A CPM RF modulation system design based on a general zero intermediate frequency architecture

Continuous phase modulation(CPM) is widely used in digital communication systems due to its high spectral efficiency. According to the different modulation parameters, continuous phase modulation corresponds to a large class of modulation methods. A general CPM RF modulation system based on AD9364 RF transceiver chip was designed to solve the problems of complexity-implementation and poor portability. Firstly, the modulation design of baseband signal is completed according to CPM signal expression, including accumulated phase unit and related phase unit. Then, a series of conversion processes including interpolation filter and spectrum shift are completed through AD9364 direct up-conversion. Finally, test result shows that the CPM RF modulation system has high spectrum utilization, low complexity and good generality.