Implementation On Key Technology Of D2D Physical Layer Communication Based On USRP

With the rapid development of mobile communications and mobile Internet, a new technology D2D (Device-to-Device) emerges. D2D technology intelligently reuse cell resources to achieve point to point communication in a cell, it can improve the spectrum utilization,reduce transmission power of mobile terminals and reduce the pressure on cellular networks. D2D technology is currently still in the theory stage, except the theoretical analysis and simulation, D2D technology has no real experimental verification.Based on TD-LTE (Time Division Long Term Evolution) physical layer protocol, the paper uses USRP software radio platform to design and implement D2D communication physical layer key technologies, including the D2D data transportation which bears the major business and data transmission control D2D CCCH channel protocol.The paper also study and solve two important problems on USRP software radio platform during the experiment. First, differences between amplitude and phase of I and Q branches causes the signal leakage in the mirror subcarriers.The paper sets up mathematical model and study the time-varying of parameters,then estimates the leakage parameters and eliminates the leakage.Second, the actual LO signal may leak, resulting in the presence of the DC component in the received signal.The paper study this phenomenon and use2stages tuning to remove the DC component,and finally uses the spectrum analyzer and D2D platform to verify the desired effect.