I was listening to Radio Kuwait on 15540 kHz and looking around the DDC spectrum when I spotted a DRM signal. As you can see, signal power steadily increased, with snippets of audio decodable beginning 18:46 UTC.
At the time, the suppressed carrier was slightly below 15120 kHz, more like 15119.78 kHz. Over the course of the broadcast it would drift higher.
Beginning 19:00 UTC, REE came on, and its upper edge occasionally bled into the lower edge of the DRM signal. The above was my futile attempt to adjust the demodulation window to mitigate some of that bleed, but there's not much to be done about co-channel interference.
The effect of a relatively high power bleed is apparent on the per-subcarrier SNR plot, knocking down the first 10 or so subcarriers. Overall SNR is marginal so this results in lost audio frames.
Towards the last half hour SNR went up to the point where co-channel interference didn't really do a lot of damage.
That said, actual audio quality was trash. It's overmodulated to the point of unintelligibility at times, and is generally unpleasant to listen to. The only decent part was a recorded phone interview, and only the interviewee had any kind of clarity. Step away from the damn microphone or something.
Also, 13.08 kbps on 64-QAM? Just use 14.06 kbps 16-QAM like Vatican Radio did before they stopped broadcasting.
Also, 13.08 kbps on 64-QAM? Just use 14.06 kbps 16-QAM like Vatican Radio did before they stopped broadcasting.
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