A novel combined channel estimation algorithm for elastic optical networks

To mitigate the mismatch of granularities between fixed grid and client traffic, the elastic optical network (EON) was proposed by using optical orthogonal frequency division multiplexing (OFDM). In EONs, every optical signal is generated with just enough sub-carriers. However, due to the consideration of optical OFDM, the fiber dispersion and cross talk between channels severely limit the communication system performance in EONs. Thus, it is very necessary to design effective channel estimation algorithms for the purpose of ensuring reliable and long-distance signal transmission. Therefore, in this paper, we design an identified channel estimation algorithm called as combined channel estimation algorithm (CCEA), with the joint consideration of improved discrete Fourier transformation and wavelet threshold de-noising method. Our CCEA avoids the generation of high-frequency components for the purpose of obtaining the accurate channel estimation and eliminates the noise information owned by effective sampling points using wavelet threshold de-noising method. The simulation results in our communication system for EONs demonstrate that: whether the bit error rate is higher or lower than the forward error correction limit, our algorithm always satisfies the requirements of communication systems well.