Two-step fmcw transmission for channel measurement accuracy enhancement

A method of wireless communication at a first wireless device, comprising:

• communicating, with a second wireless device, a first reference signal, the first reference signal based on a first frequency-modulated continuous wave (FMCW) and having a first frequency bandwidth occupied by the first FMCW;
• communicating, with the second wireless device, a second reference signal, the second reference signal based on a second FMCW and having a second frequency bandwidth occupied by the second FMCW, the second frequency bandwidth smaller than the first frequency bandwidth, and the second reference signal having a frequency location based on the first reference signal;
• and
• communicating, based on a channel estimation for a channel between the first wireless device and the second wireless device based on the second reference signal, data with the second wireless device.

An apparatus for wireless communication at a first wireless device, comprising:

• means for communicating, with a second wireless device, a first reference signal, the first reference signal based on a first frequency-modulated continuous wave (FMCW) and having a first frequency bandwidth occupied by the first FMCW;
• means for communicating, with the second wireless device, a second reference signal, the second reference signal based on a second FMCW and having a second frequency bandwidth occupied by the second FMCW, the second frequency bandwidth smaller than the first frequency bandwidth, and the second reference signal having a frequency location based on the first reference signal;
• and
• means for communicating, based on a channel estimation for a channel between the first wireless device and the second wireless device based on the second reference signal, data with the second wireless device.

A non-transitory computer-readable medium storing computer executable code at a first wireless device, wherein the code when executed by at least one processor causes the at least one processor to, individually or in any combination, implement a method of wireless communication, comprising:

• communicating, with a second wireless device, a first reference signal, the first reference signal based on a first frequency-modulated continuous wave (FMCW) and having a first frequency bandwidth occupied by the first FMCW;
• communicating, with the second wireless device, a second reference signal, the second reference signal based on a second FMCW and having a second frequency bandwidth occupied by the second FMCW, the second frequency bandwidth smaller than the first frequency bandwidth, and the second reference signal having a frequency location based on the first reference signal;
• and
• communicating, based on a channel estimation for a channel between the first wireless device and the second wireless device based on the second reference signal, data with the second wireless device.