Analysis of channel capacity for fixed broadband multimedia systems at 40 GHz

The results of a wideband radio channel sounding campaign performed at 40 GHz band are presented. We have used a sounder based on the correlation of pseudorandom m-sequences, but some novelties have been introduced in the classical scheme of this kind of sounders. Different antenna patterns and polarisations have been combined with three groups of actual environments (indoor, outdoor and indoor-outdoor) in order to achieve general conclusions, valid for a wide range of different situations. An expression relating two of the main parameters of the wideband radio channel (coherence bandwidth and delay spread) is fitted to the measured results. The experimental data as well as this expression verify Fleury-s limit, a restriction that has been extended here to define a complete region of valid values. Finally, a theoretical analysis of the channel capacity is conducted. We have stated the theoretical improvement that the channel capacity would experience owing to the use of spatial diversity or multicarrier modulations. The outcomes provide a timely insight into the expectations for the use of high data rate applications in this frequency band even in indoor conditions.