Method and apparatus for selecting random access channel in wireless communication systems
The present disclosure relates to a pre-5 th -Generation (5G) or 5G communication system to be provided for supporting higher data rates beyond 4 th -Generation (4G) communication system such as long term evolution (LTE). A method for operating a terminal in a wireless communication system is provided. The method includes acquiring information regarding resource set comprising a plurality of random access channels, selecting a random access channel among the plurality of the random access channels, and transmitting, to a base station, a preamble on the random access channel.
1. A method performed by a terminal in a wireless communication system, the method comprising:
acquiring information of a resource set at least two random access channels with different frequency-domain positions;
numbering the at least two random access channels with different frequency-domain positions in an ascending order of frequency to obtain indexes 0˜K−1;
when performing an initial random access attempt, selecting an index by rule of n RA k =g(k) to select the random access channel corresponding to the index;
when performing a random access attempt different from the initial random access attempt, selecting an index by rule of (n RA k-1 +u) mod K to select the random access channel corresponding to the index; and
transmitting, to a base station, a preamble on the random access channel,
wherein, k is an integer no less than zero, k represents times for transmitting the preamble repeatedly, when k=0, n ra k =n RA 0 represents a random access channel index used to transmit preamble at a first time, when k≥n RA k represents the random access channel index used to transmit the preamble at a k th time, u represents a frequency-domain interval parameter, g( ) represents a pseudo-random generation function, and the function g( ) is used to generate pseudo-random numbers ranging from 0˜K−1.
2. The method of claim 1 , wherein the acquiring of the information of the resource set comprises acquiring the information of the resource set from received random access channel configuration information.
3. The method of claim 2 , wherein, the random access channel configuration information comprises a master information block in broadcast channel or a system information block indicated by the master information block.
4. A terminal in a wireless communication system, the terminal comprising:
at least one processor configured to:
acquire information of a resource set including at least two random access channels with different frequency-domain positions,
number the at least two random access channels with different frequency-domain positions in an ascending order of frequency to obtain indexes 0˜K−1;
when performing an initial random access attempt, selecting an index by rule of n RA k =g(k) to select the random access channel corresponding to the index;
when performing a random access attempt different from the initial random access attempt, selecting an index by rule of (n RA k-1 +u) mod K to select the random access channel corresponding to the index; and
a transceiver configured to transmit, to a base station, a preamble on the random access channel, wherein, k is an integer no less than zero, k represents times for transmitting the preamble repeatedly, when k=0, n RA k =n RA 0 represents a random access channel index used to transmit preamble at a first time, when k≥n RA k represents the random access channel index used to transmit the preamble at a k th time, u represents a frequency-domain interval parameter, g( ) represents a pseudo-random generation function, and the function g( ) is used to generate pseudo-random numbers ranging from 0˜K−1.
5. The terminal of claim 4 , wherein the at least one processor is further configured to acquire the information of the resource set from received random access channel configuration information.
6. The terminal of claim 5 , wherein, the random access channel configuration information comprises a master information block in broadcast channel or a system information block indicated by the master information block.