Research Of The Keying SDR Technologies & Design Of The Receiver Of A SS Communication Platform

Software Define Radio(SDR) is one of communication which have vast visa. It is received recognition for it' s opening system and programmability. SDR is the revolution in radio system technology, it is going by the name of PC in the radio world.Digital Down Converter is one of the key technology of the SDR. Being based on the theory of the SDR, the topic researched the actual model of DDC. We also researched the frequency structure of DDC and interchanged the filter multiphase heft and taking out - operation using the theory of equivalent counterchange in multisampling system. The interchange is unable to change characteristic of the system, but it can decrease operation greatly. We can quantitatively calculated the reduced computational complexity by using multiphase filter and put forward the model of digital arithmetic.Synchronization is also one key technology of SDR in the receiver system. We proposed a new arithmetic of bit synchronous and come to the conclusion that we can complete synchronization track by using the method when the number of sample is less 3 in a chip.We completed a hardware roof of spread spectrum receiver. We finished the whole process of modulate and demodulate in the roof. The mode of modulate is BPSK modulate . The process is complete by software on the hardware roof. Although we only implemented one mode of modulate and demodulate , it proved that the roof is currency . What we have done is the beneficial explore to SDR.