Method And Apparatus For Software-defined Radio with Timing, Phase, and Frequency Synchronization

INV-21094

Background

Communication systems’ requirements for different applications have been changing rapidly over the years. In this regard, wireless network architectures are undergoing a radical transformation, moving away from centralized control towards a distributed paradigm where devices make local decisions towards a shared, global objective. Software Defined Radios (SDR’s) may provide flexible, upgradeable, longer lifetime, and possibly cheaper radio equipment for wireless communications infrastructure. It can also be a convenient base technology for the future context-sensitive, adaptive and learning radio units referred to as cognitive radios. However, SDR poses many challenges, including size, weight, portability and required computing power of the transceiver. Progress has been made in network densification in 5G, intelligent reflector arrays, and distributed coordinated beamforming. From a system viewpoint, many of these applications are yet to realize their full potential, as devices remain shackled to a centralized clock. To date, there is no open-source, physical layer solution that can provide sufficient signal quality required for SDR-based experimentation through the wireless medium.

Technology Overview

Researchers at Northeastern invented a low-cost, power-efficient, small, and extremely light software-defined radio hardware architecture called MetaSDR. This new SDR includes a customized SDR hardware platform, a timing, phase, and frequency synchronization platform, called RFClock utilizing a leader-follower architecture and an AI and controller platform. The RFClock system is designed to operate in generalized environments: as a standalone unit, it generates a 10MHz or 40MHz/1PPS signal reference suitable for most commercial-off-the-shelf (COTS) SDRs today; it does not require custom headers or messaging within the data-carrying protocol and is robust to interference through a frequency-agile operation. The AI and controller module coordinates all operations performed by submodules to provide a robust and reliable service. This novel technology can synchronize distributed systems such as distributed multi-user multiple-input-multiple-output (MU-MIMO) and distributed coordinated beamforming that enables a number of radios to synchronize phase offsets and start times exactly to beamform towards a target receiver. It also provides the possibility of synchronization of an intelligent reflector array that has large numbers of low-cost antennas to create smart surfaces. Hence, it can be integrated into any commercial communication system to mitigate synchronization issues while developing new applications.

Benefits