A signal receiving method, comprising: receiving , by a terminal device on a first carrier, a narrowband primary synchronization signal, NPSS, sent by a network device according to a first period and a narrowband secondary synchronization signal, NSSS, sent by the network device according to a second period, wherein a subframe number of a subframe occupied by the NPSS in each period is M and a subframe number of a subframe occupied by the NSSS in each period is N, and M is 5 and N is 0 or M is 0 and N is 5; receiving , by the terminal device on a second carrier, a narrowband physical broadcast channel, NPBCH, sent by the network device according to a third period and a system information block 1-narrowband, SIB1-NB, sent by the network device according to a fourth period, wherein a subframe number of a subframe occupied by the NPBCH in each period is P and a subframe number of a subframe occupied by the SIB1-NB in each period is Q, and P is 5 and Q is 0 or P is 0 and Q is 5; and completing , by the terminal device , downlink synchronization and obtaining system information based on the NPSS, the NSSS, the NPBCH, and the SIB1-NB; wherein the receiving of NSSS, NPSS, NPBCH and SIB1-NB on the respective first subcarrier and second subcarrier is carried out in consecutive radio frames each comprising 10 subframes and each having a time length of 10ms, wherein the first period and third period are a time length of one radio frame, the second period is a time length of two radio frames, and the fourth period is 2560 ms, wherein in each fourth period the SIB1-NB is sent for N' times in 2N'consecutive radio frames, wherein N' is a positive integer greater than 0. receiving , by a terminal device on a first carrier, a narrowband primary synchronization signal, NPSS, sent by a network device according to a first period and a narrowband secondary synchronization signal, NSSS, sent by the network device according to a second period, wherein a subframe number of a subframe occupied by the NPSS in each period is M and a subframe number of a subframe occupied by the NSSS in each period is N, and M is 5 and N is 0 or M is 0 and N is 5; receiving , by the terminal device on a second carrier, a narrowband physical broadcast channel, NPBCH, sent by the network device according to a third period and a system information block 1-narrowband, SIB1-NB, sent by the network device according to a fourth period, wherein a subframe number of a subframe occupied by the NPBCH in each period is P and a subframe number of a subframe occupied by the SIB1-NB in each period is Q, and P is 5 and Q is 0 or P is 0 and Q is 5; and completing , by the terminal device , downlink synchronization and obtaining system information based on the NPSS, the NSSS, the NPBCH, and the SIB1-NB; wherein the receiving of NSSS, NPSS, NPBCH and SIB1-NB on the respective first subcarrier and second subcarrier is carried out in consecutive radio frames each comprising 10 subframes and each having a time length of 10ms, wherein the first period and third period are a time length of one radio frame, the second period is a time length of two radio frames, and the fourth period is 2560 ms, wherein in each fourth period the SIB1-NB is sent for N' times in 2N'consecutive radio frames, wherein N' is a positive integer greater than 0. <EOS>