A method of receiving, by a base station, BS, a narrowband physical random access channel, NPRACH, preamble in a wireless communication system supporting time division duplexing, TDD, the method comprising: transmitting, to a user equipment, UE, NPRACH configuration information via a higher layer signaling; and receiving the NPRACH preamble from the UE based on the NPRACH configuration information, wherein the NPRACH preamble is repeatedly transmitted as a plurality of preamble repetition units, with each preamble repetition unit consisting of four symbol groups, and with each symbol group consisting of a cyclic prefix, CP, and a plurality of symbols, wherein (i) in a frequency domain, symbol groups of the plurality of preamble repetition units are transmitted using frequency-hopping, and (ii) in a time domain, the symbol groups of the plurality of preamble repetition units are indexed in time according to i ≥ 0, wherein a first two symbol groups of each preamble repetition unit are contiguous in time, and wherein a second two symbol groups of the each preamble repetition unit are contiguous in time, and wherein the symbol groups of the plurality of preamble repetition units are transmitted using the frequency-hopping such that: a frequency location of symbol group i is determined based on (i) a first parameter related to a starting subcarrier, and (ii) a second parameter related with the frequency-hopping for the symbol group i, wherein for each symbol group i > 0 having even-valued i, the second parameter for the symbol group i does not depend on the second parameter for symbol group i -1, wherein for each symbol group i > 0 having even-valued i, the second parameter for the symbol group i is determined based on i n ̃ SC RA 0 that is an initial value of the second parameter for i =0 and (ii) a function that is generated based on a pseudo random sequence, wherein the initial value of the second parameter is determined by a medium access control, MAC, layer, and wherein for symbol group i =2, the second parameter is equal to: n ̃ SC RA 0 + f i / 2 mod N sc RA wherein f (·) is the function that is generated based on the pseudo random sequence, and wherein N sc RA is a total number of subcarriers available as frequency locations for the frequency-hopping of the NPRACH preamble. transmitting, to a user equipment, UE, NPRACH configuration information via a higher layer signaling; and receiving the NPRACH preamble from the UE based on the NPRACH configuration information, wherein the NPRACH preamble is repeatedly transmitted as a plurality of preamble repetition units, with each preamble repetition unit consisting of four symbol groups, and with each symbol group consisting of a cyclic prefix, CP, and a plurality of symbols, wherein (i) in a frequency domain, symbol groups of the plurality of preamble repetition units are transmitted using frequency-hopping, and (ii) in a time domain, the symbol groups of the plurality of preamble repetition units are indexed in time according to i ≥ 0, wherein a first two symbol groups of each preamble repetition unit are contiguous in time, and wherein a second two symbol groups of the each preamble repetition unit are contiguous in time, and wherein the symbol groups of the plurality of preamble repetition units are transmitted using the frequency-hopping such that: a frequency location of symbol group i is determined based on (i) a first parameter related to a starting subcarrier, and (ii) a second parameter related with the frequency-hopping for the symbol group i, wherein for each symbol group i > 0 having even-valued i, the second parameter for the symbol group i does not depend on the second parameter for symbol group i -1, wherein for each symbol group i > 0 having even-valued i, the second parameter for the symbol group i is determined based on i n ̃ SC RA 0 that is an initial value of the second parameter for i =0 and (ii) a function that is generated based on a pseudo random sequence, wherein the initial value of the second parameter is determined by a medium access control, MAC, layer, and wherein for symbol group i =2, the second parameter is equal to: n ̃ SC RA 0 + f i / 2 mod N sc RA a frequency location of symbol group i is determined based on (i) a first parameter related to a starting subcarrier, and (ii) a second parameter related with the frequency-hopping for the symbol group i, wherein for each symbol group i > 0 having even-valued i, the second parameter for the symbol group i does not depend on the second parameter for symbol group i -1, wherein for each symbol group i > 0 having even-valued i, the second parameter for the symbol group i is determined based on i n ̃ SC RA 0 that is an initial value of the second parameter for i =0 and (ii) a function that is generated based on a pseudo random sequence, wherein the initial value of the second parameter is determined by a medium access control, MAC, layer, and wherein for symbol group i =2, the second parameter is equal to: n ̃ SC RA 0 + f i / 2 mod N sc RA wherein f (·) is the function that is generated based on the pseudo random sequence, and wherein N sc RA is a total number of subcarriers available as frequency locations for the frequency-hopping of the NPRACH preamble.