Reciprocity based channel state information acquisition for frequency division duplex system

A method, comprising:

• receiving, by a network device comprising a processor, an uplink reference signal from a user equipment device;
• based on the uplink reference signal, determining, by the network device, delay Doppler domain channel state information, wherein the delay Doppler domain channel state information comprises a covariance matrix;
• and
• based on a frequency difference between an uplink frequency of an uplink channel and a downlink frequency of a downlink channel, adjusting, by the network device, an array response associated with the covariance matrix.

A non-transitory machine-readable storage medium, comprising executable instructions that, when executed by a processor of a device, facilitate performance of operations, comprising:

• receiving a reference signal from a user equipment device;
• based on the reference signal, generating channel state information in a delay Doppler domain, wherein the channel state information comprises a channel response matrix, and wherein the channel response matrix represents a quality of a transmission link between a first antenna element at a transmitter and a second antenna element at a receiver;
• and
• applying a difference between an uplink frequency of an uplink channel and a downlink frequency of a downlink channel to the channel response matrix to reflect a Doppler difference in reception and transmission respectively;
• and
• adjusting an array response associated with the channel response matrix based on the difference between the uplink frequency and the downlink frequency.