Secure channel state information with adaptive obfuscation

A privacy-enhancing wireless communication method for use by a transceiver device, the method comprising:

• obtaining a sequence of frames each having a preamble that includes a pre-determined pattern enabling unauthorized detection of the transceiver device's movement or lack thereof via measurement of channel state information;
• modifying the predetermined pattern of each frame preamble in the sequence to include amplitude or phase distortion that masks said movement or lack thereof, with at least some of the frame preambles having modified predetermined patterns with different amplitude or phase distortion from the modified pre-determined patterns of other frame preambles;
• and
• transmitting the sequence of frames using the frame preambles with the modified predetermined patterns.

A wireless transmitter that comprises:

• one or more antennas;
• a processor coupled to the one or more antennas;
• and
• a memory storing instructions that when executed by the processor cause the processor to:
• obtain a sequence of frames each having a preamble that includes a predetermined pattern enabling unauthorized detection of the wireless transmitter's movement or lack thereof via measurement of channel state information;
• modify the predetermined pattern of each frame preamble in the sequence to include amplitude or phase distortion that masks said movement or lack thereof, with at least some of the frame preambles having modified predetermined patterns with different amplitude or phase distortion from the modified predetermined patterns of other frame preambles;
• and
• transmit the sequence of frames using the frame preambles with modified predetermined patterns.