Investigation of optical power budget for expanding indoor-mobile coverage in 5G indoor distributed antenna system (DAS) supporting 32 FAs transmission

Abstract

We experimentally present the maximum optical power budget in the analog IFoF-based indoor distributed antenna system (DAS) link supporting 32 FAs transmission of 5G wireless signals. For maximum optical power budget, we derive the maximum launched optical power and the optimum optical modulation index (OMI)/frequency assignment (FA) based on laser over-modulation. To investigate the effect, we analyze the impacts of nonlinear distortion of the single-mode-fiber (SMF) on the Tx side, and influence of noise and distortions of the analog IFoF-based indoor DAS link. Also, we include the avalanche photodiode (APD) as an optical receiver and the erbium-doped fiber amplifier (EDFA) as an optical power booster in mmWave 5G based indoor DAS link to meet the transmission performance at low received optical power. It is experimentally observed that the optical power budget is improved with using the laser over-modulation by 23 dB in analog IFoF based 5G indoor DAS link for 32 FAs x 100 MHz 5G wireless signals.