The increasing transmission capacity demand in access and in-building networks has motivated the actual drive to utilize the existing multimode optical fibre (MMF) infrastructure for 10 Gb/s transmission following the 10 Gigabit Ethernet standard.

The main objective of this doctoral thesis work is the proposal, analysis and experimental validation of techniques allowing transmission capacities in excess of 10 Gb/s, through short and middle-reach MMF links. MMF presents a bandwidth much lower than singlemode fibres (SMF) due to the dispersion in the propagation delays of the guided modes. In this context, it is required the availability of accurate models to describe the signal propagation through MMFs and evaluate several solutions oriented to mitigate the intermodal dispersion. We developed the first analytical model relying on the propagation of electric field signals that allows evaluating the MMF link baseband and radiofrequency response, considering both second and third order dispersion. We have analyzed different sources of impairment as the harmonic and intermodulation distortion and the modal noise impact as well. The search of increasing transmission bandwidth solutions took us to establish theoretically and experimentally two essential conditions for the potential transmission of broadband signals in RF regions far from the typical MMF bandwidth per distance product: implementation of central selective mode launching schemes and the use of low-linewidth optical sources. By combining both solutions with the application of SCM and WDM techniques we reached broadband transmission, both radio over fibre and digital baseband transmission, through silica MMF link lengths up to 5 Km. It must be noted that it has been reached 1 Tb/s$\cdot$km error-free MMF transmission, the highest value ever reported to the author's knowledge.