Light emitting diodes (LEDs) can be used as the light sources for wireless op tical communication,which are expected to be developed into optical local area n etwork.In terms of a specific transmission speed requirement,large current modulation should be adopted to ensure large area of signal coverage and signal intensity.In this paper,the mechanisms of the slower photo-electric response and smaller optical modulation bandwidth of the high power LEDs than those of th e lower power ones are investigated.The slow recombination of the electrons/holes injected into the LE D and the carrier storage effect of the transistor in the driving circuit are analyzed.The optical pulse shaping technique is selected to promote the transmission speed.FPGA is used to generate the two outputs of additional short pulses with their phases correlated to the signal pulses regenerated by th e FPGA.The two pulses synchronously control a driving circuit to apply a transient over -voltage at the pulse rising edge to speed up the carrier injection,and a short circuit to the LED at the pu lse falling edge discharging the remaining carriers.The measurement results of eye-diagram and bit error ra te (BER) of the received signals demonstrate that the optical signal quality and the transmission rate ar e significantly improved,at the nearly ampere level of the peak-peak modul ating current.