Method and apparatus for receiving random access response for MTC UE
The present disclosure relates to a downlink data transmission/reception technique for supporting a low-complexity UE category/type for a MTC operation. A method may be provided for an MTC UE to receive a random access response. The method may include: repeatedly transmitting a random access preamble to a base station through a Physical Random Access Channel (PRACH) of at least one subframe; determining a Random Access Radio Network Temporary Identifier (RA-RNTI) using first time index information, frequency index information, and second time index information on the PRACH; and receiving a random access response to the random access preamble using the RA-RNTI within a random access response window.
1. A method of receiving a random access response by a Machine-Type Communication (MTC) user equipment (UE), the method comprising:
repeatedly transmitting a random access preamble to a base station through a Physical Random Access Channel (PRACH) of at least one subframe;
determining a Random Access Radio Network Temporary Identifier (RA-RNTI) using first time index information, frequency index information, and second time index information on the PRACH; and
receiving the random access response to the random access preamble using the RA-RNTI within a random access response window,
wherein the RA-RNTI is determined by an equation below,
RA-RNTI=1 +t _ id+ 10 *f _ id+ 60 *t _ id 2,
where t_id is the first time index information, f_id is the frequency index information, and t_id 2 is the second time index information.
2. The method of claim 1 , wherein:
the first time index information comprises an index of a first subframe in which repeated transmissions of the random access preamble are started; and
the frequency index information comprises an index of a frequency resource of the PRACH.
3. The method of claim 1 , wherein the second time index information is determined based on an index of a first radio frame in which repeated transmissions of the random access preamble are started.
4. The method of claim 3 , wherein the second time index information is determined by an equation,
Second time index information=SFN mod K,
where System Frame Number (SFN) is the index of the first radio frame, and K is a natural number.
5. A method of transmitting a random access response to a Machine-Type Communication (MTC) user equipment (UE) by a base station, the method comprising:
repeatedly receiving a random access preamble from the MTC UE through a Physical Random Access Channel (PRACH) of at least one subframe;
determining a Random Access Radio Network Temporary Identifier (RA-RNTI) using first time index information, frequency index information, and second time index information on the PRACH; and
transmitting the random access response to the random access preamble using the RA-RNTI within a random access response window,
wherein the RA-RNTI is determined by an equation below,
RA-RNTI=1 +t _ id+ 10*f_ id+ 60 *t _ id 2,
where t 13 id is the first time index information, f_id is the frequency index information, and t_id 2 is the second time index information.
6. The method of claim 5 , wherein:
the first time index information comprises an index of a first subframe in which repeated receptions of the random access preamble are started; and
the frequency index information comprises an index of a frequency resource of the PRACH.
7. The method of claim 5 , wherein the second time index information is determined based on an index of a first radio frame in which repeated receptions of the random access preamble are started.
8. The method of claim 7 , wherein the second time index information is
Second time index information=SFN mod K,
where System Frame Number (SFN) is the index of the first radio frame, and K is a natural number.
9. A Machine-Type Communication (MTC) User Equipment (UE) for receiving a random access response, the MTC UE comprising:
a transmitter configured to repeatedly transmit a random access preamble to a base station through a Physical Random Access Channel (PRACH) of at least one subframe;
a controller configured to determine a Random Access Radio Network Temporary Identifier (RA-RNTI) using first time index information, frequency index information, and second time index information on the PRACH; and
a receiver configured to receive the random access response to the random access preamble using the RA-RNTI within a random access response window,
wherein the RA-RNTI is determined by an equation below,
RA-RNTI=1 +t _ id+ 10 *f _ id+ 60 *t _ id 2,
where t_id is the first time index information, f_id is the frequency index information, and t_id 2 is the second time index information.
10. The MTC UE of claim 9 , wherein:
the first time index information comprises an index of a first subframe in which repeated transmissions of the random access preamble are started; and
the frequency index information comprises an index of a frequency resource of the PRACH.
11. The MTC UE of claim 9 , wherein the second time index information is determined based on an index of a first radio frame in which repeated transmissions of the random access preamble are started.
12. The MTC UE of claim 11 , wherein the second time index information is determined by an equation,
Second time index information=SFN mod K,
where System Frame Number (SFN) is the index of the first radio frame, and K is a natural number.