Design of a Cognitive Radio System Agile Frequency Signal Source
Lei Liu · Informatization Research · 2011
Aiming to the cognitive system need of opportunistic search for spectrum white space and switch of carrier frequency,as well as adaptive adjustment date rate to fit the channel environment,a high performance cognitive radio system signal source is designed employing AD9854 chip as a DDS core and EP1C6Q240 FPGA as a controller.This signal source features dual orthogonal outputs and function of agile adjustment of frequency and modulation rate.The test result indicates that the precision and stability of frequency as well as spurious suppression satisfy the design requirements. This unit can be integrated inside the CR communication equipments.