Nujira Ltd, a leading player in Envelope Tracking (ET) technology, has successfully delivered the full efficiency benefits of ET in TD-LTE mode for the first time. In recently published test results, Nujira was able to demonstrate that its high bandwidth 20MHz NCT-L1300 ET modulator chip achieved twice the energy saving for RF power amplifiers (PAs) operating in TD-LTE mode compared to lower bandwidth ET solutions. Nujira will be demonstrating 20MHz TD-LTE ET transmission at this year’s Mobile World Congress in Barcelona, Spain.
Nujira’s Coolteq technology is currently the only solution on the market that can unlock the performance benefits of ET at the high bandwidths demanded by TD-LTE networks.
Nujira’s test results and analysis are detailed in a white paper published today and available for download from www.nujira.com/td-lte.
Commenting Tim Haynes, CEO, Nujira said, “Nujira has consistently produced ET solutions that deliver the highest bandwidths in the industry. We have already demonstrated that our patented High Accuracy Tracking architecture for ET can support 40MHz for LTE-Advanced, and these latest tests show that Nujira continues to lead the way in terms of ET performance.
“Despite being much simpler to develop, 5MHz, or even 10MHz, ET components will not deliver much benefit in a TD-LTE system. Chipset vendors and handset OEMs really need ET solutions that can support the maximum 20 MHz bandwidth in order to optimise the RF front end – extending battery life, improving coverage and increasing data rates. As the TD-LTE market develops – and gets more competitive – we are confident that the increased energy saving of our technology will provide a critical commercial advantage to handset manufacturers.”
For handset OEMs and chipset vendors, TD-LTE presents a significant challenge as handsets are only able to transmit for a fifth of the time. For a given amount of data therefore, the transmit bandwidth and power has to be five times higher than FD-LTE, increasing transmit power by 7dB. The effect of this is to double the instantaneous current consumed by the RF PA during transmit bursts. Nujira’s analysis of TD-LTE network statistics shows that 50% of the PA energy consumption is at high power/high bandwidth.
ET is crucial for reducing the peak power consumption, so the most significant power savings from ET can only be achieved by solutions that can support these higher bandwidths in ET mode. Lower performance ET solutions have to fall back to Average Power Tracking (APT) mode at high bandwidths, eliminating the performance advantage of ET and complicating the software development for chipset vendors.
More than 60 operators have committed to deploy TD-LTE networks, with the most high profile recent deployments in China, the US and India, and all major device OEMs have commercially launched TD-LTE compatible devices. A recent market report forecasts TD-LTE subscriptions will reach nearly 1 billion by 2020, with TD-LTE device shipments expected to pass 100 million units in 2014 alone.