Method for transmitting uplink channel and demodulation reference signal by MTC device
A disclosure of the present specification provides a method for transmitting an uplink channel and a demodulation reference signal (DMRS) by a machine type communication (MTC) device. The method may comprise the steps of: determining a frequency resource area for transmitting an uplink channel so as to have a size equal to or smaller than the size of a physical resource block (PRB) including 12 subcarriers; generating a DMRS sequence for some sub-carriers among the 12 subcarriers when the frequency resource area for transmitting the uplink channel is determined to have a size smaller than the size of the PRB including the 12 subcarriers; and transmitting the uplink channel and the DMRS on the some subcarriers in the PRB.
1. A method for transmitting an uplink (UL) data channel and a demodulation reference signal (DMRS), the method performed by a machine type communication (MTC) device and comprising:
receiving downlink control information (DCI);
determining a frequency resource area for transmitting the UL data channel based on the received DCI, a size of the determined frequency resource area less than a size of a physical resource block (PRB) including 12 subcarriers;
generating the DMRS having a size less than the size of the PRB based on the size of the determined frequency resource area; and
transmitting the UL data channel and the DMRS on less than the 12 subcarriers based on the determined frequency resource area,
wherein the DCI includes a frequency hopping flag field related to the less than the 12 subcarriers onto which the frequency resource area is mapped in the PRB.
2. The method of claim 1 , wherein generating the DMRS comprises:
generating an original DMRS sequence having a size of 12 subcarriers;
mapping the generated original DMRS sequence to the PRB; and
puncturing the generated original DMRS sequence mapped onto subcarriers other than the less than the 12 subcarriers.
3. The method of claim 1 , wherein generating the DMRS comprises:
generating an original DMRS sequence having a size of 12 subcarriers; and
mapping the DMRS among the generated original DMRS sequence, a size of the mapped DMRS equal to a size of the determined frequency resource area.
4. The method of claim 1 , further comprising selecting one of a plurality of DMRS sequences based on a smallest index among indexes for the less than the 12 subcarriers.
5. A machine type communication (MTC) device for transmitting an uplink (UL) data channel and a demodulation reference signal (DMRS), the MTC device comprising:
a transceiver configured to transmit and receive signals; and
a processor operatively connected to the transceiver and configured to:
control the transceiver to receive downlink control information (DCI);
determine a frequency resource area for transmitting the UL data channel based on the received DCI, a size of the determined frequency resource area less than a size of a physical resource block (PRB) including 12 subcarriers;
generate the DMRS having a size less than the size of the PRB based on the size of the determined frequency resource area; and
control the transceiver to transmit the UL data channel and the DMRS on less than the 12 subcarriers based on the determined frequency resource area,
wherein the DCI includes a frequency hopping flag field related to the less than the 12 subcarriers onto which the frequency resource area is mapped in the PRB.
6. The MTC device of claim 5 , wherein generating the DMRS comprises:
generating an original DMRS sequence having a size of 12 subcarriers;
mapping the generated original DMRS sequence to the PRB; and
puncturing the generated original DMRS sequence mapped onto subcarriers other than the less than the 12 subcarriers.
7. The MTC device of claim 5 , wherein generating the DMRS comprises:
generating an original DMRS sequence having a size of 12 subcarriers; and
mapping the DMRS among the generated original DMRS sequence, a size of the mapped DMRS equal to a size of the determined frequency resource area.
8. The MTC device of claim 5 , wherein the processor is further configured to select one of a plurality of DMRS sequences based on a smallest index among indexes for the less than the 12 subcarriers.