KAWASAKI: Fujitsu Laboratories announces its latest initiatives for 5G mobile wireless base stations and access points. The company has built a prototype wireless unit incorporating inter-subarray coding technology. The new technology makes it possible to achieve high-speed transmissions, in excess of 10 Gbps.
Fujitsu is developing a hybrid beam forming to reduce the number of circuits consuming high power, by controlling both digital and analogue circuits. The company has figured out a solution to the reduction in transmission rates by hampering the flow of signals to multiple devices. Fujitsu has developed an interleaved structure, that has the capability to cancel out interference between beams that result from undesired beams being emitted, replacing the millimetre waveband and on massive multiple input, multiple output (massive MIMO) technology.
Massive MIMO controls multiple antenna elements to send radio wave beams to each device. The antenna elements require D/A circuits, which convert digital signals to analogue in order to send signals from the antenna. With this, multiple high-speed D/A circuits become necessary, creating the problem of increased power consumption. But Fujitsu’s newly-developed technology has increased spacing between antenna elements within a subarray, which is a collection of antenna elements connected to one D/A circuit, increasing the subarray's area. When an antenna's range is spread out, its beam becomes narrower, and as the antenna elements are spread out, a type of undesired emission called a grating lobe can occur. If the elements for different subarrays are placed alternately, then the signals from both subarrays will both be sent as radio waves in both directions the arrays are transmitting.
The newly-developed technology allows users to perform data-intensive activities even in a densely-packed area with multiple users operating mobile devices at the same time. It has achieves high speed while maintaining low power consumption levels similar to Wi-Fi.
Apart from this, Fujitsu is developing a 5G ultra high-speed communication system and they aim of practically implement it by 2020. For this they are using a technology that uses the millimetre waveband and multiple antenna elements to simultaneously transmit signals as beams to each individual device.