On Linkedin, a reader posted an interesting comment about our recent blog post on massive MIMO technology (http://www.nutaq.com/blog/massive-mimo-technology-big-shift-next-generation-wireless-broadband-communications):
“When the 802.11a standard was introduced, the power output required to match the range performance of the legacy 802.11b was approximately double (20dB to 40dB), so going from 5Ghz to 60Ghz for example will require a huge hike in dB to match.”
While it's true that millimeter waves (mmWave) have higher propagation losses than bands below 6 GHz, the losses can be overcome through the use of antenna arrays with many elements. This is a big advantage of massive MIMO technology: by using a massive number of antennas, the constructive interference of all the antennas should enable a significant increase in range while maintaining an acceptable transmit power. But is the struggle with such technology and high frequencies worth it for the upcoming 5G standard? At Nokia Solutions and Networks (NSN), the answer is a definite yes!
NSN believes that 5G systems should provide a peak rate greater than 10 Gbps and a round-trip time of less than 1 ms. To meet these requirements, a large amount of additional spectrum, both above and below 6 GHz, will be needed beyond 2020. Spectrum below 6 GHz is limited, so let’s take a look at the potentially available licensed spectrum in the millimeter wave range:
The first thing to observe from this picture is the large amount of available bandwidth. This gives mmWave communications a major advantage over the current LTE standard. NSN notes that:
“Some aspects of user experience in a mmWave enhanced Local Area (eLA) system may be at least 20 times greater than that experienced with LTE. This is possible since mmWave uses 50x the bandwidth compared to LTE”
mmWave communications may seem like a new technology, but its been of interest to both academia and industry for many years. There were some challenges like difficult propagations conditions, difficulties with the manufacture of small elements, and inadequate chip processing power. But now, progress in chip and antenna technologies have moved mmWave for cellular-type communications much closer to reality.
A key element of future 5G mmWave systems is the radio frequency integrated circuit (RFIC). RFICs (like the one found in Nutaq’s Radio420x, are small and can be dynamically reconfigured, thus reducing the power consumption and system cost.
NSN is actively researching and developing a proof-of-concept system that uses 70-80 GHz mmWave. NSN strongly believes in the potential of mmWave for 5G communications beyond 2020. We can definitely expect to see more details of this significant technology and its potential in the future.
Why not follow NSN and start tackling the challenges of above-6GHz spectrum now? The Nutaq WD20G 20GHz RF Wideband Digitizer offers 100 MHz of bandwidth anywhere within the wireless frequency range of 100 kHz to 20 GHz. Connected to this RF front-end is the baseband processing system, which includes a Virtex-6 FPGA and an i7 Intel quad-core processor. Algorithms can be implemented in GNU Radio software on the i7. On the FPGA side, the Nutaq MBDK enables automatic bitstream generation directly from a Matlab/Simulink model thanks to the Xilinx System Generator block set. This makes baseband processing fast and easy and is ideal for proof-of-concept applications. For an example of this solution, see our GSM Channelizer demo on Youtube: http://www.youtube.com/watch?v=Ma_fNlouBGk.