Acquisition and tracking loops based on software defined radio

Navigation receiver is the equipment that can measuring position, velocity and time with navigation signals at any time. Traditional navigation receiver is based on application-specific hardware, which has a high sensitivity and signal processing speed, but the flexibility is poor, once confirmed it can not be changed. In contrast, the navigation software receiver based on software defined radio (SDR) technology has many advantages, e.g. agility, easy to upgrade, and so on. So SDR receives a lot of attention and the area of application is more and more widely. Aiming at studying the receiver technologies, we have developed a GPS software receiver. In our application, a FFT based acquisition is used together with a fine frequency estimation method. A widely used PLL+DLL structure is applied in the tracking process. These entire algorithms are based on “block-process” to achieve good efficiency. Base on this receiver, others can research and approve new acquisition and tracking arithmetic.