osmo-trx-lms RF Envelope FAIL on LimeSDR, but not on LimeSDR-mini
I'm observing a strange behavior when comparing the RF envelope of osmo-trx-lms on a LimeSDR and a LimeSDR-mini.
The LimeSDR-mini envelope is within spec. Specifically, the transmit power level is at full strength before the start of the next burst.
On the LimeSDR however, the next burst/timeslot starts too late, (or the slew rate is too low?):
This is using the exact same versions of LimeSuite (f1e5444496923890ad7d030abef9c224c37c46cf) and osmo-trx (70621b74844a6ea08d6da5f5b1e1835b9af91771). All I'm doing is swapping the hardware and re-starting osmo-trx-lms and osmo-bts.
It's very odd, and I currently have no clue of what might be going on here.
#2 Updated by laforge about 1 month ago
- Assignee set to roh
roh: please re-perform the LimeSDR (non-mini) tests using a LimeSDR that is clocked from the 10MHz reference of the E4406.
Please also try to modify the ts_offset found in the following line of the source code in osmo-trx/Transceiver52M/device/lms/LMSDevice.cpp:
ts_offset = static_cast<TIMESTAMP>(8.9e-5 * GSMRATE * tx_sps); /* time * sample_rate */