723 |
723 |
724 |
724 |
725 Therefore the PHY layer implements the MIMO model as the gain perceived by the receiver when using a MIMO scheme respect to the one obtained using SISO one. We note that, these gains referred to a case where there is no correlation between the antennas in MIMO scheme; therefore do not model degradation due to paths correlation. |
725 Therefore the PHY layer implements the MIMO model as the gain perceived by the receiver when using a MIMO scheme respect to the one obtained using SISO one. We note that, these gains referred to a case where there is no correlation between the antennas in MIMO scheme; therefore do not model degradation due to paths correlation. |
726 |
726 |
727 |
727 |
728 UE Measurements Model |
728 .. _phy-ue-measurements: |
729 +++++++++++++++++++++ |
729 |
|
730 UE PHY Measurements Model |
|
731 +++++++++++++++++++++++++ |
730 |
732 |
731 According to [TS36214]_, the UE has to report a set of measurements of the eNBs that the device is able to perceive: the the reference signal received power (RSRP) and the reference signal received quality (RSRQ). The former is a measure of the received power of a specific eNB, while the latter includes also channel interference and thermal noise. |
733 According to [TS36214]_, the UE has to report a set of measurements of the eNBs that the device is able to perceive: the the reference signal received power (RSRP) and the reference signal received quality (RSRQ). The former is a measure of the received power of a specific eNB, while the latter includes also channel interference and thermal noise. |
732 The UE has to report the measurements jointly with the physical cell identity (PCI) of the cell. Both measurements are performed during the reception of the RS, while the PCI is obtained with the Primary Synchronization Signal (PSS). The PSS is sent by the eNB each 5 subframes and in detail in the subframes 1 and 6. According to [TS36133]_ sections 9.1.4 and 9.1.7, RSRP is reported by PHY layer in dBm while RSRQ in dB. The values of RSRP and RSRQ are provided to higher layers through the C-PHY SAP (by means of ``UeMeasurementsParameters`` struct) every 200 ms as defined in [TS36331]_. Layer 1 filtering is performed by averaging the all the measurements collected during the last window slot. The periodicity of reporting can be adjusted for research purposes by means of the ``LteUePhy::UeMeasurementsFilterPeriod`` attribute. |
734 The UE has to report the measurements jointly with the physical cell identity (PCI) of the cell. Both the RSRP and RSRQ measurements are performed during the reception of the RS, while the PCI is obtained with the Primary Synchronization Signal (PSS). The PSS is sent by the eNB each 5 subframes and in detail in the subframes 1 and 6. In real systems, only 504 distinct PCIs are available, and hence it could occur that two nearby eNBs use the same PCI; however, in the simulator we model PCIs using simulation metadata, and we allow up to 65535 distinct PCIs, thereby avoiding PCI collisions provided that less that 65535 eNBs are simulated in the same scenario. |
|
735 |
|
736 According to [TS36133]_ sections 9.1.4 and 9.1.7, RSRP is reported by PHY layer in dBm while RSRQ in dB. The values of RSRP and RSRQ are provided to higher layers through the C-PHY SAP (by means of ``UeMeasurementsParameters`` struct) every 200 ms as defined in [TS36331]_. Layer 1 filtering is performed by averaging the all the measurements collected during the last window slot. The periodicity of reporting can be adjusted for research purposes by means of the ``LteUePhy::UeMeasurementsFilterPeriod`` attribute. |
733 |
737 |
734 The formulas of the RSRP and RSRQ can be simplified considering the assumption of the PHY layer that the channel is flat within the RB, the finest level of accuracy. In fact, this implies that all the REs within a RB have the same power, therefore: |
738 The formulas of the RSRP and RSRQ can be simplified considering the assumption of the PHY layer that the channel is flat within the RB, the finest level of accuracy. In fact, this implies that all the REs within a RB have the same power, therefore: |
735 |
739 |
736 .. math:: |
740 .. math:: |
737 |
741 |
1874 - the filterCoefficientRSRQ parameter is configured to fc4, it is the |
1878 - the filterCoefficientRSRQ parameter is configured to fc4, it is the |
1875 default value specified in the protocol specification [TS36331]_; |
1879 default value specified in the protocol specification [TS36331]_; |
1876 |
1880 |
1877 - the hysteresis and timeToTrigger parameters are configured with |
1881 - the hysteresis and timeToTrigger parameters are configured with |
1878 values equal to zero; |
1882 values equal to zero; |
|
1883 |
|
1884 - it is assumed that there is a one-to-one mapping between the PCI |
|
1885 and the E-UTRAN Global Cell Identifier (EGCI). This is consistent |
|
1886 with the PCI modeling assumptions described in :ref:`phy-ue-measurements`. |
|
1887 |
1879 |
1888 |
1880 |
1889 |
1881 Handover |
1890 Handover |
1882 ++++++++ |
1891 ++++++++ |
1883 |
1892 |