LTE Interview Questions and Answers

Q01. Why we have more sub-carrier spacing in wifi than lte network?
Q02. Which factors are determines the carrier spacing in OFDM systems?
Q03. Why we are using SC FDMA in LTE uplink instead of OFDMA
Q04. What is [PSS] and [SSS]. Explain what is the use of these?
Q05. What kind of sequences are use in PSS and SSS?
Q06. What kind of parameters we got after decode PSS and SSS
Q07. How does a UE identify that Enodeb is configured for TDD or FDD?
Q08. What kind of information ue will get after decode PBCH?
Q09. How System frame number decoded in PBCH?
Q10. Explain the ATTACH Procedure in LTE?
Q11. What is Downlink control Information (DCI)? Why it use and what kind of information it carry’s?
Q12. Difference between DCI0 vs DCI1a?
Q13. Explain the procedures what happen when a UE is powered on?
Q14. Explain LTE downlink Frame structure?
Q15. How many different-different bandwidths are using in LTE.
Q16. What is carrier aggregation [C.A.] in LTE-Advanced.
Q17. what is Sounding Reference Signal [S.R.S]. Difference between aperiodic and periodic SRS.
Q18. Explain the reasons of radio link failure [rlf] in LTE?
Q19. Explain random access procedure, [RACH] procedure in LTE
Q20. What is the use of Timing Alignement commands from eNB? What happen when the timing alignment timer expire.
Q21. What are MAC control element?
Q22. How many types of Transmission Modes are present in release-9? What kind of informations TM1, TM2, TM3, TM4 modes carries
Q23. Explain all’s downlink physical channels? And the name of some D/L physical channels that are used only in D/L physical layers?
Q24. Explain all’s uplink physical channels? And the name of some U/L physical channels that are used only in U/L physical layers?
Q25. What is the difference betweeen RRC Idle mode and RRC Connected mode?
Q26. What is a Resource block in lte? How many resource blocks are present in different different bandwidth?
Q27. What is discontinuous reception [DRx] mode and why it is used? Explain connected DRX and idle DRX? Who control Drx configuration?
Q28. What do you understand by Scheduling request and what is the need for transmitting [S.R]?
Q29. How many subcarriers are present in each bandwidth of LTE
Q30. How many types of handover will trigger by ue in LTE?