Using adjacent phone antennas could improve data transfer

The process, studied in a recent project by the university’s Centre for Communications Research (CCR), could help bypass the difficulties of fitting multiple antennas into one small device in order to speed up data transfer.

This could also be useful if a device is in an area of poor phone signal and help tackle the problem of antenna detuning that can occur when holding a device, as encountered by users of the iPhone 4.

You’re making the whole communications process much more efficient, using much less channel resource

Prof Mark Beach

Multiple-input multiple-output (MIMO) technology, which uses several antennas to transmit and receive data, is increasingly being used in devices that need a high-speed connection.

The Bristol team studied the idea of creating a ‘virtual MIMO’ system, with two devices linked by a short-range wireless connection, by examining data from a smartphone, laptop and bicycle-helmet-mounted antenna.

‘The concept of virtual MIMO has been around for a little while,’ project leader Prof Mark Beach told The Engineer. ‘We wanted to understand the impact of different form factors [devices] when you’re moving.’

By studying data from the devices, collected at different places around Bristol, the team calculated that a virtual MIMO system would improve data-transmission rates in 50 per cent of locations.

‘One of the things we found was that the detuning by somebody holding the device makes quite a significant difference to the operation of a MIMO system,’ said Beach.

‘This problem has always been with us but it’s only now with the more demanding wireless applications that the problems have really manifested themselves and I think there’s quite a hunger to do something about it.’

There are already provisions to operate a virtual MIMO system laid-down in the new fourth-generation (4G) mobile phone standards due to come into operation in the UK in the next few years.

But the full technology has still to be developed, in particular, the secure and stable short-range wireless link needed to connect the devices over a suitable distance of up to tens of metres.

Beach admitted that network operators would also need to develop a business model that would satisfy customers whose phones were being used — and the batteries being drained — to transmit data for other people.

‘This would be of benefit to a network operator because you’re making the whole communications process much more efficient, using much less channel resource. So one possible model might be to give users credit on their phone for doing so,’ he said.

‘And you could have some intelligence in there that wouldn’t allow your battery to go down more than, say, 50 per cent. So there’s a lot to do in terms of a business model, user acceptance and concerns about data security.’

Bristol University yesterday launched a new Centre for Doctoral Training (CDT) in Communications, which won £10m funding from EPSRC to study future communications engineering.