On Performance Improvements in Distributed AFDM Systems with Optimal Precoding Weights

Abstract

Future wireless networks are expected to operate in highly time-varying environments where conventional multicarrier waveforms such as Orthogonal frequency division multiplexing (OFDM) suffer from doppler-induced interference. Affine frequency division multiplexing (AFDM) has emerged as a promising waveform for doubly dispersive channels due to its inherent robustness to delay and Doppler effects. In this work, we propose a distributed AFDM (D-AFDM) system that integrates AFDM with distributed transmission to exploit both diversity and array gains. Using the structure of the effective channel matrix, we characterize the achievable gains under different multipath configurations. We also derive optimal precoding weights for maximizing received power in a K - transmitter system through an optimization framework. Simulation results validate the analysis and demonstrate notable performance improvements over single input single output (SISO) AFDM and other benchmark schemes.