Radiation Footprint Minimization Using Encoded OFDM Pilots for Cognitive Radio Communications

The limited availability of spectrum and the inefficiency of its usage necessitate new research on spectral opportunistic communication technologies including cognitive radio (CR). Such new systems are characterized by the coexistence of the heterogeneous wireless systems. In this paper, a radiation footprint minimization technique is proposed through encoded in-band pilot tones for Orthogonal frequency division multiplexing (OFDM) system. A transmission power negotiation signaling between the transmitter and receiver is established through the encoded pilot tones. Electromagnetic interference to the primary and other cognitive radios can be minimized with an automatically reduced radiation footprint. In addition, system performance of the receiver can be guaranteed in the process of mutual interference minimization. The transceiver structure and the inband pilot tone detection algorithm are investigated. The principle and performance of the system are validated through numerical simulations.