Orthogonal frequency division multiplexing in wireless communication systems with multimode fibre feeds

The feasibility of using multimode fibre as an inexpensive cell feed in broadband indoor picocellular systems is investigated. The performance of coded orthogonal frequency division multiplexing for a variety of multimode fibre profiles, including stepped index and /spl alpha/-profile graded index fibres is assessed. In addition to its ability to perform well in a frequency selective multipath environment, OFDM is shown to offer good protection against the frequency selectivity of a dispersive multimode fibre. Data-rates in excess of 100 Mb/s (without equalisation) over a multimode fibre channel are possible, whereas they may be limited to some 20-30 Mb/s using conventional ASK modulation.