Researchers from the University of Cambridge have developed a digital signal processing solution which overcomes the current limitations of in-building wireless signal propagation for advanced services such as 3G and LTE. Most large buildings requiring improved in-building radio coverage, such as shopping malls and airports, are installing Distributed Antenna Systems (DAS) which require dedicated high-specification infrastructure such as optical fibre, high linearity and dynamic range, and suffer from high energy consumption. Femtocells provide an alternative solution which avoid some of these issues but are still restricted to single service and fixed configurations.

    The proposed digital DAS (DDAS) solution substantially compresses the data signals thereby reducing the infrastructure bandwidth requirement ultimately towards use of copper rather than optical fibre and also allowing multiple services (voice, data, video…) to be combined onto a single infrastructure. The use of DDAS also enables more flexible architectures, including per-service or per stream reconfigurability and remote service distribution for multiple buildings over a common infrastructure. This would allow easier upgrade and secure maintenance using software rather than the current hardware approach.

    We are now looking for industrial partners to help us develop this technology further to exploit the exciting market opportunity which this technology presents.