• Table of contents
• LimeSDR
  • RF Output Power
  • Clock
    • Clock Calibration
    • Using external clock reference
  • OsmoTRX on LimeSDR
    • Verifying the driver stack

LimeSDR¶

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

Key characteristics include:

• RF Transceiver: Lime Microsystems LMS7002M MIMO FPRF
• FPGA: Altera Cyclone IV EP4CE40F23 – also compatible with EP4CE30F23
  M* emory: 256 MBytes DDR2 SDRAM
• USB 3.0 controller: Cypress USB 3.0 CYUSB3014-BZXC
• Oscillator: Rakon RPT7050A @ 30.72MHz
• Continuous frequency range: 100 kHz – 3.8 GHz
• Bandwidth: 61.44 MHz
• RF connection: 10 U.FL connectors (6 RX, 4 TX)
• Power Output (CW): up to 10 dBm
• Multiplexing: 2×2 MIMO
• Power: micro USB connector or optional external power supply
• Status indicators: programmable LEDs
• Dimensions: 100 mm x 60 mm

RF Output Power¶

TBD

Clock¶

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

Clock Calibration¶

TBD

Using external clock reference¶

TBD

OsmoTRX on LimeSDR¶

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

• LimeSuite containing the actual drivers and utilities for LimeSDR
• SoapySDR as middleware that wraps LimeSuite
• SoapyUHD 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:

1. SoapyUHD depends on SoapySDR
2. LimeSuite depends on SoapySDR.

Verifying the driver stack¶

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

$ LimeUtil --find                109/0/0
  * [LimeSDR-USB, media=USB 3.0, module=STREAM, addr=1d50:6108, serial=0009060B00xxyyzz]

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

$ ./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