Next-generation high-speed wireless handsets are getting closer to having improved upload speeds.

Nokia Siemens Networks has successfully tested a new technology that combines transmission capacity of mobile phones using the same channel to substantially increase data speeds, the company has said.

The newly formed joint venture between Nokia and Siemens has shown how Virtual Multiple Input Multiple Output (MIMO) technology, also known as Space Division Multiple Access (SDMA), can be used in next-generation LTE (Long-Term Evolution) mobile phones.

MIMO, an antenna technology already being used in Wi-Fi networks, combines multiple antennas at each end of the communications circuit to minimise errors and optimise data speeds, without requiring additional bandwidth or transmission power.

In the test that Nokia Siemens conducted with the Fraunhofer Institute for Telecommunications, two devices shared their antennas to form a Virtual MIMO system, offering an aggregated uplink transmission speed of 108M bps (bits per second) or 54M bps per device.

In a typical mobile phone network, when two people use the same frequency band to transmit to a base station, the connection becomes congested and data throughput drops, according to Nokia Siemens spokesman Bareld Meijering. "With virtual MIMO, the two connections are coordinated in such a way that each can transmit at 54M bps over the same channel or together at 108M bps," he said.

A key advantage of this technology – in addition to increased capacity – is that handsets would not be required to have two antennas, thus saving on space and, equally important, power.

Power is required to amplify transmission signals to and from antennas, according to Meijering. The fewer the antennas, the lower the power consumption requirements, he said.

MIMO, which is also being standardized for cellular W-CDMA (Wideband Code Division Multiple Access), is one of several pieces of fourth-generation (4G) technology designed for future use in both wireless WiMax and cellular LTE networks.