Method and apparatus for random access procedure
A random access procedure, performed by a network device, includes selecting one of a plurality of preamble indexes of a first resource, and at least one set of the plurality of preamble indexes is mapped to at least one second resource based on a first number of the at least one set of the plurality of preamble indexes and a second number of the at least one second resource. A first message is transmitted to a network node, the first message including a preamble at the selected preamble index of the first resource and a payload in the second resource associated to the selected preamble index. A second message is received from the network node in response to a first message.
1 . A method for a random access procedure, performed by a user equipment, the method comprising:
selecting one of a plurality of preamble indexes of a physical random access channel occasion, wherein at least one set of the plurality of preamble indexes is mapped to at least one physical uplink shared channel occasion based on a first number of the at least one set of the plurality of preamble indexes and a second number of the at least one physical uplink shared channel occasion, wherein X preamble index or indexes is/are mapped to a demodulation reference signal port index of an associated physical uplink shared channel occasion, with:
X
=
⌈
N_ro
*
P
/
D
⌉
,
where N_ro represents a number of at least one PRACH occasion, P represents a number of preamble index(es), D represents a number of demodulation reference signal port index(es) of at least one PUSCH occasion, and where X, N_ro, P and D are positive integers, wherein a DRMS port index indicates a DMRS port number based on a DMRS sequence;
transmitting, to a network node, a first message comprising a preamble with the selected preamble index of the physical random access channel occasion and a payload in the at least one physical uplink shared channel occasion associated to the selected preamble index; and
receiving, from the network node, a second message in response to the first message,
wherein the at least one set of the plurality of preamble indexes is mapped to a plurality of physical uplink shared channel occasions, wherein indexes of the plurality of PUSCH occasions increases first in frequency domain and then second in time domain,
wherein the order of the X preamble indexes increases in code domain first, frequency domain, and then time domain, and
wherein the at least one set of preamble indexes is mapped to the at least one physical uplink shared channel occasion based on at least one ratio parameter when the first number is greater than the second number, wherein the at least one ratio parameter is determined based on service requirements.
2 . The method of claim 1 , wherein a difference between the numbers of preamble indexes in two of the at least one set of preamble indexes is equal to or smaller than 1.
3 . The method of claim 1 , wherein the second number is determined based on a number of synchronization signal blocks per physical random access channel occasion or based on available time-frequency resources or based on a number of demodulation reference signal port indexes of each physical uplink shared channel occasion.
4 . The method of claim 1 , wherein each of the at least one set of preamble indexes is mapped to one physical uplink shared channel occasion when the first number is equal to the second number.
5 . The method of claim 1 , wherein X preamble indexes are mapped to demodulation reference signal port indexes and wherein the order of demodulation reference signal port indexes increases in code domain, frequency domain and then time domain.
6 . A method for a random access procedure, performed by a base station, the method comprising:
receiving, from a network device, a first message comprising a preamble at one of a plurality of preamble indexes of a physical random access channel occasion and a payload in one of at least one physical uplink shared channel occasion, wherein at least one set of the plurality of preamble indexes is mapped to the at least one physical uplink shared channel occasion based on a first number of the at least one set of the plurality of preamble indexes and a second number of the at least one second physical uplink shared channel occasion, wherein X preamble index or indexes is/are mapped to a demodulation reference signal port index of an associated physical uplink shared channel occasion, with:
X
=
⌈
N_ro
*
P
/
D
⌉
,
where N_ro represents a number of at least one PRACH occasion, P represents a number of preamble index(es), D represents a number of demodulation reference signal port index(es) of at least one PUSCH occasion, and where X, N_ro, P and D are positive integers, wherein a DRMS port index indicates a DMRS port number based on a DMRS sequence; and
transmitting, to the network device, a second message in response to the first message,
wherein the at least one set of the plurality of preamble indexes is mapped to a plurality of physical uplink shared channel occasions, wherein indexes of the plurality of PUSCH occasions increases first in frequency domain and then second in time domain,
wherein the order of the X preamble indexes increases in code domain first, frequency domain, and then time domain, and
wherein the at least one set of preamble indexes is mapped to the at least one physical uplink shared channel occasion based on at least one ratio parameter when the first number is greater than the second number, wherein the at least one ratio parameter is determined based on service requirements.
7 . The method of claim 6 , wherein a difference between the numbers of preamble indexes in two of the at least one set of preamble indexes is equal to or smaller than 1.
8 . The method of claim 6 , wherein the second number is determined based on a number of synchronization signal blocks per physical random access channel occasion or based on available time-frequency resources or based on a number of demodulation reference signal port indexes of each physical uplink shared channel occasion.
9 . The method of claim 6 , wherein each of the at least one set of preamble indexes is mapped to one physical uplink shared channel occasion when the first number is equal to the second number.
10 . The method of claim 6 , wherein X preamble indexes are mapped to demodulation reference signal port indexes and wherein the order of demodulation reference signal port indexes increases in code domain, frequency domain and then time domain.
11 . A user equipment comprising a processor and a storage unit, wherein the processor is configured to read a program code from the storage unit and implement:
selecting one of a plurality of preamble indexes of a physical random access channel occasion, wherein at least one set of the plurality of preamble indexes is mapped to at least one physical uplink shared channel occasion based on a first number of the at least one set of the plurality of preamble indexes and a second number of the at least one physical uplink shared channel occasion, wherein X preamble index or indexes is/are mapped to a demodulation reference signal port index of an associated physical uplink shared channel occasion, with:
X
=
⌈
N_ro
*
P
/
D
⌉
,
where N_ro represents a number of at least one PRACH occasion, P represents a number of preamble index(es), D represents a number of demodulation reference signal port index(es) of at least one PUSCH occasion, and where X, N_ro, P and D are positive integers, wherein a DRMS port index indicates a DMRS port number based on a DMRS sequence;
transmitting, to a network node, a first message comprising a preamble with the selected preamble index of the physical random access channel occasion and a payload in the at least one physical uplink shared channel occasion associated to the selected preamble index; and
receiving, from the network node, a second message in response to the first message,
wherein the at least one set of the plurality of preamble indexes is mapped to a plurality of physical uplink shared channel occasions, wherein indexes of the plurality of PUSCH occasions increases first in frequency domain and then second in time domain,
wherein the order of the X preamble indexes increases in code domain first, frequency domain, and then time domain, and
wherein the at least one set of preamble indexes is mapped to the at least one physical uplink shared channel occasion based on at least one ratio parameter when the first number is greater than the second number, wherein the at least one ratio parameter is determined based on service requirements.
12 . A base station comprising a processor and a storage unit, wherein the processor is configured to read a program code from the storage unit and implement:
receiving, from a network device, a first message comprising a preamble at one of a plurality of preamble indexes of a physical random access channel occasion and a payload in one of at least one physical uplink shared channel occasion, wherein at least one set of the plurality of preamble indexes is mapped to the at least one physical uplink shared channel occasion based on a first number of the at least one set of the plurality of preamble indexes and a second number of the at least one second physical uplink shared channel occasion, wherein X preamble index or indexes is/are mapped to a demodulation reference signal port index of an associated physical uplink shared channel occasion, with:
X
=
⌈
N_ro
*
P
/
D
⌉
,
where N_ro represents a number of at least one PRACH occasion, P represents a number of preamble index(es), D represents a number of demodulation reference signal port index(es) of at least one PUSCH occasion, and where X, N_ro, P and D are positive integers, wherein a DRMS port index indicates a DMRS port number based on a DMRS sequence; and
transmitting, to the network device, a second message in response to the first message,
wherein the at least one set of the plurality of preamble indexes is mapped to a plurality of physical uplink shared channel occasions, wherein indexes of the plurality of PUSCH occasions increases first in frequency domain and then second in time domain,
wherein the order of the X preamble indexes increases in code domain first, frequency domain, and then time domain, and
wherein the at least one set of preamble indexes is mapped to the at least one physical uplink shared channel occasion based on at least one ratio parameter when the first number is greater than the second number, wherein the at least one ratio parameter is determined based on service requirements.