (.001 of a second) (600ms for preamble, 550ms for the 16x75 BPSKBinary Phase-Shift Keying (1 bit per symbol) waveform). An interesting characteristic is the 4xBPSK mode right after the toned preamble but before the 16x75 waveform.