Envelope tracking for TD-LTE terminals
More than 60 operators have committed to deploy TD-LTE networks, with high profile 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. Most operators, including China Mobile, are expected to deploy TD-LTE with an asymmetric timeslot allocation of 4:1 (download:upload) to reflect aggregate data traffic across the network. For handset OEMs and chipset vendors, this presents a significant challenge, as handsets are only able to transmit for a fifth of the time.