Enhanced secrecy for orthogonal time frequency space (otfs) waveforms at the physical layer

A method for wireless communications at a user equipment (UE), comprising:

• receiving control signaling indicating that a secure downlink message is scheduled for transmission from a network entity;
• transmitting, in response to the control signaling, a sounding reference signal for generating a channel estimate for a channel between the network entity and the UE;
• receiving, via the channel, the secure downlink message that includes added interference over a slot duration, the added interference being based at least in part on the channel estimate, wherein the secure downlink message is encoded in accordance with an orthogonal time frequency space precoding scheme;
• and
• decoding the secure downlink message in accordance with the orthogonal time frequency space precoding scheme.

An apparatus for wireless communications at a network entity, comprising:

• a processor;
• memory coupled with the processor;
• and
• instructions stored in the memory and executable by the processor to cause the apparatus to:
• transmit control signaling indicating that a secure downlink message is scheduled for transmission to a user equipment (UE);
• receive, in response to the control signaling, a sounding reference signal for generating a channel estimate for a channel between the network entity and the UE;
• encode the secure downlink message in accordance with an orthogonal time frequency space precoding scheme;
• add interference to the encoded secure downlink message over a slot duration, the added interference being based at least in part on the channel estimate;
• and
• transmit, via the channel, the encoded secure downlink message that includes the added interference.

An apparatus for wireless communications at a user equipment (UE), comprising:

• a processor;
• memory coupled with the processor;
• and
• instructions stored in the memory and executable by the processor to cause the apparatus to:
• receive control signaling indicating that a secure downlink message is scheduled for transmission from a network entity;
• transmit, in response to the control signaling, a sounding reference signal for generating a channel estimate for a channel between the network entity and the UE;
• receive, via the channel, the secure downlink message that includes added interference over a slot duration, the added interference being based at least in part on the channel estimate, wherein the secure downlink message is encoded in accordance with an orthogonal time frequency space precoding scheme;
• and
• decode the secure downlink message in accordance with the orthogonal time frequency space precoding scheme.