Abstract:

The spectrum sensor and transceiver can be jointly designed for the orthogonal frequencydivision multiplexing(OFDM)based cognitive radio. Which does spectrum sensing and transmission alternatively. Furthermore, it can sense multiple licensed bands simultaneously. The time length of sensing can be decided according to the sensing performance requirement. The choice of the sensing period is modeled as a nonlinear optimization problem with the constraint of the probability of interference with the licensed users. Through the sensing period optimization, the OFDMbased cognitive radio can take full advantage of the spectrum opportunity and guarantee the lower interference with the licensed users.

Key words: cognitive radio, orthogonal frequencydivision multiplexing, spectrum sensing, sensing period