Cellular Network Infrastructure » Radio Access Network » OsmoTRX

{{>toc}}

h1. LimeSDR

The LimeSDR is a low-cost SDR board featuring the Lime Microsystems LMS7002 RF chip.

h2. RF Power

h2. Clock

The on-board clock is a 250ppb VCTCXO.  GSM strictly requires 30ppb, but 250ppb _should_  be sufficient for laboratory use.

h3. Clock Calibration

TBD

h3. Using external clock reference

TBD

h2. OsmoTRX on LimeSDR

In terms of OsmoTRX support, you will a relatively complex driver stack consisting of:

* "LimeSuite":https://github.com/myriadrf/LimeSuite.git containing the actual drivers and utilities for LimeSDR

* "SoapySDR":https://github.com/pothosware/SoapySDR.git as middleware that wraps LimeSuite

* "SoapyUHD":https://github.com/pothosware/SoapyUHD.git as plug-in exposing SoapySDR devices to UHD

* UHD as the driver interface below OsmoTRX

You will need to observe the following dependencies when building the above:

# SoapyUHD depends on SoapySDR

# LimeSuite depends on SoapySDR.

h3. Verifying the driver stack

You can ensure that LimeSuite recognizes your device using the *LimeUtil* part of LimeSuite:

<pre>

$ LimeUtil --find                109/0/0

  * [LimeSDR-USB, media=USB 3.0, module=STREAM, addr=1d50:6108, serial=0009060B00xxyyzz]

</pre>

You can ensure that SoapySDR and LimeSuite work together as expected using the *SoapySDRUtil* part of SoapySDR:

<pre>

$ ./SoapySDRUtil --find                  101/0/0

######################################################

## Soapy SDR -- the SDR abstraction library

######################################################

linux; GNU C++ version 6.3.0 20170221; Boost_106200; UHD_003.009.005-0-unknown

Found device 0

  addr = 1d50:6108

  driver = lime

  label = LimeSDR-USB [USB 3.0] 9060B00462B1C

  media = USB 3.0

  module = STREAM

  name = LimeSDR-USB

  serial = 0009060B00xxyyzz

</pre>