Publications
Publications
Fiber-Optic Communications Using Nonlinear Fourier Transforms, Masters in Systems and Control: Algorithms and a Bound, TU Delft, Sep. 2022. PDF
Improved Fast Inverse Nonlinear Fourier Transform for Multi-solitons: A Discrete Darboux Based Approach, Masters in Systems and Control, TU Delft, Aug. 2017. PDF
S. Chimmalgi, L. Schmalen and V. Aref, "End-to-End Learning of Probabilistic Constellation Shaping through Importance Sampling," Photonics Technology Letters, Jun. 2025. PDF
A. Rode, B. Geiger, S. Chimmalgi, L. Schmalen, "End-to-end Optimization of Constellation Shaping for Wiener Phase Noise Channels with a Differentiable Blind Phase Search," Journal of Lightwave Technology, Vol. 41, No. 12, pp. 3849-3859, Jun. 2023. PDF
S. Chimmalgi and S. Wahls, "On Computing High-dimensional Riemann Theta Functions," Communications in Nonlinear Science and Numerical Simulation, Vol. 123, Apr. 2023. PDF
S. Chimmalgi and S. Wahls, "Bounds on the Transmit Power of b-Modulated NFDM Systems in Anomalous Dispersion Fiber," Entropy, Vol. 22, No. 6, Article 639, 2020. Special Issue Information Theory of Optical Fiber. PDF
V. Bajaj, S. Chimmalgi, V. Aref and S. Wahls, "Exact NFDM Transmission in the Presence of Fiber-Loss," IEEE/OSA Journal of Lightwave Technology, Vol. 38, No. 11, pp. 3051–3058, Jun. 2020. PDF
S. Chimmalgi, P. J. Prins and S. Wahls, "Fast Nonlinear Fourier Transform Algorithms Using Higher Order Exponential Integrators," IEEE Access, Vol. 7, No. 1, pp. 145161–145176, Dec. 2019. PDF
S. Wahls, S. Chimmalgi and P. J. Prins, "FNFT: A Software Library for Computing Nonlinear Fourier Transforms," The Journal of Open Source Software, vol. 3, no. 23, paper 597, 2018. PDF
C. Muth, L. Schmidt, S. Chimmalgi and Laurent Schmalen, "Improved Estimation Accuracy in OFDM-Based Joint Communication and Sensing Through Kalman Tracking and Interpolation," Proc. 14th International ITG Conference on Systems, Communications and Coding (SCC), Karlsruhe, Germany, Mar. 2025. PDF
A. Rode, S. Chimmalgi, B. Geiger and L. Schmalen, "Joint Geometric and Probabilistic Constellation Shaping With MOKka," Demo at IEEE International Conference on Machine Learning for Communication and Networking, Stockholm, Sweden, May 2024. PDF
A. Rode, W. A. Gebrehiwot, S. Chimmalgi and L. Schmalen, "Optimized Geometric Constellation Shaping for Wiener Phase Noise Channels with Viterbi-Viterbi Carrier Phase Estimation," Accepted for poster presentation at 49th European Conference on Optical Communication (ECOC), Glasgow, Scotland, Oct. 2023. PDF
S. Chimmalgi, A. Rode, L. Schmid and L. Schmalen, "Approximate Maximum a Posteriori Carrier Phase Estimator for Wiener Phase Noise Channels using Belief Propagation," Accepted for oral presentation at 49th European Conference on Optical Communication (ECOC), Glasgow, Scotland, Oct. 2023. PDF
S. Chimmalgi and S. Wahls, "Theoretical Analysis of Maximum Transmit Power in a b-Modulator," Proc. 45th European Conference on Optical Communication (ECOC), Dublin, Ireland, Sep. 2019. PDF
V. Bajaj, S. Chimmalgi, V. Aref and S. Wahls, "Exact nonlinear frequency division multiplexing in lossy fibers," Proc. 45th European Conference on Optical Communication (ECOC), Dublin, Ireland, Sep. 2019. PDF
S. Wahls, S. Chimmalgi, P. J. Prins, "Wiener-Hopf Method for b-Modulation," Proc. Optical Fiber Communication Conference and Exhibition (OFC), San Diego, USA, Mar. 2019. PDF
M. Brehler, C. Mahnke, S. Chimmalgi and S. Wahls, "NFDMLab: Simulating Nonlinear Frequency Division Multiplexing in Python," Proc. Optical Fiber Communication Conference and Exhibition (OFC), San Diego, USA, Mar. 2019. PDF
S. Chimmalgi, P. J. Prins and S. Wahls, "Nonlinear Fourier Transform Algorithm Using a Higher Order Exponential Integrator," Proc. OSA Advanced Photonics Congress, Zuerich, Switzerland, Jul. 2018. PDF
S. Chimmalgi and S. Wahls, "Discrete Darboux based Fast Inverse Nonlinear Fourier Transform Algorithm for Multi-solitons," Proc. European Conference on Optical Communcation (ECOC), Gothenburg, Sweden, Sep. 2017. PDF