Fig. 3

Proposed ranging code tracking loop. If the iteration process of \(\tau\) adopts the left partial derivative of the cost function, this method needs the late branch \(L\) and the punctual branch \(P\). If the iteration process of \(\tau\) employs the right partial derivative of the cost function, this method utilizes the early branch \(E\) and the punctual branch \(P\). IF is the abbreviation of intermediate frequency. NCO is the abbreviation of numerical controlled oscillator