Configuration of additional synchronization signal
According to certain embodiments, a method in a network node comprises determining ( 1306 ) whether an additional synchronization signal should be transmitted to one or more wireless devices. The method further comprises transmitting ( 1308 ) an indication whether the additional synchronization signal is available for use. For example, in response to determining that the additional synchronization signal should be transmitted, the indication signals a presence of the additional synchronization signal to the one or more wireless devices.
1. A method in a network node, the method comprising:
determining whether to transmit an additional synchronization signal to a wireless device;
transmitting a synchronization signal block (SSB) to the wireless device, the SSB comprising synchronization information;
transmitting the additional synchronization signal to the wireless device, wherein the additional synchronization signal comprises additional synchronization information; and
transmitting, to the wireless device, an indication whether the additional synchronization signal is available for use for synchronization,
wherein:
the indication indicates whether the additional synchronization signal is available for use together with the SSB for performing synchronization; or
the indication indicates whether the additional synchronization signal is available for use instead of the SSB for performing synchronization.
2. The method of claim 1 , wherein the indication indicates whether the additional synchronization signal is available for use together with the SSB for synchronization for decoding of a physical downlink shared channel (PDSCH) transmitted by the network node.
3. The method of claim 1 , wherein the indication indicates whether the additional synchronization signal is available for use together with the SSB for synchronization for decoding of a physical downlink control channel (PDCCH) and a physical downlink shared channel (PDSCH) transmitted by the network node.
4. The method of claim 1 , wherein determining whether to transmit the additional synchronization signal is based at least in part on position and movement parameters of the wireless device.
5. The method of claim 1 , further comprising:
receiving a request from the wireless device;
wherein determining whether to transmit the additional synchronization signal is based at least in part on receiving the request from the wireless device.
6. A network node comprising:
processing circuitry configured to determine whether to transmit an additional synchronization signal to a wireless device; and
an interface communicatively coupled to the processing circuitry, the interface configured to:
transmit a synchronization signal block (SSB) to the wireless device, the SSB comprising synchronization information;
transmit the additional synchronization signal to the wireless device, wherein the additional synchronization signal comprises additional synchronization information; and
transmit, to the wireless device, an indication whether the additional synchronization signal is available for use for synchronization,
wherein:
the indication indicates whether the additional synchronization signal is available for use together with the SSB for performing synchronization; or
the indication indicates whether the additional synchronization signal is available for use instead of the SSB for performing synchronization.
7. A method in a wireless device, the method comprising:
receiving, from a network node, an indication whether an additional synchronization signal is available for use;
receiving a synchronization signal block (SSB) from the network node, the SSB comprising synchronization information;
in response to receiving an indication that the additional synchronization signal is available for use:
receiving the additional synchronization signal from the network node, wherein the additional synchronization signal comprises additional synchronization information; and
performing synchronization using the additional synchronization signal; and
in response to receiving an indication that the additional synchronization signal is not available for use, performing synchronization using the SSB without the additional synchronization signal;
wherein performing synchronization using the additional synchronization signal comprises:
using the additional synchronization signal instead of the SSB; or
using the additional synchronization signal together with, or in addition to, the SSB.
8. The method of claim 7 , further comprising:
determining whether to request the additional synchronization signal from the network node, the determining based at least in part on one or more of the following:
an estimated speed or Doppler spread of the wireless device,
a signal-to-noise ratio (SNR) or signal-to-interference-plus-noise ratio (SINR) associated with the wireless device,
a frequency offset estimate, or
an estimation of timing or frequency offset variance.
9. The method of claim 7 , further comprising:
transmitting, to the network node, a request indicating to the network to transmit the additional synchronization signal.
10. The method of claim 7 , wherein performing synchronization using the additional synchronization signal comprises using the additional synchronization signal instead of the SSB.
11. The method of claim 7 , wherein performing synchronization using the additional synchronization signal comprises using the additional synchronization signal together with, or in addition to, the SSB.
12. The method of claim 7 , wherein the indication is received during paging.
13. The method of claim 7 , wherein the wireless device is in idle state or inactive state.
14. The method of claim 7 , wherein performing synchronization comprises decoding a physical downlink shared channel (PDSCH) that has been transmitted by the network node.
15. The method of claim 7 , wherein performing synchronization comprises decoding a physical downlink control channel (PDCCH) and a physical downlink shared channel (PDSCH) that have been transmitted by the network node.
16. The method of claim 7 , wherein the indication is received in downlink control information (DCI) in a physical downlink control channel (PDCCH), wherein performing synchronization comprises decoding a physical downlink shared channel (PDSCH) that has been transmitted by the network node, and wherein the PDCCH and the PDSCH are contained in a random access response (RAR).
17. A wireless device, the wireless device comprising:
an interface configured to:
receive, from a network node, an indication whether an additional synchronization signal is available for use;
receive a synchronization signal block (SSB) from the network node, the SSB comprising synchronization information; and
in response to receiving an indication that the additional synchronization signal is available for use, receive the additional synchronization signal from the network node, wherein the additional synchronization signal comprises additional synchronization information; and
processing circuitry communicatively coupled to the interface, the processing circuitry configured to:
perform synchronization using the additional synchronization signal in response to receiving an indication that the additional synchronization signal is available for use; and
perform synchronization using the SSB without the additional synchronization signal in response to receiving an indication that the additional synchronization signal is not available for use;
wherein performing synchronization using the additional synchronization signal comprises:
using the additional synchronization signal instead of the SSB; or
using the additional synchronization signal together with, or in addition to, the SSB.
18. The wireless device of claim 17 , wherein the interface is further configured to:
transmit, to the network node, a request indicating to the network node to transmit the additional synchronization signal.
19. The method of claim 17 , wherein the interface is configured to receive the indication during paging.
20. The method of claim 17 , wherein the interface is configured to receive the indication while the wireless device is in idle state or inactive state.