Chirp Nonlinearity Compensation for Cost Effective Optical FMCW radar

Cheap laser sources should be used to generate the input chirped signal for cost efficient monitoring of optical access networks by using optical FMCW radar systems. These laser sources usually do not provide highly linear chirps hence resulting in low range accuracy and decreased spatial resolution. A possible solution of this problem is to use linearization circuits or precompensation methods which are costly and inefficient. A post processing method which uses a target of opportunity is presented to fully compensate chirp nonlinearities. Unlike precompensation the proposed method does not need any adaptive channel estimation hence making it fast and computationally efficient. The proposed approach increases the range accuracy significantly hence reducing the cost of maintenance in a long range optical access network considerably.