HELENA: High-Efficiency Learning-based channel Estimation using dual Neural Attention

Accurate channel estimation is critical for high-performance Orthogonal Frequency-Division Multiplexing systems such as 5G New Radio, particularly under low signal-to-noise ratio and stringent latency constraints. This letter presents HELENA, a compact deep learning model that combines a lightweight convolutional backbone with two efficient attention mechanisms: patch-wise multi-head self-attention for capturing global dependencies and a squeeze-and-excitation block for local feature refinement. Compared to CEViT, a state-of-the-art vision transformer-based estimator, HELENA reduces inference time by 45.0% (0.175,ms vs. 0.318,ms), achieves comparable accuracy (-16.78,dB vs. -17.30,dB), and requires 8× fewer parameters (0.11M vs. 0.88M), demonstrating its suitability for low-latency, real-time deployment.