| 摘要 |
<p>The present invention relates to a multimode optical fibre communications system (30), and in particular to a system in which non-linearities in the propagation of the signal through a multimode optical communications channel degrade the signal presented to the receiver. The system (30) includes an optical transmitter unit (35) for connection to a multimode optical fibre transmission link (33). The transmitter unit (35) has a data input (44) for receiving an input data signal (43), a data signal processing circuit (47-62) and a source of optical radiation (36). The data signal processing circuit is arranged to receive (45) the input data signal (43) from the data input (44) and to provide a processed data signal (63) to the source of optical radiation (36) and the source of optical radiation is arranged to generate from this an optical signal for transmission by a multimode optical fibre (33). The data processing circuit (47-62) is arranged to provide from the input data signal (43) a non-inverted data signal (45) and an inverted data signal (48), receive a control signal (70,71) for controlling the generation of the processed data signal (63), apply a controllable delay (46,49) in accordance with the control signal (70,71) to at least one of said non-inverted and inverted data signals (45,48), apply a controllable gain factor (55,56) in accordance with the control signal (70,71) to at least one of said non-inverted and inverted data signals (45,48), and combine the non-inverted and inverted signals after the application of the controllable delay(s) (46,49) and gain factor(s) (55,56) to generate the processed data signal (63).</p> |
