Coherent range and Doppler-walk compensation in PBR applications

The focus of PBR research has shifted from FM to also include DVB-T and DAB over the last years, and are facing the challenges of higher bandwidth, i.e. improved range resolution. While the FM based PBR systems primarily had to deal with Doppler migration, the DVB-T based PBR systems are using CPIs which, combined with the higher bandwidth, leads to range and Doppler walk. The Doppler resolution is inversely proportional to the CPI, and longer CPI will therefore lead to finer Doppler resolution. And thus the higher bandwidth and longer CPI leads to increased propability of both range and Doppler walk. This paper describes a method to coherently compensate for both range and Doppler walk of targets already detected. The method coherently compensates both the translational movement and non-linear phase caused by range and Doppler walk.