RS-PRS (LTE-Advanced)

Default: 3GPP

Range: 3GPP, Custom

RS-PRS specifies whether or not the demodulator should expect the cell-specific reference signal sequence to adhere to the standard.

When 3GPP is selected, the demodulator will expect the C-RS Cell-specific RS pseudorandom sequence to follow the formula given in the standard in Section 6.10.1.1 of 3GPP TS Technical Specification 36.211.

When Custom is selected, the demodulator will autodetect the C-RS sequence (including non-standard sequences). Since the C-RS points can only be in certain positions, the demodulator will assume that the point closest to the measured point is the desired reference signal point and will calculate the EVM Error vector magnitude (EVM): A quality metric in digital communication systems. See the EVM metric in the Error Summary Table topic in each demodulator for more information on how EVM is calculated for that modulation format. and other metrics using the assumed reference signal constellation point.

When Sync Type is set to C-RS, autodetecting a Custom RS-PRS is not supported since the demodulator needs to know the RS-PRS to be able to synchronize the signal using C-RS.

When RS-PRS is set to Custom and any of the antenna port signals are phase delayed by more than 45 degrees, the demodulator will autodetect a different RS-PRS. This will cause equalization to be incorrect and demodulation will fail. To ensure correct demodulation of signals containing an antenna port transmission with a phase rotation of more than 45 degrees, set RS-PRS to 3GPP to allow RS-PRS to be determined by Cell ID according to the standard.