Maximizing the energy efficiency in broadband communications

The basics

Koala Tech (KT) Quantized Digital Amplification (QDA) technology addresses the design of energy-efficient transmitter architectures able to provide the desired spectrally efficient signals, with a strongly varying envelope, by using switched mode amplifiers, which is not possible with existing amplification technologies. KT proposes a new disruptive technology concept for power amplification on telecommunication systems. This technology will permit to reach an energy efficiency up to 70% on signal power amplification. Since QDA is standard agnostic it means that can be applied to a wide range of systems from actual 4G and Wi-Fi, to the new 5G, Wi-Fi 6 and wired communications, from the network radio transmitters (e.g. Base Station, Wi-Fi Access Point) to the wireless user equipment (e.g. mobile handsets, computers, tablets, IoT ) what will contribute for a reduction of operator’s operational costs, enhance battery life in mobile devices, enhance system performances, and allows smaller size of LSI (Large Scale Integration).

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The innovations

The new paradigm proposed by the QDA technology for Radio Frequency Power Amplifier (RF PA) stage of a Wireless Transmitter consists on the digital decomposition of the original complex signal into a set of simple constant envelope signals and each one is individually amplified by switched amplifiers operating at their maximum energy efficiency point. This opens the door to the use of switched mode amplifiers, characterized by a higher efficiency and near zero consumption in idle state when compared with the current source amplifiers that are employed in current amplification techniques. QDA technology has 3 different variants with the simplest one, first chip prototype, assuring an average efficiency of 40% for multi-carrier multi-carrier signals for bandwidths up to 250 MHz.

The power signal to be transmitted at the output of this parallelized structure is obtained by combining the set of amplified signals in highly efficient smart combiners specially conceived for QDA. Also, the modular approach of the new concept of QDA technology simplifies implementation of the RF PA: a digital signal processing part that permits higher flexibility on addressing a wider range of applications, with different types of signals and bandwidth needs, unlikely other technologies, by a simple firmware reprogramming; and a power amplifier hardware that can be implemented in diverse technologies (CMOS – Complementary Metal Oxide Semiconductor, GaN – Gallium Nitrite, GaS – Gallium Arsenide and Bipolar).

The patents

The key aspects of the QDA technology are already protected by patents. Koala Tech pursuits an intensive IP policy in order to protect all innovative aspects of QDA technology with more than 10 patents already submitted in US (with several already assigned in US) and several territorial extensions in the countries where the largest telecommunication hardware manufacturers are located: USA, European Union, China, South Korea, Japan, and India.

QDA based products will allow:

The mobile operators’ OPEX reduction on energy consumption and subsequently their carbon footprint;

Wi-Fi Routers reduced consumption;

Mobile phones with reduced consumption, improving battery life and then reduction on user “phone heating sensation” when talking for longer times, and lower poduction costs

The impact

QDA adoption will contribute to a significant reduction on the carbon footprint of the existing and future wireless and mobile communications systems networks. Therefore, the QDA technology will contribute to reduce by 25% up to 60% the negative impacts on the environment caused by mobile cellular networks base station transmitters, with wider cross-sector impact in environmental protection, CO2 and greenhouse gas reduction, social costs and public health. In fact, the adoption of QDA in 4G/5G base stations in Europe can lead to a reduction of one million metric tons or more on greenhouse emissions. In satellite communications QDA will allow higher EIRP, better QoS and consequently higher transmission rates due the higher efficiency.

 

The applications

QDA technology addresses directly the field of telecommunications and security applications. Being standard agnostic, it can be employed in existing telecommunication systems like LTE Advanced 4G mobile phone standard, 5G, Satellite Communications, both at ground and space segment, Wi-Fi and any very high bit rate wired or wireless communication link.

Main advantages of QDA technology can be summarized as follows:

The expected impacts of QDA based products are:

  • the Mobile operators’ OPEX reduction on energy consumption and subsequently reduction on their carbon footprint;
  • Wi-Fi Routers with reduced consumption;
  • Higher EIRP and QoS in wireless communications with less energy consumption;
  • Mobile phones reduced consumption and improved battery life and lower production costs.

This also means a significant reduction in the carbon footprint of the existing and future wireless and mobile communications systems networks. Therefore, the QDA technology will contribute to reduce by 25% up to 60% the negative impacts on the environment caused by mobile cellular networks base station transmitters, with wider cross-sector impact in environmental protection, CO2 and greenhouse gas reduction, social costs and public health. Main advantages of QDA technology can be summarized as follows:

  • Broad spectrum of application since this amplification method can be applied to both single carrier and multi-carrier signals and do not have a specific constellation, bandwidth or signal as a target.
  • Suited for broadband, since the PAs operation does not need to change over time.
  • Fully digital, with Switched amplifiers the implementation can be fully digital up to PAs inputs without need of DACs (Digital to Analogue Converter). Thus, the whole QDA system acts as a DAC.
  • Easy to Integrate and Adapt to any existing standard, from 2G to 5G in wireless communications.
  • Versatility, suitable for any multi-carrier or single carrier system with variable envelope.
  • Higher flexibility and scalability achieved by programming flexibility and digital processing of the signals on FPGA (Field Programable Gate Array) or DSP (Digital Signal Processor).
  • Maximum energy efficiency since all the amplifiers work in compression point or near it (without any nonlinear repercussion in the amplified signals) we can achieve up to 75% efficiency.