Methods and apparatuses for timing advance adjustment
Embodiments of the present disclosure relate to methods and devices for timing advance adjustment. In example embodiments, a method implemented in a network device is provided. According to the method, in response to receiving a Physical Random Access Channel (PRACH) sequence from a terminal device served by the network device, a first value indicating an adjustment of timing advance is determined based on the PRACH sequence and at least one value of subcarrier spacing. An indication of the first value is transmitted to the terminal device to enable the terminal device to adjust timing of uplink transmission.
1. A terminal comprising a processor configured to:
transmit a PRACH (Physical Random Access Channel) sequence to the network device; then
receive a timing advance command in a Random Access Response indicating X from the network device; and
start transmitting an uplink frame a period of time before start of a downlink frame corresponding to the uplink frame, wherein
the period of time is {(the X+Y) *Z}, where
the X is inversely proportional to a value of subcarrier spacing,
the Y represents a fixed offset value, and
the Z represents a basic time unit, wherein
the value of subcarrier spacing is one of {120, 240} kHz.
2. The terminal according to claim 1 , wherein
the value of subcarrier spacing is one of {15, 30, 60, 120, 240} kHz.
3. The terminal according to claim 1 , wherein
(the X *the Z) is a multiple of (240 *a basic time unit for LTE).
4. A network device comprising a processor configured to:
receive a PRACH (Physical Random Access Channel) sequence from a terminal; then
transmit a timing advance command in a Random Access Response indicating X to the terminal; and
receive an uplink frame transmission being started a period of time before start of a downlink frame corresponding to the uplink frame by the terminal, wherein
the period of time is {(the X+Y) *Z}, where
the X is inversely proportional to a value of subcarrier spacing,
the Y represents a fixed offset value, and
the Z represents a basic time unit, wherein
the value of subcarrier spacing is one of {120, 240} kHz.
5. The network device according to claim 4 , wherein
the value of subcarrier spacing is one of {15, 30, 60, 120, 240} kHz.
6. The network device according to claim 4 , wherein
(the X *the Z) is a multiple of (240 *a basic time unit for LTE).
7. A method comprising:
transmitting a PRACH (Physical Random Access Channel) sequence; then
receiving a timing advance command in a Random Access Response indicating X; and
starting transmitting an uplink frame a period of time before start of a downlink frame corresponding to the uplink frame, wherein
the period of time is {(the X+Y) *Z}, where
the X is inversely proportional to a value of subcarrier spacing,
the Y represents a fixed offset value, and
the Z represents a basic time unit, wherein
the value of subcarrier spacing is one of {120, 240} kHz.
8. The method according to claim 7 , wherein
the value of subcarrier spacing is one of {15, 30, 60, 120, 240} kHz.
9. The method according to claim 7 , wherein
(the X *the Z) is a multiple of (240 *a basic time unit for LTE).
10. A method comprising:
receiving a PRACH (Physical Random Access Channel) sequence; then
transmitting a timing advance command in a Random Access Response indicating X; and
receiving an uplink frame transmission being started a period of time before start of a downlink frame corresponding to the uplink frame, wherein
the period of time is {(the X+Y) *Z}, where
the X is inversely proportional to a value of subcarrier spacing,
the Y represents a fixed offset value, and
the Z represents a basic time unit, wherein
the value of subcarrier spacing is one of {120, 240} kHz.
11. The method according to claim 10 , wherein
the value of subcarrier spacing is one of {15, 30, 60, 120, 240} kHz.
12. The method according to claim 10 , wherein
(the X *the Z) is a multiple of (240 *a basic time unit for LTE).