Signal sending method, signal receiving method, and apparatus

1. 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 wherein M is 5 and N is 0 or M is 0 and N is 5, and wherein a Hadamard sequence set used in the NSSS comprises four Hadamard sequences that are mapped to a frequency spacing between the first carrier and a second carrier;

receiving, by the terminal device on the 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 wherein 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.

2. The signal receiving method according to claim 1 , wherein the frequency spacing between the first carrier and the second carrier is a preset frequency spacing.

3. The signal receiving method according to claim 1 , wherein the first carrier used by the network device to send the NPSS and the NSSS is a carrier that is pre-agreed on by the network device and the terminal device.

4. The signal receiving method according to claim 1 , wherein the second carrier used to send the NPBCH and the SIB1-NB is a carrier that has an association relationship with the first carrier.

5. A signal transmitting method, comprising:

generating, by a network device, a narrowband primary synchronization signal (NPSS) and a narrowband secondary synchronization signal (NSSS), and sending the NPSS according to a first period and the NSSS according to a second period on a first carrier to a terminal device, 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 wherein M is 5 and N is 0 or M is 0 and N is 5, and wherein a Hadamard sequence set used in the NSSS comprises four Hadamard sequences that are mapped to a frequency spacing between the first carrier and a second carrier; and

generating, by the network device, a narrowband physical broadcast channel (NPBCH) and a system information block 1-narrowband (SIB1-NB), and sending the NPBCH according to a third period and the SIB1-NB according to a fourth period on the second carrier to the terminal device, 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 wherein P is 5 and Q is 0 or P is 0 and Q is 5.

6. The signal transmitting method according to claim 5 , wherein the frequency spacing between the first carrier and the second carrier is a preset frequency spacing.

7. The signal transmitting method according to claim 5 , wherein the first carrier used by the network device to send the NPSS and the NSSS is a carrier that is pre-agreed on by the network device and the terminal device.

8. The signal transmitting method according to claim 5 , wherein the second carrier used to send the NPBCH and the SIB1-NB is a carrier that has an association relationship with the first carrier.

9. A terminal device, comprising:

a transceiver unit, configured to receive, 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 wherein M is 5 and N is 0 or M is 0 and N is 5, and wherein a Hadamard sequence set used in the NSSS comprises four Hadamard sequences that are mapped to a frequency spacing between the first carrier and a second carrier;

wherein the transceiver unit is configured to receive, on the 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 wherein P is 5 and Q is 0 or P is 0 and Q is 5; and

a processing unit, configured to complete downlink synchronization and obtain system information based on the NPSS, the NSSS, the NPBCH, and the SIB1-NB that are received by the transceiver unit.

10. The terminal device according to claim 9 , wherein the frequency spacing between the first carrier and the second carrier is a preset frequency spacing.

11. The terminal device according to claim 9 , wherein the first carrier used by the network device to send the NPSS and the NSSS is a carrier that is pre-agreed on by the network device and the terminal device.

12. The terminal device according to claim 9 , wherein the second carrier used to send the NPBCH and the SIB1-NB is a carrier that has an association relationship with the first carrier.