Method and apparatus for designing downlink control information in wireless communication system
A method and apparatus for allocating resources for a machine type communication user equipment (MTC UE) in a wireless communication system is provided. A base station indicates a transport block size (TBS) directly, adapts a code rate according to repetition numbers across multiple subframes in a MTC physical downlink shared channel (M-PDSCH) for the MTC UE, and allocates resources for the M-PDSCH by using the indicated transport block size and the adapted code rate. The TBS may be determined based on a modulation and coding scheme (MCS) only.
1. A method performed by a user equipment (UE) in a wireless communication system, the method comprising:
receiving downlink control information (DCI) for downlink (DL) data from a network, wherein the DCI includes a modulation and coding scheme (MCS) field, wherein a size of the MCS field is less than 5 bits, and wherein the MCS field is used for a transport block size (TBS) index;
determining a TBS based on the TBS index; and
receiving the DL data based on the determined TBS, wherein a modulation for the DL data is a quadrature phase shift keying (QPSK).
2. The method of claim 1 , wherein the UE is a machine-type communication (MTC) UE, and
wherein the MTC UE is in coverage enhancement (CE) mode B.
3. The method of claim 1 , wherein the modulation for the DL data is fixed as the QPSK, but not determined based on the MCS field.
4. The method of claim 1 , wherein the DL data is mapped to 6 physical resource blocks (PRBs).
5. A user equipment (UE) in a wireless communication system, the UE comprising:
a memory;
a transceiver; and
a processor, operably coupled to the memory and the transceiver, that:
controls the transceiver to receive downlink control information (DCI) for downlink (DL) data from a network, wherein the DCI includes a modulation and coding scheme (MCS) field, wherein a size of the MCS field is less than 5 bits, and wherein the MCS field is used for a transport block size (TBS) index,
determines a transport block size (TBS) based on the TBS index; and
controls the transceiver to receive the DL data based on the determined TBS, wherein a modulation for the DL data is a quadrature phase shift keying (QPSK).
6. The UE of claim 5 , wherein the modulation for the DL data is fixed as the QPSK, but not determined based on the information on the MCS field.