An Adaptive Dual-mode Frequency Hopping OFDM System for Cognitive Radio
Kewu Peng · Radio Engineering · 2011
The idle spectrum sensed by cognitive radio is always discontinuous and non-uniform,it is a real challenge for cognitive radio physical realization.Frequency hopping OFDM has the advantages of both frequency hopping and OFDM,and is used in wideband wireless transmission.An adaptive dual-mode frequency hopping OFDM system,which combines RF-FH-OFDM and BB-FH-OFDM,has been proposed.Switches are carried out adaptively between the two modes based on the spectrum sensing information and the capability of baseband processing.Design rules and realizing flow chart for the system are provided.Analysis shows that it can improve the utilization ratio for those discontinuous and non-uniform idle spectrums,and can act as a practical physical realization mechanism for cognitive radio.