Patent ID: 11871367
Assignee: AVAGO TECHNOLOGIES INTERNATIONAL SALES PTE. LIMITED
Field: Digital communication (Electrical engineering)
Classification: CPC H | IPC H

Claim 4:
5. A first access point comprising:
a transceiver; and
circuitry configured to:
cause the transceiver to transmit to a second access point during a first time period, information for a joint transmission by the first access point and the second access point to a device, the second access point to estimate synchronization information for the joint transmission according to the information for the joint transmission, and

cause the transceiver to transmit to the device during a second time period after the first time period, a portion of a null data packet, while the second access point transmits the portion of the null data packet to the device according to the synchronization information, the device to determine, according to the null data packet, steering information for a multiple-input multiple-output (MIMO) communication to determine steering vectors for the joint transmission by the first access point and the second access point to the device, wherein the circuitry is further configured to cause the transceiver to:
transmit, during a third time period before the first time period, a trigger frame to the second access point, the second access point to estimate, according to the trigger frame, additional synchronization information for a null data packet announcement, and
transmit, during a fourth time period between the third time period and the first time period, the null data packet announcement to the device, while the second access point transmits the null data packet announcement to the device during the fourth time period according to the additional synchronization information, the device to prepare for the null data packet, according to the null data packet announcement transmitted by the first access point and the second access point.