This example uses both channels of USRP® B210, X300 or X310 to receive an LTE downlink signal. Then, the example uses the LTE Toolbox™ to perform the cell search procedure and to decode the master information block (MIB) and system information block type 1 (SIB1) messages if present.
LTE Toolbox provides functions and tools to decode LTE waveforms. This example shows how to capture an LTE waveform by using a software-defined radio (SDR) hardware such as a USRP®-based radio, then analyze and decode the signal. This example searches for the presence of a suitable LTE signal in the captured waveform, then, if found, decodes the MIB and SIB1 messages.
This example decodes the MIB for a burst of captured frames, and then decodes the control format indicator (CFI) for each subframe, which informs the user equipment (UE) of the size of the control region. Then, the example decodes the physical downlink control channel (PDCCH) and, finally, recovers the SIB1 message in the physical downlink shared channel (PDSCH).
The example recovers cell wide information including the detected cell identity and checks the SIB1 CRC. The example also plots the signal spectrum, the PDCCH constellation and the magnitude of the channel estimate.
If you have a second SDR platform, you can generate a suitable signal by using the Two-Antenna LTE SIB1 Transmission Using USRP®-Based SDR example.
Use the Add-On Explorer to install the required support package.
More information about other supported SDR platforms can be found here.
The full example description and source code can be found in the Communications Toolbox Support Package for USRP Radio documentation under the name LTE Cell Search, MIB and SIB1 Recovery with Two Antennas (Communications Toolbox Support Package for USRP Radio).
Universal Software Radio Peripheral® and USRP® are trademarks of National Instruments Corp.