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Cellular COMMUNICATIONS

Cellular COMMUNICATIONS. LTE. Data Rate. Requirements And Targets to LTE. reduced delays, in terms of both connection establishment and transmission latency; increased user data rates; increased cell-edge bit-rate, for uniformity of service provision;

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Cellular COMMUNICATIONS

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  1. Cellular COMMUNICATIONS

  2. LTE

  3. Data Rate

  4. Requirements And Targets to LTE • reduced delays, in terms of both connection establishment and transmission latency; • increased user data rates; • increased cell-edge bit-rate, for uniformity of service provision; • reduced cost per bit, implying improved spectral efficiency; • greater flexibility of spectrum usage, in both new and pre-existing bands; • simplified network architecture; • seamless mobility, including between different radio-access technologies; • reasonable power consumption for the mobile terminal

  5. Cell/User Throughput • Average cell throughput [bps/cell] and spectral efficiency [bps/Hz/cell]. • Average user throughput [bps/user] and spectral efficiency [bps/Hz/user]. • Cell-edge user throughput [bps/user] and spectral efficiency [bps/Hz/user]. • The metric used for this assessment is the 5-percentile user throughput, obtained from the cumulative distribution function of the user throughput.

  6. Key Performance Requirements

  7. Key Performance Requirements

  8. Multiple Antenna Technology • Diversity gain. Use of the space-diversity provided by the multiple antennas to improve the robustness of the transmission against multipath fading. • Array gain. Concentration of energy in one or more given directions via precoding or beamforming. This also allows multiple users located in different directions to be served simultaneously (so-called multi-user MIMO). • Spatial multiplexing gain. Transmission of multiple signal streams to a single user on multiple spatial layers created by combinations of the available antennas.

  9. MIMO

  10. Packet-Switched Radio Interface • Completely Packet Oriented Systems

  11. LTE User Equipment

  12. Network

  13. The Access Network

  14. Bearers • Minimum Guaranteed Bit Rate (GBR) bearers which can be used for applications such as VoIP. • have an associated GBR value for which dedicated transmission resources are permanently allocated • Non-GBR bearers which do not guarantee any particular bit rate. • web browsing or FTP transfer. • bandwidth resources are allocated permanently to the bearer.

  15. QoS

  16. Handover

  17. Lossless Handover

  18. Logical and Physical Channel

  19. Discontinuous Reception(DRX) • Reduce time in a reception mode in order to save battery

  20. Logical Channel Priority

  21. OFDM

  22. OFDM

  23. Peak-To-Average Power Ratio • PAPR • Power amplifiers that are linear at wide range of inputs are costly • Handset: Reduce PAPR

  24. OFDMA

  25. OFDMA/TDMA

  26. Physical Layer

  27. Channel Estimation • Transmission distort the signal and add noise • If transmitted signal is known, can estimate distortion and apply inverse transformation on other signals • Reference signal

  28. Reference Signal

  29. Two antennas

  30. Link Adaptation

  31. Channel Quality Indicator

  32. Multiple Antenna

  33. Multiple Antenna

  34. Optimal Power Allocation

  35. Multi-User Scheduling

  36. Resource Scheduler

  37. Partial Frequency Reuse

  38. Partial Frequency Reuse

  39. Handover

  40. Evolution of the Radio Interface Standards availability EDGE EDGE+ 1Mb/s 384Kb/s W-CDMA HSPA HSPA+ 384Kb/s 18Mb/s 42Mb/s LTE LTE-Advanced 1000Mb/s 100Mb/s 2000 2010 40

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