Nokia LTE RRM Framework consists of RRM building blocks, RRM functions and RRM algorithms. L3 RRM: ICIC: Selects certain parts of the Frequency Spectrum of the LTE Carrier. Exclusively for PDSCH and PUSCH on Cell Basis. Remaining channels not affected. DRX/DTX algorithm: To support provisioning of measurement gaps for Inter-RATHO and DRX/DTX mode in later product releases. Not supported in RL09. Differences with RRM WCDMA: • Softer and Soft handovers are not supported by the LTE system • LTE requirements on power control are much less stringent due to the different nature of LTE radio interface i.e. OFDMA (WCDMA requires fast power control to address the “Near-Far” problem and intra-frequency interferences) • On the other hand LTE system requires much more stringent timing synchronization for OFDMA signals.
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LTE FDD RRM Overview
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LTE FDD RRM Overview
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LTE FDD RRM Overview
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LTE FDD RRM Overview
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LTE FDD RRM Overview
RL30
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LTE FDD RRM Overview
RL40
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LTE FDD RRM Overview
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LTE FDD RRM Overview
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LTE FDD RRM Overview
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LTE FDD RRM Overview
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LTE FDD RRM Overview
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LTE FDD RRM Overview
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LTE FDD RRM Overview
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LTE FDD RRM Overview
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LTE FDD RRM Overview
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LTE FDD RRM Overview
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LTE FDD RRM Overview
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LTE FDD RRM Overview
RL30
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LTE FDD RRM Overview
• High interference from neighboring cells in downlink direction leads to bad end user experience. • Effect on throughput due inter cell interference. • Reference Signal power de-boosting is an extension of feature LTE430 DL power boosting for control channels. • DL power boosting for control channels allows to increase the transmit power of cell specific reference signals in order to increase the cell coverage in downlink direction. • Reference Signal power de-boosting allows to reduce the power of cell specific reference signals by -3dB leading to reduction in interference. RL70
The cyclic delay operation for the second antenna causes a linear phase shift along the frequency dimension. Thus, summing the cyclically delayed signal in the receiver and the un-delayed signal from the first antenna causes a frequency selective fading pattern UE provides feedback in terms of: CQI Rank Indication (RI) – number of layers to use Precoding Matrix Indicator (PMI) – set of weights to apply during precoding
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LTE FDD RRM Overview
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LTE FDD RRM Overview
Note: CQI adaptation needs to be supported/enabled ;Tx diversity needs to be supported/enabled. MIMO This feature was introduced in RL10. In LTE70, ①UE radio capabilities, and ②UE CQI, and ③UE rank information, are considered. Performance counter for transmission mode usage is supported per cell
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LTE FDD RRM Overview
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LTE FDD RRM Overview
• DL adaptive closed loop MIMO (4x2) supports Transmit Diversity for 4 antenna ports in Transmission Mode 4 (TM4) and in Transmission Mode 2 (TM2). • 3GPP has specified open loop Transmit Diversity using one codeword: Precoding Feedback and Rank Information is not required! • Transmit Diversity using 4 antenna ports is used whenever there is no valid, complete and consistent Channel State Information available as detected by eNodeB. • During Initialization when RRC setup is performed • No update of valid CSI reports for single layer (RI=1) and dual layer (RI=2) transmissions since a characteristic update time. • UE does not send valid reports (e.g. Category 1 UEs). Transmit Diversity for 4 antenna ports is implemented as a combination of SFBC (Space Frequency Block Coding) with FSTD (Frequency Switched Time Diversity). RL50
