Hi Marcus,
On Tue, May 9, 2017 at 9:53 AM, Marcus Dias vmarcusv@gmail.com wrote:
Most BTS code I have, generate only one or two 200 kHz channels, but I need to test a receiver using several (multiplexed) 200 kHz channels, composing approximately 5 MHz of total bandwidth. This should be a "valid" multiplex signal (correct and "decodable" control channel). Can anyone pointout where should I start to put together the software to generate a binary file with such signal? I guess I can inspect the code of a BTS that supports two TRX (two 200 kHz channels) but I would like to double check whether there is a more direct approach.
It sounds like you need a raw IQ sampled binary file at about 5 Msps. Is that correct?
There are a variety of methods to achieve this depending on your requirements. You could generate the multiplexed signal live with up to 3 adjacent ARFCN channels (800 kHz separation) with a B200 and osmo-trx with multi-ARFCN enabled.
But, it sounds like you just need a test file, so you could post-process an existing single ARFCN signal file in Octave or Matlab to carry multiple versions of the same GSM signal. That may or may not be sufficient depending on your needs.
-TT