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Marcus Dias vmarcusv at gmail.com>It sounds like you need a raw IQ sampled binary file at about 5 Msps. >Is that correct? Thanks a lot for your hints! If my math (sampling theorem) is not wrong, because I need a bandwidth of 5 MHz (assuming only downstream transmission, given I will not use upstream), it would require 5 Msps in case each sample is a complex number or 10 Msps in case the samples are real-valued. >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. That is a good starting point. But I would need to increase the number of 200 kHz to reach a total of 5 MHz. >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. Yes, exactly: just a test file. I am still studying the GSM PHY and I suspect if I simply position the ARFCNs in different frequencies I will end up with an invalid GSM signal (that is, it will not be properly decoded by the Keysight VSA equipment that I have to interface to). Marcus Dias UFPA - Lasse - LaPS 2017-05-09 15:41 GMT-03:00 Tom Tsou <tom at tsou.cc>: > Hi Marcus, > > On Tue, May 9, 2017 at 9:53 AM, Marcus Dias <vmarcusv at 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 > -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.osmocom.org/pipermail/openbsc/attachments/20170511/69a0dbf9/attachment.htm>