Method and apparatus for UE signal transmission in 5G cellular communications
A communication method and a system that combines fifth generation (5G) communication systems with internet of things (IoT) technologies to support much higher data rates than fourth generation (4G) communication systems are provided. Based on 5G communication technologies and IoT technologies, the present disclosure can be applied to intelligent services, such as smart home, smart building, smart city, smart car or connected cars, health care, digital education, retail business, and security and safety measure. A method of communication for a user equipment includes receiving a random access channel (RACH) configuration from a base station (an evolved nodeB (eNB)), and transmitting to the eNB a random access preamble (RAP) message in an uplink subframe of an unlicensed band matching a subframe configured as a RACH resource according to the RACH configuration.
1. A method performed by a terminal in a wireless communication system, the method comprising:
transmitting, to a base station, at least one random access preamble using at least one resource for transmitting the at least one random access preamble;
monitoring a random access response based on a random access response window;
identifying that the random access response is not received within the random access response window;
determining to retransmit, to the base station, at least one random access preamble in case that the random access response is not received within the random access response window;
identifying whether a transmission beam for a retransmission is changed based on the determining to retransmit the at least one random access preamble;
determining to suspend a power ramping counter in case that the transmission beam for the retransmission is changed; and
retransmitting, to the base station, at least one random access preamble, based on the determined power ramping counter.
2. The method of claim 1 , further comprising:
determining to increment a power ramping counter by a predetermined value, in case that the transmission beam for the retransmission is not changed.
3. The method of claim 1 , wherein transmitting the at least one random access preamble further comprises:
receiving, from the base station, at least one synchronization signal;
in case that a measurement result of the at least one synchronization signal is greater than a predetermined threshold value, identifying an index of the at least one synchronization signal;
determining at least one resource for transmitting at least one random access preamble corresponding to the identified index of the synchronization signal; and
transmitting, to the base station, the at least one random access preamble based on the determined at least one resource for transmitting the at least one random access preamble.
4. The method of claim 3 , further comprising:
receiving, from the base station, information on mapping between the index of at least one synchronization signal and at least one resource for a random access preamble transmission.
5. A method performed by a base station in a wireless communication system, the method comprising:
receiving, from a terminal, at least one random access preamble using at least one resource for transmitting the at least one random access preamble; and
receiving, from the terminal, at least one random access preamble which is retransmitted based on a power ramping counter,
wherein a random access response is monitored based on a random access response window, by the terminal, that the random access response is not received within the random access response window is identified, a retransmission is determined, to suspend a power ramping counter is determined in case that a transmission beam for the retransmission is changed.
6. The method of claim 5 , wherein to increment a power ramping counter by a predetermined value is determined, in case that the transmission beam for the retransmission is not changed.
7. The method of claim 5 , wherein receiving the at least one random access preamble further comprises:
transmitting, to the terminal, at least one synchronization signal; and
receiving, from the terminal, the at least one random access preamble based on at least one resource for transmitting the at least one random access preamble, the at least one resource for transmitting the at least one random access preamble being determined based on a reception result of the at least one synchronization signal,
wherein the at least one resource for transmitting the at least one random access preamble corresponds to an index of the synchronization signal, in case that a measurement result of the at least one synchronization signal is greater than a predetermined threshold value.
8. The method of claim 7 , further comprising:
transmitting, to the terminal, information on mapping between the index of at least one synchronization signal and at least one resource for a random access preamble transmission.
9. A terminal in a wireless communication system, the terminal comprising:
a transceiver; and
at least one processor configured to:
transmit, to a base station via the transceiver, at least one random access preamble using at least one resource for transmitting the at least one random access preamble,
monitor a random access response based on a random access response window,
identify that the random access response is not received within the random access response window,
determine to retransmit, to the base station, at least one random access preamble in case that the random access response is not received within the random access response window,
identify whether a transmission beam for a retransmission is changed based on the determining to retransmit the at least one random access preamble,
determine to suspend a power ramping counter in case that the transmission beam for the retransmission is changed, and
retransmit, to the base station via the transceiver, at least one random access preamble, based on the determined power ramping counter.
10. The terminal of claim 9 , wherein the at least one processor is further configured to:
determine to increment a power ramping counter by a predetermined value, in case that the transmission beam for the retransmission is not changed.
11. The terminal of claim 9 , wherein the at least one processor is further configured to:
receive, from the base station via the transceiver, at least one synchronization signal,
in case that a measurement result of at least one synchronization signal is greater than a predetermined threshold value, identify an index of the at least one synchronization signal,
determine at least one resource for transmitting at least one random access preamble corresponding to the identified index of the synchronization signal, and
transmit, to the base station via the transceiver, the at least one random access preamble based on the determined at least one resource for transmitting the at least one random access preamble.
12. The terminal of claim 11 , wherein the at least one processor is further configured to:
receive, from the base station via the transceiver, information on mapping between the index of at least one synchronization signal and at least one resource for a random access preamble transmission.
13. A base station in a wireless communication system, the base station comprising:
a transceiver; and
at least one processor configured to:
receive, from a terminal via the transceiver, at least one random access preamble using at least one resource for transmitting the at least one random access preamble, and
receive, from the terminal via the transceiver, at least one random access preamble which is retransmitted based on a power ramping counter,
wherein a random access response is monitored based on a random access response window, by the terminal, that the random access response is not received within the random access response window is identified, a retransmission is determined, to suspend a power ramping counter is determined in case that a transmission beam for the retransmission is changed.
14. The base station of claim 13 , wherein to increment a power ramping counter by a predetermined value is determined, in case that the transmission beam for the retransmission is not changed.
15. The base station of claim 13 , wherein the at least one processor is further configured to:
transmit, to the terminal via the transceiver, at least one synchronization signal, and
receive, from the terminal via the transceiver, the at least one random access preamble based on at least one resource for transmitting the at least one random access preamble, the at least one resource for transmitting the at least one random access preamble being determined based on a reception result of the at least one synchronization signal,
wherein the at least one resource for transmitting the at least one random access preamble corresponds to an index of the synchronization signal, in case that a measurement result of the at least one synchronization signal is greater than a predetermined threshold value.
16. The base station of claim 15 , wherein the at least one processor is further configured to:
transmit, to the terminal via the transceiver, information on mapping between the index of at least one synchronization signal and at least one resource for a random access preamble transmission.