Wideband mm-wave Spectrum-Efficient Transmitter Using Low-Pass Sigma–Delta-Over-Fiber Architecture

Journal article, 2023

The millimeter-wave band offers large bandwidth and promises high data rates for wireless communication systems. This work proposes a millimeter-wave radio-over-fiber architecture suitable for wideband mm-wave communication, using a lowpass sigma-delta modulation approach. The central unit
generates baseband sigma-delta bitstreams, in-phase/quadrature (I/Q) components, which are transported to a remote radio head
(RRH) using a standard QSFP28 optical interconnect link connection. In the RRH, the baseband I/Q signals are upconverted to the millimeter-wave band, amplified, and transmitted through an antenna. The performance of the resulting sigma-delta-over-fiber transmitter architecture is experimentally verified at 28 GHz, demonstrating a state-of-the-art symbol rate up to 1.5 Gsym/s. Furthermore, in over-the-air measurements, the architecture is
shown to support 1 Gsym/s with 5.9% error vector magnitude for 64/256/1024 quadrature amplitude modulation cases over a 5 m wireless distance. The results demonstrate the feasibility of the proposed architecture for the realization of wideband millimeterwave distributed antenna systems.