Orthogonal Time Frequency Space

A New Generation of Wireless Applications is creating an unprecedented demand for network capacity

From gigabit broadband at 500km/h to smart cities and homes, from massive Internet of Things (IoT) to connected cars, this new generation of applications has complex requirements that must scale to support tens of billions of devices, which is nearly impossible with existing technology. A whole new approach to wireless communication is required.

A New Generation of Wireless Communication

Cohere Technologies’ mission is to transform wireless communication and maximize the full potential of this new generation of applications. Cohere has invented a wireless modulation called Orthogonal Time Frequency and Space (OTFS), that implements a 2-Dimensional representation of the channel making all wireless transmission resilient to channel dynamics regardless of conditions. OTFS delivers a stable, reliable, predictable and consistent signal everywhere that scales linearly with the network. So, network operators can now deliver profitable wireless services that work in the real world: from trains moving at 500km/h to autonomous cars, from low bitrate battery operated massive internet of things to smart homes and cities to Gbps per user everywhere. The possibilities are limitless.

Multipath Wireless Transmission

All wireless communication involves multiple paths of signal propagation. Multipath wireless transmission occurs when radio signals from a transmitter reach a receiver from two or more paths.

OFDM IS AFFECTED BY CHANNEL FADING

 

Compared to the main signal path, each multipath signal reflects off objects – both stationary and moving – to arrive with a different delay and a shift in Doppler (that is, shift of the transmission frequency). This results in a loss of signal energy, with the aggregate amount of signal energy in the multipath signals being ~ 50% of the main path energy.

Today’s wireless technologies (that is, OFDM) have difficulties dealing with multipath, since the receiver only considers the energy from signals within a narrow range of the main path as DESIRED – all other received energy is treated as INTERFERENCE. This degrades the received signal energy, thus lowering the throughput (bps) of data modulated on the frequency. Moreover, multiple signals that arrive from different directions can become inverted in phase, thus canceling each other out to further reduce the signal energy. The result is that only a single, best energy signal is captured at the receiver. For end-user devices, like smartphones, this signal degradation causes many of the problems we experience today (one bar).

Major Problems in Wireless Today

The major problems with wireless communications today that impact application performance are:

– Fading of signal due to multipath.

– Unstable signal reception (one bar to five bars) at different places.

– Inability to scale with the growth of devices and endpoints.

– Inconsistent coverage and dropped connections at high speeds.

Two-Dimensional Modulation

Unlike current wireless technologies, Cohere’s OTFS implements a 2-Dimensional representation of the wireless channel making all wireless transmission under any conditions resilient to channel dynamics. OTFS delivers a stable, reliable, predictable and consistent signal everywhere that scales linearly with the network. OTFS is built to handle multipath and collects all transmitted energy resulting in an aggregated signal energy that maximizes the signal while minimizing interference.

OTFS Maximizes Signal Energy and Minimizes Interference

 

The aggregated signal energy results in a coherent reconstruction of the transmitted signal at the receiver, which contributes to a stable, reliable and consistent behavior of the connection. By contrast, with OFDM, multipath signals that are out of phase cancel each other at the receiver resulting in a net reduction of signal energy that contributes to an unstable, unreliable and erratic behavior of the connection.

5G & Beyond: A New Generation of Wireless

All previous generations of wireless technology, from 1G to 4G, were step transitions targeting a single application. 1G analog voice to 2G digital voice to 3G data to 4G high speed data each required a change in the wireless technology. 5G brings a whole new world of applications that previous generations simply cannot support.

With 5G and beyond, mobile broadband undergoes a transformation to 10Gbps peak rates, 1Gbps at 500km/h, 10,000x the network traffic. With its high tolerance to Doppler shifts, superior multipath separation and linear scaling with MIMO, OTFS is the only wireless modulation that can meet these enhanced mobile broadband requirements to usher in a new generation of wireless services and applications.

5G demands a 1000x increase in capacity to handle all types of new end devices and traffic. OTFS scales linearly with channel bandwidth and MIMO to achieve Shannon capacity under all conditions, enabling a 10x increase in spectral efficiency, a 100x increase in cell capacity and consequently, a 1000x increase in network capacity.

1000x Network Capacity With OTFS

OTFS Results in 1000x increase in network capacity compared to OFDM

 

Autonomous cars, Vehicle-to-Vehicle, Vehicle-to-infrastructure, Remote health monitoring are some of the use cases that require ultra-reliable communications with latency below 1ms. OTFS extracts full diversity of the wireless channel independent of the packet size and thus yields high reliability and resilience to interference.

More than 50 billion devices will be connected over the next decade generating more than $12 trillion of goods and services. Humans, machines, cars, drones, homes, buildings, entire cities and industries will be interconnected in a global internet of things. Future networks will need to support these energy-efficient, low-data rate connections on a massive scale. OTFS is designed for low-power, reliable and efficient transmission to enable the intelligent and flexible tradeoff between coverage and capacity.

A digital transformation is underway that’s enabling cities, countries and entire continents to connect, communicate, collaborate and improve quality of life in unprecedented ways. This places new demands on the communications network to be high bandwidth, fast, resilient, secure and reliable. Future networks for Smart Cities will need to address these demands and be responsive, adaptive and scalable. With low complexity of implementation and real-time flexibility, OTFS is built from the ground up to usher in this new era of communications.

Home is the new frontier for an intelligent, distributed network of sensors and communications devices, that connect and interact to secure, simplify and significantly enhance quality of life. Everything from thermostats to alarms, cameras and lights to home appliances need to connect seamlessly in an autonomous network. OTFS delivers a wire-like performance for such a network that guarantees the bandwidth and reliability to make the dream of a smart home a reality.

OTFS Can Meet 5G Requirements Across All Emerging Applications

Current OFDM-based Solution Inadequate to Meet New Demands for Unprecedented Capacity, Scale, Efficiency and Reliability Across All Applications

A new generation of wireless is here. Cohere Technologies is on a mission to transform wireless communications empowering a whole new generation of applications.