FAQs from Rohde & Schwarz

CQI (Chanel Quality Identifier) report from UE and coresponding mapping of Modulation and TBS tests on CMW500 / CMW290


How can the CQI (Chanel Quality Identifier) from UE and coresponding 3GPP specified mapping to Modulation and TBS be tested?


  • Setup the LTE Signaling cell to a high RS EPRE level so that there is a good reception level on the UE.
  • Configure "CQI-PMI-RI" and "Follo2 CQI (TM1..9)" as scheduling type.
  • To follow the 3GPP modulation sceem and TBS size mapping tabel that corresponse with the reported CQI value from the UE Table-Mod /TBSI has to be set to "Acc. to 3GPP"".
  • Enable UE Measurement Report
  • Switch the LTE Signaling Cell
  • After UE has attached press "Connect" softkey to establish a connection
  • Start LTE RX Measrument and select "CQI Reporting" via the Select View soft key

When the signal quality is good the UE will report CQI = 15 and will use maximum TBS and highest supported Modulation:

When the the signal quality went down (reduction of RS EPRE level) the UE will report lower CQI value and CMW reduced TBS and downgrade the used Modulation: