Carrier frequency offset estimation for DSSS signals in the wired test of beamforming networks

Beamforming for satellite-borne communications systems has attracted intensive attention in the past decade as it enables frequency reuse among the areas covered by different beams, and hence greatly improves bandwidth efficiency. This paper considers carrier frequency offset estimation for DSSS signals in the wired test of beamforming networks. A two-stage frequency offset estimation algorithm is proposed and implemented, whose resource consumption is far less than the traditional frequency offset estimation methods based on the use of FFT. The first stage is to employ FFT to achieve a frequency offset coarse estimation. After compensating the coarse estimation value, the system carries out the second stage, which uses phase calculating to estimate the residual frequency offset accurately. So far, the two-stage frequency offset estimation algorithm has been applied in project successfully, where practical test results have well demonstrated its practicability and accuracy.