A lens-less receiver with a monolithically integrated avalanche photodiode (APD) in 0.35 µm BiCMOS technology has been developed for establishing an indoor 2 Gb/s optical wireless communication (OWC) over a distance of 6.5 m with a receiving angle of 22°. Immunity toward background light was demonstrated up to 6000 lux. Four additional PIN photodiodes with highly sensitive differential nonlinear transimpedance amplifiers (TIA) were implemented on the receiver chip for centering the highly collimated transmitter beam position.