What is CSI reference signal?
CSI-RSChannel State Information Reference Signal is the Channel State Information Reference Signal and is used by the UEUser Equipment (e.g. cell phone) to estimate the channel and report channel quality information (CQI ) to the base station.
What are reference signals?
One reference signal is transmitted from each downlink antenna port. The downlink reference signal can be used for the following purposes: Downlink channel quality measurements. Downlink channel estimation for coherent demodulation/detection at the UE.
What is reference signal in 5G?
The four main reference signals are the demodulation reference signal (DMRS), phase-tracking reference signal (PTRS), sounding reference signal (SRS) and channel-state information reference signal (CSI-RS). DMRS is used to estimate the radio channel for demodulation.
What is CSI RS port?
CSI-RS ports are the number of radiating elements (or group of antennas) of an active antenna unit. So there can be 4×4 MIMO with 8 CSI-RS ports with 16 CSI-RS ports or with 4 CSI-RS ports. Are not related with each other. Only conditions is that MIMO layers cannot be higher than CSI-RS ports.
What is the purpose of CSI-RS?
3 CSI Reference Signals. Support for CSI reference signals (CSI-RS) was introduced in LTE release 10. CSI-RS is intended to be used by terminals to acquire channel-state information when demodulation reference signals are used for channel estimation. More specifically, CSI-RS are to be used in transmission mode 9.
What is a CSI-RS resource?
CSI-RS refers to channel state information reference signal and these signals are downlink only signal. It is used for DL CSI acquisition. Used for RSRP measurements used during mobility and beam management. Also used for frequency/time tracking, demodulation and UL reciprocity based pre-coding.
Why reference signals are used in LTE?
The purpose of this Reference Signal is to deliver the reference point for the downlink power. These reference signal are carried by multiples of specific Resource Elements in each slots and the location of the resource elements are specifically determined by antenna configuration.
What is the use of reference signals in LTE?
UE-specific reference signal are transmitted using resource elements with the same index pair k, l regardless of their antenna port p . UE-specific reference signals are denser in frequency but only transmitted when data is transmitted on the corresponding layer.
What is TRS in 5G?
In 3GPP TSG RAN1 Meeting# 86bis, agreement is achieved that the reference signal for phase tracking is supported for both 5G downlink and uplink. The preliminary design of tracking reference signal (TRS) for orthogonal frequency division multiplexing (OFDM) waveform has been done.
Which reference signal is used with Pdcch in 5G?
| Reference Signal | Functionality | Reference |
|---|---|---|
| PDCCH DMRS | Required for PDCCH Demodulation | 38.211-7.4.1.3 |
| PBCH DMRS | Required for PBCH Demodulation | 38.211-7.4.1.4 |
| PTRS | Used for Phase Tracking for PDSCH | 38.211-7.4.1.2 |
| Tracking Reference Signal | Used for Time Tracking | 38.211-7.4.1.6 |
What is the purpose of CSI RS?
What is a CSI RS resource?
Which is the reference signal used for CSI?
CSI-RS refers to channel state information reference signal and these signals are downlink only signal. It is used for DL CSI acquisition. Used for RSRP measurements used during mobility and beam management Also used for frequency/time tracking, demodulation and UL reciprocity based pre-coding
How is the CSI-RS used in MIMO?
Channel State Information Reference Signal (CSI-RS) As a DL-only signal, the CSI-RS the UE receives is used to estimate the channel and report channel quality information back to the gNB. During MIMO operations, NR uses different antenna approaches based on the carrier frequency.
How is channel state information reference signal used?
As already mentioned early in Section 10.2, the cell-specific reference signals (CRS), available since the first release of LTE, can also be used to acquire channel-state information.
How is the CSI-RS used in the UE?
The CSI-RS, when configured, spans the whole system bandwidth and as can be seen in Table 8.3, the UE can utilize RS measurements from the whole bandwidth to estimate the channel of every subcarrier. In specifications, the CSI-RS used to measure the channel is known as the non-zero power (NZP) CSI-RS.
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