Huawei H35-481_V2.0 Exam - Topic 2 Question 61 Discussion

the cell-specific reference signal (CRS) that is always sent in LTE cells is not used in NR to reduce interference under light loads and control channel overhead. Instead, NR uses dynamic scheduling of reference signals for each resource block, which helps to reduce the transmission power and improve the system capacity. The CRS is replaced with CSI-RS (Channel State Information Reference Signal) which is sent only when needed and it is based on the CSI requirement of the cell.

The official site for 3GPP specifications is https://www.3gpp.org/specifications. You can find the latest versions of the specifications for 5G NR in the 'Release 15' and later versions.

You can refer to the specification 38.211 (Physical channels and modulation) specifically section 7.4 'Cell-specific reference signal (CRS)' and section 7.5 'Channel state information-reference signal (CSI-RS)'.

Here is an excerpt from the specification 38.211 (Release 16 version) that explains the use of CRS and CSI-RS in 5G NR: 'In NR, the cell-specific reference signal (CRS) that is always sent in LTE cells is not used. Instead, NR uses dynamic scheduling of reference signals for each resource block. This is done to improve system capacity and reduce transmission power. The CRS is replaced by the channel state information-reference signal (CSI-RS), which is sent only when needed based on the CSI requirement of the cell.'