MOTIFS

Modern communications is characterized by the need for mobility and increased bandwidth: data rates of at least 1 Gb/s for wireless systems are needed in order to support emerging applications such as delivery of high definition TV over the "last mile" between the end user and the optical fibre backbone.

The interface between wireless and fibre networks is the domain of radio-over-fibre and designing RoF systems is complicated by the multipath fading of the wireless channel and optical fibre dispersion. In recent years, the application of orthogonal frequency division multiplexing (OFDM) has been investigated for RoF systems, since this provides a robust modulation technique capable of combatting such channel impairments whilst offering high spectral efficiency.

Our aim is to develop a comprehensive methodology for investigation of advanced OFDM techniques in radio-over-fibre (RoF) systems which will allow designers to optimize system performance. Due to the complexity of OFDM and the nature of the wireless and optical channel impairments in RoF, analytical methods must be augmented with simulation tools. A well designed simulator can help the RoF system designer to look at the impact of nonlinearities, fibre dispersion, noise and wireless multipath fading on the bit error rate (BER). In this project we aim to investigate OFDM transmission through a complete radio-over-fibre system. This is the first time that we will treat OFDM in RoF as a multivariable optimisation problem in an attempt to identify the best architecture and to develop adaptive OFDM schemes for reducing BER.

In MOTIFS, Sigint contributes with research radio planning activities.