Towards Unified Modulator for Mobility Scenarios: A CGRA-Based Approach

Abstract

To overcome the limitations of Orthogonal Frequency Division Multiplexing (OFDM) under mobility conditions, several alternative waveforms have been proposed, each offering distinct benefits and limitations. A promising approach for future wireless communications, including 6G and beyond, is to unify these waveforms to accommodate diverse operating conditions and user requirements. However, processing multiple computationally intensive waveforms on a traditional Application-Specific Integrated Circuit (ASIC) is impractical due to its fixed design. In contrast, Coarse-Grained Reconfigurable Array (CGRA), a typical class of reconfigurable architectures, provides greater flexibility and efficiency, making it a more feasible alternative for such demanding workloads. In this paper, we propose a unified modulator framework that integrates five different waveforms onto a single CGRA platform. This approach demonstrates the run-time reconfiguration capabilities of CGRAs, enabling seamless switching between waveforms to support a unified modulation model. To optimize execution, this work explores overlapping computational and memory-access patterns for the target waveforms, enhancing performance and efficiency. For evaluation, the proposed design is synthesized on a Stratix-IV FPGA device and compared against existing implementations that focus on fixed, single-waveform architectures. The unified modulator implementation achieves an operating frequency of 170.0 MHz, a throughput of 10.88 GOPS and a dynamic power dissipation of 528 mW. Additionally, the scalability of the proposed approach is evaluated across various input sizes (8×4, 8×8, 16×16), demonstrating its flexibility with promising results.