The number of cellular devices connected to each base station is on the rise and the number is expected to continue to grow over the next few years. To cater to this increase in devices, the coverage of each base station will have to be reduced and more base stations will need to be added to the network. The reduced coverage can reduce the size of the bases stations, however will increase the number, which makes the price, size and power consumption requirements of base stations and mobile phones converge.
A team of researchers from Aalto University have developed a novel 5G radio transmitter in collaboration with Tampere University of Technology and Nokia Bell Labs. The operating principle of the transmitter is as digital as possible; the signal is only converted to the analog form at the final amplification stage. The development of semiconductor processes has enabled processing the signal in the digital form in the radio transmitter almost up to the antenna, where it is converted for electromagnetic radiation.
The researchers have developed a completely new integrated electronic circuit for the transmitter to enable a notable increase in the frequency bandwidth. This makes the data transmission capacity of the base stations up to 20 times larger. The data transfer bandwidth of 4G transmitters is approximately 20 MHz, whereas this digital 5G transmitter can achieve a bandwidth of up to 400 MHz.
The developed electronic circuit enables flexible modification of the transmitted signal. Flexibility has often been realised by utilising parallel transmitters that can be turned on or off depending on the location of the base station and the required data transfer bandwidth. The transmitter enables new possibilities for modifying and programming the transmitted signal. The quality of the transmitted signal can be enhanced and you can freely choose the frequencies the transmitter uses without parallel radio transmitters.
This new generation base stations enable the operators to choose which devices they share the signal to and how. This can be done by adjusting the parameters. Until now, targeting has been done in a fixed frequency band.
Aalto University has developed the technology together with Tampere University of Technology and Nokia Bell Labs. The research project has been funded by Nokia and Tekes, the Finnish Funding Agency for Innovation. The research results were published at the International IEEE Solid-State Circuits conference in the United States in early February. The conference is an event in which the semiconductor industry and the academic research community present their best results in the field of integrated electronic circuits.
