Simulation of Effect of Periodically Missing Samples on Decoding in Passive Synthetic Aperture Radar System Using OFDM

Paper in proceeding, 2019

Passive synthetic aperture radar using transmitters of opportunity can be used for remote sensing, using frequency bands that are not normally allowed for transmitting radars. Passive radars do not transmit but instead use signals from other transmitting sources. Useful signal modulations for passive radar include OFDM (Orthogonal Frequency Division Multiplexing) signals for digital TV following the standard Digital Video Broadcasting Terrestrial (DVB-T) [1]. In this paper, we simulate the performance with an open software to decode the OFDM signal registered with the airborne synthetic aperture radar LORA. The LORA system does not register measured samples continuously but some percentage of consecutive samples are thrown away periodically. Moreover, the sampling rate of the LORA system gives a non-integer rational number of samples during the OFDM symbol time period. We conclude that the missing data samples can become deleterious for decoding the DVB-T signal and give guidelines to the maximum allowable data gaps.