Method and device for random access
The present application relates to the field of wireless communications, and in particular, to a method and device for random access, for use in resolving the problem in the prior art of conflict between a time domain resource used by a terminal for random access and a time domain resource occupied for transmission of a SS Block and/or RMSI. In embodiments of the present application, a terminal determines a PRACH time domain resource configured by a base station for the terminal; when determining that at least one time slot comprises a first type of OFDM symbols used for transmission of a SS Block and/or RMSI, the terminal performs random access by means of OFDM symbols different from the first type of OFDM symbols in the at least one time slot. In the embodiments of the present application, the terminal performs random access by means of OFDM symbols different from the first type of OFDM symbols in the time slot, so that conflict between the time domain resource used for random access and the time domain resource occupied for transmission of the SS Block and/or RMSI is avoided, and the system performance is further improved.
1. A random access method, comprising:
determining, by a terminal, a Physical Random Access Channel (PRACH) time domain resource configured by a base station for the terminal, wherein the PRACH time domain resource comprises at least one time slot; and
when it is determined that the at least one time slot comprises a first type of Orthogonal Frequency Division Multiplexing (OFDM) symbols used for transmitting Synchronization Signal Blocks (SS Blocks) and/or Remaining Minimum System Information (RMSI), performing, by the terminal, random access through an OFDM symbol different from the first type of OFDM symbols in the at least one time slot;
wherein the performing, by the terminal, random access according to any one of following manners:
Manner I, performing, by the terminal, the random access at a time slot which does not comprise the first type of OFDM symbols; and
Manner II, performing, by the terminal, the random access through continuous OFDM symbols except the first type of OFDM symbols in the time slot comprising the first type of OFDM symbols;
wherein before performing, by the terminal, the random access through the continuous OFDM symbols except the first type of OFDM symbols in the time slot comprising the first type of OFDM symbols, the method further comprises:
determining, by the terminal, that in the time slot comprising the first type of OFDM symbols, a quantity of remaining continuous OFDM symbols for uplink transmission except the first type of OFDM symbols is not less than a quantity of actually used OFDM symbols for the random access;
wherein the terminal determines the quantity of the remaining continuous OFDM symbols for uplink transmission according to followings:
determining, by the terminal, a ratio of a Subcarrier Spacing (SCS) of a PRACH configured by the base station to an SCS of an SS Block; and
determining, by the terminal, a product of the quantity of remaining continuous OFDM symbols in the time slot comprising the first type of OFDM symbols and the ratio as the quantity of the remaining continuous OFDM symbols for uplink transmission.
2. The method according to claim 1 , wherein the terminal determines a random access manner according to followings:
determining, by the terminal, a random access manner according to a pre-configured rule; or
receiving, by the terminal, an indication signaling transmitted by the base station through the RMSI, and determining a random access manner according to the indication signaling.
3. The method according to claim 1 , wherein the performing, by the terminal, the random access through the continuous OFDM symbols except the first type of OFDM symbols in the time slot comprising the first type of OFDM symbols comprises:
selecting, by the terminal, at least one idle OFDM symbol between the first type of OFDM symbols from the time slot comprising the first type of OFDM symbols, or at least one idle OFDM symbol at end of the time slot comprising the first type of OFDM symbols; and
performing, by the terminal, the random access through selected OFDM symbol.
4. A random access method, comprising:
configuring, by a base station, a Physical Random Access Channel (PRACH) time domain resource for a terminal, wherein the PRACH time domain resource comprises at least one time slot; and
when it is determined that the at least one time slot comprises a first type of Orthogonal Frequency Division Multiplexing (OFDM) symbols used for transmitting Synchronization Signal Blocks (SS Blocks) and/or Remaining Minimum System Information (RMSI), receiving and detecting, by the base station, the PRACH on an OFDM symbol different from the first type of OFDM symbols in the at least one time slot;
wherein the receiving and detecting, by the base station, the PRACH according to any one of following manners:
Manner I, receiving and detecting, by the base station, the PRACH at a time slot which does not comprise the first type of OFDM symbols; and
Manner II, receiving and detecting, by the base station, the PRACH on continuous OFDM symbols except the first type of OFDM symbols in the time slot comprising the first type of OFDM symbols;
wherein before the receiving and detecting, by the base station, the PRACH on the continuous OFDM symbols except the first type of OFDM symbols in the time slot comprising the first type of OFDM symbols, the method further comprises:
determining, by the base station, that in the time slot comprising the first type of OFDM symbols, a quantity of remaining continuous OFDM symbols for uplink transmission except the first type of OFDM symbols is not less than a quantity of actually used OFDM symbols for random access;
wherein the base station determines a quantity of the remaining continuous OFDM symbols for uplink transmission according to followings:
determining, by the base station, a ratio of a Subcarrier Spacing (SCS) of a PRACH configured for the terminal to an SCS of an SS Block; and
determining, by the base station, a product of the quantity of remaining continuous OFDM symbols in the time slot comprising the first type of OFDM symbols and the ratio as the quantity of the remaining continuous OFDM symbols for uplink transmission.
5. The method according to claim 4 , wherein the receiving and detecting, by the base station, the PRACH on the continuous OFDM symbols except the first type of OFDM symbols in the time slot comprising the first type of OFDM symbols comprises:
selecting, by the base station, at least one idle OFDM symbol between the first type of OFDM symbols from the time slot comprising the first type of OFDM symbols, or at least one idle OFDM symbol at end of the time slot comprising the first type of OFDM symbols; and
receiving and detecting, by the base station, the PRACH on selected OFDM symbol.
6. A terminal, comprising: a processor, a memory, and a transceiver,
wherein the processor is configured to read a program in the memory to perform followings:
determining a Physical Random Access Channel (PRACH) time domain resource configured by a base station for the terminal, wherein the PRACH time domain resource comprises at least one time slot; and when it is determined that the at least one time slot comprises a first type of Orthogonal Frequency Division Multiplexing (OFDM) symbols used for transmitting Synchronization Signal Blocks (SS Blocks) and/or Remaining Minimum System Information (RMSI), performing random access through an OFDM symbol different from the first type of OFDM symbols in the at least one time slot;
wherein the processor is configured to perform the random access according to any one of following manners:
Manner I, performing the random access at a time slot which does not comprise the first type of OFDM symbols; and
Manner II, performing the random access through continuous OFDM symbols except the first type of OFDM symbols in the time slot comprising the first type of OFDM symbols;
wherein the processor is further configured to:
before performing the random access through the continuous OFDM symbols except the first type of OFDM symbols in the time slot comprising the first type of OFDM symbols, determine that in the time slot comprising the first type of OFDM symbols, a quantity of remaining continuous OFDM symbols for uplink transmission except the first type of OFDM symbols is not less than a quantity of actually used OFDM symbols for the random access;
wherein the processor is configured to determine the quantity of the remaining continuous OFDM symbols for uplink transmission according to followings:
determining a ratio of a Subcarrier Spacing (SCS) of a PRACH configured by the base station to an SCS of an SS Block; and determining a product of the quantity of remaining continuous OFDM symbols in the time slot comprising the first type of OFDM symbols and the ratio as the quantity of the remaining continuous OFDM symbols for uplink transmission.
7. The terminal according to claim 6 , wherein the processor is configured to determine a random access manner according to followings:
determining the random access manner according to a pre-configured rule; or
receiving an indication signaling transmitted by the base station through the RMSI, and determining the random access manner according to the indication signaling.
8. The terminal according to claim 6 , wherein the processor is configured to:
select at least one idle OFDM symbol between the first type of OFDM symbols from the time slot comprising the first type of OFDM symbols, or at least one idle OFDM symbol at the end of the time slot comprising the first type of OFDM symbols; and perform the random access through selected OFDM symbol.
9. A base station, comprising: a processor, a memory, and a transceiver,
wherein the processor is configured to read a program in the memory to perform the method according to claim 4 .
10. The base station according to claim 9 , wherein the processor is configured to:
select at least one idle OFDM symbol between the first type of OFDM symbols from the time slot comprising the first type of OFDM symbols, or at least one idle OFDM symbol at end of the time slot comprising the first type of OFDM symbols; and receive and detect the PRACH on selected OFDM symbol.