Photonic-aided wideband mm-wave transmission with scalable subband-selective reception based on AGFB-OFDM

As the bandwidth of photonic-aided millimeter-wave (mm-wave) transmission continues to expand, a growing mismatch emerges between the wideband capability of the photonic front end and the limited digital processing capability at the receiver. To address this mismatch while supporting flexible spectral access and heterogeneous services, this paper proposes a photonic-aided wideband mm-wave transmission architecture with scalable subband-selective reception based on adaptive generalized filter bank orthogonal frequency-division multiplexing (AGFB-OFDM). AGFB-OFDM establishes an interface between wideband transmission and receiver processing through structured subbands with well-defined boundaries, generated using a two-stage inverse fast Fourier transform (IFFT) and adaptive polyphase filtering. At the receiver, selective subband extraction enables the processing granularity to be matched to the required spectral resources. Simulations with 8, 10, and 12 subbands demonstrate the scalability of the proposed scheme, with comparable or lower average bit error rate (BER) than conventional full-band reception at a given optical signal-to-noise ratio (OSNR). Experimentally, a 6-GHz signal comprising 10 subbands is transmitted over a 10-km standard single-mode fiber (SMF) and a 1.5-m wireless link at 26 GHz, achieving an aggregate data rate of 22.5 Gbit/s, a spectral utilization of 93.75%, and a spectral efficiency of 3.75 bit/s/Hz. At a photodiode (PD) input power of −6 dBm, all subbands achieve BERs below the hard-decision forward error correction (HD-FEC) threshold. The receiver can process each selected subband using a 512-point FFT instead of a monolithic 5120-point FFT for the entire aggregated bandwidth, demonstrating flexible receiver processing granularity. Furthermore, heterogeneous 16QAM/QPSK transmission across different subbands demonstrates the capability to support heterogeneous services.