Timing synchronization method and apparatus
This application provides a timing synchronization method and an apparatus, to improve precision of a downlink transmit timing of a relay node. The method includes: The first node receives first indication information from a donor node, where the first indication information is used to indicate information about a plurality of second nodes, and the second node is a parent node of the first node. The first node receives a plurality of pieces of timing information from the plurality of second nodes. The first node determines a first downlink transmit timing of the first node based on the plurality of pieces of timing information.
1. A method, comprising:
determining a sending moment of a distributed unit (DU) of a first node for sending data in a downlink transmit frame of the DU, the sending moment for the downlink transmit frame being earlier than a receiving moment of a downlink receive frame of a mobile terminal (MT) of the first node by an advanced time, the downlink receive frame configured for receiving data from a parent node of the first node, and the advanced time satisfying:
( N TA +N TA,offset )· T c /2+ T _delta,
wherein N TA is an index indicating a timing advance (TA) of the first node for uplink transmission, N TA,offset is a timing advance offset of a serving cell, T c =1/(Δf max ·N f ), Δf max =480·10 3 , and N f =4096, and T_delta is a timing adjustment amount received from the parent node by the first node to compensate for a difference between TA/2, which is determined from N TA received from the parent node by the first node, and a transmission time Tp between the first node and the parent node; and
sending data by the DU of the first node according to the sending moment,
wherein T_delta satisfies:
(− N TA,offset /2+ N T_delta,min +N T_delta ·G T_delta ) T c ,
wherein n T_delta is configured by the parent node of the first node, and N T_delta,min and G T_delta are values that are configured by the parent node, or are determined by using a protocol text.
2. The method according to claim 1 , wherein when an operating frequency band of the first node is frequency range 1 defined in the 3GPP standard technical specification, a value of N T_delta,min is −70528, −35328, or −17664.
3. The method according to claim 1 , wherein when an operating frequency band of the first node is frequency range 2 defined in the 3GPP standard technical specification, a value of N T_delta,min is −17664, or −8816.
4. The method according to claim 1 , wherein when an operating frequency band of the first node is frequency range 1 defined in the 3GPP standard technical specification, G T delta is 64.
5. The method according to claim 1 , wherein when an operating frequency band of the first node is frequency range 2 defined in the 3GPP standard technical specification, G T delta is 32.
6. The method according to claim 1 , wherein n T delta is indicated to the first node using multimedia access control-control element (MAC-CE) signaling.
7. The method according to claim 1 , wherein n T delta is indicated to the first node using 11-bit signaling.
8. A first node, comprising:
a transceiver;
at least one processor; and
a non-transitory computer-readable storage medium storing a program to be executed by the at least one processor, the program including instructions to:
determine a sending moment of a distributed unit (DU) of the first node for sending data in a downlink transmit frame of the DU, the sending moment for the downlink transmit frame being earlier than a receiving moment of a downlink receive frame of a mobile terminal (MT) of the first node by an advanced time, the downlink receive frame configured for receiving data from a parent node of the first node, and the advanced time satisfying:
( N TA +N TA,offset )· T c /2+ T _delta,
wherein N TA is an index indicating a timing advance (TA) of the first node for uplink transmission, N TA,offset is a timing advance offset of a serving cell, T c =1/(Δf max ·N f ), Δf max =480·10 3 , and N f =4096, and T_delta is a timing adjustment amount received from the parent node by the first node to compensate for a difference between TA/2, which is determined from N TA received from the parent node by the first node, and a transmission time Tp between the first node and the parent node; and
send data according to the sending moment,
wherein T_delta satisfies:
(− N TA,offset /2+ N T_delta,min +N T_delta ·G T_delta ) T c ,
wherein N T_delta is configured by the parent node of the first node, and N T_delta,min and G T_delta are values that are configured by the parent node, or are determined by using a protocol text.
9. The first node according to claim 8 , wherein when an operating frequency band of the first node is frequency range 1 defined in the 3GPP standard technical specification, a value of N T_delta,min is −70528, −35328, or −17664.
10. The first node according to claim 8 , wherein when an operating frequency band of the first node is frequency range 2 defined in the 3GPP standard technical specification, a value of N T_delta,min is −17664, or −8816.
11. The first node according to claim 8 , wherein when an operating frequency band of the first node is frequency range 1 defined in the 3GPP standard technical specification, G T delta is 64.
12. The first node according to claim 8 , wherein when an operating frequency band of the first node is frequency range 2 defined in the 3GPP standard technical specification, G T delta is 32.
13. The first node according to claim 8 , wherein n T delta is indicated to the first node using multimedia access control-control element (MAC-CE) signaling.
14. The first node according to claim 8 , wherein n T delta is indicated to the first node using 11-bit signaling.
15. A non-transitory computer storage medium, storing computer instructions that, when executed by a network device, cause the network device to perform:
determining a sending moment of a distributed unit (DU) of a first node for sending data in a downlink transmit frame of the DU, the sending moment for the downlink transmit frame being earlier than a receiving moment of a downlink receive frame of a mobile terminal (MT) of the first node by an advanced time, the downlink receive frame configured for receiving data from a parent node of the first node, and the advanced time satisfying:
( N TA +N TA,offset )· T c /2+ T _delta,
wherein N TA is an index indicating a timing advance (TA) of the first node for uplink transmission, N TA,offset is a timing advance offset of a serving cell, T c =1/(Δf max ·N f ), Δf max =480·10 3 , and N f =4096, and T_delta is a timing adjustment amount received from the parent node by the first node to compensate for a difference between TA/2, which is determined from N TA received from the parent node by the first node, and a transmission time Tp between the first node and the parent node; and
sending data by the first node according to the sending moment,
wherein T_delta satisfies:
(− N TA,offset /2+ N T_delta,min +n T_delta ·G T_delta ) T c ,
wherein n T_delta is configured by the parent node of the first node, and N T_delta,min and G T_delta are values that are configured by the parent node, or are determined by using a protocol text.
16. The non-transitory computer storage medium according to claim 15 , wherein when an operating frequency band of the first node is frequency range (FR) 1 defined in the 3GPP standard technical specification, a value of N T_delta,min is −70528, −35328, or −17664, and G T_delta is 64; and
wherein when an operating frequency band of the first node is FR 2 defined in the 3GPP standard technical specification, a value of N T_delta,min is −17664, or −8816, and G T_delta is 32.
17. The non-transitory computer storage medium according to claim 15 , wherein n T_delta is indicated using multimedia access control-control element (MAC-CE) signaling.
18. The non-transitory computer storage medium according to claim 15 , wherein when an operating frequency band of the first node is frequency range 1 defined in the 3GPP standard technical specification, G T_delta is 64.
19. The non-transitory computer storage medium according to claim 15 , wherein when an operating frequency band of the first node is frequency range 2 defined in the 3GPP standard technical specification, G T_delta is 32.
20. The non-transitory computer storage medium according to claim 15 , wherein N T delta is indicated to the first node using 11-bit signaling.