Distributed Friendly Jamming for Wireless Secrecy

The patent applies local quality by making the jamming signal's impact location-dependent. Through precoding, the jamming signal is designed to have high power at eavesdropper locations while being nulled or reduced at legitimate receiver locations. This spatial differentiation allows the system to provide strong security where needed (at eavesdroppers) while minimizing harmful interference where it is not needed (at legitimate receivers), thus resolving the contradiction between improving secrecy rate and reducing interference.

The patent introduces precoding as an intermediary mechanism that mediates between the jamming signal and the receivers. The precoder processes the jamming signal before transmission, shaping its spatial distribution to achieve the desired effect: high interference at eavesdroppers and low interference at legitimate receivers. This intermediary processing layer enables the system to simultaneously achieve both goals of the contradiction.

The patent applies parameter changes by dynamically adjusting the jamming power for each user based on their specific channel conditions and eavesdropping risks. Instead of using a fixed or uniform jamming approach, the system modifies the jamming signal parameters (power level, precoding matrix) for each user to achieve optimal secrecy rate while minimizing interference to others. This parameter adaptation enables multiple users to share the band efficiently without requiring complex centralized coordination.

The patent implements self-service through distributed jamming where each user independently generates and transmits their own jamming signal based on local channel state information. Each user's jamming signal is designed to protect their own communication without requiring coordination with other users or centralized control. This self-service approach simplifies interference management in multi-user scenarios while maintaining high network capacity.