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CELLULAR COMMUNICATIONS
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LTE
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Data Rate
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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
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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.
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Key Performance Requirements
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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.
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MIMO
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Packet-Switched Radio Interface Completely Packet Oriented Systems
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LTE User Equipment
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Network
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The Access Network
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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.
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QoS
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Handover
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Lossless Handover
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Logical and Physical Channel
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Discontinuous Reception(DRX) Reduce time in a reception mode in order to save battery
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Logical Channel Priority
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OFDM
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Peak-To-Average Power Ratio PAPR Power amplifiers that are linear at wide range of inputs are costly Handset: Reduce PAPR
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OFDMA
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OFDMA/TDMA
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Physical Layer
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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
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Reference Signal
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Two antennas
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Link Adaptation
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Channel Quality Indicator
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Multiple Antenna
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Optimal Power Allocation
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Multi-User Scheduling
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Resource Scheduler
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Partial Frequency Reuse
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Handover
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40 Evolution of the Radio Interface EDGE EDGE+ W-CDMA HSPA HSPA+ 2000 LTE LTE-Advanced 40 2010 384Kb/s 1Mb/s 384Kb/s 42Mb/s18Mb/s 100Mb/s 1000Mb/s Standards availability
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