LTE Sounding Reference Signals (SRS)

 

SRS shall be transmitted at the last symbol of the subframe.

PUSCH:
• The mapping to resource elements only considers those not used for transmission of reference signals.
PUCCH Format 1a and 1b (HARQ-ACK):
• One SC-FDMA symbol on PUCCH shall be punctured.
PUCCH Format 1 (SR) and 2, 2a, 2b (CQI):
• A UE shall not transmit SRS whenever SRS collide with PUCCH format 1 (SR), and 2, 2a and 2b (CQI).


 

Sounding Reference Signals
Details about UE sounding procedure can be found in TS36.211 and TS36.213 §8.3.
The reference signal sequence shall be multiplied with the amplitude scaling factor and mapped
resource elements. The resource element mapping shall be in increasing order of first k, then l, and finally the slot number.

There are many FDD sounding reference signal subframe configurations as per TS36.211 §5.5.3.3.
The sounding reference signal shall be transmitted at the last symbol of the subframe according to 36.211.
A UE shall not transmit SRS whenever SRS and CQI transmissions happen to coincide in the same subframe.
A UE shall not transmit SRS whenever SRS and SR transmissions happen to coincide in the same subframe.
When a UE is configured by higher layers to support both A/N and SRS transmissions in the same subframe, then the UE shall transmit A/N using a shortened PUCCH format where the A/N symbol corresponding to the SRS location is punctured.